WorldWideScience

Sample records for hydraulic gold mining

  1. Gold-Mining

    DEFF Research Database (Denmark)

    Raaballe, J.; Grundy, B.D.

    2002-01-01

    of operating gold mines. Asymmetric information on the reserves in the mine implies that, at a high enough price of gold, the manager of high type finds the extraction value of the company to be higher than the current market value of the non-operating gold mine. Due to this under valuation the maxim of market...... value maximization forces the manager of high type to extract the gold.The implications are three-fold. First, all managers (except the lowest type) extract the gold too soon compared to the first-best policy of leaving the gold in the mine forever. Second, a manager of high type extracts the gold...... sooner than a manager of lower type. Third, a non-operating gold mine is valued as being of the lowest type in the pool and all else equal, high-asymmetri mines are valued lower than low-asymmetri mines. In a qualitative sense these results are robust with respect to different assumptions (re cost...

  2. Hydraulic mining method

    Science.gov (United States)

    Huffman, Lester H.; Knoke, Gerald S.

    1985-08-20

    A method of hydraulically mining an underground pitched mineral vein comprising drilling a vertical borehole through the earth's lithosphere into the vein and drilling a slant borehole along the footwall of the vein to intersect the vertical borehole. Material is removed from the mineral vein by directing a high pressure water jet thereagainst. The resulting slurry of mineral fragments and water flows along the slant borehole into the lower end of the vertical borehole from where it is pumped upwardly through the vertical borehole to the surface.

  3. Mercury-contaminated hydraulic mining debris in San Francisco Bay

    Science.gov (United States)

    Bouse, Robin M.; Fuller, Christopher C.; Luoma, Samuel N.; Hornberger, Michelle I.; Jaffe, Bruce E.; Smith, Richard E.

    2010-01-01

    The hydraulic gold-mining process used during the California Gold Rush and in many developing countries today contributes enormous amounts of sediment to rivers and streams. Commonly, accompanying this sediment are contaminants such as elemental mercury and cyanide used in the gold extraction process. We show that some of the mercurycontaminated sediment created by hydraulic gold mining in the Sierra Nevada, between 1852 and 1884, ended up over 250 kilometers (km) away in San Francisco Bay; an example of the far-reaching extent of contamination from such activities.

  4. Deep gold mine fracture zone behaviour

    CSIR Research Space (South Africa)

    Napier, JAL

    1998-12-01

    Full Text Available The investigation of the behaviour of the fracture zone surrounding deep level gold mine stopes is detailed in three main sections of this report. Section 2 outlines the ongoing study of fundamental fracture process and their numerical...

  5. Opposition to gold mining at Bergama, Turkey

    NARCIS (Netherlands)

    M. Arsel (Murat)

    2012-01-01

    textabstractIntroduction For much of the 1990s, the tourist town of Bergama was the epicentre of Turkey's most effective and visible environmental social movement against a multinational mining corporation aiming to establish the first modern gold mine in the country. Bringing

  6. Opposition to gold mining at Bergama, Turkey

    NARCIS (Netherlands)

    M. Arsel (Murat)

    2012-01-01

    textabstractIntroduction For much of the 1990s, the tourist town of Bergama was the epicentre of Turkey's most effective and visible environmental social movement against a multinational mining corporation aiming to establish the first modern gold mine in the country. Bringing relatively prosperous

  7. Grinding efficiency improvement of hydraulic cylinders parts for mining equipment

    National Research Council Canada - National Science Library

    Aleksandr Korotkov; Vitaliy Korotkov; Leonid Mametyev; Lidia Korotkova; Tatiana Terjaeva

    2017-01-01

    The aim of the article is to find out ways to improve parts treatment and components of mining equipment on the example of hydraulic cylinders parts, used as pillars for mine roof supports, and other actuator mechanisms...

  8. Review of Hydraulic Fracturing for Preconditioning in Cave Mining

    Science.gov (United States)

    He, Q.; Suorineni, F. T.; Oh, J.

    2016-12-01

    Hydraulic fracturing has been used in cave mining for preconditioning the orebody following its successful application in the oil and gas industries. In this paper, the state of the art of hydraulic fracturing as a preconditioning method in cave mining is presented. Procedures are provided on how to implement prescribed hydraulic fracturing by which effective preconditioning can be realized in any in situ stress condition. Preconditioning is effective in cave mining when an additional fracture set is introduced into the rock mass. Previous studies on cave mining hydraulic fracturing focused on field applications, hydraulic fracture growth measurement and the interaction between hydraulic fractures and natural fractures. The review in this paper reveals that the orientation of the current cave mining hydraulic fractures is dictated by and is perpendicular to the minimum in situ stress orientation. In some geotechnical conditions, these orientation-uncontrollable hydraulic fractures have limited preconditioning efficiency because they do not necessarily result in reduced fragmentation sizes and a blocky orebody through the introduction of an additional fracture set. This implies that if the minimum in situ stress orientation is vertical and favors the creation of horizontal hydraulic fractures, in a rock mass that is already dominated by horizontal joints, no additional fracture set is added to that rock mass to increase its blockiness to enable it cave. Therefore, two approaches that have the potential to create orientation-controllable hydraulic fractures in cave mining with the potential to introduce additional fracture set as desired are proposed to fill this gap. These approaches take advantage of directional hydraulic fracturing and the stress shadow effect, which can re-orientate the hydraulic fracture propagation trajectory against its theoretical predicted direction. Proppants are suggested to be introduced into the cave mining industry to enhance the

  9. Finding Gold in Data Mining

    Science.gov (United States)

    Flaherty, Bill

    2013-01-01

    Data-mining systems provide a variety of opportunities for school district personnel to streamline operations and focus on student achievement. This article describes the value of data mining for school personnel, finance departments, teacher evaluations, and in the classroom. It suggests that much could be learned about district practices if one…

  10. Finding Gold in Data Mining

    Science.gov (United States)

    Flaherty, Bill

    2013-01-01

    Data-mining systems provide a variety of opportunities for school district personnel to streamline operations and focus on student achievement. This article describes the value of data mining for school personnel, finance departments, teacher evaluations, and in the classroom. It suggests that much could be learned about district practices if one…

  11. Phytomining for Artisanal Gold Mine Tailings Management

    Directory of Open Access Journals (Sweden)

    Baiq Dewi Krisnayanti

    2016-08-01

    Full Text Available Mine tailings are generally disposed of by artisanal and small scale gold miners in poorly constructed containment areas and this leads to environmental risk. Gold phytomining could be a possible option for tailings management at artisanal and small-scale gold mining (ASGM locations where plants accumulate residual gold in their above ground biomass. The value of metal recovered from plants could offset some of the costs of environmental management. Getting gold into plants has been repeatedly demonstrated by many research groups; however, a simple working technology to get gold out of plants is less well described. A field experiment to assess the relevance of the technology to artisanal miners was conducted in Central Lombok, Indonesia between April and June 2015. Tobacco was planted in cyanidation tailings (1 mg/kg gold and grown for 2.5 months before the entire plot area was irrigated with NaCN to induce metal uptake. Biomass was then harvested (100 kg, air dried, and ashed by miners in equipment currently used to ash activated carbon at the end of a cyanide leach circuit. Borax and silver as a collector metal were added to the tobacco ash and smelted at high temperature to extract metals from the ash. The mass of the final bullion (39 g was greater than the mass of silver used as a collector (31 g, indicating recovery of metals from the biomass through the smelt process. The gold yield of this trial was low (1.2 mg/kg dry weight biomass concentration, indicating that considerable work must still be done to optimise valuable metal recovery by plants at the field scale. However, the described method to process the biomass was technically feasible, and represents a valid technique that artisanal and small-scale gold miners are willing to adopt if the economic case is good.

  12. Strategies for Creating Prescribed Hydraulic Fractures in Cave Mining

    Science.gov (United States)

    He, Q.; Suorineni, F. T.; Oh, J.

    2017-04-01

    The cave mining method was traditionally applied to massive low-grade, weak orebodies at shallow depths (less than 500 m) that favour cave propagation under gravity. Currently, this method is being applied to stronger orebodies and is taking place at depths of up to 2000 m below the surface. To ensure continuous cave propagation, preconditioning of the orebody is essential in this latter caving environment to improve rock mass caveability and to decrease fragmentation sizes. Hydraulic fracturing was initiated in the oil industry and is now being used in the cave mining industry as a preconditioning method and for stalled caves reactivation. A limitation of conventional hydraulic fracturing in the cave mining industry is that the hydraulic fracture orientation is uncontrollable and is dictated by the minimum in situ stress orientation. The preconditioning effectiveness of orientation-uncontrollable hydraulic fractures is limited in some geotechnical conditions, and the concept of creating orientation-controllable hydraulic fractures, here termed prescribed hydraulic fractures, is proposed to fill this gap. In this paper, the feasibility of the proposed approaches to creating prescribed hydraulic fractures is presented based on previous studies and numerical modelling. The numerical modelling code reliability in simulating the hydraulic fracture propagation and reorientation process was validated by comparing with laboratory results in the reported literature. In addition, the sensitivity of the prescribed hydraulic fracturing to the in situ stress condition and rock mass properties is examined.

  13. Hydraulic conductivity of natural soils permeated with acid mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Yanful, E.K.; Shikatani, K.S.; Quirt, D.H. [University of Western Ontario, London, ON (Canada). Department of Civil Engineering

    1995-08-01

    The results of a laboratory study on the interactions of three natural soils (some under consideration as candidate cover materials) with acid mine drainage (AMD) are presented. Soil hydraulic conductivity measurements were used to assess soil compatibility with AMD. A silty clay from the decommissioned Waite Amulet tailings site in Quebec, glacial tills from the Heath Steele mine site in New Brunswick, and soil from the Faro mine site in the Yukon Territory were examined. Soil mineralogy and chemistry were examined before and after hydraulic conductivity testing to identify any changes. 20 refs., 25 figs., 8 tabs.

  14. Neutron stars are gold mines

    Science.gov (United States)

    Lattimer, James M.

    Neutron stars are not only mines for clues to dense matter physics but may also be the auspicious sources of half of all nuclei heavier than A = 60 in the universe, including the auric isotopes. Although the cold dense matter above the nuclear saturation density cannot be directly explored in the laboratory, gilded constraints on the properties of matter from 1 to 10 times higher density can now be panned from neutron star observations. We show how upcoming observations, such as gravitational wave from mergers, precision timing of pulsars, neutrinos from neutron star birth and X-rays from bursts and thermal emissions, will provide the bullion from which further advances can be smelted.

  15. Usage of Safety Gloves in the Gold Mining Industry

    CSIR Research Space (South Africa)

    Scheepers, JCE

    1978-10-01

    Full Text Available The safety departments of 31 mines were visited, and the data obtained was used to determine to what extent safety gloves were being used in the gold mining industry. The frequency of occurrence of hand injuries amongst black workers of the gold...

  16. Pollution reality of gold mining waste on the Witwatersrand

    CSIR Research Space (South Africa)

    Hobbs

    2010-05-01

    Full Text Available system still remain. The pollution reality of gold mining waste is illustrated by a case study in the West Rand area, where decant from gold mines started in 2002. Potential receptors of the pollution in the cast study area include neighbouring property...

  17. The Largest Gold Mine in Asia was Found in Gansu

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>Recently,at Yangshan,a place bordering with Shaanxi and Sichuan provinces,of Wen County in Gansu Province,the largest gold mine in Asia was found with proved gold reserve of 308 tons,changing the history of having no super large independent gold deposits over 200 tons in China.

  18. Constraining Modern and Historic Mercury Emissions From Gold Mining

    Science.gov (United States)

    Strode, S. A.; Jaeglé, L.; Selin, N. E.; Sunderland, E.

    2007-12-01

    Mercury emissions from both historic gold and silver mining and modern small-scale gold mining are highly uncertain. Historic mercury emissions can affect the modern atmosphere through reemission from land and ocean, and quantifying mercury emissions from historic gold and silver mining can help constrain modern mining sources. While estimates of mercury emissions during historic gold rushes exceed modern anthropogenic mercury emissions in North America, sediment records in many regions do not show a strong gold rush signal. We use the GEOS-Chem chemical transport model to determine the spatial footprint of mercury emissions from mining and compare model runs from gold rush periods to sediment and ice core records of historic mercury deposition. Based on records of gold and silver production, we include mercury emissions from North and South American mining of 1900 Mg/year in 1880, compared to modern global anthropogenic emissions of 3400 Mg/year. Including this large mining source in GEOS-Chem leads to an overestimate of the modeled 1880 to preindustrial enhancement ratio compared to the sediment core record. We conduct sensitivity studies to constrain the level of mercury emissions from modern and historic mining that is consistent with the deposition records for different regions.

  19. Hydraulic Mining, Extreme Floods, and the Geomorphic Context of the Trinity River, CA

    Science.gov (United States)

    Krause, A.

    2012-12-01

    The geomorphology of modern Trinity River is the product of remarkable human impacts to the flow and sediment regimes. Virtually nothing is known about the river prior to the first discovery of gold in 1848. The Trinity River experienced 110 years of hydraulic mining from 1860 to 1970, a time period nearly four time as long as hydraulic mining in the Sierra Nevada Mountains. Hydraulic mining produced vast amounts of debris that aggraded unconfined valleys of the Trinity River creating sediment wedges up to 4 meters high and 20 kilometers long. Subsequent dredger gold mining dug though the valley alluvium to the bedrock interface, mixing the sediment profile and creating large tailings piles that artificially constrain the valley width. A series of large storms in the mid 20th century reworked these mining sediments, creating the modern terraces and large hydraulic controls that persist today. Subsequent flow regulation diverted up to 90 percent of the basin runoff out of the Trinity River and virtually eliminated floods, causing riparian encroachment, channel narrowing, and a largely static channel. Established in 2000, the Trinity River Restoration Program uses a process-based restoration strategy to create a dynamic channel capable of creating and maintaining sufficient salmonid habitat to meet fish population targets. The associated restoration management actions include: flow releases, coarse sediment augmentation, mechanical channel rehabilitation, and watershed restoration. Full implementation of high flow releases to promote channel dynamism began in 2005. In May 2011, a release of 11,000 cfs was conducted for river restoration purposes. The 11,000 cfs peak magnitude release is the maximum authorized for restoration purposes, the largest release in since 1974, and the third largest release since flow regulation began in November 1960. The release caused scour and deposition, creating gravel bars in several locations. The location and magnitude of scour and

  20. Grinding efficiency improvement of hydraulic cylinders parts for mining equipment

    Directory of Open Access Journals (Sweden)

    Korotkov Aleksandr

    2017-01-01

    Full Text Available The aim of the article is to find out ways to improve parts treatment and components of mining equipment on the example of hydraulic cylinders parts, used as pillars for mine roof supports, and other actuator mechanisms. In the course of the research work methods of machine retaining devices design were used, the scientific approaches for the selection of progressive grinding schemes were applied; theoretical and practical experience in the design and production of new constructions of grinding tools was used. As a result of this work it became possible to create a progressive construction of a machine retaining device for grinding of large parts of hydraulic cylinders, to apply an effective scheme of rotary abrasive treatment, to create and implement new design of grinding tools by means of grains with controllable shape and orientation. Implementation of the results obtained in practice will improve the quality and performance of repairing and manufacturing of mining equipment.

  1. Malaria in gold-mining areas in Colombia

    Directory of Open Access Journals (Sweden)

    Angélica Castellanos

    2016-01-01

    Full Text Available Gold-mining may play an important role in the maintenance of malaria worldwide. Gold-mining, mostly illegal, has significantly expanded in Colombia during the last decade in areas with limited health care and disease prevention. We report a descriptive study that was carried out to determine the malaria prevalence in gold-mining areas of Colombia, using data from the public health surveillance system (National Health Institute during the period 2010-2013. Gold-mining was more prevalent in the departments of Antioquia, Córdoba, Bolívar, Chocó, Nariño, Cauca, and Valle, which contributed 89.3% (270,753 cases of the national malaria incidence from 2010-2013 and 31.6% of malaria cases were from mining areas. Mining regions, such as El Bagre, Zaragoza, and Segovia, in Antioquia, Puerto Libertador and Montelíbano, in Córdoba, and Buenaventura, in Valle del Cauca, were the most endemic areas. The annual parasite index (API correlated with gold production (R2 0.82, p < 0.0001; for every 100 kg of gold produced, the API increased by 0.54 cases per 1,000 inhabitants. Lack of malaria control activities, together with high migration and proliferation of mosquito breeding sites, contribute to malaria in gold-mining regions. Specific control activities must be introduced to control this significant source of malaria in Colombia.

  2. Regularity and prediction of ground pressure in Haigou Gold Mine

    Institute of Scientific and Technical Information of China (English)

    Meifeng Cai; Shuhua Hao; Hongguang Ji

    2008-01-01

    Previous mining excavation in upper sublevels left several mined-out areas in Haigou gold mine. To ensure safety of the main and auxiliary shafts and mining production in deeper sublevels, systematical studies on regularity, prediction, and control of ground pressure in the mine were carded out. Through 3D-numerical modeling and in-situ monitoring of acoustic emission, pressure and displacement, the ground pressure activity and the stability status of surrounding rock masses and the two shafts were assessed.Based on in-situ monitoring practice in Haigou mine, 4 modes to judge rock stability according to the monitoring information of acoustic emission, pressure, and displacement were presented.

  3. Mine waste management legislation. Gold mining areas in Romania

    Science.gov (United States)

    Maftei, Raluca-Mihaela; Filipciuc, Constantina; Tudor, Elena

    2014-05-01

    Problems in the post-mining regions of Eastern Europe range from degraded land and landscapes, huge insecure dumps, surface cracks, soil pollution, lowering groundwater table, deforestation, and damaged cultural potentials to socio economic problems like unemployment or population decline. There is no common prescription for tackling the development of post-mining regions after mine closure nor is there a common definition of good practices or policy in this field. Key words : waste management, legislation, EU Directive, post mining Rosia Montana is a common oh 16 villages; one of them is also called Rosia Montana, a traditional mining Community, located in the Apuseni Mountains in the North-Western Romania. Beneath part of the village area lays one of the largest gold and silver deposits in Europe. In the Rosia Montana area mining had begun ever since the height of the Roman Empire. While the modern approach to mining demands careful remediation of environmental impacts, historically disused mines in this region have been abandoned, leaving widespread environmental damage. General legislative framework Strict regulations and procedures govern modern mining activity, including mitigation of all environmental impacts. Precious metals exploitation is put under GO no. 190/2000 re-published in 2004. The institutional framework was established and organized based on specific regulations, being represented by the following bodies: • The Ministry of Economy and Commerce (MEC), a public institution which develops the Government policy in the mining area, also provides the management of the public property in the mineral resources area; • The National Agency for the development and implementation of the mining Regions Reconstruction Programs (NAD), responsible with promotion of social mitigation measures and actions; • The Office for Industry Privatization, within the Education Ministry, responsible with privatization of companies under the CEM; • The National

  4. Environmental Monitoring at the Nalunaq Gold Mine, South Greenland, 2011

    DEFF Research Database (Denmark)

    Bach, Lis; Asmund, Gert; Søndergaard, Jens

    This eighth environmental monitoring programme was conducted in the Nalunaq area, about 40 km from Nanortalik, South Greenland, from 29 August to 12 September 2011. The environmental monitoring program is conducted to trace and avoid unwanted impacts of the mining industry to the environment. Since...... to the use of cyanide to extract gold from the ore, strict control with the outfl ow of cyanide from the mine to the Kirkespir Valley is performed. The described impact on the environment of the Kirkespir Valley, both terrestrial, freshwater and marine, is considered to be minor, and is generally lower than...... the monitoring in 2010, the mining company Gold Angel Mining A/S is breaking new ore, but is also carrying previously broken ore with low grade back to the mine with vehicles with limited speed and load capacity. The gold is recovered by the use of chemical extraction (carbon-in-pulp) using cyanide. Due...

  5. Gold and other mines - History, Chemistry and Environment

    Science.gov (United States)

    Ribeiro, Carla; Moutinho, Amélia

    2016-04-01

    The Castromil gold mines is near to our school, and they were explored by the Romans around 2000 years ago, which sows the seeds of an eTwinning project about mines. Although an important source of resources, mines and their industry can lead to a negative impact on the environment. It is important for students to understand the pros and cons of the mining industry using the Castromil gold mine as an example. With a European project as eTwinning, students can share the stories of "their" mines from different countries and since it is a trans-disciplinary subject, it can involve different subjects, from Chemistry to Environment Education, from Geology to ITC. The project's profile can be found at https://www.etwinning.net/en/pub/profile.cfm?f=2&l=en&n=121456 and because the project is ongoing, we expect that more schools will join us.

  6. Malaria in gold-mining areas in Colombia.

    Science.gov (United States)

    Castellanos, Angélica; Chaparro-Narváez, Pablo; Morales-Plaza, Cristhian David; Alzate, Alberto; Padilla, Julio; Arévalo, Myriam; Herrera, Sócrates

    2016-01-01

    Gold-mining may play an important role in the maintenance of malaria worldwide. Gold-mining, mostly illegal, has significantly expanded in Colombia during the last decade in areas with limited health care and disease prevention. We report a descriptive study that was carried out to determine the malaria prevalence in gold-mining areas of Colombia, using data from the public health surveillance system (National Health Institute) during the period 2010-2013. Gold-mining was more prevalent in the departments of Antioquia, Córdoba, Bolívar, Chocó, Nariño, Cauca, and Valle, which contributed 89.3% (270,753 cases) of the national malaria incidence from 2010-2013 and 31.6% of malaria cases were from mining areas. Mining regions, such as El Bagre, Zaragoza, and Segovia, in Antioquia, Puerto Libertador and Montelíbano, in Córdoba, and Buenaventura, in Valle del Cauca, were the most endemic areas. The annual parasite index (API) correlated with gold production (R2 0.82, p Colombia.

  7. Mercury and gold mining in Colombia: a failed state

    Directory of Open Access Journals (Sweden)

    Leonardo Güiza M

    2013-04-01

    Full Text Available Identifying and analyzing the causes and consequences that generate the high consumption of mercury in gold mining activities is an international priority. In Colombia, eighty-seven percent of the country’s gold mines have no mining title and only 3% possess environmental licenses. High mining and environmental lawlessness, the failures of formalization programs and the inadequacy of importation controls on the supply are the cause of the high consumption of mercury in Colombian mining. To diagnose the country’s gold mining activities and the excessive use of mercury in them, we used six information sources (semi-structured interviews, 2011 Census on Mining Activities, nine dependent and 21 independent variables. The study evidenced the miners’ partiality in favor of the use of mercury in the procurement of gold; the process is easy, quick and inexpensive. Mercury concentrations were found to be above tolerable levels. In response, government has opted for a policy of persecution of the activity rather than the promotion of their formalization.

  8. Magnitude and extent of the impact of a small-scale gold-mine on the geochemistry of stream bed and floodplain sediments in the Horsefly catchment, British Columbia, Canada

    OpenAIRE

    Perk, Marcel; Vogels, Marjolein F. A.; Clark, Deirdre E.; Owens, Philip N.; Petticrew, Ellen L.

    2014-01-01

    Mining represents a major source of metal contamination for fluvial systems worldwide. Monitoring and understanding the effects on downstream water and sediment quality is essential for effective management of active and abandoned mine sites. This study aims to determine the downstream effects of the abandoned, small-scale hydraulic Black Creek gold mine on the geochemistry of fine (

  9. Knowledge-driven GIS modeling technique for gold exploration, Bulghah gold mine area, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Ahmed A. Madani

    2011-12-01

    Full Text Available This research aims to generate a favorability map for gold exploration at the Bulghah gold mine area using integration of geo-datasets within a GIS environment. Spatial data analyses and integration of different geo-datasets are carried out based on knowledge-driven and weighting technique. The integration process involves the weighting and scoring of different layers affecting the gold mineralization at the study area using the index overlay method within PCI Geomatica environment. Generation of the binary predictor maps for lithology, lineaments, faults and favorable contacts precede the construction of the favorability map. About 100 m buffer zones are generated for favorable contacts, lineaments and major faults layers. Internal weighting is assigned to each layer based on favorability for gold mineralization. The scores for lithology, major faults, lineaments and favorable contacts layers in the constructed favorability map are 50%, 25%, 10% and 15%, respectively. Final favorability map for the Bulghah gold mine area shows the recording of two new sites for gold mineralization located at the northern and southern extensions of tonalite–diorite intrusions. The northern new site is now exploited for gold from the Bulghah North mine. The southern new site is narrow and small; its rocks resemble those of the Bulghah gold mine.

  10. China Gold Group Invested 2.18 billion Yuan to Buy Gold Mine

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Ministry of Finance recently proclaimed that China Gold Group has invested 2.18 billion Yuan to gain the exploration right on the Yang- shan gold mine in Wen County,Gansu Prov- ince.Yangshan is located at the place where

  11. Peptide-functionalized iron oxide magnetic nanoparticle for gold mining

    Science.gov (United States)

    Shen, Wei-Zheng; Cetinel, Sibel; Sharma, Kumakshi; Borujeny, Elham Rafie; Montemagno, Carlo

    2017-02-01

    Here, we present our work on preparing a novel nanomaterial composed of inorganic binding peptides and magnetic nanoparticles for inorganic mining. Two previously selected and well-characterized gold-binding peptides from cell surface display, AuBP1 and AuBP2, were exploited. This nanomaterial (AuBP-MNP) was designed to fulfill the following two significant functions: the surface conjugated gold-binding peptide will recognize and selectively bind to gold, while the magnetic nano-sized core will respond and migrate according to the applied external magnetic field. This will allow the smart nanomaterial to mine an individual material (gold) from a pool of mixture, without excessive solvent extraction, filtration, and concentration steps. The working efficiency of AuBP-MNP was determined by showing a dramatic reduction of gold nanoparticle colloid concentration, monitored by spectroscopy. The binding kinetics of AuBP-MNP onto the gold surface was determined using surface plasmon resonance (SPR) spectroscopy, which exhibits around 100 times higher binding kinetics than peptides alone. The binding capacity of AuBP-MNP was demonstrated by a bench-top mining test with gold microparticles.

  12. Gold mining areas in Suriname: reservoirs of malaria resistance?

    Directory of Open Access Journals (Sweden)

    Adhin MR

    2014-05-01

    Full Text Available Malti R Adhin,1 Mergiory Labadie-Bracho,2 Stephen Vreden31Faculty of Medical Sciences, Department of Biochemistry, Anton de Kom Universiteit van Suriname, 2Prof Dr Paul C Flu Institute for Biomedical Sciences, 3Academic Hospital Paramaribo, Paramaribo, SurinameBackground: At present, malaria cases in Suriname occur predominantly in migrants and people living and/or working in areas with gold mining operations. A molecular survey was performed in Plasmodium falciparum isolates originating from persons from gold mining areas to assess the extent and role of mining areas as reservoirs of malaria resistance in Suriname.Methods: The status of 14 putative resistance-associated single nucleotide polymorphisms in the pfdhfr, pfcrt, pfmdr1, and pfATP6 genes was assessed for 28 samples from gold miners diagnosed with P. falciparum malaria using polymerase chain reaction amplification and restriction fragment length polymorphism analysis, and the results were compared with earlier data from nonmining villagers.Results: Isolates from miners showed a high degree of homogeneity, with a fixed pfdhfr Ile51/Asn108, pfmdr1 Phe184/Asp1042/Tyr1246, and pfcrt Thr76 mutant genotype, while an exclusively wild-type genotype was observed for pfmdr1 Asn86 and pfdhfr Ala16, Cys59, and Ile164, and for the pfATP6 positions Leu263/Ala623/Ser769. Small variations were observed for pfmdr1 S1034C. No statistically significant difference could be detected in allele frequencies between mining and nonmining villagers.Conclusion: Despite the increased risk of malaria infection in individuals working/living in gold mining areas, we did not detect an increase in mutation frequency at the 14 analyzed single nucleotide polymorphisms. Therefore, mining areas in Suriname cannot yet be considered as reservoirs for malaria resistance.Keywords: Plasmodium falciparum, gold mining, mutation frequency, Suriname

  13. Environmental monitoring at the Nalunaq Gold Mine, South Greenland, 2010

    DEFF Research Database (Denmark)

    Glahder, Christian Martin; Søndergaard, Jens; Asmund, Gert

    This seventh monitoring study was performed in the Nalunaq Gold Mine area, Nanortalik, South Greenland during 25-31 August 2010. No ore had been shipped to foreign gold production since the monitoring study in August 2009. Most work has dealt with the excavation of a production chamber...... an uncontaminated area. Samples were analysed for 11 elements with ICP-MS. In lichens, elevated concentrations (2-9 times of background levels) of copper (Cu), chromium (Cr), arsenic (As) and cobalt (Co) were found at the waste rock stockpile and in the mine area. A non-linear temporal trend with decreasing...

  14. Gold King Mine Release New Mexico Response Activities

    Science.gov (United States)

    DALLAS - (August 8, 2015) EPA Region 6 deployed a federal on-scene coordinator from its emergency response team and scientific technicians under contract to EPA to assist the state in preparations for the potential impacts from the Gold King Mine re

  15. Seal Hairs Tell World History of Gold and Silver Mining

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ The fluctuation of mercury (Hg) concentration in seal hairs over the past 2,000years in a lake-sediment core on King George Island, West Antarctica, has been found to be closely correlated with ancient activities of gold and silver mining by using Hg-amalgamation process around the world.

  16. Women, mercury and artisanal gold mining : Risk communication and mitigation

    Science.gov (United States)

    Hinton, J. J.; Veiga, M. M.; Beinhoff, C.

    2003-05-01

    Artisanal miners employ rudimentary techniques for minéral extraction and often operate under hazardous, labour intensive, highly disorganized and illegal conditions. Gold is the main mineral extracted by artisanal miners, and the ecological and human health impacts resulting from mercury (Hg) use in gold extraction warrant special consideration. More than 30% of world's 13 million artisanal miners are women and, as they are often perceived to be less suited for labour intensive mining methods, the majority of women work in the processing aspect of artisanal mining, including amalgamation with Hg. As women are also predominantly responsible for food preparation, they are in an excellent position to respond to health risks associated with consumption of Hg-contaminated foods in impacted areas. In addition to their influence on consumption habits, women in artisanal mining communities may be in a position to effect positive change with respect to the technologies employed. Thus, gender sensitive approaches are necessary to reduce exposure risks to women and their families, promote clean technologies and support the development of stronger, healthier artisanal mining communities. This paper describes the roles of women in artisanal gold mining, highlights their importance in reducing the Hg exposure in these communities, and provides insight into how risks from Hg pollution can effectively be communicated and mitigated.

  17. Characterization and treatment of artisanal gold mine tailings.

    Science.gov (United States)

    de Andrade Lima, L R P; Bernardez, L A; Barbosa, L A D

    2008-02-11

    The solid waste generated by artisanal gold mining, with high mercury and gold contents, can be found in several areas in the South America. The present study focused on the tailings of an artisanal gold mine area located in the Brazilian northeastern. Samples of the mine tailings were taken and used to perform a physical and chemical characterization study using X-ray diffraction, scanning electron microscopy, neutron activation, X-ray fluorescence, induced coupled plasma-mass spectrometry, among others analytical methods. The results indicate that the material is composed mainly by quartz and goethite, the characteristic size of the particles (d(50)) is about 150 microm, and the density is close of that of quartz. The main constituents are silicon, iron, and aluminum. The tailings gold content is of about 1.8 mg/kg and the mercury content is of about 10 mg/kg. A remarkable feature of this solid waste is that the gold and mercury are both concentrated in both the fine and the coarse particles, but not in particles of intermediary size. Leaching studies indicated that the tailings are stable in weak organic acids, but soluble in alkaline and aired cyanide solutions, in which 89% of gold and 100% of mercury are extracted in 24 h. Electroleaching experiments, performed using sodium chloride as electrolyte, indicated that mercury and gold are extracted simultaneously and the recovery of both metals can be as high as 70% in 4 h. In addition, chromium, nickel, and lead are found in relatively large amounts in the solution, which indicate an effectively action of the electroleaching method to clean up solid wastes contaminated with metals.

  18. Environmental stewardship for gold mining in tropical regions

    Directory of Open Access Journals (Sweden)

    A Isahak

    2013-10-01

    Full Text Available Mining has gained strong popularity in recent years due to the increase in global demand for metals and other industrial raw material derived from the ground. However, information and good governance regarding activities related to mining is still very much lacking especially in underdeveloped and developing countries in the tropics. In Malaysia, the importance of environmental stewardship in mining is a new phenomenon. The new National Mineral Policy 2 calls for compliance with existing standards and guidelines, stresses on progressive and post mining rehabilitation as well as promotes the gathering and dissemination of information, best mining practices, public disclosure and corporate social responsibility. Our preliminary studies however have shown that its implementation may have been hampered by inadequate legal and administrative structures, lack of freedom of information, physical inaccessibility, lack of information and public participation. In this presentation, the above issues and measures to reduce the impact of mining, particularly that of gold on the environment with a special focus on Malaysia is discussed. These measures include alternative gold extraction methods, appropriate tailing dam construction and management, health risk assessment and risk management, compliance with the Cyanide Code and liberalization of access to information, facilitation of access to justice, the strengthening of legal and administrative structures as well as corporate accountability to the public as part of corporate social responsibility.

  19. Environmental stewardship for gold mining in tropical regions

    Directory of Open Access Journals (Sweden)

    A.Isahak

    2013-10-01

    Full Text Available Mining has gained strong popularity in recent years due to the increase in global demand for metals and other industrial raw material derived from the ground. However, information and good governance regarding activities related to mining is still very much lacking especially in underdeveloped and developing countries in the tropics. In Malaysia, the importance of environmental stewardship in mining is a new phenomenon. The new National Mineral Policy 2 calls for compliance with existing standards and guidelines, stresses on progressive and post mining rehabilitation as well as promotes the gathering and dissemination of information, best mining practices, public disclosure and corporate social responsibility. Our preliminary studies however have shown that its implementation may have been hampered by inadequate legal and administrative structures, lack of freedom of information, physical inaccessibility, lack of information and public participation. In this presentation, the above issues and measures to reduce the impact of mining, particularly that of gold on the environment with a special focus on Malaysia is discussed. These measures include alternative gold extraction methods, appropriate tailing dam construction and management, health risk assessment and risk management, compliance with the Cyanide Code and liberalization of access to information, facilitation of access to justice, the strengthening of legal and administrative structures as well as corporate accountability to the public as part of corporate social responsibility.

  20. The environmental impact of gold mines: pollution by heavy metals

    Science.gov (United States)

    Abdul-Wahab, Sabah; Marikar, Fouzul

    2012-06-01

    The gold mining plant of Oman was studied to assess the contribution of gold mining on the degree of heavy metals into different environmental media. Samples were collected from the gold mining plant area in tailings, stream waters, soils and crop plants. The collected samples were analyzed for 13 heavy metals including vanadium (V), chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), cadmium (Cd), cobalt (Co), lead (Pb), zinc (Zn), aluminium (Al), strontium (Sr), iron (Fe) and barium (Ba). The water in the acid evaporation pond showed a high concentration of Fe as well as residual quantities of Zn, V, and Al, whereas water from the citizens well showed concentrations of Al above those of Omani and WHO standards. The desert plant species growing closed to the gold pit indicated high concentrations of heavy metals (Mn, Al, Ni, Fe, Cr, and V), while the similar plant species used as a control indicated lesser concentrations of all heavy metals. The surface water (blue) indicated very high concentrations of copper and significant concentrations of Mn, Ni, Al, Fe, Zn, lead, Co and Cd. The results revealed that some of the toxic metals absorbed by plants indicated significant metal immobilization.

  1. Refurbishing technologies of hydraulic actuators applied in mining industry

    Directory of Open Access Journals (Sweden)

    P. Gendarz

    2010-07-01

    Full Text Available Purpose: of this paper: Mainly, future design and manufacturing processes should be oriented to refurbishing and overhaul, such as mining machines, hydraulics, military industry, heavy industry products, etc.. This paper shows method which can improve indirectly profitability also in environment protection area.Design/methodology/approach: Methodology that solves refurbishing and overhaul problem of application, is based on CAD/CAM integration, and predicts possibility to even prepare design for refurbishing. With help of reverse engineering techniques, also exist approach to refurbish elements that has no overhaul documentation prepared before.Findings: Preparation of overhaul documentation for families of constructions, should be computer aided with use of prepared dedicated software. Time need to prepare refurbishing technology, can be considerably reduced.Research limitations/implications: Refurbishing and overhaul in existence cycle of product should have same rights as technology or design processes. Future development of new refurbishing technologies should be prepared in software combined with CAD/CAM modules used in advanced CAE programs.Practical implications: Mining industry after possible initiate refurbishing methods, can extend exploit time of exerted machines. Simultaneously producers of mining machines and equipment, after bringing in design for refurbishing strategy in to production, can enhance economical profits from maintenance and service time prolongation.Originality/value: For last twenty years no development in area of patents were noticed. That came with increase of consumption strategy progressed by produces. Presented method solves issues of materials raise in prices and relatively short time of maintenance and service time period. New workstations in industry can be created with application of the method.

  2. Effect of traditional gold mining to surface water quality in Murung Raya District, Central Kalimantan Province

    OpenAIRE

    W.Wilopo; R.Resili; D.P.E. Putra

    2013-01-01

    There are many locations for traditional gold mining in Indonesia. One of these is in Murung Raya District, Central Kalimantan Province. Mining activities involving the application of traditional gold processing technology have a high potential to pollute the environment, especially surface water. Therefore, this study aims to determine the impact of gold mining and processing on surface water quality around the mine site. Based on the results of field surveys and laboratory analysis, our dat...

  3. Limitations in small artisanal gold mining addressed by educational components paired with alternative mining methods.

    Science.gov (United States)

    Zolnikov, Tara R

    2012-03-01

    Current solutions continue to be inadequate in addressing the longstanding, worldwide problem of mercury emissions from small artisanal gold mining. Mercury, an inexpensive and easily accessible heavy metal, is used in the process of extracting gold from ore. Mercury emissions disperse, affecting human populations by causing adverse health effects and environmental and social ramifications. Many developing nations have sizable gold ore deposits, making small artisanal gold mining a major source of employment in the world. Poverty drives vulnerable, rural populations into gold mining because of social and economic instabilities. Educational programs responding to this environmental hazard have been implemented in the past, but have had low positive results due to lack of governmental support and little economic incentive. Educational and enforced intervention programs must be developed in conjunction with governmental agencies in order to successfully eliminate this ongoing problem. Industry leaders offered hopeful suggestions, but revealed limitations when trying to develop encompassing solutions to halt mercury emissions. This research highlights potential options that have been attempted in the past and suggests alternative solutions to improve upon these methods. Some methods include buyer impact recognition, risk assessment proposals exposing a cost-benefit analysis and toxicokinetic modeling, public health awareness campaigns, and the education of miners, healthcare workers, and locals within hazardous areas of mercury exposure. These methods, paired with the implementation of alternative mining techniques, propose a substantial reduction of mercury emissions.

  4. Environmental monitoring at the Nalunaq Gold Mine, South Greenland, 2004

    DEFF Research Database (Denmark)

    Glahder, C. M.; Asmund, G.

    Monitoring was performed in the Nalunaq Gold Mine area, Nanortalik mu-nicipality, South Greenland during 20-26 August 2004. This was eight months after the first shipment of ore. Samples were collected at four marine stations in the Kirkespir Bay, Arctic char were sampled in the Kirkespir River......, and li-chens were collected at 20 stations in the Kirkespir Valley. Samples were analysed for 10 elements with an ICP-MS. Concentrations of Zn, Cu, Cr, As and Co were elevated 3-9 times compared to background concentrations found prior to mine start. The increased level of contamination in the local area...

  5. Sustainable gold mining management waste policy in Romania

    Science.gov (United States)

    Tudor, Elena; Filipciuc, Constantina

    2016-04-01

    Sustainable mining practices and consistent implementation of the mining for the closure planning approach, within an improved legislative framework, create conditions for the development of creative, profitable, environmentally-sound and socially-responsible management and reuse of mine lands. According to the World Commission on Environment and Development definition, sustainable development is the type of development that meets the needs of the present without compromising the ability of future generations to meet their own needs. Romania has the largest gold reserves in Europe (760 million tons of gold-silver ores, of which 40 million tons in 68 gold deposits in the Apuseni Mountains. New mining projects draw particular attention regarding the environmental risks they cause. Rehabilitation is an ongoing consideration throughout the mine's lifecycle, both from a technical and a financial standpoint. The costs of land rehabilitation are classified as the mine's operating costs. According to Directive 2004/35/EC on environmental liability, the prevention and remedying of environmental damage should be implemented by applying the "polluter pays" principle, in line with the principle of sustainable development. Directive on the management of waste from extractive industries and amending Directive obliges operators to provide (and periodically adjust in size) a financial guarantee for waste facility maintenance and post-closure site restoration, including land rehabilitation. According to the Romanian Mining Law, the license holder has the following obligations related to land use and protection: to provide environmental agreements as one of the prerequisites for a building permit; to regularly update the mine closure plan; to set up and maintain the financial guarantee for environmental rehabilitation; and to execute and finalize the environmental rehabilitation of affected land in the mining site, according to the mine closure plan, including the post

  6. Development and construction of HBT type light metallic hydraulic mine props

    Energy Technology Data Exchange (ETDEWEB)

    Korbuly, J.; Szilvassy, Z.

    1986-01-01

    The chronology of various checking devices produced in the stages of development and the improvement of light metallic (aluminium-bearing) hydraulic mine props of Hungarian construction is presented. The main task was to produce hydraulic props that are interchangeable with the previous devices. In the last 10 years more than 50,000 mine props of HBT type were produced and are used both in Hungary and abroad.

  7. Environmental monitoring at the Nalunaq Gold Mine, South Greenland, 2010

    DEFF Research Database (Denmark)

    Glahder, Christian Martin; Søndergaard, Jens; Asmund, Gert

    and the preparation of the gold separation. Low grade ore stored at the pier was transported back to the mine. Mussels, seaweed and sculpins were collected in the Kirkespir Bay, resident Arctic char were caught in the river and lichens were collected both in the area and transplanted to the valley from....... Concentrations of elements in transplanted lichens had decreased to lower levels than those found in 2009 and 2008. No elevated concentrations were found in mussels, sculpins and chars, while seaweed had slightly elevated Co concentrations at one station. In 2010, an impact from the mining activities...... was primarily seen in the Kirkespir Valley due to dust dispersal. The impact of the mine on the marine environment was negligible....

  8. Environmental monitoring at the Nalunaq Gold Mine, South Greenland, 2004

    DEFF Research Database (Denmark)

    Glahder, C. M.; Asmund, G.

    Monitoring was performed in the Nalunaq Gold Mine area, Nanortalik mu-nicipality, South Greenland during 20-26 August 2004. This was eight months after the first shipment of ore. Samples were collected at four marine stations in the Kirkespir Bay, Arctic char were sampled in the Kirkespir River......, and li-chens were collected at 20 stations in the Kirkespir Valley. Samples were analysed for 10 elements with an ICP-MS. Concentrations of Zn, Cu, Cr, As and Co were elevated 3-9 times compared to background concentrations found prior to mine start. The increased level of contamination in the local area...... is moderate compared to contaminations found around closed mines in Greenland, i.e. Maarmorilik, Ivittuut and Mestersvig....

  9. Mercury hazards from gold mining to humans, plants, and animals

    Science.gov (United States)

    Eisler, R.

    2004-01-01

    Mercury contamination of the environment from historical and ongoing mining practices that rely on mercury amalgamation for gold extraction is widespread. Contamination was particularly severe in the immediate vicinity of gold extraction and refining operations; however, mercury--especially in the form of water-soluble methylmercury--may be transported to pristine areas by rainwater, water currents, deforestation, volatilization, and other vectors. Examples of gold mining-associated mercury pollution are shown for Canada, the United States, Africa, China, the Philippines, Siberia, and South America. In parts of Brazil, for example, mercury concentrations in all abiotic materials, plants, and animals--including endangered species of mammals and reptiles--collected near ongoing mercury-amalgamation gold mining sites were far in excess of allowable mercury levels promulgated by regulatory agencies for the protection of human health and natural resources. Although health authorities in Brazil are unable to detect conclusive evidence of human mercury intoxication, the potential exists in the absence of mitigation for epidemic mercury poisoning of the mining population and environs. In the United States, environmental mercury contamination is mostly from historical gold mining practices, and portions of Nevada remain sufficiently mercury-contaminated to pose a hazard to reproduction of carnivorous fishes and fish-eating birds. Concentrations of total mercury lethal to sensitive representative natural resources range from 0.1 to 2.0 ug/L of medium for aquatic organisms; from 2200 to 31,000 ug/kg body weight (acute oral) and 4000 to 40,000 ug/kg (dietary) for birds; and from 100 to 500 ug/kg body weight (daily dose) and 1000 to 5000 ug/kg diet for mammals. Significant adverse sublethal effects were observed among selected aquatic species at water concentrations of 0.03 to 0.1 ug Hg/L. For some birds, adverse effects--mainly on reproduction--have been associated with total

  10. Determining change in managerial practices implementation readiness in a gold mine / Yolandie Jansen van Vuuren

    OpenAIRE

    Jansen van Vuuren, Yolandie

    2011-01-01

    Performance Effectiveness Appraisal, Performance Effectiveness Review as well as Coaching and training are crucial elements of the performance management process included in a set of managerial competencies required by managers in a deep level gold mine in South Africa. This dissertation provides a contemporary review of performance management and gold mining in a South African deep level gold mine context. It provides a theoretical framework for the processes of Performance Effectiveness ...

  11. Elevated rates of gold mining in the Amazon revealed through high-resolution monitoring

    OpenAIRE

    Asner, Gregory P.; Llactayo, William; Tupayachi, Raul; Luna, Ernesto Ráez

    2013-01-01

    Commodity gold prices increased substantially following the 2008 global financial crisis. Gold demand has fueled a massive increase in mining activity, some of which is centered in the Amazon basin. Western Amazonian forests of Peru have become an epicenter for mostly illegal gold mining, but the clandestine nature of mining activities has made monitoring and reporting of forest losses extremely challenging. We combined high-resolution satellite and aircraft-based imaging with field surveys t...

  12. Arsenic hazards to humans, plants, and animals from gold mining

    Science.gov (United States)

    Eisler, R.

    2004-01-01

    Arsenic sources to the biosphere associated with gold mining include waste soil and rocks, residual water from ore concentrations, roasting of some types of gold-containing ores to remove sulfur and sulfur oxides, and bacterially-enhanced leaching. Arsenic concentrations near gold mining operations were elevated in abiotic materials and biota: maximum total arsenic concentrations measured were 560 ug/L in surface waters, 5.16 mg/L in sediment pore waters, 5.6 mg/kg dry weight (DW) in bird liver, 27 mg/kg DW in terrestrial grasses, 50 mg/kg DW in soils, 79 mg/kg DW in aquatic plants, 103 mg/kg DW in bird diets, 225 mg/kg DW in soft parts of bivalve molluscs, 324 mg/L in mine drainage waters, 625 mg/kg DW in aquatic insects, 7700 mg/kg DW in sediments, and 21,000 mg/kg DW in tailings. Single oral doses of arsenicals that were fatal to 50% of tested species ranged from 17 to 48 mg/kg body weight (BW) in birds and from 2.5 to 33 mg/kg BW in mammals. Susceptible species of mammals were adversely affected at chronic doses of 1 to 10 mg As/kg BW, or 50 mg As/kg diet. Sensitive aquatic species were damaged at water concentrations of 19 to 48 ug As/L, 120 mg As/kg diet, or tissue residues (in the case of freshwater fish) >1.3 mg/kg fresh weight. Adverse effects to crops and vegetation were recorded at 3 to 28 mg of water-soluble As/L (equivalent to about 25 to 85 mg total As/kg soil) and at atmospheric concentrations >3.9 ug As/m3. Gold miners had a number of arsenic-associated health problems including excess mortality from cancer of the lung, stomach, and respiratory tract. Miners and schoolchildren in the vicinity of gold mining activities had elevated urine arsenic of 25.7 ug/L (range 2.2-106.0 ug/L). Of the total population at this location, 20% showed elevated urine arsenic concentrations associated with future adverse health effects; arsenic-contaminated drinking water is the probable causative factor of elevated arsenic in urine. Proposed arsenic criteria to protect

  13. Occurrences of dendritic gold at the McLaughlin Mine hot-spring gold deposit

    Science.gov (United States)

    Sherlock, R. L.; Lehrman, N. J.

    1995-06-01

    Two styles of gold dendrites are variably developed at the McLaughlin Mine. The most abundant occurrence is hosted by amber-coloured hydrocarbon-rich opal. Silica likely precipitated from a boiling hydrothermal fluid and complexed with immiscible hydrocarbons forming an amorphous hydrocarbon-silica phase. This phase likely scavenged particulate gold by electrostatic attraction to the hydrocarbon-silica phase. The dendritic nature of the gold is secondary and is the result of dewatering of the amorphous hydrocarbon-silica phase and crystallization of gold into syneresis fractures. The second style of dendritic gold is hosted within vein swarms that focused large volumes of fluid flow. The dendrites occur along with hydrocarbon-rich silica at the upper contact of the vein margins which isolated the dendrites allowing sufficient time for them to grow. In a manner similar to the amber-coloured opal, the dendrites may have formed by scavenging particulate gold by electrostatic attraction to the hydrocarbon-silica phase.

  14. Field investigation into directional hydraulic fracturing for hard roof in Tashan Coal Mine

    Institute of Scientific and Technical Information of China (English)

    Bing-Xiang HUANG; Bin YU; Feng FENG; Zhao LI; You-Zhuang WANG; Jin-Rong LIU

    2013-01-01

    Research and development of safe and effective control technology of hard roof is an inevitable trend at present.Directional hydraulic fracturing technology is expected to become a safe and effective way to control and manage hard roof.In order to make hard roof fracture in a directional way,a hydraulic fracture field test has been conducted in the third panel district of Tashan Coal Mine in Datong.First,two hydraulic fracturing drilling holes and four observing drilling holes were arranged in the roof,followed by a wedge-shaped ring slot in each hydraulic fracturing drilling hole.The hydraulic fracturing holes were then sealed and,hydraulic fracturing was conducted.The results show that the hard roof is fractured directionally by the hydraulic fracturing function of the two fracturing drilling holes; the sudden drop,or the overall downward trend of hydraulic pressure from hydraulic monitoring is the proof that the rock in the hard roof has been fractured.The required hydraulic pressure to fracture the hard roof in Tashan coal mine,consisting of carboniferous sandstone layer,is 50.09 MPa,and the fracturing radius of a single drilling hole is not less than 10.5 m.The wedge-shaped ring slot made in the bottom of the hydraulic fracturing drilling hole plays a guiding role for crack propagation.After the hydraulic fracturing drill hole is cracked,the propagation of the resulting hydraulic crack,affected mainly by the regional stress field,will turn to other directions.

  15. Closure of the Brewer Gold Mine by pit backfilling

    Energy Technology Data Exchange (ETDEWEB)

    Lewis-Russ, A.; Lupo, J.F. [Titan Environmental Corp., Englewood, CO (United States); Bronson, J.M. [Titan Environmental Corp., Tempe, AZ (United States)] [and others

    1996-12-31

    Brewer Gold Mine, located in north-central South Carolina, is implementing an innovative reclamation plan that includes backfilling the main Brewer open pit with mine waste. The primary goals of the closure are to reduce acid rock drainage and minimize or eliminate long-term operation and maintenance requirements by restoring the site property to approximate pre-mining topography. The plan calls for consolidation of approximately 200 acres of waste into approximately 20 hectares (50 acres). Much of the material to be backfilled into the pit, including spent heap leach material and waste rock, has acid-generating potential. Therefore, the backfill design integrated geochemical properties of the backfill materials with expected post-closure conditions. A prime consideration was the final position of the water table. Since mining at the site started in the early 1800`s, no records exist of the original groundwater levels. Therefore, the design incorporates a large anoxic limestone drain to control the final groundwater level. Additional amendments are to be placed in targeted areas of the backfill to maximize their utilization. A low-permeability cap system that includes a GEOSYNTHETIC clay liner has been designed to limit infiltration into the backfill.

  16. Sediment and Mercury Loads to Humbug Creek: A Sierra Nevada Tributary Impacted by the Malakoff Diggins Hydraulic Mine

    Science.gov (United States)

    Monohan, C.; Brown, D. L.; Nepal, H.

    2016-12-01

    Mercury contaminated sediment from legacy gold mines in the Sierra continues to be a source of inorganic mercury (Hg) to the environment. The discharge from Malakoff Diggins, once one of the largest hydraulic mines in California, is a source of Hg and sediment to Humbug Creek. The purpose of this study was to estimate the load of particulate bound Hg and suspended sediment in Humbug Creek for Water Years 2012 and 2013. Grab samples were taken from baseflow conditions and from multiple storm events and analyzed for nonfiltered Hg, filtered Hg and total suspended sediment (TSS) (EPA 1669, EPA 1631, EPA 160.2). A stage discharge relationship was developed for the Humbug Creek gage station over a range of flow conditions. Samples were collected from Humbug Creek upstream of the Malakoff Diggins discharge point, from the discharge point and downstream of the discharge and Humbug Creek confluence at a stream gage. The annual load in Humbug Creek for suspended sediment and particulate bound Hg was calculated at the gage using relationships established with continuously monitored turbidity (15 min data) and grab samples of total suspended sediment (n = 25, R2 = 0.82) and particulate bound Hg (n = 15, R2 = 0.80). The annual load was 100-120 grams of particulate bound Hg and 475,000-575,000 kg of suspended sediment. For both water years, as much as half of the annual sediment load was from a single storm event during which 3-4g of particulate bound mercury was released per day. The contribution of mercury loads from legacy hydraulic gold mines should be quantified as it is a critical source control strategy for California Total Maximum Daily Load programs.

  17. Assessment of the impacts of gold mining on soil and vegetation in Brownsberg Nature Park, Suriname

    NARCIS (Netherlands)

    Arets, E.J.M.M.; Meer, van der P.J.; Brink, van den N.W.; Tjon, K.; Atmopawiro, V.P.; Ouboter, P.E.

    2006-01-01

    This report describes the assessment of the impacts of small scale gold-mining on soil and vegetation in Brownsberg Nature Park. In the past 10 years small-scale gold mining with heavy machinery has been illegally practiced within Brownsberg Nature Park (BNP). During this process the vegetation and

  18. Biodiversity conservation versus artisanal gold mining: a case study of Chimanimani National Park, Zimbabwe

    NARCIS (Netherlands)

    Gandiwa, E.; Gandiwa, P.

    2012-01-01

    Artisanal gold mining plays an important role in sustainable development of rural communities. The objectives of this study were to: i) assess the environmental impacts of recent artisanal gold mining activities in Chimanimani National Park (CNP), eastern Zimbabwe, and ii) discuss the associated

  19. Biodiversity conservation versus artisanal gold mining: a case study of Chimanimani National Park, Zimbabwe

    NARCIS (Netherlands)

    Gandiwa, E.; Gandiwa, P.

    2012-01-01

    Artisanal gold mining plays an important role in sustainable development of rural communities. The objectives of this study were to: i) assess the environmental impacts of recent artisanal gold mining activities in Chimanimani National Park (CNP), eastern Zimbabwe, and ii) discuss the associated imp

  20. Seismic attribute analysis to enhance detection of thin gold-bearing reefs: South Deep gold mine, Witwatersrand basin, South Africa

    CSIR Research Space (South Africa)

    Manzi, MSD

    2013-11-01

    Full Text Available The gold-bearing Upper Elsburg Reef clastic wedge (UER) in the South Deep gold mine in the Witwatersrand basin (South Africa) hosts the highly auriferous basal conglomerate known as the Elsburg Conglomerate (EC) reef. The reef is less than 20 m...

  1. Mercury Pollution Due to Small-Scale Gold Mining in the Philippines: An Economic Analysis

    OpenAIRE

    Aniceto C. Orbeta; Israel, Danilo C.; Asirot, Jasminda

    2000-01-01

    The study reviews small-scale gold mining in the Philippines and economically assesses mercury pollution and other development problems in the industry. The end purpose is to suggest measures to address the problems and promote better environmental and overall management of small-scale mining. The study has used secondary data from mining institutions and primary data from key informants and small-scale gold miners and processors in the two case study sites. brazzer

  2. Gold Minerogenetic Prognosis Using Satellite Data: Case Study of Paishanlou Gold Mine, Liaoning Province, China

    Institute of Scientific and Technical Information of China (English)

    Malogo J M Kongola; Wang Ende

    2005-01-01

    The major scientific goal of using satellite data for mineral prospecting in the study area was two-fold: (a) mapping geology, faults and fractures that localize ore deposits; (b) recognizing hydrothermally altered rocks by interpreting their spectral signatures. The lithology, properties, and geological relations of the rocks were key to understanding such varied phenomena as convection, melting and transport mechanisms, rock deformation and alteration, the sources of magnetic anomalies, and the hydrothermal circulation and formation of gold deposits. Satellite data were enhanced using the following techniques: band combinations, ratios, directional sharpening filtering, Laplacian transform, spatial convolution, and density slicing. By mapping a larger area, the Paishanlou Gold Mine was discovered to be located within an accommodation zone, with three significant populations of faults having bearings of 95, 145, and 180 degrees. Faults bearing 145 degrees make up the faults of the main shear zone. The faults bearing 180 degrees have large sinistral offsets, typically 1.5 km, and form a synthetic-antithetic set with the faults bearing 145 degrees, which have dextral displacements of tens of meters. In the Landsat ETM+ image composed of bands 7-4-2 RGB, gneiss rocks were clearly seen as red purple, and granitic and plagioclase bodies in pale brown/pink. The strongest alteration signature in the image was found along the detachment fault antiform located closest to the mine and the plutons responsible for the Paishanlou gold mineralization. Satellite image interpretation coupled with field surveys led to the identification of iron mineral composites, hydrothermally altered areas, fractures, and an accommodation zone. These anomalies finally resulted in the discovery of three new gold-mineralized sites.

  3. Stratigraphy and mineralogy of a carbonate-hosted gold deposit: Kings Mountain gold mine, NC

    Energy Technology Data Exchange (ETDEWEB)

    Supplee, J.; Lapoint, D.; Feiss, P.G.

    1985-01-01

    The Kings Mountain Gold Mine, Cleveland Company, North Carolina, is unique in the Appalachians in that it is carbonate-hosted, with a distinctive ore mineralogy. The mine stratigraphy is upright, younging east to west. The basal unit is a volcanic to subvolcanic chlorite, feldspar, quartz-eye porphyry, cut by a silicic porphyry, interpreted as a shallow level intrusion. Above and gradational to the chloritic porphyry, unless separated by the intrusive silicic porphyry, is a sericitic, quartz-eye porphyry, probably a metatuff. A north-thinning, graphite schists is above the sericitic porphyry. Carbonates overlie the graphite schist except to the north where they are above the sericitic porphyry. The carbonates consist of basal and upper sequences separated by a sericite, quartz-eye schists (metatuff) which is capped by a chlorite-sericite-graphite schist. Mineralization occurs within each carbonate sequence. This is overlain by interbedded chlorite and graphite schists with two horizons of exhalative iron formation (I.F.). Above the I.F. is a thick sequence of sericitic chlorite schists (turbidites). The mineralized carbonates are pervasively silicified with a disseminated assemblage of pyrite, pyrrhotite, sphalerite, chalcopyrite, galena, gold, altaite (PbTe), tetrahedrite, and pyrargyrite in quartz and dolomite +/- fluorite gangue. We suggest that the mineralization is associated with hydrothermal activity during emplacement of the silicic porphyry and following carbonate diagenesis. Mineralization was syn- or post-depositional with respect to the I.F.

  4. Geochemistry of mercury in tropical swamps impacted by gold mining.

    Science.gov (United States)

    Marrugo-Negrete, José; Pinedo-Hernández, José; Díez, Sergi

    2015-09-01

    Artisanal and small-scale gold mining (ASGM) poses a serious threat to the local environment. Colombia has very active ASGM activities, where mercury (Hg) ends in piles of mining waste, soils, and waterways. In this study, we assessed Hg speciation and bioavailability in sediments of two tropical swamps, impacted by ASGM. In Ayapel swamp, total Hg (T-Hg) concentrations in sediments ranged between 145 and 313 ng g(-1) dry weight (dw) (mean: 235 ± 49 ng g(-1) dw), whereas Grande Achi swamp levels are 3-fold higher (range: 543-1021 ng g(-1) dw; mean: 722 ± 145 ng g(-1) dw). Even though lower levels of Hg were found in Ayapel, methylation was found to be significantly higher than in Grande Achi, and it is significantly higher in the dry than in the rainy season for both swamps. This increased methylation is linked to the statistically significant correlation between T-Hg, MeHg and organic matter in the Ayapel swamp. In fact, Hg content in both swamps is mainly associated to the organic fraction (Hg-o), with a higher statistically significant difference in Ayapel (43 ± 5%) compared to Grande Achi (33 ± 5%). On the other hand, a significant percentage (30 ± 6%) of elemental Hg fraction (Hg-e) was found in Grande Achi, directly related with Hg released during the gold recovery process from upstream ASGM sites. The percentage of the bioavailable fraction (Hg-w and Hg-h) is elevated (up to 15%), indicating a potential risk to the aquatic environment and human health because these labile Hg species could enter the water column and bioaccumulate in biota.

  5. Hydraulic characterisation of the tailings associated with the abandoned mine at Frongoch, Mid-Wales

    OpenAIRE

    Banks, V.J.; Kirkham, M.

    2011-01-01

    This report describes the material classification and results of field and laboratory hydraulic testing of tailings from the Frongoch Tailings Lagoon, situated immediately to the south of the abandoned Frongoch mine site in mid-Wales. The results are considered in the context of the conceptual site model.

  6. Profile constructing and elevation design of soil reclaimed by hydraulic dredge pump in mining areas

    Energy Technology Data Exchange (ETDEWEB)

    Longqian, C.; Aiqin, S.; Tianjian, Z. [China Univ. of Mining and Technology, Xuzhou, Jiangsu (China). School of Environmental Science and Spatial Informatics; Mei, L. [China Univ. of Mining and Technology, Xuzhou, Jiangsu (China)

    2007-07-01

    Underground coal mining is the main method of coal mining in China. The hydraulic dredge pump reclamation method is the basic method used for repairing hydraulic erosion. This paper reviewed land reclamation by hydraulic dredge pump in the Yi'an coal mine of Xuzhou mining area in the east of China, and analyzed the constructing theory of soil profiling. It examined factors such as the height of the ground-water table; the thickness of plough horizon; the length of crops root and the state of soil erosion; and the methods of profile construction and elevation design of soil reclaimed by hydraulic dredge pump. A relevant mathematical model was also developed. The paper discussed the general situation of the study site as well as the basic theory of profile constructing and the profile constructing method. The paper also discussed the elevation design of the reclaimed land. It was concluded that the practice has proved that the methods can make the reclaimed soil keep a similar characteristics to that of original cropped soil, and meet the requirements for elevation of reclaimed land. 8 refs., 1 tab., 2 figs.

  7. Geochemical and GIS study of the Zarshuran Gold mine in Iran

    Science.gov (United States)

    Sedighi, Tahereh; Sedighi, Ahmad

    2015-04-01

    Geochemical and GIS study of the Zarshuran Gold mine in Iran Sedighi Tahere 1 Sedighi Ahmad 2 (1) Geological survey of Iran ,GIS branch (2) Shabeke Pars Enginearing Company Zarshuran Gold mine is located in the north of Takab , in West of Azarbayejan Provinc There are four Gold ore types in Zarshuran ; black gouge ,Carbonate tectonized and breccia mineralized ,Massive Jasperiod and Marble and sanded. Refractory ore off Zarshuran are Gold and co-paragenetic ore like;Arsenopyrite and Orpiment. Geographic information system (GIS) has been used to determine the Gold potential of this area. By the GIS system there are different stages with contains, Gathering of all available data, Application of the integration model and the Data processing. By mineralization and Geochemical studies it is indicated that only small fraction of free Gold (21%) is present in the cyanide-soluble salpho-arsenic compound. Major Gold distribution in orpiment, regular and Arsenian Pyrite (32%) oxides, carbonates and labile sulphides (18%) and sulphides pyrite and arsenopyrite (22%). We used several information layers of the geological layer , ore deposit layer , geochemical layer , heavy mineral layer airborn Geophysical layer and remote sensing layer . Also we used from geological maps of this area. By using of the ARCGIS software , we identified the mining potentials for Gold and finally determined the Gold mining area. In this project we used the methods of simple overlay and Fuzzy logic were used. In this presentation, the authors have outlined a strategy to take up Gold mining and refractory and undersetting of the potential for refractory Gold ores in Zarshuran area ,and these results might be used for the other similar gold mines studies.

  8. Technology, managerial, and policy initiatives for improving environmental performance in small-scale gold mining industry.

    Science.gov (United States)

    Hilson, Gavin; Van der Vorst, Rita

    2002-12-01

    This paper reviews a series of strategies for improving environmental performance in the small-scale gold mining industry. Although conditions vary regionally, few regulations and policies exist specifically for small-scale gold mining activity. Furthermore, because environmental awareness is low in most developing countries, sites typically feature rudimentary technologies and poor management practices. A combination of policy-, managerial- and technology-related initiatives is needed to facilitate environmental improvement in the industry. Following a broad overview of these initiatives, a recommended strategy is put forth for governments keen on improving the environmental conditions of resident small-scale gold mines.

  9. Atmospheric mercury emissions from polluted gold mining areas (Venezuela).

    Science.gov (United States)

    García-Sánchez, A; Contreras, F; Adams, M; Santos, F

    2006-12-01

    Soil, waste rock and mud from mercury-gold amalgamation mining areas of El Callao (Venezuela) are highly enriched in Hg (0.5-500 microg g(-1)) relative to natural background concentrations (mining districts (>100,000 ng m(-2) h(-1)). The results from this study also show that Hg emissions from the soil are influenced by solar radiation, soil temperature and soil Hg concentration. Our data suggest that solar radiation may be the dominant factor affecting Hg degrees emission since the major species of mercury in polluted soil is Hg degrees (85-97% of total Hg). The simple release of Hg degrees vapor is probably the dominant process occurring with incident light in the field. The apparent activation energy for mercury emission indicates that the volatilization of mercury mainly occurred as a result of the vaporization of elemental mercury in soil. The degree of Hg emission differed significantly among the soil sites studied, which may be due to variations in soil texture, organic matter content and soil compaction.

  10. Community-company relations in gold mining in Ghana.

    Science.gov (United States)

    Garvin, Theresa; McGee, Tara K; Smoyer-Tomic, Karen E; Aubynn, Emmanuel Ato

    2009-01-01

    As a result of Structural Adjustment Programme from the 1980s, many developing countries have experienced an increase in resource extraction activities by international and transnational corporations. The work reported here examines the perceived impacts of gold mining at the community level in the Wassa West District of Ghana, Africa and discusses those perceived impacts in the context of globalization processes and growing multinational corporate interest in Corporate Social Responsibility (CSR). Interview data compared community members' perceptions with those of company representatives in three communities. The results indicate that communities held companies responsible for a series of economic, social, and environmental changes. While recognizing some of the benefits brought by the mines, communities felt that the companies did not live up to their responsibility to support local development. Companies responded by denying, dismissing concerns, or shifting blame. Findings from this work show that lack of engagement and action by government agencies at all levels resulted in companies acting in a surrogate governmental capacity. In such situations, managing expectations is key to community-company relations.

  11. Prediction and prevention of rockburst in metal mines – A case study of Sanshandao gold mine

    Directory of Open Access Journals (Sweden)

    Meifeng Cai

    2016-04-01

    Full Text Available Rockburst is a kind of artificial earthquake induced by human activities, such as mining excavations. The mechanism of rockburst induced by mining disturbance is revealed in terms of energy in this context. For understanding the rockburst mechanism, two necessary conditions for the occurrence of rockburst are presented: (1 the rock mass has the capability to store huge amount of energy and possesses a strong bumping-prone characteristic when damaged; and (2 the geological conditions in the mining area have favorable geo-stress environments that can form high-stress concentration area and accumulate huge energy. These two conditions are also the basic criteria for prediction of rockburst. In view of energy analysis, it is observed that artificial and natural earthquakes have similar regularities in many aspects, such as the relationship between the energy value and burst magnitude. By using the relationship between energy and magnitude of natural earthquake, rockburst is predicted by disturbance energy analysis. A practical example is illustrated using the above-mentioned theorem and technique to predict rockburst in a gold mine in China. Finally, the prevention and control techniques of rockburst are also provided based on the knowledge of the rockburst mechanism.

  12. Research on the Mechanism and Prevention of Rockburst at the Yinxin Gold Mine

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The occurrence and nature of shaft rockburst in the Yinxin gold mine are recorded and analyzed.Rockburst happens along an obvious south-north orientation.The ground and surrounding rock stresses are measured in this mine.The research indicates that the directivity of rockburst is closely related to geological structure and to abnormal distribution of ground stress in some parts of the mining area.The mechanism of past rockbursts is discussed based upon the theory of fracture mechanics.Some rockburst release measures and their execution in the Yinxin Gold Mine are described.These measures have been successful in eliminating rockburst.

  13. 76 FR 9449 - National Emission Standards for Hazardous Air Pollutants: Gold Mine Ore Processing and Production...

    Science.gov (United States)

    2011-02-17

    ... add carbon adsorbers to control the ore pre-heaters. Based on this beyond-the-floor analysis, we... controls on all thermal units at Nevada gold mines. According to the commenters, these permits are...

  14. [Study of hydrogen cyanide activity in various working environment in gold-mining industry].

    Science.gov (United States)

    Dedkova, L A; Dorogova, V B; Petrov, V F

    2008-01-01

    The study concerned an influence of saline content of liquid phase of crushed ore and presence or absence of solution blending on the process of cyanic hydrogen release in air of working area gold-mining industry.

  15. Reliable practical technique for in-situ rock stress measurements in deep gold mines.

    CSIR Research Space (South Africa)

    Stacey, TR

    1998-03-01

    Full Text Available The proposed primary output of this research project is the development of a set of equipment and method of in situ stress measurements in a high stress environment typical of the deep level gold mines....

  16. International SUSMIN-project aims at sustainable gold mining in EU

    Science.gov (United States)

    Backnäs, Soile; Neitola, Raisa; Turunen, Kaisa; Lima, Alexandre; Fiúza, António; Szlachta, Malgorzata; Wójtowicz, Patryk; Maftei, Raluca; Munteanu, Marian; Alakangas, Lena; Baciu, Calin; Fernández, Dámaris

    2015-04-01

    Although the gold demand has been constantly increasing in past years, the commodity findings have been decreasing and the extraction of gold has complicated due to increasing complexity and decreasing grade of the ores. Additionally, even gold mining could increase economical development, it has also challenges in eco-efficiency and extraction methods (e.g. cyanide). Thus, the novel energy and resource-efficient methods and technologies for mineral processing should be developed to concentrate selectively different gold bearing minerals. Furthermore, technologies for efficient treatment of mine waters, sustainable management of wastes, and methods to diminish environmental and social impacts of mining are needed. These problems will be addressed by the three year long project SUSMIN. The SUSMIN-project identifies and evaluates environmental impacts and economical challenges of gold mining within EU. The objective of the project is to increase the transnational cooperation and to support environmentally, socially and economically sustainable viable gold production. The focus is to develop and test geophysical techniques for gold exploration, eco-efficient ore beneficiation methods and alternatives for cyanide leaching. Additionally, the research will improve treatment methods for mine waters by the development and testing of advanced adsorbents. The research on socio-economic issues pursues to develop tools for enhancing the mechanisms of the corporate social responsibility as well as community engagement and management of the relations with the stakeholders. Moreover, with the environmental risk assessment and better knowledge of the geochemistry and long-term transformation of the contaminants in mining wastes and mine waters, the mining companies are able to predict and prevent the impacts to the surrounding environment, resulting in an improved environmental management solution. The SUSMIN consortium led by Geological Survey of Finland (GTK) includes seven

  17. Hydraulics.

    Science.gov (United States)

    Decker, Robert L.; Kirby, Klane

    This curriculum guide contains a course in hydraulics to train entry-level workers for automotive mechanics and other fields that utilize hydraulics. The module contains 14 instructional units that cover the following topics: (1) introduction to hydraulics; (2) fundamentals of hydraulics; (3) reservoirs; (4) lines, fittings, and couplers; (5)…

  18. 78 FR 54674 - Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Gold Rock Mine...

    Science.gov (United States)

    2013-09-05

    ...: 14X5017] Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Gold Rock Mine... upon publication of the Draft EIS. ADDRESSES: You may submit comments related to the Gold Rock Mine Project by any of the following methods: Email: BLM_NV_EYDO_Midway_Gold_Rock_EIS@blm.gov Fax:...

  19. Relationship between ductile shear zone and gold mineralization——Taking Jinchangyu gold mine, Eastern Hebei Province, China

    Institute of Scientific and Technical Information of China (English)

    林传勇; 何永年; 陈孝德; 史兰斌; 张小鸥; 祁学义; 郝荣; 龚瑞勋; 张继林

    1995-01-01

    Take Jinchangyu gold mine in Eastern Hebei Province, China, for example, the characteristics, formation conditions, evolution process of ductile shear zone, as well as its relation to gold mineralization have been in detail studied. It is suggested that the ductile shear zone developed in source bed may have a close relation to gold mineralization. The stress cycle during the development of the ductile shear zone acts as a driving force of the directional migration of the auriferous fluid, while the associated retrograde metamorphism may provide geochemical conditions necessary to the activation, migration, enrichment and precipitation of gold. The development of ductile shear zone provides not only the channel way for the migration of the auriferous fluid, but also a suitable site for gold precipitation.

  20. Monitoring the radon flux from gold-mine dumps by gamma-ray mapping

    NARCIS (Netherlands)

    Lindsay, R; de Meijer, RJ; Maleka, PP; Newman, RT; Motlhabane, TGK; de Villiers, D

    2004-01-01

    The exhalation of radon from the large mine dumps at the gold mines in South Africa is a potential health hazard. Determination of radon fluxes from these dumpsites is problematic due to the scatter in the data in time and place and the cost involved in getting a representative sample. gamma-ray spe

  1. Plan to build lab in mine aims to strike scientific gold

    CERN Multimedia

    Mercer, B

    2004-01-01

    Article describing plans to build a neutrino research laboratory in the Homestake gold mine in South Dakota. Assuming that the funding comes through, the timetable calls for construction work inside the mine to start in 2006, with the first detector equipment for experiments installed from 2007 to 2009 (1 page).

  2. Risks posed by large seismic events in the gold mining districts of South Africa

    CSIR Research Space (South Africa)

    Durrheim, RJ

    2011-01-01

    Full Text Available Examining the occurrence of seismic activity in South Africa, the authors point out that the seismic event on 9 March 2005 could be ascribed to past mining, and that seismic events will continue to occur in the gold mining districts as long as deep...

  3. Guide to the measurement and assessment of heat stress in Gold Mines

    CSIR Research Space (South Africa)

    Stewart, JM

    1978-04-01

    Full Text Available This report is intended primarily for ventilation staff on mines, but is also of importance to management. In the gold mining industry the assessment of heat stress is likely to be for one of three purposes: to assess either the average or the worst...

  4. Teleservice for hydraulic excavators operating in open-cast mines; Teleservice bei Tagebau-Hydraulikbaggern

    Energy Technology Data Exchange (ETDEWEB)

    Poettker, A. [Terex Germany GmbH und Co. KG, Dortmund (Germany)

    2005-04-01

    Hydraulic excavators in open-cast mines are cost-intensive capital assets, which must be constantly observed during production in order to ensure availability. Teleservice is one way of reducing the service costs. As open-cast mines are generally developed in areas with a poor infrastructure, the excavators can be reliably reached only via satelite. Several network operators with different data transmission rates are suitable according to the required purpose. Satellite communication is expensive compared to the fixed network. New intelligent network topologies (MANET) are currently undergoing the first field tests. (orig.)

  5. Implications of mining practices in an open-pit gold mine for monitoring of a comprehensive test-ban treaty

    Energy Technology Data Exchange (ETDEWEB)

    Jarpe, S.P.; Moran, B.; Goldstein, P.; Glenn, L.A.

    1996-01-01

    This report summarizes the results of an experiment at the Gold Quarry pit, operated by the Newmont Gold Company at Carlin, NV The purpose of the experiment was to obtain local and regional seismic data, together with ``ground truth``, from conventional surface blasting activity and to use these data to help determine the effectiveness with which conventional mining blasts can be discriminated from underground nuclear explosions.

  6. The magnetic signature of the San Gregorio gold mine area, Uruguay

    Energy Technology Data Exchange (ETDEWEB)

    Barcellos, Andre Bernardi Bicca de; Koppe, Jair Carlos [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil); Ferreira, Francisco Jose Fonseca [Parana Univ., Curitiba, PR (Brazil). Dept. de Geologia; Costa, Antonio Flavio Uberti [Companhia de Pesquisas de Recursos Minerais (CPRM), Rio de Janeiro, RJ (Brazil)

    1995-12-31

    The San Gregorio gold mine lies on a northwest trending shear structure in the Uruguay shield, southwest Minas de Corrales. Ground magnetic surveys in the vicinity of the gold deposit suggest several structures that appear to have controlled the gold mineralization. The analysis of magnetic susceptibility values allowed to concluded that the most important anomaly sources of the San Gregorio mine are the non altered basic rocks, mainly the quartz diorites which generally occur in the hanging wall of the mineralized zone. Other lithologies shows low levels of magnetic susceptibility with weak contrast between mineralization and host rocks. (author). 3 refs., 1 fig., 1 tab

  7. Natural Resources and Local Economic Development: Evidence from a Peruvian Gold Mine

    OpenAIRE

    Aragon, Fernando M.; Juan Pablo Rud

    2010-01-01

    This paper uses the case of Yanacocha, a large gold mine in Peru, to examine the link between natural resources and local economic development. We find evidence of a positive and sizeable effect of the mine on real income, household consumption and poverty reduction. The effects are driven by the mine's demand of local inputs, not by the expansion of local public spending or by compensating differentials for negative spillovers. Using a spatial general equilibrium model, we interpret these re...

  8. Impact of Mercury Use in Artisanal Gold Mining on Community Health: Kahama Case Study, Tanzania

    OpenAIRE

    Kalwani, Jumanne Daudi; Fumbuka, Colorine

    2014-01-01

    This study is part of the main research carried out in 2010 which investigated social economic impact of uncontrolled artisanal mining on local communities and the environment using a case study of sampled gold mining sites in selected villages in Lunguya and Segese wards in Kahama District, Tanzania. The methodology involved a study sample size of 210 households, forming 70% of the targeted mining villages. They were interviewed on various social economic variables related to artisanal minin...

  9. Study on blister of the coating on solid cantilevers of hydraulic supports for coal mining

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this work, blister of the Cu-Sn plus Cr coating on solid cantilevers of hydraulic supports for coal mining was investigated by hydrogen-charging, Devanathan-Stachurski method and electrochemical impedance spectroscopy (EIS) measurement. It was found that the permeation hydrogen during the pickling process and the electroplating process was responsible for the blisters. The residual tensile stress due to the machining process would increase the permeation hydrogen amount during pickling and electroplating processes.

  10. Directional hydraulic fracturing to control hard-roof rockburst in coal mines

    Institute of Scientific and Technical Information of China (English)

    Fan Jun; Dou Linming; He Hu; Du Taotao; Zhang Shibin; Gui Bing; Sun Xinglin

    2012-01-01

    Hard roof is the main factor that induces rock-burst.In view of the present obvious weakness of control measures for hard roof rockburst in domestic collieries,the mechanism and field application of directional hydraulic fracturing technology for rock-burst prevention have been investigated in this paper using theoretical analysis and numerical simulation.The results show that the weighting span of the main roof and the released kinetic energy as well as the total elastic energy decreased greatly after the directional fracturing of hard roof with the mining progression,thereby reducing the rockburst hazard degree to coal body.The directional hydraulic fracturing technology was carried out in 6305 working face of Jisan Coal Mine to prevent rockburst.Field practices have proved that this technology is much simpler and safer to operate with better prevention effect compared with blasting.By optimizing the operation procedures and developing a new technology of automated high-pressure delivery pipe,the maximum fracturing radius now reaches more than 9 m and the borehole depth exceeds 20 m.Additionally,drilling cutting method was applied to monitor the stress of the coal mass before and after the fracturing,and the drill cuttings dropped significantly which indicates that the burst prevention effect of directional hydraulic fracturing technology is very remarkable.The research results of this paper have laid a theoretical and practical foundation for the widespread application of the directional hydraulic fracturing technology in China.

  11. Mining the Final Frontier: Keeping Earth's Asteroid Mining Ventures from Becoming the Next Gold Rush

    Directory of Open Access Journals (Sweden)

    Matthew Feinman

    2014-05-01

    Full Text Available “Space: The Final Frontier.”  While that phrase has been a call to arms for generations of science fiction fans and space enthusiasts to look up at the night sky in wonder and amazement, it has increasingly become a siren call for private space pioneers. Since man first went to space, humankind has been pushing the boundaries of experimentation, research, and exploration into the cosmos. Even though Earth’s supply of certain rare and precious metals may be reaching depletion, researchers have found that asteroids are likely to contain vast quantities of these resources.  Today, several companies are attempting to tap into this potential wealth of resources for use, both on Earth and in space.  Before these companies can begin mining, however, stronger property laws are needed to ensure the Asteroid Belt of our solar system is not described as the next California Gold Rush.  This Article argues that the international community must be united on the policies and customs surrounding property ownership in space so these mining operations can be performed in a peaceful and safe manner.

  12. Impact of gold mining associated with mercury contamination in soil, biota sediments and tailings in Kenya.

    Science.gov (United States)

    Odumo, Benjamin Okang'; Carbonell, Gregoria; Angeyo, Hudson Kalambuka; Patel, Jayanti Purshottam; Torrijos, Manuel; Rodríguez Martín, José Antonio

    2014-11-01

    This work considered the environmental impact of artisanal mining gold activity in the Migori-Transmara area (Kenya). From artisanal gold mining, mercury is released to the environment, thus contributing to degradation of soil and water bodies. High mercury contents have been quantified in soil (140 μg kg(-1)), sediment (430 μg kg(-1)) and tailings (8,900 μg kg(-1)), as expected. The results reveal that the mechanism for transporting mercury to the terrestrial ecosystem is associated with wet and dry depositions. Lichens and mosses, used as bioindicators of pollution, are related to the proximity to mining areas. The further the distance from mining areas, the lower the mercury levels. This study also provides risk maps to evaluate potential negative repercussions. We conclude that the Migori-Transmara region can be considered a strongly polluted area with high mercury contents. The technology used to extract gold throughout amalgamation processes causes a high degree of mercury pollution around this gold mining area. Thus, alternative gold extraction methods should be considered to reduce mercury levels that can be released to the environment.

  13. Effect of traditional gold mining to surface water quality in Murung Raya District, Central Kalimantan Province

    Directory of Open Access Journals (Sweden)

    W.Wilopo

    2013-10-01

    Full Text Available There are many locations for traditional gold mining in Indonesia. One of these is in Murung Raya District, Central Kalimantan Province. Mining activities involving the application of traditional gold processing technology have a high potential to pollute the environment, especially surface water. Therefore, this study aims to determine the impact of gold mining and processing on surface water quality around the mine site. Based on the results of field surveys and laboratory analysis, our data shows that the concentration of mercury (Hg and Cyanide (CN has reached 0.3 mg/L and 1.9 mg/L, respectively, in surface water. These values exceed the drinking water quality standards of Indonesia and WHO. Many people who live in the mining area use surface water for daily purposes including drinking, cooking, bathing and washing. This scenario is very dangerous because the effect of surface water contamination on human health cannot be immediately recognized or diagnosed. In our opinion the dissemination of knowledge regarding the treatment of gold mining wastewater is urgently required so that the quality of wastewater can be improved before it is discharged into the environment.

  14. Effect of traditional gold mining to surface water quality in Murung Raya District, Central Kalimantan Province

    Directory of Open Access Journals (Sweden)

    W.Wilopo

    2013-10-01

    Full Text Available There are many locations for traditional gold mining in Indonesia. One of these is in Murung Raya District, Central Kalimantan Province. Mining activities involving the application of traditional gold processing technology have a high potential to pollute the environment, especially surface water. Therefore, this study aims to determine the impact of gold mining and processing on surface water quality around the mine site. Based on the results of field surveys and laboratory analysis, our data shows that the concentration of mercury (Hg and Cyanide (CN has reached 0.3 mg/L and 1.9 mg/L, respectively, in surface water. These values exceed the drinking water quality standards of Indonesia and WHO. Many people who live in the mining area use surface water for daily purposes including drinking, cooking, bathing and washing. This scenario is very dangerous because the effect of surface water contamination on human health cannot be immediately recognized or diagnosed. In our opinion the dissemination of knowledge regarding the treatment of gold mining wastewater is urgently required so that the quality of wastewater can be improved before it is discharged into the environment

  15. Methods to reduce mercury pollution in small gold mining operations

    Directory of Open Access Journals (Sweden)

    Pantoja-Timarán, F.

    2005-06-01

    Full Text Available The use of mercury for gold beneficiation is still a current practice in small mining operations, mainly in underdeveloped countries, due to the low investment required and necessity of easy to operate systems. But the lack of basic protections makes unavoidable the high pollution of water streams, soils, and in fact, human bodies. Some improvements have been done at site like that related to the removal of the mercury from the amalgam, that usually was done in the open air and now have been changed to the utilization of artisan iron retorts which considerably reduce the emissions of mercury vapors to the atmosphere, but there are still high losses of mercury into the waste solids or tailings coming from the amalgamation process (nearly most of the total weight of the ore treated. In order to reduce the mercury losses into the tailings from the process, this research work has been based in the use of cheap systems, available to the isolated miners, to proof that it is feasible to get an important reduction of the losses and the pollution. The procedure has been accomplished by means of washing the ores with alkaline or detergent agents, together with the use of activated mercury purified by electrowinning in a simple device, easily manufactured in site by the own workers. It is also proven herewith that controlling the time of amalgamation and the total amount of mercury used could reduce the total pollution, and in addition, the gold recovery would be improved. This investigation reports the possibility of a reduction of mercury losses down to 2.4 g per 100 g of gold produced (case of rich ores like La Bruja, with gold recovery up to 94 %; and 8,6 g per 100 g of gold produced (from ores with average grades like La Gruesa, and gold recoveries in the range of 92 %. All that is about 20 to 100 times lower than data reported in current bibliography. The introduction of a previous step of the ore concentration in shaking tables, decreases the total

  16. A Water Hammer Protection Method for Mine Drainage System Based on Velocity Adjustment of Hydraulic Control Valve

    OpenAIRE

    Yanfei Kou; Jieming Yang; Ziming Kou

    2016-01-01

    Water hammer analysis is a fundamental work of pipeline systems design process for water distribution networks. The main characteristics for mine drainage system are the limited space and high cost of equipment and pipeline changing. In order to solve the protection problem of valve-closing water hammer for mine drainage system, a water hammer protection method for mine drainage system based on velocity adjustment of HCV (Hydraulic Control Valve) is proposed in this paper. The mathematic mode...

  17. Mercury and methylmercury contamination related to artisanal gold mining, Suriname

    Science.gov (United States)

    Gray, John E.; Labson, Victor F.; Weaver, Jean N.; Krabbenhoft, David P.

    2002-12-01

    Elemental Hg-Au amalgamation mining practices are used widely in many developing countries resulting in significant Hg contamination of surrounding ecosystems. We have measured total Hg and methyl-Hg concentrations in sediment and water collected from artisanal Au mines and these are the first Hg speciation data from such mines in Suriname. Total Hg and methyl-Hg contents in mine-waste sediment and water are elevated over local uncontaminated baselines. Total Hg (10-930 ng/L) and methyl-Hg (0.02-3.8 ng/L) are highly elevated in mine waters. Increasing total Hg contents in discharged mine waters correlate with increasing water turbidity indicating that most Hg transport is on suspended particulates. Our Hg results are similar to those found in artisanal Au mines in the Amazon basin, where Hg contamination has led to adverse effects on tropical ecosystems.

  18. Physical habitat and water chemistry changes induced by logging and gold mining in French Guiana streams

    Directory of Open Access Journals (Sweden)

    Dedieu N.

    2014-01-01

    Full Text Available Understanding the effects of disturbances on the physical-chemical quality of ecosystems is a crucial step to the development of ecosystem assessment tools. 95 sampling sites distributed among 4 categories of disturbance, i.e.: reference, logging, formerly and currently gold mining, were characterized using stream physical and chemical variables. Our hypotheses were: (i logging and gold mining activities primarily affect the physical habitat structure of streams and (ii both have an effect on chemical environments through nutrient and/or fine particulate resuspension. We demonstrate that physical variables describing the river bottom, and suspended solids discriminate both current and formerly gold mined sites from reference sites, while, whatever the type of impact encountered, nutrient concentrations do not prove relevant to measure human impacts. To understand distribution patterns of aquatic organism across FG, future research should thus aim at examining the match between physical-chemical and biological classifications of small streams under reference and impacted conditions.

  19. Measuring total mercury due to small-scale gold mining activities to determine community vulnerability in Cihonje, Central Java, Indonesia.

    Science.gov (United States)

    Sari, Mega M; Inoue, Takanobu; Matsumoto, Yoshitaka; Yokota, Kuriko

    2016-01-01

    This research is comparative study of gold mining and non-gold mining areas, using four community vulnerability indicators. Vulnerability indicators are exposure degree, contamination rate, chronic, and acute toxicity. Each indicator used different samples, such as wastewater from gold mining process, river water from Tajum river, human hair samples, and health questionnaire. This research used cold vapor atomic absorption spectrometry to determine total mercury concentration. The result showed that concentration of total mercury was 2,420 times than the maximum content of mercury permitted in wastewater based on the Indonesian regulation. Moreover, the mercury concentration in river water reached 685 ng/l, exceeding the quality threshold standards of the World Health Organization (WHO). The mercury concentration in hair samples obtained from the people living in the research location was considered to identify the health quality level of the people or as a chronic toxicity indicator. The highest mercury concentration--i.e. 17 ng/mg, was found in the gold mining respondents. Therefore, based on the total mercury concentration in the four indicators, the community in the gold mining area were more vulnerable to mercury than communities in non-gold mining areas. It was concluded that the community in gold mining area was more vulnerable to mercury contamination than the community in non-gold mining area.

  20. Environmental stewardship for gold mining in tropical regions

    OpenAIRE

    A.Isahak; S. Surif; Gill, A; J. Phang

    2013-01-01

    Mining has gained strong popularity in recent years due to the increase in global demand for metals and other industrial raw material derived from the ground. However, information and good governance regarding activities related to mining is still very much lacking especially in underdeveloped and developing countries in the tropics. In Malaysia, the importance of environmental stewardship in mining is a new phenomenon. The new National Mineral Policy 2 calls for compliance with existing stan...

  1. Impact of mercury emissions from historic gold and silver mining: Global modeling

    Science.gov (United States)

    Strode, Sarah; Jaeglé, Lyatt; Selin, Noelle E.

    We compare a global model of mercury to sediment core records to constrain mercury emissions from the 19th century North American gold and silver mining. We use information on gold and silver production, the ratio of mercury lost to precious metal produced, and the fraction of mercury lost to the atmosphere to calculate an a priory mining inventory for the 1870s, when the historical gold rush was at its highest. The resulting global mining emissions are 1630 Mg yr -1, consistent with previously published studies. Using this a priori estimate, we find that our 1880 simulation over-predicts the mercury deposition enhancements archived in lake sediment records. Reducing the mining emissions to 820 Mg yr -1 improves agreement with observations, and leads to a 30% enhancement in global deposition in 1880 compared to the pre-industrial period. For North America, where 83% of the mining emissions are located, deposition increases by 60%. While our lower emissions of atmospheric mercury leads to a smaller impact of the North American gold rush on global mercury deposition than previously estimated, it also implies that a larger fraction of the mercury used in extracting precious metals could have been directly lost to local soils and watersheds.

  2. Niacin Alternatives for Dyslipidemia: Fool's Gold or Gold Mine? Part II: Novel Niacin Mimetics.

    Science.gov (United States)

    Goel, Harsh; Dunbar, Richard L

    2016-04-01

    Two cardiovascular outcome trials established niacin 3 g daily prevents hard cardiac events. However, as detailed in part I of this series, an extended-release (ER) alternative at only 2 g nightly demonstrated no comparable benefits in two outcome trials, implying the alternative is not equivalent to the established cardioprotective regimen. Since statins leave a significant treatment gap, this presents a major opportunity for developers. Importantly, the established regimen is cardioprotective, so the pathway is likely beneficial. Moreover, though effective, the established cardioprotective regimen is cumbersome, limiting clinical use. At the same time, the ER alternative has been thoroughly discredited as a viable substitute for the established cardioprotective regimen. Therefore, by exploiting the pathway and skillfully avoiding the problems with the established cardioprotective regimen and the ER alternative, developers could validate cardioprotective variations facing little meaningful competition from their predecessors. Thus, shrewd developers could effectively tap into a gold mine at the grave of the ER alternative. The GPR109A receptor was discovered a decade ago, leading to a large body of evidence commending the niacin pathway to a lower cardiovascular risk beyond statins. While mediating niacin's most prominent adverse effects, GPR109A also seems to mediate anti-lipolytic, anti-inflammatory, and anti-atherogenic effects of niacin. Several developers are investing heavily in novel strategies to exploit niacin's therapeutic pathways. These include selective GPR109A receptor agonists, niacin prodrugs, and a niacin metabolite, with encouraging early phase human data. In part II of this review, we summarize the accumulated results of these early phase studies of emerging niacin mimetics.

  3. Water hammer in coarse-grained solid-liquid flows in hydraulic hoisting for ocean mining

    Institute of Scientific and Technical Information of China (English)

    韩文亮; 王光谦; 吴保生; 刘少军; 邹伟生

    2002-01-01

    The particles of polymetallic nodules in hydraulic hoisting flows that are used for mining in deep sea are rather coarse, therefore their flow velocity is smaller than that of the surrounding water. The characteristics of solid-liquid flows such as their density, concentration, elastic modulus and resistance were discussed. The wave propagation speed and the continuity and momentum equations of water hammer in coarse-grained solid-liquid flows were theoretically derived, and a water hammer model for such flows was developed.

  4. Quantification of dust generating sources in gold and platinum mines.

    CSIR Research Space (South Africa)

    Biffi, M

    2003-03-01

    Full Text Available This report outlines the findings of a study performed to establish the respirable dust generation characteristics of a number of mining activities. A series of thirty-eight tests were performed on five mines in order to establish the respirable...

  5. Gold mining for PDT: Great expectations from tiny nanoparticles.

    Science.gov (United States)

    Gamaleia, Nikolai F; Shton, Irina O

    2015-06-01

    Among many and various products, born by the modern nanotechnology, gold nanoparticles roused a special interest of biomedical researchers. Unique features of the nanoparticles allow to use them not only as effective transporters for therapeutic agents but also as basic components of nanocomposite preparations intended for targeted photodynamic and photothermal therapy of tumours. In the review, physical, chemical and biological properties of gold nanoparticles which can promote PDT efficiency of a designed nanocomposite, are briefly characterized, and promising trends in creation of gold-containing composite photosensitizers are analysed.

  6. Developing and exploiting a unique seismic dataset from South African gold mines for source characterization and wave propagation

    CSIR Research Space (South Africa)

    Julia, J

    2008-09-01

    Full Text Available is being developed using mining-induced events from three deep gold mines in South Africa recorded on in-mine networks (<1 km) composed of tens of high-frequency sensors, a network of four broadband stations installed as part of this project at the surface...

  7. An Integrated Assessment Approach to Address Artisanal and Small-Scale Gold Mining in Ghana

    Science.gov (United States)

    Basu, Niladri; Renne, Elisha P.; Long, Rachel N.

    2015-01-01

    Artisanal and small-scale gold mining (ASGM) is growing in many regions of the world including Ghana. The problems in these communities are complex and multi-faceted. To help increase understanding of such problems, and to enable consensus-building and effective translation of scientific findings to stakeholders, help inform policies, and ultimately improve decision making, we utilized an Integrated Assessment approach to study artisanal and small-scale gold mining activities in Ghana. Though Integrated Assessments have been used in the fields of environmental science and sustainable development, their use in addressing specific matter in public health, and in particular, environmental and occupational health is quite limited despite their many benefits. The aim of the current paper was to describe specific activities undertaken and how they were organized, and the outputs and outcomes of our activity. In brief, three disciplinary workgroups (Natural Sciences, Human Health, Social Sciences and Economics) were formed, with 26 researchers from a range of Ghanaian institutions plus international experts. The workgroups conducted activities in order to address the following question: What are the causes, consequences and correctives of small-scale gold mining in Ghana? More specifically: What alternatives are available in resource-limited settings in Ghana that allow for gold-mining to occur in a manner that maintains ecological health and human health without hindering near- and long-term economic prosperity? Several response options were identified and evaluated, and are currently being disseminated to various stakeholders within Ghana and internationally. PMID:26393627

  8. Technologies required for safe and profitable deep level gold mining, South Africa

    CSIR Research Space (South Africa)

    Willis

    2000-01-01

    Full Text Available Since the 14th CMMI conference, held in Edinburgh in 1990, at which a paper was presented by the author (Willis, 1990) reviewing the role of integrating new technology as a survival strategy for South African gold mines, considerable change has...

  9. Foreign direct investment and poverty alleviation : the case of Bulyanhulu and Geita gold mines, Tanzania

    NARCIS (Netherlands)

    Nyankweli, Emmanuel M.

    2012-01-01

    This PhD thesis seeks to quantify the economic, social and environmental effects of the gold mining sector as a component of foreign direct investments in Tanzania and its contribution to poverty alleviation. In addition to highlighting the socio-economic gains and losses, by exploring the corporate

  10. An Integrated Assessment Approach to Address Artisanal and Small-Scale Gold Mining in Ghana

    Directory of Open Access Journals (Sweden)

    Niladri Basu

    2015-09-01

    Full Text Available Artisanal and small-scale gold mining (ASGM is growing in many regions of the world including Ghana. The problems in these communities are complex and multi-faceted. To help increase understanding of such problems, and to enable consensus-building and effective translation of scientific findings to stakeholders, help inform policies, and ultimately improve decision making, we utilized an Integrated Assessment approach to study artisanal and small-scale gold mining activities in Ghana. Though Integrated Assessments have been used in the fields of environmental science and sustainable development, their use in addressing specific matter in public health, and in particular, environmental and occupational health is quite limited despite their many benefits. The aim of the current paper was to describe specific activities undertaken and how they were organized, and the outputs and outcomes of our activity. In brief, three disciplinary workgroups (Natural Sciences, Human Health, Social Sciences and Economics were formed, with 26 researchers from a range of Ghanaian institutions plus international experts. The workgroups conducted activities in order to address the following question: What are the causes, consequences and correctives of small-scale gold mining in Ghana? More specifically: What alternatives are available in resource-limited settings in Ghana that allow for gold-mining to occur in a manner that maintains ecological health and human health without hindering near- and long-term economic prosperity? Several response options were identified and evaluated, and are currently being disseminated to various stakeholders within Ghana and internationally.

  11. Air mercury contamination in the gold mining town of Portovelo, Ecuador.

    Science.gov (United States)

    González-Carrasco, Víctor; Velasquez-Lopez, Patricio C; Olivero-Verbel, Jesús; Pájaro-Castro, Nerlis

    2011-09-01

    Portovelo is one of the oldest gold mining towns in Ecuador. Artisanal gold mining still uses mercury in the process of gold recovery. In this study, mercury concentrations in the air of Portovelo were evaluated. High mercury levels in the ambient were found in El Pache sector, where most gold mining processing plants are located. These varied between 2,356.7 ± 1,807.6 and 3,699.5 ± 1,225.3 ng/m(3) during the rainy and dry seasons, respectively. Lower levels were detected in the urban (central) area of Portovelo, with 214.6 ± 43.7 ng/m(3) in the rainy season and 574.2 ± 72.8 ng/m(3) in the dry season, exceeding the Agency for Toxic Substances and Disease Registry minimum risk level of 200 ng/m(3). Average mercury concentrations in exhaled air from miners, measured before and after amalgam burning ranged between 179-1,352 and 2,007-3,389 ng/m(3), respectively. These data suggest Portovelo air is polluted with mercury and humans are being dangerously exposed. Therefore, strong actions must be undertaken to protect human and environmental health, including changing gold recovery systems.

  12. New development of hydraulic fracturing technique for in-situ stress measurement at great depth of mines

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In-situ stress measurement using the hydraulic fracturing technique was made at Wanfu Coal Mine in Shandong Province,China.To solve problems caused by great measuring depth and extra thick overburden soil layers in the mine,a series of improved techniques were developed for the traditional hydraulic fracturing technique and equipment to increase their pressure-enduring ability and to ensure safe and flexible removal of the sealing packers with other experimental apparatus.Successful in-situ stress measurement at 37 points within 7 boreholes,which were mostly over 1000 m deep,was completed.Through the measurement,detailed in

  13. On the possibility of magnetic nano-markers use for hydraulic fracturing in shale gas mining

    Science.gov (United States)

    Zawadzki, Jaroslaw; Bogacki, Jan

    2016-04-01

    Recently shale gas production became essential for the global economy, thanks to fast advances in shale fracturing technology. Shale gas extraction can be achieved by drilling techniques coupled with hydraulic fracturing. Further increasing of shale gas production is possible by improving the efficiency of hydraulic fracturing and assessing the spatial distribution of fractures in shale deposits. The latter can be achieved by adding magnetic markers to fracturing fluid or directly to proppant, which keeps the fracture pathways open. After that, the range of hydraulic fracturing can be assessed by measurement of vertical and horizontal component of earth's magnetic field before and after fracturing. The difference in these components caused by the presence of magnetic marker particles may allow to delineate spatial distribution of fractures. Due to the fact, that subterranean geological formations may contain minerals with significant magnetic properties, it is important to provide to the markers excellent magnetic properties which should be also, independent of harsh chemical and geological conditions. On the other hand it is of great significance to produce magnetic markers at an affordable price because of the large quantities of fracturing fluids or proppants used during shale fracturing. Examining the properties of nano-materials, it was found, that they possess clearly superior magnetic properties, as compared to the same structure but having a larger particle size. It should be then possible, to use lower amount of magnetic marker, to obtain the same effect. Although a research on properties of new magnetic nano-materials is very intensive, cheap magnetic nano-materials are not yet produced on a scale appropriate for shale gas mining. In this work we overview, in detail, geological, technological and economic aspects of using magnetic nano-markers in shale gas mining. Acknowledgment This work was supported by the NCBiR under Grant "Electromagnetic method to

  14. Ecological and human health risks associated with abandoned gold mine tailings contaminated soil

    DEFF Research Database (Denmark)

    Ngole-Jeme, Veronica Mpode; Fantke, Peter

    2017-01-01

    Gold mining is a major source of metal and metalloid emissions into the environment. Studies were carried out in Krugersdorp, South Africa, to evaluate the ecological and human health risks associated with exposure to metals and metalloids in mine tailings contaminated soils. Concentrations...... of arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), lead (Pb), manganese (Mn), nickel (Ni), and zinc (Zn) in soil samples from the area varied with the highest contamination factors (expressed as ratio of metal or metalloid concentration in the tailings contaminated soil......×10−2 for As and Ni respectively among children, and 5×10−3 and 4×10−3 for As and Ni respectively among adults. There is significant potential ecological and human health risk associated with metal and metalloid exposure from contaminated soils around gold mine tailings dumps. This could be a potential contributing...

  15. Chromosome Aberrations of East Asian Bullfrog (Hoplobatrachus rugulosus around a Gold Mine Area with Arsenic Contamination

    Directory of Open Access Journals (Sweden)

    Atidtaya Suttichaiya

    2016-01-01

    Full Text Available The objectives of this study are to investigate the chromosome aberrations of the East Asian Bullfrog (Hoplobatrachus rugulosus in the gold mine area compared to an unaffected area. Three H. rugulosus were collected, and chromosome aberrations were studied using bone marrow. The level of arsenic was measured in water, sediment and H. rugulosus samples. The average concentrations of arsenic in the water and sediment samples from the gold mine and unaffected areas were 0.03 ± 0.003 mg/l and not detected in water as well as 351.59 ± 5.73 and 1.37 ± 1.07 mg/kg in sediment, respectively. The gold mine values were higher than the permissible limit of the water and soil quality standards, but the arsenic concentrations in the samples from the unaffected area were within prescribed limit. The average concentrations of arsenic in H. rugulosus samples from the gold mine and unaffected areas were 0.39 ± 0.30 and 0.07 ± 0.01 mg/kg, respectively, which were both lower than the standard of arsenic contamination in food. The diploid chromosome number of H. rugulosus in both areas was 2n=26, and the percentage of chromosome breakages of H. rugulosus in the gold mine area were higher than the unaffected area. There were eight types of chromosome aberrations, including a single chromatid gap, isochromatid gap, single chromatid break, isochromatid break, centric fragmentation, deletion, fragmentation and translocation. The most common chromosome aberration in the samples from the affected area was deletion. The difference in the percentage of chromosome breakages in H. rugulosus from both areas was statistically significant (p<0.05.

  16. Trends in cyanide solution concentrations and mine operations at gold mines in Nevada and their potential effects on cyanide-related mortality of vertebrates

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Information on trends in practices at gold mines in Nevada using CN extraction technology and its relation to mortality of vertebrates, especially birds, was needed...

  17. THE CONTRIBUTION OF „RUDA 12 APOSTOLI” MINING ASSOCIATION IN BRAD TO THE DEVELOPMENT OF TRANSYLVANIAN GOLD MINING BETWEEN 1884 – 1921

    Directory of Open Access Journals (Sweden)

    MIRCEA BARON

    2012-01-01

    Full Text Available One of the major gold mining regions in Romania is part of the gold rectangle in the Apuseni Mountains and lies around the town of Brad. It is here that the ”Ruda 12 Apostoli” Mining Association of cuxas was established at the end of the XVIIIth century. This association was to become the most important unit for the mining of precious metals in the entire Austrian – Hungarian Empire after 1884, when it was taken over by the German company ”Harkortschen Bergwerke und Chemische Fabriken zu Schwelm und Harkorten A.G. zu Gotha”, preserving its status in the interwar Romanian as a component of the ”Mica” Mining company. This mining complex had a production of 27,919.520 kg of gold between 1884 – July 1, 1911.

  18. Unexpected Evidence concerning Gold Mining in Early Byzantium

    Directory of Open Access Journals (Sweden)

    Tatyana I. Afanas’eva

    2013-02-01

    Full Text Available The prayer in the liturgy of Basil for those condemned to the mines, taken to be a relic of  the time of pagan persecutions, is shown by Slavonic mss. to have addressed a continuing practice of the Christian emperors themselves.

  19. Disputes over land and water rights in gold mining

    NARCIS (Netherlands)

    Stoltenborg, Didi; Boelens, Rutgerd

    2016-01-01

    This article analyzes different visions and positions in a conflict between the developer of an open-pit mine in Mexico and project opponents using the echelons of rights analysis framework, distinguishing four layers of dispute: contested resources; contents of rules and regulations; decision-ma

  20. Quantification of dust generating sources in gold and platinum mines

    CSIR Research Space (South Africa)

    Biffi, M

    2003-03-01

    Full Text Available dust generation rates linked to activities presumed to be hazardous in this respect. The aim of this study was to identify prominent dust sources that occur in hard rock mines and to characterise these by means of on-site measurement of dust generations...

  1. Gold mining as a source of mercury exposure in the Brazilian Amazon.

    Science.gov (United States)

    Malm, O

    1998-05-01

    Amalgamation has been used for more than 4500 years in mining processes. Mercury has been extensively used in South America by Spanish colonizers for precious metal recovery. It is estimated that between 1550 and 1880, nearly 200,000 metric tonnes of mercury was released to the environment. During the present gold rush, Brazil is first in South America and second in the world in gold production (with 90% coming from informal mining or garimpos). At least 2000 tonnes of mercury has been released to the environment in the present gold rush. From the mid 1980s, environmental research has been carried out in impacted Amazon rivers, later followed by human exposure studies. The river basins studied were the Tapajós, Madeira, and Negro, but also some man-made reservoirs and areas in central Brazil. The analyses mainly involved sediments, soil, air, fish, human hair, and urine. The results show high variability, perhaps related to biological diversity, biogeochemical differences in the river basins, and seasonal changes. High mercury values also occur in some areas with no known history of gold mining. The results available document a considerable impact on environmental mercury concentrations and frequent occurrence of human exposure levels that may lead to adverse health effects.

  2. Adaptation and detoxification mechanisms of Vetiver grass (Chrysopogon zizanioides) growing on gold mine tailings.

    Science.gov (United States)

    Melato, F A; Mokgalaka, N S; McCrindle, R I

    2016-01-01

    Vetiver grass (Chrysopogon zizanioides) was investigated for its potential use in the rehabilitation of gold mine tailings, its ability to extract and accumulate toxic metals from the tailings and its metal tolerant strategies. Vetiver grass was grown on gold mine tailings soil, in a hothouse, and monitored for sixteen weeks. The mine tailings were highly acidic and had high electrical conductivity. Vetiver grass was able to grow and adapt well on gold mine tailings. The results showed that Vetiver grass accumulated large amounts of metals in the roots and restricted their translocation to the shoots. This was confirmed by the bioconcentration factor of Zn, Cu, and Ni of >1 and the translocation factor of Vetiver grass against metal stress that include: chelation of toxic metals by phenolics, glutathione S-tranferase, and low molecular weight thiols; sequestration and accumulation of metals within the cell wall that was revealed by the scanning electron microscopy that showed closure of stomata and thickened cell wall and was confirmed by high content of cell wall bound phenolics. Metal induced reactive oxygen species are reduced or eliminated by catalase, superoxide dismutase and peroxidase dismutase.

  3. Determination of Heavy Metals and Other Elements in Artisanal Gold Mining Soils

    Directory of Open Access Journals (Sweden)

    S. Girigisu

    2012-01-01

    Full Text Available Problem statement: The possible exposure of heavy elements to life as a result of artisanal gold mining activities can be of great concern because of its associated effect on health. Approach: Soil samples from the artisanal gold mining sites of Awwal and Bagega villages in Kebbi and Zamfara states of Nigeria were collected and analyzed for heavy and other elements by X-Ray Fluorescence (XRF technique. Ten of the element analyses are presented in this study, based on their toxicity levels. Results: Four of the ten elements (Pb, Si, Rb and Fe showed relatively high concentrations. Two of these four elements presented, (Si and Pb may pose latent and immediate hazards to health. Respiratory crystalline silica is the major element constituent of the ever-well-pronounced mining dusts of the two sites. Its form of occurrence portends irreversible health problem called silicosis and is well linked to cancer forming properties; both of which develop through latency periods. Pb at whatever concentration portends both immediate and long term hazards to women and children at the greatest risks of exposures. Conclusion: Based on the results presented, there exist a possibility of an immediate and long term health risks associated with the artisanal gold mining exercises in the two sites studied if the said uncoordinated and unprofessional activities of the miners are left unchecked.

  4. Distribution and assessment of residual mercury from gold mining in Changbai Mountain Range Northeastern China

    Science.gov (United States)

    Meng, D.; Wang, N.; Ai, J. C.; Zhang, G.; Liu, X. J.

    2016-08-01

    Gold mining was first initiated in Jiapigou area, Huadian city of Northeastern China about 200 years ago. Before 2006, the mercury amalgamation technique was used in the gold mining process, which led to severe mercury contamination. The aim of this paper is to explore the influences of residual mercury on the environment media after eliminating the amalgamation process to extract gold. The mercury concentrations of the atmosphere and the soil were determined in autumn of 2011 and spring of 2012. The soil environmental quality was assessed by the index of geoaccumulation. The results indicated that the maximum value of gaseous mercury was 25ng•m-3 in autumn and 19.5ng•m-3 in spring; the maximum value of mercury in the soil was 2.06mg•kg-1 in autumn and 2.51mg•kg-1in spring. It can be seen that the peak concentrations of the gaseous mercury happened at the gold mine area and tailings, while the peak mercury concentrations in the soil were located at the places near the mining sites and the residential area in the valley. Furthermore, the regression analysis of the total mercury contents between the atmosphere and the soil showed a significant correlation, which indicated that there was certain circulation of the mercury between the regional atmosphere and soil. In general, after the elimination of the amalgamation technique in gold extraction, the distance to the mercury source, the special conditions of hilly weather and landforms and the mercury exchange flux are the main factors of mercury contamination.

  5. Gold mining in the Peruvian Amazon: global prices, deforestation, and mercury imports.

    Directory of Open Access Journals (Sweden)

    Jennifer J Swenson

    Full Text Available Many factors such as poverty, ineffective institutions and environmental regulations may prevent developing countries from managing how natural resources are extracted to meet a strong market demand. Extraction for some resources has reached such proportions that evidence is measurable from space. We present recent evidence of the global demand for a single commodity and the ecosystem destruction resulting from commodity extraction, recorded by satellites for one of the most biodiverse areas of the world. We find that since 2003, recent mining deforestation in Madre de Dios, Peru is increasing nonlinearly alongside a constant annual rate of increase in international gold price (∼18%/yr. We detect that the new pattern of mining deforestation (1915 ha/year, 2006-2009 is outpacing that of nearby settlement deforestation. We show that gold price is linked with exponential increases in Peruvian national mercury imports over time (R(2 = 0.93, p = 0.04, 2003-2009. Given the past rates of increase we predict that mercury imports may more than double for 2011 (∼500 t/year. Virtually all of Peru's mercury imports are used in artisanal gold mining. Much of the mining increase is unregulated/artisanal in nature, lacking environmental impact analysis or miner education. As a result, large quantities of mercury are being released into the atmosphere, sediments and waterways. Other developing countries endowed with gold deposits are likely experiencing similar environmental destruction in response to recent record high gold prices. The increasing availability of satellite imagery ought to evoke further studies linking economic variables with land use and cover changes on the ground.

  6. Gold mining in the Peruvian Amazon: global prices, deforestation, and mercury imports.

    Science.gov (United States)

    Swenson, Jennifer J; Carter, Catherine E; Domec, Jean-Christophe; Delgado, Cesar I

    2011-04-19

    Many factors such as poverty, ineffective institutions and environmental regulations may prevent developing countries from managing how natural resources are extracted to meet a strong market demand. Extraction for some resources has reached such proportions that evidence is measurable from space. We present recent evidence of the global demand for a single commodity and the ecosystem destruction resulting from commodity extraction, recorded by satellites for one of the most biodiverse areas of the world. We find that since 2003, recent mining deforestation in Madre de Dios, Peru is increasing nonlinearly alongside a constant annual rate of increase in international gold price (∼18%/yr). We detect that the new pattern of mining deforestation (1915 ha/year, 2006-2009) is outpacing that of nearby settlement deforestation. We show that gold price is linked with exponential increases in Peruvian national mercury imports over time (R(2) = 0.93, p = 0.04, 2003-2009). Given the past rates of increase we predict that mercury imports may more than double for 2011 (∼500 t/year). Virtually all of Peru's mercury imports are used in artisanal gold mining. Much of the mining increase is unregulated/artisanal in nature, lacking environmental impact analysis or miner education. As a result, large quantities of mercury are being released into the atmosphere, sediments and waterways. Other developing countries endowed with gold deposits are likely experiencing similar environmental destruction in response to recent record high gold prices. The increasing availability of satellite imagery ought to evoke further studies linking economic variables with land use and cover changes on the ground.

  7. Balancing environmental and industry sustainability: a case study of the US gold mining industry.

    Science.gov (United States)

    Finnie, Bruce; Stuart, Jeffrey; Gibson, Linda; Zabriskie, Fern

    2009-09-01

    Mandatory insurance requirements and/or mitigation fees (royalties) for mining companies may help reduce environmental risk exposure for the federal government. Mining is examined since the Environmental Protection Agency (EPA) Toxic Release Inventory reveals that this sector produces more hazardous waste than any other industrial sector. Although uncommon, environmental expense can exceed hundreds of millions of dollars per development. Of particular concern is the potential for mines to become unfunded Superfund sites. Monte Carlo simulation of risk exposure is used to establish a plausible range of unfunded federal liabilities associated with cyanide-leach gold mining. A model is developed to assess these costs and their impact on both the federal budget and corporate profitability (i.e., industry sustainability), particularly if such costs are borne by offending firms.

  8. Mercury Pollution from Small-Scale Gold Mining Can Be Stopped by Implementing the Gravity-Borax Method

    DEFF Research Database (Denmark)

    Køster-Rasmussen, Rasmus; Westergaard, Maria L; Brasholt, Marie

    2016-01-01

    Mercury is used globally to extract gold in artisanal and small-scale gold mining. The mercury-free gravity-borax method for gold extraction was introduced in two mining communities using mercury in the provinces Kalinga and Camarines Norte. This article describes project activities and quantitat......Mercury is used globally to extract gold in artisanal and small-scale gold mining. The mercury-free gravity-borax method for gold extraction was introduced in two mining communities using mercury in the provinces Kalinga and Camarines Norte. This article describes project activities...... gathered on mining practices and knowledge about mercury toxicology. Most miners in Kalinga converted to the gravity-borax method, whereas only a few did so in Camarines Norte. Differences in the nature of the social systems impacted the success of the implementation, and involvement of the tribal...... organization facilitated the shift in Kalinga. In conclusion, the gravity-borax method is a doable alternative to mercury use in artisanal and small-scale gold mining, but support from the civil society is needed....

  9. Assessing the impacts of gold mining assessing the impacts of gold mining operations on river sediments and water samples from ilesa west local government area ILESA West Local Government Area of Osun State, Nigeria

    Directory of Open Access Journals (Sweden)

    Makinde W. O.

    2014-07-01

    Enrichment Factor of the elements obtained showed high contamination of both the stream water and sediments with toxic metals as a result of high illegal gold mining operations in the area under study.

  10. Impacts of Open Placer Gold Mining on Aquatic Communities in Rivers of the Khentii Mountains, North-East Mongolia

    Directory of Open Access Journals (Sweden)

    Daniel A. Krätz

    2010-06-01

    Full Text Available Since the political change and due to high market prices for gold the mining sector has consid- erably grown in Mongolia and has become one of the most important economical sectors. With in- creasing mining activities the mining related environmental problems also increased, especially those, which are caused by open placer gold mining. Placer gold deposits are located in the alluvial sedi- ments of river fl oodplains and the exploitation of these deposits often induces severe impacts to river ecosystem and its different components. In this paper we describe the effects of open placer gold min- ing on diatoms, benthic invertebrates and fi sh in four rivers in the north-east of Mongolia. Our fi ndings are based on a comparative analysis of these biocoenotic groups in pristine and mining affected river sections, taking into account also abiotic habitat characteristics. Our analyses revealed that placer gold mining causes multiple stressors acting on different trophic levels. The biocoenotic groups under in- vestigation reacted differently against stressors, and we indentifi ed a wide range of direct and indirect effects. These fi ndings are new for Mongolia and are essential to defi ne adapted and successful strate- gies for an ecologically based management and monitoring of open placer gold mining pressures and ecological impacts.

  11. Mercury in the gold mining district of San Martin de Loba, South of Bolivar (Colombia).

    Science.gov (United States)

    Olivero-Verbel, Jesus; Caballero-Gallardo, Karina; Turizo-Tapia, Alexi

    2015-04-01

    Gold mining is responsible for most Hg pollution in developing countries. The aims of this study were to assess the levels of total Hg (T-Hg) in human hair, fish, water, macrophyte, and sediment samples in the gold mining district of San Martin de Loba, Colombia, as well as to determine fish consumption-based risks for T-Hg ingestion. T-Hg levels were measured by electrothermal atomization and atomic absorption spectroscopy. The overall mean T-Hg level in hair for humans in the mining district of San Martin de Loba was 2.12 μg/g, whereas for the reference site, Chimichagua, Cesar, it was 0.58 μg/g. Mean T-Hg levels were not different when considered within localities belonging to the mining district but differed when the comparison included Chimichagua. T-Hg levels in examined locations were weakly but significantly associated with age and height, as well as with fish consumption, except in San Martin de Loba. High T-Hg concentrations in fish were detected in Pseudoplatystoma magdaleniatum, Caquetaia kraussii, Ageneiosus pardalis, Cyrtocharax magdalenae, and Triportheus magdalenae, whereas the lowest appeared in Prochilodus magdalenae and Hemiancistrus wilsoni. In terms of Hg exposure due to fish consumption, only these last two species offer some guarantee of low risk for Hg-related health problems. Water, floating macrophytes, and sediments from effluents near mining sites also had high Hg values. In mines of San Martin de Loba and Hatillo de Loba, for instance, the geoaccumulation index (I(geo)) for sediments reached values greater than 6, indicating extreme pollution. In short, these data support the presence of a high Hg-polluted environment in this mining district, with direct risk for deleterious effects on the health of the mining communities.

  12. Drug Discovery in Psychiatric Illness: Mining for Gold

    OpenAIRE

    Elmer, Greg I; Kafkafi, Neri

    2009-01-01

    The discovery of truly efficacious treatments that lead to full recovery is a daunting task in psychiatric illness. A systems-based orientation to in vivo pharmacology has been suggested as a way to transform psychiatric drug discovery and development. A critical catalyst in the success of recent systems biology efforts has been the incorporation of data mining strategies. Our approach to the drug discovery problem has been to utilize the whole animal to provide a systems response that is sub...

  13. Drug discovery in psychiatric illness: mining for gold.

    Science.gov (United States)

    Elmer, Greg I; Kafkafi, Neri

    2009-03-01

    The discovery of truly efficacious treatments that lead to full recovery is a daunting task in psychiatric illness. A systems-based orientation to in vivo pharmacology has been suggested as a way to transform psychiatric drug discovery and development. A critical catalyst in the success of recent systems biology efforts has been the incorporation of data mining strategies. Our approach to the drug discovery problem has been to utilize the whole animal to provide a systems response that is subsequently mined for predictive attributes with known psychopharmacological value. Our in vivo data mining approach, termed Pattern Array, establishes a framework for screening novel chemical entities based upon a response that represents the net pharmacological effect on the system of interest, namely the central nervous system (CNS). Large scale screening of small molecules by non-conventional approaches such as this at a systems level may improve the identification of novel chemical entities with psychiatric utility. This type of approach will compliment the more labor-intensive models based upon construct validity. It will take the collective effort of many disciplines and numerous strategies in close association with clinical colleagues to address quality of life issues and breakthrough treatment barriers in psychiatric illness.

  14. Modelling of Radiological Health Risks from Gold Mine Tailings in Wonderfonteinspruit Catchment Area, South Africa

    Directory of Open Access Journals (Sweden)

    Manny Mathuthu

    2016-06-01

    Full Text Available Mining is one of the major causes of elevation of naturally-occurring radionuclide material (NORM concentrations on the Earth’s surface. The aim of this study was to evaluate the human risk associated with exposure to NORMs in soils from mine tailings around a gold mine. A broad-energy germanium detector was used to measure activity concentrations of these NORMs in 66 soil samples (56 from five mine tailings and 10 from the control area. The RESidual RADioactivity (RESRAD OFFSITE modeling program (version 3.1 was then used to estimate the radiation doses and the cancer morbidity risk of uranium-238 (238U, thorium-232 (232Th, and potassium-40 (40K for a hypothetical resident scenario. According to RESRAD prediction, the maximum total effective dose equivalent (TEDE during 100 years was found to be 0.0315 mSv/year at year 30, while the maximum total excess cancer morbidity risk for all the pathways was 3.04 × 10−5 at year 15. The US Environmental Protection Agency considers acceptable for regulatory purposes a cancer risk in the range of 10−6 to 10−4. Therefore, results obtained from RESRAD OFFSITE code has shown that the health risk from gold mine tailings is within acceptable levels according to international standards.

  15. Modelling of Radiological Health Risks from Gold Mine Tailings in Wonderfonteinspruit Catchment Area, South Africa

    Science.gov (United States)

    Mathuthu, Manny; Kamunda, Caspah; Madhuku, Morgan

    2016-01-01

    Mining is one of the major causes of elevation of naturally-occurring radionuclide material (NORM) concentrations on the Earth’s surface. The aim of this study was to evaluate the human risk associated with exposure to NORMs in soils from mine tailings around a gold mine. A broad-energy germanium detector was used to measure activity concentrations of these NORMs in 66 soil samples (56 from five mine tailings and 10 from the control area). The RESidual RADioactivity (RESRAD) OFFSITE modeling program (version 3.1) was then used to estimate the radiation doses and the cancer morbidity risk of uranium-238 (238U), thorium-232 (232Th), and potassium-40 (40K) for a hypothetical resident scenario. According to RESRAD prediction, the maximum total effective dose equivalent (TEDE) during 100 years was found to be 0.0315 mSv/year at year 30, while the maximum total excess cancer morbidity risk for all the pathways was 3.04 × 10−5 at year 15. The US Environmental Protection Agency considers acceptable for regulatory purposes a cancer risk in the range of 10−6 to 10−4. Therefore, results obtained from RESRAD OFFSITE code has shown that the health risk from gold mine tailings is within acceptable levels according to international standards. PMID:27338424

  16. A Water Hammer Protection Method for Mine Drainage System Based on Velocity Adjustment of Hydraulic Control Valve

    Directory of Open Access Journals (Sweden)

    Yanfei Kou

    2016-01-01

    Full Text Available Water hammer analysis is a fundamental work of pipeline systems design process for water distribution networks. The main characteristics for mine drainage system are the limited space and high cost of equipment and pipeline changing. In order to solve the protection problem of valve-closing water hammer for mine drainage system, a water hammer protection method for mine drainage system based on velocity adjustment of HCV (Hydraulic Control Valve is proposed in this paper. The mathematic model of water hammer fluctuations is established based on the characteristic line method. Then, boundary conditions of water hammer controlling for mine drainage system are determined and its simplex model is established. The optimization adjustment strategy is solved from the mathematic model of multistage valve-closing. Taking a mine drainage system as an example, compared results between simulations and experiments show that the proposed method and the optimized valve-closing strategy are effective.

  17. Mercury use in artisanal small-scale gold mining threatens human health: measures to describe and reduce the health risk

    OpenAIRE

    Steckling, Nadine

    2016-01-01

    **Background:** Mercury is used in more than 70 countries to extract gold in artisanal small-scale gold mining (ASGM). The application of mercury is simple and plays a key role in the livelihood for more than 16 million gold miners. Mercury is added to the crushed ore and builds an amalgam with the gold it contains. The amalgam is then smelted, the mercury evaporates, and gold remains. The amalgam smelting is the main source of mercury exposure in ASGM. ASGM is the largest anthropogenic sourc...

  18. ENVIRONMENTAL MONITORING AT THE NALUNAQ GOLD MINE, SOUTH GREENLAND, 2015

    DEFF Research Database (Denmark)

    Bach, Lis; Birch Larsen, Morten

    This twelfth environmental monitoring programme was conducted in the Nalunaq area, about 40 km from Nanortalik, South Greenland, from 18-31 August 2015. The environmental monitoring programme is conducted to discover and avoid unwanted environmental impacts of the former mining industry. Since...... into the Kirkespir Valley and Kirkespir Bay environment. The content of metals in the terrestrial, freshwater, and marine environment in the Kirkespir Valley and Bay is decreasing and is considered minor. DCE/GINR assess that no requirement for further actions to reduce the environmental impact is needed....... Environmental monitoring will continue in 2016 and 2019....

  19. Mercury contamination from artisanal gold mining in Antioquia, Colombia: The world's highest per capita mercury pollution.

    Science.gov (United States)

    Cordy, Paul; Veiga, Marcello M; Salih, Ibrahim; Al-Saadi, Sari; Console, Stephanie; Garcia, Oseas; Mesa, Luis Alberto; Velásquez-López, Patricio C; Roeser, Monika

    2011-12-01

    The artisanal gold mining sector in Colombia has 200,000 miners officially producing 30tonnes Au/a. In the Northeast of the Department of Antioquia, there are 17 mining towns and between 15,000 and 30,000 artisanal gold miners. Guerrillas and paramilitary activities in the rural areas of Antioquia pushed miners to bring their gold ores to the towns to be processed in Processing Centers or entables. These Centers operate in the urban areas amalgamating the whole ore, i.e. without previous concentration, and later burn gold amalgam without any filtering/condensing system. Based on mercury mass balance in 15 entables, 50% of the mercury added to small ball mills (cocos) is lost: 46% with tailings and 4% when amalgam is burned. In just 5 cities of Antioquia, with a total of 150,000 inhabitants: Segovia, Remedios, Zaragoza, El Bagre, and Nechí, there are 323 entables producing 10-20tonnes Au/a. Considering the average levels of mercury consumption estimated by mass balance and interviews of entables owners, the mercury consumed (and lost) in these 5 municipalities must be around 93tonnes/a. Urban air mercury levels range from 300ng Hg/m(3) (background) to 1million ng Hg/m(3) (inside gold shops) with 10,000ng Hg/m(3) being common in residential areas. The WHO limit for public exposure is 1000ng/m(3). The total mercury release/emissions to the Colombian environment can be as high as 150tonnes/a giving this country the shameful first position as the world's largest mercury polluter per capita from artisanal gold mining. One necessary government intervention is to cut the supply of mercury to the entables. In 2009, eleven companies in Colombia legally imported 130tonnes of metallic mercury, much of it flowing to artisanal gold mines. Entables must be removed from urban centers and technical assistance is badly needed to improve their technology and reduce emissions. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. The models of optimization for increasing of copper and gold recoveries in Bucim Mine

    OpenAIRE

    Gocev, Zivko; Krstev, Aleksandar; Krstev, Boris; Golomeova, Mirjana; Zendelska, Afrodita

    2015-01-01

    The increasing in the chalcopyrite copper Bucim mine are gone forward to renewed reagent regime, including and involving new reagents for increased recovery of copper and gold. The optimization and mathematical linear are good example for improvement of industrial recoveries in flotation circuit. Nevertheless, the choice between flotation and new leaching or bioleaching method are challenge for future. The optimization techniques, for matting the mathematical model and adequate...

  1. [Rapid ecological assessment of tropical fish communities in a gold mine area of Costa Rica].

    Science.gov (United States)

    Espinoza Mendiola, Mario

    2008-12-01

    Gold mining impacts have generated a great concern regarding aquatic systems and habitat fragmentation. Anthropogenic disturbances on the structure and heterogeneity of a system can have an important effect on aquatic community stability. Ecological rapid assessments (1996, 2002, and 2007) were employed to determine the structure, composition and distribution of tropical fish communities in several rivers and smaller creeks from a gold mining area in Cerro Crucitas, Costa Rica. In addition, species composition and relative abundance were related with habitat structure. A total of 35 species were registered, among which sardine Astyanax aeneus (Characidae) and livebearer Alfaro cultratus (Poeciliidae) were the most abundant fish (71%). The highest species richness was observed in Caño Crucitas (s=19) and Minas Creek (s=18). Significant differences in fish communities structure and composition from Infiernillo river and Minas creek were observed (lamda = 0.0, F(132, 66) = 2.24, p fish species and habitat structure was observed. This study reveals a high complexity in tropical fish communities that inhabit a gold mine area. Furthermore, it highlights the importance of habitat heterogeneity in fish community dynamics. The loss and degradation of aquatic systems in Cerro Crucitas can have a strong negative effect on fish community structure and composition of local species. A better understanding of the use of specific habitats that serve as essential fish habitats can improve tropical fish conservation and management strategies, thus increasing local diversity, and thereby, the biological importance of the area.

  2. A practice of ultra-fine tailings disposal as filling material in a gold mine.

    Science.gov (United States)

    Deng, D Q; Liu, L; Yao, Z L; Song, K I-I L; Lao, D Z

    2017-07-01

    A practice of cemented backfill technology with ultra-fine tailings in a gold mine was comprehensively presented, and a series of tests were conducted in accordance with the peculiar properties of ultra-fine tailings and the mining technology conditions. The test results show that, the tailings from Shuiyindong Gold Mine have a great grinding fineness, with the average particle diameter 22.03 μm, in which the ultra-fine particles with the diameter below 20 μm occupying 66.13%. The analysis results of chemical components of tailings indicate that the content of SiO2 is relatively low, i.e., 33.08%, but the total content of CaO, MgO and Al2O3 is relatively high i.e., 36.5%. After the settlement of 4-6 h, the tailing slurry with the initial concentration of 40% has the maximum settling concentration of 54.692%, and the corresponding maximum settling unit weight is 1.497 g/cm(3). During the field application, the ultra-fine tailings and PC32.5 cement were mixed with the cement-tailings ratios of 1:3-1:8, and the slurry concentration of 50 wt% was prepared. Using the slurry pump, the prepared cemented backfill slurries flowed into the goaf, and then the strength of the cemented backfill body met the mining technique requirements in Shuiyindong Gold Mine, where the ore body has a smooth occurrence, with the average thickness of approximately 2 m and the inclination angle ranging from 5 to 10°. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Distribution and mobility of mercury in soils of a gold mining region, Cuyuni river basin, Venezuela.

    Science.gov (United States)

    Santos-Francés, F; García-Sánchez, A; Alonso-Rojo, P; Contreras, F; Adams, M

    2011-04-01

    An extensive and remote gold mining region located in the East of Venezuela has been studied with the aim of assessing the distribution and mobility of mercury in soil and the level of Hg pollution at artisanal gold mining sites. To do so, soils and pond sediments were sampled at sites not subject to anthropological influence, as well as in areas affected by gold mining activities. Total Hg in regionally distributed soils ranged between 0.02 mg kg(-1) and 0.40 mg kg(-1), with a median value of 0.11 mg kg(-1), which is slightly higher than soil Hg worldwide, possibly indicating long-term atmospheric input or more recent local atmospheric input, in addition to minor lithogenic sources. A reference Hg concentration of 0.33 mg kg(-1) is proposed for the detection of mining affected soils in this region. Critical total Hg concentrations were found in the surrounding soils of pollutant sources, such as milling-amalgamation sites, where soil Hg contents ranged from 0.16 mg kg(-1) to 542 mg kg(-1) with an average of 26.89 mg kg(-1), which also showed high levels of elemental Hg, but quite low soluble+exchangeable Hg fraction (0.02-4.90 mg kg(-1)), suggesting low Hg soil mobility and bioavailability, as confirmed by soil column leaching tests. The vertical distribution of Hg through the soil profiles, as well as variations in soil Hg contents with distance from the pollution source, and Hg in pond mining sediments were also analysed.

  4. Mercury contamination associated with small-scale gold mining in Tanzania and Zimbabwe.

    Science.gov (United States)

    van Straaten, P

    2000-10-01

    Mercury contamination associated with small-scale gold mining and processing represents a major environmental and human health concern in Eastern and Southern Africa. Approximately 200,000-300,000 persons are involved in small-scale gold mining activities in Tanzania and > 200,000 persons in Zimbabwe. Mercury (Hg) is used mainly for the processing of primary gold quartz veins and supergene gold mineralizations. Gravimetric material flow analyses show that 70-80% of the Hg is lost to the atmosphere during processing, 20-30% are lost to tailings, soils, stream sediments and water. For every 1 g Au produced, 1.2-1.5 g Hg are lost to the environment. Cumulatively, the anthropogenic Hg released annually into the atmosphere is approximately 3-4 t in the whole Lake Victoria Goldfields of Tanzania and > 3 t in Zimbabwe. Tailings are local 'hot spots' with high concentrations of As, Pb, Cu and Hg. Lateral and vertical dispersion of Hg lost to soils and stream sediments is very limited (laterally Dispersion of mercury from tailings is low because Hg is transported largely in the elemental, metallic form. In addition, Fe-oxide rich laterites and swamps appear to be natural barriers for the dispersion of metals in soils and streams. Ground and surface water quality data indicate very low dispersion rates during the dry season.

  5. InSAR analysis of aquifer-system response to 20 years of mine-dewatering in the Carlin gold trend, north-central Nevada

    Science.gov (United States)

    Bell, J. W.; Katzenstein, K.

    2012-12-01

    The Carlin trend in north-central Nevada has the second largest gold resources in the world, most of it produced from large open-pit mines. Heavy groundwater dewatering is required at the mines to lower water levels below the depth of mining which can exceed 400-500 m. The resulting water level declines have produced surface deformation (subsidence) that can be detected and modeled with InSAR to characterize the aquifer-system response and to estimate hydraulic parameters in order to test and refine groundwater models. In a series of studies we examined the effects of dewatering at mines operated by Newmont Mining Corporation and Barrick Gold of North America near Battle Mountain and Carlin, Nevada. The Lone Tree mine operated a large-scale dewatering program between 1992-2006 using deep bedrock wells that pumped between 64-92 hm3/yr (52,000-75,000 acre-ft/yr) and lowered bedrock water levels more than 120 m. InSAR analysis of ERS and Envisat data for the 1992-2000 and 2004-2010 periods showed that as much as 50 cm of aquifer-system compaction occurred in bedrock and in alluvial basin deposits with subsidence rates ranging between 3-6 cm/yr. Since dewatering ended in late 2006 and water levels began rising, only 7 cm of aquifer-system recovery (uplift) has occurred as of 2010 suggesting that most of the aquifer-system compaction was likely inelastic, apparently in the pumped fractured bedrock. The InSAR subsidence data differ significantly from the pre-pumping groundwater model which predicted 2.5 m of subsidence for the 1992-2000 period. The results yield bulk storage coefficients in the range of 7 x 10-3 to 5.6 x 10-5 with a most frequent value of 1.0 x 10-3 (Baffoe-Twum, 2007), InSAR-derived hydraulic values that can provide better constraints on specific storage estimates in future groundwater models. The Betze-Post mine has been dewatering continually since late 1989 with maximum pumping rates of greater than 140 hm3/yr (110,000 acre-ft/yr) in the early and

  6. Total mercury loadings in sediment from gold mining and conservation areas in Guyana.

    Science.gov (United States)

    Howard, Joniqua; Trotz, Maya A; Thomas, Ken; Omisca, Erlande; Chiu, Hong Ting; Halfhide, Trina; Akiwumi, Fenda; Michael, Ryan; Stuart, Amy L

    2011-08-01

    The Low Carbon Development Strategy proposed in June 2009 by the government of Guyana in response to the Reducing Emissions from Deforestation and Forest Degradation in Developing Countries program has triggered evaluation of forest-related activities, thereby acting as a catalyst for improvements in Guyana's small- to medium-scale gold mining industry. This has also shed light on areas committed to conservation, something that has also been handled by Non Governmental Organizations. This paper compares water quality and mercury concentrations in sediment from four main areas in Guyana, two that are heavily mined for gold using mercury amalgamation methods (Arakaka and Mahdia) and two that are considered conservation areas (Iwokrama and Konashen). Fifty-three sediment and soil mercury loadings ranged from 29 to 1,200 ng/g and averaged 215 ± 187 ng/g for all sites with similar averages in conservation and mining areas. Sediment loadings are within the range seen in French Guiana and Suriname, but conservation area samples had higher loadings than the corresponding uncontaminated baselines. Type of ore and location in the mining process seemed to influence mercury loadings. Mercury sediment loadings were slightly positively correlated with pH (correlation coefficient = 0.2; p value < 0.001) whereas no significant correlations were found with dissolved oxygen or turbidity.

  7. Health Risk Assessment of Heavy Metals in Soils from Witwatersrand Gold Mining Basin, South Africa.

    Science.gov (United States)

    Kamunda, Caspah; Mathuthu, Manny; Madhuku, Morgan

    2016-01-01

    The study evaluates the health risk caused by heavy metals to the inhabitants of a gold mining area. In this study, 56 soil samples from five mine tailings and 17 from two mine villages were collected and analyzed for Asernic (As), Lead (Pb), Mercury (Hg), Cadmium (Cd), Chromium (Cr), Cobalt (Co), Nickel (Ni), Copper (Cu) and Zinc (Zn) using ICP-MS. Measured concentrations of these heavy metals were then used to calculate the health risk for adults and children. Their concentrations were such that Cr > Ni > As > Zn > Cu > Co > Pb > Hg > Cd, with As, Cr and Ni higher than permissible levels. For the adult population, the Hazard Index value for all pathways was found to be 2.13, making non-carcinogenic effects significant to the adult population. For children, the Hazard Index value was 43.80, a value >1, which poses serious non-carcinogenic effect to children living in the gold mining area. The carcinogenic risk was found to be 1.7 × 10(-4) implying that 1 person in every 5882 adults may be affected. In addition, for children, in every 2725 individuals, 1 child may be affected (3.67 × 10(-4)). These carcinogenic risk values were both higher than acceptable values.

  8. Removal of mercury from gold mine effluents using Limnocharis flava in constructed wetlands.

    Science.gov (United States)

    Marrugo-Negrete, José; Enamorado-Montes, Germán; Durango-Hernández, José; Pinedo-Hernández, José; Díez, Sergi

    2017-01-01

    Phytoremediation has received increased attention over the recent decades, as an emerging and eco-friendly approach that utilizes the natural properties of plants to remediate contaminated water, soils or sediments. The current study provides information about a pilot-scale experiment designed to evaluate the potential of the anchored aquatic plant Limnocharis flava for phytoremediation of water contaminated with mercury (Hg), in a constructed wetland (CW) with horizontal subsurface flow (HSSF). Mine effluent used in this experiment was collected from a gold mining area located at the Alacran mine in Colombia (Hg: 0.11 ± 0.03 μg mL(-1)) and spiked with HgNO3 (1.50 ± 0.09 μg mL(-1)). Over a 30 day test period, the efficiency of the reduction in the heavy metal concentration in the wetlands, and the relative metal sorption by the L. flava, varied according to the exposure time. The continued rate of removal of Hg from the constructed wetland was 9 times higher than the control, demonstrating a better performance and nearly 90% reduction in Hg concentrations in the contaminated water in the presence of L. flava. The results in this present study show the great potential of the aquatic macrophyte L. flava for phytoremediation of Hg from gold mining effluents in constructed wetlands. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. AN EXPERT SYSTEM ON ASSESSING ROCKBURST RISKS FOR SOUTH AFRICAN DEEP GOLD MINES

    Institute of Scientific and Technical Information of China (English)

    冯夏庭; S.Webber; M.U.Ozbay; 王永嘉

    1996-01-01

    Expert systems are methods that can cope with rock engineer's expertise effectively.An expert system on assessing rockburst risks for South African deep gold mines is described.Expertise was represented by rules, frames and mathematical models integratively. About 9.50rules was built in the knowledge base, which can be learned by the suggested learning algorithm.A new uncertain reasoning algorithm was proposed. According to the features such as depth be-low surface, energy release rate (ERR), excess shear stress (ESS), geological structure, faceangle with structure, distance from structure, extent of mining, mining type, width of bracket pil-lar, stope width, local support, regional support and gully support, rockburst risk is assessed ei-ther”Low”, ”Moderate”, ”High” or ”Severe”.Turbo Prolog. The results of testing cases showA computer program system was developed byits applicability of the system.

  10. Intermediate-Scale Hydraulic Fracturing in a Deep Mine - kISMET Project Summary 2016

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, C. M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dobson, P. F. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wu, Y. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cook, P. J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kneafsey, T. J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Nakagawa, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ulrich, C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Siler, D. L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Guglielmi, Y. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ajo-Franklin, J. B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rutqvist, J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Daley, T. M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Birkholzer, J. T. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wang, H. F. [Univ. of Wisconsin, Madison, WI (United States); Lord, N. E. [Univ. of Wisconsin, Madison, WI (United States); Haimson, B. C. [Univ. of Wisconsin, Madison, WI (United States); Sone, H. [Univ. of Wisconsin, Madison, WI (United States); Vigilante, P. [Univ. of Wisconsin, Madison, WI (United States); Roggenthen, W. M. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Doe, T. W. [Golder Associates Inc., Toronto, ON (Canada); Lee, M. Y. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ingraham, M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Huang, H. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mattson, E. D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhou, J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Johnson, T. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Morris, J. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); White, J. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Johnson, P. A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Coblentz, D. D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Heise, J. [Stanford Underground Research Facility, Lead, SD (United States); Zoback, M. D. [Stanford Univ., CA (United States)

    2016-11-04

    In support of the U.S. DOE SubTER Crosscut initiative, we established a field test facility in a deep mine and designed and carried out in situ hydraulic fracturing experiments in the crystalline rock at the site to characterize the stress field, understand the effects of rock fabric on fracturing, and gain experience in monitoring using geophysical methods. The project also included pre- and post-fracturing simulation and analysis, laboratory measurements and experiments, and we conducted an extended analysis of the local stress state using previously collected data. Some of these activities are still ongoing. The kISMET (permeability (k) and Induced Seismicity Management for Energy Technologies) experiments meet objectives in SubTER’s “stress” pillar and the “new subsurface signals” pillar. The kISMET site was established in the West Access Drift of SURF 4850 ft (1478 m) below ground (on the 4850L) in phyllite of the Precambrian Poorman Formation. We drilled and cored five near-vertical boreholes in a line on 3 m spacing, deviating the two outermost boreholes slightly to create a five-spot pattern around the test borehole centered in the test volume at ~1528 m (5013 ft). Laboratory measurements of core from the center test borehole showed P-wave velocity heterogeneity along each core indicating strong, fine-scale (~1 cm or smaller) changes in the mechanical properties of the rock. The load-displacement record on the core suggests that the elastic stiffness is anisotropic. Tensile strength ranges between 3-7.5 MPa and 5-12 MPa. Permeability measurements are planned, as are two types of laboratory miniature hydraulic fracturing experiments to investigate the importance of rock fabric (anisotropy and heterogeneity) on near-borehole hydraulic fracture generation. Pre-fracturing numerical simulations with INL’s FALCON discrete element code predicted a fracture radius of 1.2 m for a corresponding injection volume of 1.2 L for the planned fractures, and

  11. Arsenic speciation and mobility in surface water at Lucky Shot Gold Mine, Alaska.

    Science.gov (United States)

    Torrance, Keith; Keenan, Helen; Munk, Leeann; Hagedorn, Birgit

    2012-12-01

    Historical mining in Alaska has created a legacy of approximately 6,830 abandoned mine sites which include adits, tailing piles and contaminated land that continue to impact surface and groundwater quality through run-off and leaching of potentially toxic metals, especially arsenic (As). One such site is the Lucky Shot Gold Mine in Hatcher Pass, south-central Alaska, which operated from 1920 until 1942, mining gold-bearing quartz veins hosted in a Cretaceous tonalite intrusion. Arsenopyrite (FeAsS) and pyrite (FeS(2)) present in the quartz veins contribute to elevated As levels in water draining, abandoned mine adits. As future underground mining at Lucky Shot may further adversely impact water quality, baseline geochemical studies were undertaken to assess As mobility in the vicinity of the mine adits. Water samples were collected from streams, adits and boreholes around the mine and analysed for major and minor elements using inductively coupled plasma-mass spectrometry (ICP-MS) and for anions by ion chromatography (IC). Arsenic species separation was performed in the field to determine the ratio of inorganic As(III)/As(V) using anion-exchange chromatography, following established methods. It was determined that water draining the adits had elevated levels of As roughly seventy times the United States Environmental Protection Agency Drinking Water Standard of 10 μg L(-1), although this was rapidly diluted downstream in Craigie Creek to water pH was circum-neutral and displayed no characteristics of acid mine drainage. Despite being well oxygenated, As(III) is the dominant As species in adit water, accounting for close to 100 % of total As. The proportion of As(V) increases downstream of the adits, as some As(III) is oxidized, but the speciation enhances arsenic mobility at the site. The δ(18)O measurements indicate that the water in the system has a short residence time as it is very similar to meteoric water, supporting the observation that the predominance of

  12. Geochemical characteristics of Au in the water systemfrom abandoned gold mines area

    Science.gov (United States)

    Cho, Kanghee; Kim, Bongju; Kim, Byungjoo; Park, Cheonyoung; Choi, Nagchoul

    2013-04-01

    The AMD (acid mine drainage) poses a threat not only to the aquatic life in mountain streams and rivers, but can also contaminate groundwater and downstream water bodies. Besides pyrite, sulfides of copper, zinc, cadmium, lead and arsenic in the drainage tunnels and tailings piles also undergo similar geochemical reactions, releasing toxic metals and more H+ into the mine drainage. The fate of gold in the AMD system is reduced and precipitated with iron oxides by oxidation-reduction reaction between ferrous/ferric iron and Au3+/Au0. The objective of this study was to investigate the influence of the transport characteristic on the distance through distribution of heavy metals and gold on the interrelation between acid mine drainage and sediments in the abandoned Gwang-yang gold mine, Korea. We conducted to confirm the chemical (chemical analysis and sequential extraction) and mineralogical property (XRD, SEM-EDS and polarization microscope) from AMD, sediments and tailing samples. The result of chemical analysis showed that Fe contents in the AMD and sediments from the upstream to the downstream ranged of 10.99 to 18.60 mg/L and 478.74 to 542.98 mg/kg, respectively. Also the contents of Au and As in the sediment were respectively ranged from 14.06 to 22.85 g/t and 0.245 to 0.612 mg/kg. In XRD analysis of the sediments, x-ray diffracted d-value belong to quartz, geothite was observed. The results of SEM-EDS analysis revealed that iron hydroxide were observed in the sediment and tailing. The result of sequential extraction for Au from the sediment showed that Au predominated in 26 to 27% of Organic matter fraction(STEP 4), and 24 to 25% of Residual fraction(STEP 5).

  13. Analysis and control of hydraulic support stability in fully-mechanized longwall face to the dip with great mining height

    Institute of Scientific and Technical Information of China (English)

    HUA Xin-zhu; WANG Jia-chen

    2008-01-01

    The working condition of the hydraulic support in working face can be dividedinto three kinds of situations in the following: roof fall and collapse with cavity, advancingsupport and supporting. Took single support with four-pole in Iongwall face to the dip asresearch object, control method was studied to avoid support instability in three situationsmentioned above. Based on these researches, the major factors of influencing on supportstability and its controlling measures were put forward. According to specific conditions ofworking face 1215(3), which is fully-mechanized and Iongwall face to the dip with greatmining height in Zhangji Coal Mine, Huainan Mining Group, the effective measures wastaken to control supports stability.

  14. Exposure and toxic effects of elemental mercury in gold-mining activities in Ecuador.

    Science.gov (United States)

    Harari, Raúl; Harari, Florencia; Gerhardsson, Lars; Lundh, Thomas; Skerfving, Staffan; Strömberg, Ulf; Broberg, Karin

    2012-08-13

    Traditional gold mining, using metallic mercury (Hg(0)) to form gold amalgam, followed by burning to remove the Hg(0), is widely used in South America, Africa and Asia. The gold is sold to merchants who burn it again to eliminate remaining Hg(0). In Ecuador, 200 gold miners, 37 gold merchants and 72 referents were studied. The median Hg concentrations in urine (U-Hg) were 3.3 (range 0.23-170), 37 (3.2-420), and 1.6 (0.2-13)μg/g creatinine, respectively, and in whole blood (B-Hg) were 5.2, 30, and 5.0 μg/L, respectively. Biomarker concentrations among merchants were statistically significantly higher than among miners and referents; also the miners differed from the referents. Burning of gold amalgam among miners was intermittent; U-Hg decreased in the burning-free period. In computerized neuromotor examinations, B-Hg and U-Hg concentrations were associated with increases in the centre frequency of the tremor, as well as in reaction time and postural stability.Retention of Hg (B-Hg), and the elimination rate (U-Hg) appears to be modified by polymorphism in a gene of an enzyme in the glutathione synthesis (GCLM), but there were no significant genetic modifications for the associations between exposure and neurotoxicity.Thus, the gold merchants have a much higher exposure and risk than the miners, in whom the exposure varies over time. The metabolism of Hg is modified by genetic traits. The present exposure to Hg had limited neurotoxic effects.

  15. Measurement and scaling of air-surface mercury exchange from substrates in the vicinity of two Nevada gold mines.

    Science.gov (United States)

    Miller, Matthieu B; Gustin, Mae S; Eckley, Chris S

    2011-09-01

    The state of Nevada has extensive mineral resources, and is the largest producer of gold in the USA as well as fourth in world gold production. Mercury (Hg) is often present in the hydrothermal systems that produce gold deposits, and can be found in elevated concentrations in gold ore. As a result, mining of gold ore in Nevada has been shown to release Hg to the atmosphere from point and non-point sources. This project focused on measurement of air-soil Hg exchange associated with undisturbed soils and bedrock outcrops in the vicinity of two large gold mines. Field and laboratory data collected were used to identify the important variables controlling Hg flux from these surfaces, and to estimate a net flux from the areas adjacent to the active mines as well as that occurring from the mined area pre-disturbance. Mean daily flux by substrate type ranged from 9 ng m(-2) day(-1) to 140 ng m(-2) day(-1). Periods of net deposition of elemental Hg were observed when air masses originating from a mine site moved over sampling locations. Based on these observations and measured soil Hg concentrations we suggest that emissions from point and non-point sources at the mines are a source of Hg to the surrounding substrates with the amount deposited not being of an environmental concern but of interest mainly with respect to the cycling of atmospheric elemental Hg. Observations indicate that while some component of the deposited Hg is sequestered in the soil, this Hg is gradually released back to the atmosphere over time. Estimated pre-disturbance emissions from the current mine footprints based on field data were 0.1 and 1.7 kg yr(-1), compared to that estimated for the current non-point mining sources of 19 and 109 kg yr(-1), respectively.

  16. The Ventersdorp Contact Reef model in the Kloof Gold Mine as derived from 3D seismics, geological mapping and exploration borehole datasets

    CSIR Research Space (South Africa)

    Manzi, MSD

    2014-02-01

    Full Text Available A model of the Ventersdorp Contact Reef (VCR) orebody at Kloof Gold Mine was derived by integrating 3D reflection seismic data with information derived from underground mine mapping and exploration drilling. The study incorporated the depth...

  17. Distribution, speciation, and risk assessment of selected metals in the gold and iron mine soils of the catchment area of Miyun Reservoir, Beijing, China.

    Science.gov (United States)

    Huang, Xingxing; Zhu, Yi; Ji, Hongbing

    2013-10-01

    In order to investigate the metal distribution, speciation, correlation and origin, risk assessment, 86 surface soil samples from the catchment area around the Miyun Reservoir, Beijing, including samples from gold and iron mine areas, were monitored for fractions of heavy metal and total contents. Most of the metal concentrations in the gold and iron mine soil samples exceeded the metal background levels in Beijing. The contents of most elements in the gold mine tailings were noticeably higher than those in the iron mine tailings. Geochemical speciation data of the metals showed that the residual fraction dominated most of the heavy metals in both mines. In both mine areas, Mn had the greatest the acid-soluble fraction (F1) per portion. The high secondary-phase fraction portion of Cd in gold mine samples indicated that there was a direct potential hazard to organisms in the tested areas. Multivariate analysis coupled with the contents of selected metals, showed that Hg, Pb, Cr, and Ni in gold mine areas represented anthropogenic sources; Cd, Pb, and Cr in iron mine areas represented industrial sources. There was moderate to high contamination of a few metals in the gold and iron soil samples, the contamination levels were relatively higher in gold mine than in iron mine soils.

  18. Historic Gold Mining in the Apuseni Mountains Recorded in Stalagmite Geochemistry

    Directory of Open Access Journals (Sweden)

    Cristina Montana PUȘCAȘ

    2014-11-01

    Full Text Available In antiquity “Patrulaterul de Aur” (The Golden Quadrilateral, ca. 550 km2 of the Apuseni Mountains was one of Eurasia’s richest gold and silver mining region. It is estimated that 60 – 64 M ounces of gold have been extracted from Romania during the past 2 ka, about 75% of which was sourced from this particular area [1]. Activities such as mining and smelting of ores and the associated biomass burning produced ample amounts of aerosols that were carried downwind and accumulated as wet or dry deposition. Meteoric water remobilized these trace elements by leaching from the soil as solute or particle/colloidal phase in aqueous solution through the bedrock and into the cave. Here we present the trace elemental compositions (22 elements, obtained by means of LA-ICP-MS in a ca. 2 ka old stalagmite from the Frumoasă Cave (Trascău Mountains, SE Apuseni Mountains; Fig. 1 as a proxy for historical Au, Ag, and Cu mining and smelting. The most prominent sites (Roșia Montană, Zlatna, and Abrud where ores were extracted and/or processed over the past 2 ka are < 30 km upwind of the Frumoasă Cave.

  19. Heavy metals contamination and human health risk assessment around Obuasi gold mine in Ghana.

    Science.gov (United States)

    Bempah, Crentsil Kofi; Ewusi, Anthony

    2016-05-01

    Gold mining has increased the prevalence and occurrence of heavy metals contamination at the Earth's surface and is causing major concern due to the potential risk involved. This study investigated the impact of gold mine on heavy metals (As, Cd, Cr, Cu, Pb, Hg, Ni, Fe, Mn, and Zn) pollution and evaluated the potential health risks to local residents via consumption of polluted groundwater, agricultural soils, and vegetable crops grown at three community farms surrounding the mine at Obuasi municipality of Ghana. The results showed levels of As, Cd, Cr, Hg, Fe, and Mn higher than the allowable drinking water standards. The vegetable samples analyzed showed high accumulation of As and Ni above the normal value. Bioaccumulation factors of heavy metals were significantly higher for vegetables grown in the Sanso soils. Estimated average daily intake and hazard quotient for As in drinking water as well as As, Pb, and Hg in vegetable samples exceeded permissible limit. Unacceptable non-cancer health risk levels were found in vegetable samples analyzed for As, Pb, and Hg. An unacceptable cancer risk was found via drinking of groundwater, in consumption of vegetables, and in soil. The hazard index for vegetables was higher than 1, indicating very high health risk to heavy metals contamination through consumption of vegetables grown around the sampling sites. The results recommend the need for regular monitoring of groundwater and food crops to protect consumers' health.

  20. USING THE SULFUR POLYMER STABILIZATION SOLIDIFICATION PROCESS TO TREAT RESIDUAL MERCURY WASTES FROM GOLD MINING OPERATIONS.

    Energy Technology Data Exchange (ETDEWEB)

    BOWERMAN,B.ADAMS,J.KALB,P.WAN,R.Y.LEVIER,M.

    2003-02-24

    Large quantities of mercury are generated as a by-product during the processing of gold ore following mining operations. Newmont Mining Corporation (NMC), which operates some of the world's largest gold mines, sought a method to permanently ''retire'' its mercury by-products, thereby avoiding potential environmental liability. Sulfur Polymer Stabilization-Solidification (SPSS) is an innovative technology developed at Brookhaven National Laboratory (BNL) for treatment of mercury and mercury contaminated materials, such as soil, sludge and debris. BNL conducted a treatability study to determine the potential applicability of SPSS for treatment of Newmont mercury, and the treated product passed the U.S. Environmental Protection Agency (EPA) test for toxicity. The SPSS process has been shown to be effective on radioactive and nonradioactive mercury and mercury-contaminated materials with a pilot-scale batch system capable of producing 0.03 m{sup 3} (1 ft{sup 3}) per batch. Engineering scale-up issues are discussed and material property tests addressing these issues are described.

  1. 煤矿液压支架焊接技术探讨%Discussion on the Welding Technology of Coal Mine Hydraulic Support

    Institute of Scientific and Technical Information of China (English)

    杨磊

    2015-01-01

    分析了煤矿液压支架焊接技术要求和技术分类,阐述了煤矿液压支架焊接技术和煤矿液压支架焊接机器人的应用。%This paper analyzed welding technical requirements and technical classification of coal mine hydraulic support, and expounded the application of the coal hydraulic support welding technology and coal hydraulic support welding robot.

  2. Heavy Metal Concentration in Drinking Water Sources Affected by Dredge Mine Operations of a Gold Mining Company in Ghana

    Directory of Open Access Journals (Sweden)

    Apori Ntiforo

    2012-06-01

    Full Text Available The study assesses concentration of certain heavy metals in water sources affected by the operations of defunct dredged gold mine operations more than a decade to evaluate its quality as a source of drinking water. The concentration of heavy metals were determined from nine (9 surface water sampling points and three (3 boreholes in the Awusu-River basin in comparison with their maximum contaminant levels to assess their suitability as drinking water sources. Results obtained from the analysis of water samples indicated that the concentrations of four heavy metals (Fe, 0.01-14.93 mg/L; Cd, <0.002-0.01 mg/L; As, <0.002-0.003 mg/L and Pb, <0.005-0.05 mg/L analyzed in surface water samples were above WHO threshold values (Fe 300, Cd 3, As 10 and Pb 10 ug/L for drinking water and two (Cu, <0.002-0.05 mg/L and Zc, <0.005-0.03 mg/L were below (Cu 2000 ug/L and Zc 3000 ug/L. Dissolved iron registered the highest concentrations with the Slime Retention Area (SRA dominating with a mean concentration of 4.979 mg/L. All the sampling points were being used as drinking water sources by the two communities. An integrated approach to management of sources of drinking water quality in the mining areas is needed and should involve not only the mining companies and regulatory agencies but also the local communities to enable the latter understand and appreciate post mining issues of water quality.

  3. Assessment of the effluent quality from a gold mining industry in Ghana.

    Science.gov (United States)

    Acheampong, Mike A; Paksirajan, Kannan; Lens, Piet N L

    2013-06-01

    The physical and chemical qualities of the process effluent and the tailings dam wastewater of AngloGold-Ashanti Limited, a gold mining company in Ghana, were studied from June to September, 2010. The process effluent from the gold extraction plant contains high amounts of suspended solids and is therefore highly turbid. Arsenic, copper and cyanide were identified as the major pollutants in the process effluent with average concentrations of 10.0, 3.1 and 21.6 mg L(-1), respectively. Arsenic, copper, iron and free cyanide (CN(-)) concentrations in the process effluent exceeded the Ghana EPA discharge limits; therefore, it is necessary to treat the process effluent before it can be discharged into the environment. Principal component analysis of the data indicated that the process effluent characteristics were influenced by the gold extraction process as well as the nature of the gold-bearing ore processed. No significant correlation was observed between the wastewater characteristics themselves, except for the dissolved oxygen and the biochemical oxygen demand. The process effluent is fed to the Sansu tailings dam, which removes 99.9 % of the total suspended solids and 99.7 % of the turbidity; but copper, arsenic and cyanide concentrations were still high. The effluent produced can be classified as inorganic with a high load of non-biodegradable compounds. It was noted that, though the Sansu tailings dam stores the polluted effluent from the gold extraction plant, there will still be serious environmental problems in the event of failure of the dam.

  4. The Forgotten Legacy: Sediment From Historical Gold Mining Greatly Exceeds all Other Anthropogenic Sources in SE Australian Rivers

    Science.gov (United States)

    Rutherfurd, I.; Davies, P.; Macklin, M. G.; Grove, J. R.

    2016-12-01

    Coarse and fine sediment has been a major pollutant of Australian rivers and receiving waters since European settlement in 1788. Anthropogenic sediment budget models demonstrate that catchment and channel erosion has increased background sediment delivery by 10 to 20 times across SE Australia, but these estimates ignore the contribution of historical gold mining. Detailed historical records allow us to reconstruct the delivery of coarse and fine sediment (including contaminated sediment) to the fluvial system. Between 1851 and 1900 alluvial gold mining in the state of Victoria liberated between 1.2 billion and 1.4 billion m3 of coarse and fine sediment into streams. Catchment scale modelling demonstrates that this volume is at least twice the volume of all anthropogenic (post-European) erosion from hillslopes, river banks, and gullies. We map the deposition and remobilization of these contaminated legacy mining sediments down selected valleys, and find that many contemporary floodplains are blanketed with mining sediments (although mercury contamination is present but low), and discrete sediment-slugs can be recognized migrating down river beds. Overall, the impact of gold mining is one of the strongest indicators of the Anthropocene in the Australian landscape, and the level of impact on rivers is substantially greater than recognized in the past. Perhaps of most interest is the rapid recovery of many river systems from the substantial impacts of gold mining. The result is that these major changes to the landscape are largely forgotten.

  5. Remote sensing supported surveillance and characterization of tailings behavior at a gold mine site, Finland.

    Science.gov (United States)

    Rauhala, Anssi; Tuomela, Anne; Rossi, Pekka M.; Davids, Corine

    2017-04-01

    The management of vast amounts of tailings produced is one of the key issues in mining operations. The effective and economic disposal of the waste requires knowledge concerning both basic physical properties of the tailings as well as more complex aspects such as consolidation behavior. The behavior of tailings in itself is a very complex issue that can be affected by flocculation, sedimentation, consolidation, segregation, deposition, freeze-thaw, and desiccation phenomena. The utilization of remote sensing in an impoundment-scale monitoring of tailings could benefit the management of tailings, and improve our knowledge on tailings behavior. In order to gain better knowledge of tailings behavior in cold climate, we have utilized both modern remote sensing techniques and more traditional in situ and laboratory measurements in characterizing thickened gold tailings behavior at a Finnish gold mine site, where the production has been halted due to low gold prices. The remote sensing measurements consisted of elevation datasets collected from unmanned aerial vehicles during summers 2015 and 2016, and a further campaign is planned for the summer 2017. The ongoing traditional measurements include for example particle-size distribution, frost heave, frost depth, water retention, temperature profile, and rheological measurements. Initial results from the remote sensing indicated larger than expected settlements on parts of the tailings impoundment, and also highlighted some of the complexities related to data processing. The interpretation of the results and characterization of the behavior is in this case complicated by possible freeze-thaw effects and potential settlement of the impoundment bottom structure consisting of natural peat. Experiments with remote sensing and unmanned aerial vehicles indicate that they could offer potential benefits in frequent mine site monitoring, but there is a need towards more robust and streamlined data acquisition and processing. The

  6. Arsenic mobilization from sulfidic materials from gold mines in Minas Gerais State

    Directory of Open Access Journals (Sweden)

    Renato Pereira de Andrade

    2008-01-01

    Full Text Available Acid drainage results from exposition of sulfides to the atmosphere. Arsenopyrite is a sulfide that releases arsenic (As to the environment when oxidized. This work evaluated the As mobility in six sulfidic geomaterials from gold mining areas in Minas Gerais State, Brazil. Grained samples (<2 mm were periodically leached with distilled water, during 70 days. Results suggested As sorption onto (hydroxides formed by oxidation of arsenopyrite. Low pH accelerated the acid generation, dissolving Fe oxihydroxides and releasing As. Presence of carbonates decreased oxidation rates and As release. On the other hand, lime added to a partially oxidized sample increased As mobilization.

  7. Heavy Metal Pollution from Gold Mines: Environmental Effects and Bacterial Strategies for Resistance

    Science.gov (United States)

    Fashola, Muibat Omotola; Ngole-Jeme, Veronica Mpode; Babalola, Olubukola Oluranti

    2016-01-01

    Mining activities can lead to the generation of large quantities of heavy metal laden wastes which are released in an uncontrolled manner, causing widespread contamination of the ecosystem. Though some heavy metals classified as essential are important for normal life physiological processes, higher concentrations above stipulated levels have deleterious effects on human health and biota. Bacteria able to withstand high concentrations of these heavy metals are found in the environment as a result of various inherent biochemical, physiological, and/or genetic mechanisms. These mechanisms can serve as potential tools for bioremediation of heavy metal polluted sites. This review focuses on the effects of heavy metal wastes generated from gold mining activities on the environment and the various mechanisms used by bacteria to counteract the effect of these heavy metals in their immediate environment. PMID:27792205

  8. Heavy Metal Pollution from Gold Mines: Environmental Effects and Bacterial Strategies for Resistance

    Directory of Open Access Journals (Sweden)

    Muibat Omotola Fashola

    2016-10-01

    Full Text Available Mining activities can lead to the generation of large quantities of heavy metal laden wastes which are released in an uncontrolled manner, causing widespread contamination of the ecosystem. Though some heavy metals classified as essential are important for normal life physiological processes, higher concentrations above stipulated levels have deleterious effects on human health and biota. Bacteria able to withstand high concentrations of these heavy metals are found in the environment as a result of various inherent biochemical, physiological, and/or genetic mechanisms. These mechanisms can serve as potential tools for bioremediation of heavy metal polluted sites. This review focuses on the effects of heavy metal wastes generated from gold mining activities on the environment and the various mechanisms used by bacteria to counteract the effect of these heavy metals in their immediate environment.

  9. Characterisation and modelling of mercury speciation in urban air affected by gold mining - assessment of bioavailability

    Directory of Open Access Journals (Sweden)

    Cukrowska E. M.

    2013-04-01

    Full Text Available The growing global concern over the release of mercury to the environment has prompted specific inventories that quantify mercury emissions from various sources. Investigations of atmospheric mercury have been mostly done on gaseous species. Although, to assess human expose to mercury, especially in urban areas, the inhalable dust should be included in a study. The Witwatersrand Basin in South Africa is one of the most important gold mining regions in the world. Mercury (Hg, which occurs in gold-bearing ores, was also used for gold recoveries in previous centuries (19th and early 20th century and presently in illegal artisanal mining. The consequences of these mining activities were the release of Hg to the environment, mainly due to AMD from tailings dumps which are presently reprocessed. The city of Johannesburg is a multimillion population exposed strongly to industrial pollution. The aim of this study was to determine the magnitude of mercury pollution in this urban area and assess its bioavailability. The gaseous samples were collected by trapping mercury on various gold traps. Dust samples were collected from a ground and on inhalation levels (1–2 m above a ground. They were later separated into different fractions by micro sieving. Bioavailability of mercury in inhalable dust (25 μm was tested by leaching collected samples with artificial lung fluid (ALF, pH 4.5, Gray’s solution (pH 7.4 and water. The leaching conditions were selected to mimic lungs environment (incubator at 30°C, time 24 hrs, rotation of samples 150 rpm. Total concentrations of mercury in dust fractions were also determined after microwave digestion. The results showed extremely high concentration levels of mercury in air and dust in industrial areas. Especially high levels were found around presently reprocessed old gold tailings dumps, up to 900 000 μgl–1. The levels dropped significantly in CBD area but still showing elevated concentrations up to 10 μgl−1

  10. Mobility and microbially mediated mobilization of gold and arsenic in soils from two gold mines in semi-arid and tropical Australia

    Science.gov (United States)

    Reith, F.; McPhail, D. C.

    2007-03-01

    The mobility and microbially mediated solubilization of Au and As in regolith materials from two Au mines in Australia, i.e., the Peak Hill Gold Mine in semi-arid New South Wales and the Hit or Miss Gold Mine in tropical northern Queensland, was studied using a combination of geochemical and microbiological techniques. Gold is highly mobile in both environments, the mobility of Au increases with increasing degree of weathering of host materials, and the resident microbiota are capable of mediating its solubilization. The results of the microcosm experiments demonstrate that the activity of microorganisms needs to be taken into account when studying the mobility and solubilization of Au in the Australian regolith. In primary, unweathered mineralization material from the Hit or Miss mine 99 wt% of Au was extracted only in the strongest final step of the sequential extractions, in concentrated aqua regia. In alteration zone material from the Peak Hill Gold Mine 80 wt% of Au was associated with the operationally defined Mn and Fe oxides. In contrast, in auriferous soils overlying mineralization at both sites 90-95 wt% of Au was associated with the operationally defined exchangeable, clay-bound and organic fractions. Microcosm experiments were incubated biologically active and inactive (sterilized) in 1:4 (w/v) aqueous slurries at 25 °C in the dark for up to 95 days. In biologically active microcosms with soils from the Peak Hill- and the Hit or Miss Gold Mines approximately 55 wt% (907 ng g -1 d.w. soil) and 20 wt% (233 ng g -1 d.w. soil) of the total Au, respectively, was solubilized during the incubation. In contrast, no or significantly lower Au concentrations were observed in biologically inactive microcosms. The mobility and microbially mediated release of As was limited at both sites and appears to be mostly controlled by abiotic adsorption and desorption on Mn- and Fe-oxides. Arsenic has a low solubility in the more mobile fractions and is mostly associated

  11. Design of Fogging Nozzles as Alternative Stock Pile Dust Suppression Medium at Gold Mining Sites

    Directory of Open Access Journals (Sweden)

    Stephen Kwasi Adzimah

    2012-01-01

    Full Text Available The aim of this study is to design fogging nozzles as alternative stock pile dust suppression medium at gold mining sites. Furthermore, this fogging medium helps to arrest the dust without getting the area wet and without any substantial expenditure. Emission of dust, which is one of the main contributors to the pollution of the environment, has been associated with mining industries for years, especially in the mining towns of Ghana and Liberia. The emission of dust takes place mainly around the haul roads, ore drilling, blasting and trafficking areas, crushers and, and especially, the stock pile unit. The intensity of the emissions of the dust is such that all the plants, objects, living things, gadgets, instruments and structures in the area are engulfed in the dust. Residents, who are hard hit by this phenomenon, backed by their traditional rulers often take the mining companies to task through legal or unlawful actions, which, many a time, become violent and confrontational. Sprinkling of water has been done to alleviate the situation but this process rather creates more problems in that, the area, especially roads, once wet becomes dry again, and the emission of dust gets intensified and aggravated.

  12. Investigation of arsenic species in tailings and windblown dust from a gold mining area.

    Science.gov (United States)

    Ono, F B; Tappero, R; Sparks, D; Guilherme, L R G

    2016-01-01

    Research has shown the presence of high levels of arsenic (up to 2666 mg As kg(-1)) in tailings from a gold mining area of Brazil. This is an important point of attention, generating concerns about impacts on human health. Yet, a recent study showed that As bioaccessibility in the same area was very low (mine tailings and windblown dust is needed to explain this low bioaccessibility. Mine samples were collected from four subareas and windblown dust from eight sites. Synchrotron-based bulk-X-ray absorption near-edge structure (bulk-XANES) spectroscopy, micro-X-ray absorption near-edge structure (μ-XANES), and μ-X-ray fluorescence (μ-SXRF) spectroscopy were applied to determine As speciation. Bulk-XANES spectra indicated that As occurs as the As(V) oxidation state. Micro-XANES and μ-SXRF analyses revealed that As was also present as arsenopyrite (FeAsS) and its weathering products, but mostly it was As(V) as poorly crystalline ferric arsenate. This supports the findings of low bioaccessible As and highlights the importance of Fe oxides in immobilizing As in the terrestrial environment. All air particulate samples exhibited As-rich particles (up to 313 mg As kg(-1)). The air particulates exhibited solid-phase As species very similar to those found in the mine samples, which indicates that As in the windblown dust is not easily available.

  13. Feasibility of a mine-wide continuous closure monitoring system for gold mines.

    CSIR Research Space (South Africa)

    Malan, DF

    2000-09-01

    Full Text Available magnetic field ranging device is proposed. As an alternative, a method of estimating the distance to face with reasonable accuracy is proposed. The third generic issue was assigning responsibility for moving the meters (typically every two weeks... the position of the closure transducers ……………………………… 14 2.3 Responsibility for moving the transducers forward on a regular basis ….……..16 3 Alternative hardware designs for a mine-wide closure system………. 18 3.1 Specifications for the closure transducers...

  14. Feasibility of Applying Clean Development Mechanism and GHGs Emission Reductions in the Gold Mining Industry: A Case of Thailand

    Science.gov (United States)

    Kittipongvises, Suthirat

    2015-12-01

    There is presently overwhelming scientific consensus that global climate change is indeed occurring, and that human activities are the primary driver. An increasingly resource and carbon constrained world will continue to pose formidable challenges to major industries, including mining. Understanding the implications of climate change mitigation for the mining industry, however, remains limited. This paper presents the results of a feasibility study on the implementation of a clean development mechanism and greenhouse gases (GHGs) emission reductions in the gold mining industry. It draws upon and extends the analysis of a case study conducted on gold mining operations in Thailand. The results from the case study indicated that total GHGs emissions by company A were approximately 36,886 tons carbon dioxide equivalents (tCO2e) per annual gold production capacity that meet the eligibility criteria for small-scaled clean development mechanism (CDM) projects. The electrostatic separation process was found to release the lowest amount of GHGs, whereas comminution (i.e. crushing and grinding) generated the highest GHGs emissions. By scope, the emission from purchased electricity (scope 2) is the most significant source. Opportunities for CDM projects implementation in the gold mining sector can be found in employing energy efficiency measures. Through innovation, some technical efficiency and technological development in gold processing (i.e. high pressure grinding rolls (HPGR), vertical roller mills (VRM), gravity pre-concentration and microwave heating technologies) that have the potential to reduce energy use and also lower carbon footprint of the gold mining were further discussed. The evidence reviews found that HPGR and VRM abatement technologies have shown energy and climate benefits as electricity savings and CO2 reduction of about 8-25.93 kWh/ton ore processed and 1.8-26.66 kgCO2/ton ore processed, respectively. Implications for further research and practice were

  15. Feasibility of Applying Clean Development Mechanism and GHGs Emission Reductions in the Gold Mining Industry: A Case of Thailand

    Directory of Open Access Journals (Sweden)

    Kittipongvises Suthirat

    2015-12-01

    Full Text Available There is presently overwhelming scientific consensus that global climate change is indeed occurring, and that human activities are the primary driver. An increasingly resource and carbon constrained world will continue to pose formidable challenges to major industries, including mining. Understanding the implications of climate change mitigation for the mining industry, however, remains limited. This paper presents the results of a feasibility study on the implementation of a clean development mechanism and greenhouse gases (GHGs emission reductions in the gold mining industry. It draws upon and extends the analysis of a case study conducted on gold mining operations in Thailand. The results from the case study indicated that total GHGs emissions by company A were approximately 36,886 tons carbon dioxide equivalents (tCO2e per annual gold production capacity that meet the eligibility criteria for small-scaled clean development mechanism (CDM projects. The electrostatic separation process was found to release the lowest amount of GHGs, whereas comminution (i.e. crushing and grinding generated the highest GHGs emissions. By scope, the emission from purchased electricity (scope 2 is the most significant source. Opportunities for CDM projects implementation in the gold mining sector can be found in employing energy efficiency measures. Through innovation, some technical efficiency and technological development in gold processing (i.e. high pressure grinding rolls (HPGR, vertical roller mills (VRM, gravity pre-concentration and microwave heating technologies that have the potential to reduce energy use and also lower carbon footprint of the gold mining were further discussed. The evidence reviews found that HPGR and VRM abatement technologies have shown energy and climate benefits as electricity savings and CO2 reduction of about 8-25.93 kWh/ton ore processed and 1.8-26.66 kgCO2/ton ore processed, respectively. Implications for further research and

  16. Geochemical characteristics and source analysis of inflow of mine water in Wang'ershan Gold Mine, Shandong

    Institute of Scientific and Technical Information of China (English)

    QIAN Jianping; LI Shuangli; CAO Chao

    2008-01-01

    Through a systematic observation of water level and temperature, and a comprehensive analysis of the data on major/trace elements, nitrite, hydrogen-oxygen isotopes, the conclusion has been drawn that there are two relatively independent groundwater systems (cool water and hot water), and the geochemical indicators of hot/cool waters are described. The cool water system is relatively enriched in Ca2+, Mg2+ and HCO3-. Its TDS is relatively low, about 1400-1800 mg/L. The hot water system is relatively enriched in K+, Na+, Cl- and SO42-. Its TDS is relatively high, about 2200-2300 mg/L. The cool water system is enriched in Ba, Ga, Cd, and the hot water system is enriched in B, Ti, Cr, Ni, Cu, Mo, Rb, and Cs, relatively. Especially, the contents of Rb and Cs in the hot water system are more than five times as high as those in the cool water system. The NO3- contents of cool water discharged from the gold mine are relatively high, and those of hot water are extremely low. The δD and δ18O values follow an increasing order of surface water>mine cool water>mine hot water. The cool water comes mainly from the lateral supply of phreatic water, while the hot water comes mainly from the vertical supply of deeply circulating structure-fracture water. The ratio of cool water over hot water was estimated to be about 1:1 by a water quality model..

  17. Soil biological attributes in arsenic-contaminated gold mining sites after revegetation.

    Science.gov (United States)

    Dos Santos, Jessé Valentim; de Melo Rangel, Wesley; Azarias Guimarães, Amanda; Duque Jaramillo, Paula Marcela; Rufini, Márcia; Marra, Leandro Marciano; Varón López, Maryeimy; Pereira da Silva, Michele Aparecida; Fonsêca Sousa Soares, Cláudio Roberto; de Souza Moreira, Fatima Maria

    2013-12-01

    Recovery of arsenic contaminated areas is a challenge society faces throughout the world. Revegetation associated with microbial activity can play an essential role in this process. This work investigated biological attributes in a gold mining area with different arsenic contents at different sites under two types of extant revegetation associated with cover layers of the soil: BS, Brachiaria sp. and Stizolobium sp., and LEGS, Acacia crassicarpa, A. holosericea, A. mangium, Sesbania virgata, Albizia lebbeck and Pseudosamanea guachapele. References were also evaluated, comprising the following three sites: B1, weathered sulfide substrate without revegetation; BM, barren material after gold extraction and PRNH (private reserve of natural heritage), an uncontaminated forest site near the mining area. The organic and microbial biomass carbon contents and substrate-induced respiration rates for these sites from highest to lowest were: PRNH > LEGS > BS > B1 and BM. These attributes were negatively correlated with soluble and total arsenic concentration in the soil. The sites that have undergone revegetation (LEGS and BS) had higher densities of bacteria, fungi, phosphate solubilizers and ammonium oxidizers than the sites without vegetation. Principal component analysis showed that the LEGS site grouped with PRNH, indicating that the use of leguminous species associated with an uncontaminated soil cover layer contributed to the improvement of the biological attributes. With the exception of acid phosphatase, all the biological attributes were indicators of soil recovery, particularly the following: microbial carbon, substrate-induced respiration, density of culturable bacteria, fungi and actinobacteria, phosphate solubilizers and metabolic quotient.

  18. Localized Profile of Arsenic in Soil and Water in the Area Around Gold Mine

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    Thanes Weerasiri

    2013-08-01

    Full Text Available Soil and water samples from the area vicinity to gold mine at Wangsaphung District, Loei province, have been collected to investigate the arsenic concentration. Five boreholes were drilled into the ground until reaching to gravel layer or bedrock, and Soil samples were collected at every 0.50 - meter depth. Four boreholes are located inside the catchment in which the gold mine situated whereas the other one was bored at the outside. In addition, 13 sets of surface water and 8 sets of groundwater were also collected. The results of concentration test indicated that soil samples within at least 3 boreholes have arsenic content enormously exceeded the maximum concentration limits (MCL specified by the Office of National Environment Board of Thailand. Geologic condition underneath soil layer also play an important role on the concentration of arsenic. Soil column placed on the originally-deposited gravel bed can retain less concentration of arsenic, whereas soil column on bedrock can retain much more. For water samples, arsenic contents were generally less than 10 µg/l, the MCL specified by U.S.EPA, except that there is one interesting location found extremely high. That location give an useful information for further finding of arsenic pathway.

  19. Human health risks in an old gold mining area with circum-neutral drainage, central Portugal.

    Science.gov (United States)

    Carvalho, P C S; Neiva, A M R; Silva, M M V G; Santos, A C T

    2017-02-01

    The former mine of Escádia Grande was active at the middle of 1900 and was exploited for Au and Ag. The mineralized quartz veins consist mainly of quartz, arsenopyrite, pyrite, rare chalcopyrite, galena, sphalerite, gold and argentite. The mine dumps and tailings were deposited close to a stream, and there is a river beach downstream used for recreational proposes. Two villages are also located close to the old mining area. Mine wastes contained up to 8090 mg/kg of As and 70.1 mg/kg of Sb. The waters of the stream that cross the mining area have circum-neutral pH values and contained elevated concentrations of As reaching up to 284 µg/L. However, geochemical speciation modeling (Phreeq C) revealed that As was mainly present as As (V). Arsenic concentrations in waters are attenuated throughout the stream, mainly by the iron-(hydro)-oxides adsorption upstream. However, at 2 km downstream of mine wastes in the river beach, the waters still exceeded 10 µg/L of As, the drinking water limit. The waters also have NO2(-), Cu and Cd concentrations higher than drinking water limit. The stream sediments have As concentrations up to 45 times higher (3140 mg/kg) than the limit of the sediment guideline values of NWQMS (2000). The maximum arsenic concentrations in soils are also up to 27 times higher (5940 mg/kg) than the maximum concentrations in streams from FOREGS Geochemical Atlas of Europe. The use of river beach for recreational purposes causes cancer risk (4.48 × 10(-6)) higher than USEPA limit, mainly due to the arsenic exposure. Even for recreational purposes, stream sediments and soils in the old mining area have high non-carcinogenic effects (2.76 and 4.78, respectively) for children, also related to the arsenic exposure mainly by the ingestion pathway, and the risk is unacceptable according to the limits of USEPA. Moreover, the cancer risk resulting from exposure of adults to arsenic in soils also has unacceptable non-cancer risk (1.13). Arsenic is the

  20. A deployment of broadband seismic stations in two deep gold mines, South Africa

    Science.gov (United States)

    McGarr, Arthur F.; Boettcher, Margaret S.; Fletcher, Jon Peter B.; Johnston, Malcolm J.; Durrheim, R.; Spottiswoode, S.; Milev, A.

    2009-01-01

    In-mine seismic networks throughout the TauTona and Mponeng gold mines provide precise locations and seismic source parameters of earthquakes. They also support small-scale experimental projects, including NELSAM (Natural Earthquake Laboratory in South African Mines), which is intended to record, at close hand, seismic rupture of a geologic fault that traverses the project region near the deepest part of TauTona. To resolve some questions regarding the in-mine and NELSAM networks, we deployed four portable broadband seismic stations at deep sites within TauTona and Mponeng for one week during September 2007 and recorded ground acceleration. Moderately large earthquakes within our temporary network were recorded with sufficiently high signal-to-noise that we were able to integrate the acceleration to ground velocity and displacement, from which moment tensors could be determined. We resolved the questions concerning the NELSAM and in-mine networks by using these moment tensors to calculate synthetic seismograms at various network recording sites for comparison with the ground motion recorded at the same locations. We also used the peak velocity of the S wave pulse, corrected for attenuation with distance, to estimate the maximum slip within the rupture zone of an earthquake. We then combined the maximum slip and seismic moment with results from laboratory friction experiments to estimate maximum slip rates within the same high-slip patches of the rupture zone. For the four largest earthquakes recorded within our network, all with magnitudes near 2, these inferred maximum slips range from 4 to 27 mm and the corresponding maximum slip rates range from 1 to 6 m/s. These results, in conjunction with information from previous ground motion studies, indicate that underground support should be capable of withstanding peak ground velocities of at least 5 m/s.

  1. Mercury Exposure Assessment and Spatial Distribution in A Ghanaian Small-Scale Gold Mining Community

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    Mozhgon Rajaee

    2015-09-01

    Full Text Available Mercury is utilized worldwide in artisanal and small-scale gold mining (ASGM and may pose a risk for miners and mining communities. While a number of studies have characterized mercury in ASGM communities, most have focused on a single media and few have taken a holistic approach. Here, a multiple media exposure assessment and cross-sectional study of mercury was conducted in 2010 through 2012 in northeast Ghana with a small-scale gold mining community, Kejetia, a subsistence farming community, Gorogo, and an urban ASGM gold refinery in Bolgatanga. The objective was to assess mercury in a range of human (urine and hair and ecological (household soil, sediment, fish, and ore samples to increase understanding of mercury exposure pathways. All participants were interviewed on demographics, occupational and medical histories, and household characteristics. Participants included 90 women of childbearing age and 97 adults from Kejetia and 75 adults from Gorogo. Median total specific gravity-adjusted urinary, hair, and household soil mercury were significantly higher in Kejetia miners (5.18 µg/L, 0.967 µg/g, and 3.77 µg/g, respectively than Kejetia non-miners (1.18 µg/L, 0.419 µg/g, and 2.00 µg/g, respectively and Gorogo participants (0.154 µg/L, 0.181 µg/g, and 0.039 µg/g in 2011. Sediment, fish, and ore Hg concentrations were below guideline values. Median soil mercury from the Bolgatanga refinery was very high (54.6 µg/g. Estimated mean mercury ingestion for Kejetia adults from soil and dust exceeded the U.S. Environmental Protection Agency reference dose (0.3 µg Hg/kg·day for pica (0.409 µg Hg/kg·day and geophagy (20.5 µg Hg/kg·day scenarios. Most participants with elevated urinary and household soil mercury were miners, but some non-miners approached and exceeded guideline values, suggesting a health risk for non-mining residents living within these communities.

  2. Vulnerability of soils towards mining operations in gold-bearing sands in Chile

    Science.gov (United States)

    Jordán, Manuel Miguel; González, Irma; Bech, Jaume; Sanfeliu, Teófilo; Pardo, Francisco

    2015-04-01

    The contamination levels in handicraft mining, despite less production and processing less equipment, have high repercussions upon the environment in many cases. High-grade ore extraction, flotation, gravity concentration, acid leaching cementation and mercury amalgamation are the main metallurgical technologies employed. Gold recovery involving milling and amalgamation appears to the most contamination source of mercury. This research work is only a starting point for carrying out a risk probability mapping of pollutants of the gold bearing sands. In southern Chile, with a mild and rainy climate, high levels of pollutants have been detected in some gold placer deposits. The handicraft gold-bearing sands studied are located in X Region of "Los Lagos" in southern Chile. A great quantity of existing secondary deposits in the X Region is located in the coastal mountain range. The lithological units that are found in this range correspond with metamorphic rocks of a Paleozoic crystalline base that present an auriferous content liberated from the successive erosive processes suffered. Metasedimentary and metavolcanic rocks also make up part of this range, but their auriferous load is much smaller. The methodology used in the characterization of the associated mineralization consists of testing samples with a grain size distribution, statistical parameter analysis and mineralogical analysis using a petrographic microscope, XRD and SEM/EDX. The chemical composition was determined by means of XRF and micro-chemical analysis. The major concentrations of heavy minerals are located in areas of dynamic river energy. In the studied samples, more the 75 % of the heavy minerals were distributed among grain sizes corresponding to thin sand (0.25-0.05 mm) with good grain selection. The main minerals present in the selected analysed samples were gold, zircon, olivine, ilmenite, hornblende, hematite, garnet, choromite, augite, epidote, etc. The main heavy metals found were mercury

  3. The fate of cyanide in leach wastes at gold mines: an environmental perspective

    Science.gov (United States)

    Johnson, Craig A.

    2015-01-01

    This paper reviews the basic chemistry of cyanide, methods by which cyanide can be analyzed, and aspects of cyanide behavior that are most relevant to environmental considerations at mineral processing operations associated with gold mines. The emphasis is on research results reported since 1999 and on data gathered for a series of U.S. Geological Survey studies that began in the late 1990s. Cyanide is added to process solutions as the CN− anion, but ore leaching produces numerous other cyanide-containing and cyanide-related species in addition to the desired cyanocomplex of gold. These can include hydrogen cyanide (HCN); cyanometallic complexes of iron, copper, zinc, nickel, and many other metals; cyanate (CNO−); and thiocyanate (SCN−). The fate of these species in solid wastes and residual process solutions that remain once gold recovery activities are terminated and in any water that moves beyond the ore processing facility dictates the degree to which cyanide poses a risk to aquatic organisms and aquatic-dependent organisms in the local environment.

  4. Gold Rush!

    Science.gov (United States)

    Brahier, Daniel J.

    1997-01-01

    Describes a mathematical investigation of gold--how it is weighed, stored, used, and valued. For grades 3-4, children estimate the value of treasure chests filled with gold coins and explore the size and weight of gold bars. Children in grades 5-6 explore how gold is mined and used, and how the value of gold changes over time. (PVD)

  5. Issues in the analyze of low content gold mining samples by fire assay technique

    Science.gov (United States)

    Cetean, Valentina

    2016-04-01

    during oxidation stage. The better metal recovery and the decreasing of the amount of errors for low gold content samples are controlled in this case by: - the management of the quantity of one or more components of the flux, depending on the chemical composition of the sample (sometimes just by observing the behavior and the visual characteristics of lead Au + Ag button/bead and the resulted slag); - addition of gold-free silver, which will be removed by chemical reduction with aqua regia after the fire assay stage. Regarding the instrumental analyze stage of the samples with less than 100 ppb gold content, there were obtained similar values by both techniques: atomic absorption and inductively coupled mass spectrometry, taking into account each of them has different detection limit. It is mandatory the quality control with a certified reference material with known content, both in the fire assay stage and the reading instrumental stage. This abstract are written in the frame of the SUSMIN project: "Tools for sustainable gold mining in EU".

  6. Mercury-contaminated sediments in the North Bay: A legacy of the Gold Rush

    Science.gov (United States)

    Jaffe, Bruce E.

    2001-01-01

    A legacy of the Gold Rush is mercury-contaminated sediments in the Bay. Miners used mercury to extract gold from tailings during the gold rush. A large amount of this mercury (some estimates are as great as 10,000 tons) was lost during extraction to the watershed during the gold rush era. This mercury-contaminated hydraulic mining debris made its way to the Bay.

  7. Linking geology and health sciences to assess childhood lead poisoning from artisanal gold mining in Nigeria

    Science.gov (United States)

    Plumlee, Geoffrey S.; Durant, James T.; Morman, Suzette A.; Neri, Antonio; Wolf, Ruth E.; Dooyema, Carrie A.; Hageman, Philip L.; Lowers, Heather; Fernette, Gregory L.; Meeker, Gregory P.; Benzel, William M.; Driscoll, Rhonda L.; Berry, Cyrus J.; Crock, James G.; Goldstein, Harland L.; Adams, Monique; Bartrem, Casey L.; Tirima, Simba; Behrooz, Behbod; von Lindern, Ian; Brown, Mary Jean

    2013-01-01

    Background: In 2010, Médecins Sans Frontières discovered a lead poisoning outbreak linked to artisanal gold processing in northwestern Nigeria. The outbreak has killed approximately 400 young children and affected thousands more. Objectives: Our aim was to undertake an interdisciplinary geological- and health-science assessment to clarify lead sources and exposure pathways, identify additional toxicants of concern and populations at risk, and examine potential for similar lead poisoning globally. Methods: We applied diverse analytical methods to ore samples, soil and sweep samples from villages and family compounds, and plant foodstuff samples. Results: Natural weathering of lead-rich gold ores before mining formed abundant, highly gastric-bioaccessible lead carbonates. The same fingerprint of lead minerals found in all sample types confirms that ore processing caused extreme contamination, with up to 185,000 ppm lead in soils/sweep samples and up to 145 ppm lead in plant foodstuffs. Incidental ingestion of soils via hand-to-mouth transmission and of dusts cleared from the respiratory tract is the dominant exposure pathway. Consumption of water and foodstuffs contaminated by the processing is likely lesser, but these are still significant exposure pathways. Although young children suffered the most immediate and severe consequences, results indicate that older children, adult workers, pregnant women, and breastfed infants are also at risk for lead poisoning. Mercury, arsenic, manganese, antimony, and crystalline silica exposures pose additional health threats. Conclusions: Results inform ongoing efforts in Nigeria to assess lead contamination and poisoning, treat victims, mitigate exposures, and remediate contamination. Ore deposit geology, pre-mining weathering, and burgeoning artisanal mining may combine to cause similar lead poisoning disasters elsewhere globally.

  8. DEGRADATION DUE TO GOLD EXPLORATION IN THE CAXIAS MINE, LUÍS DOMINGUES – MA

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    Lílian Daniele Pantoja Gonçalves

    2005-05-01

    Full Text Available The gold is one of few metals that exist in the nature in natural state, showing natural brightness and great beauty. For these features it is supposed to be the first metal to call the attention from primitive man about 20.000 years ago. This mineral is supposed to be the first metal, whose importance was recognized by the human being, but its use only was possible in the Bronze Age, with the development of the foundry art.The actions that result from the mining demonstrate a degradation environmental feature bigger than what seem, because, when it is practiced in a disordered way and with low technologic control, it is a negative aspect because of the environmental devastation that occurs.It is undeniable that, in a modern world, the mining in general has decisive importance for the economic progress and development, since the mining mineral of the nature are present in almost all manufactured goods, and this generate the human dependence on the minerals. However, this dependence implies charges to the society by the development of huge degraded areas, which after the exploration, most time, cannot be occupied or explorated economicallly.

  9. Mercury speciation and dispersion from an active gold mine at the West Wits area, South Africa.

    Science.gov (United States)

    Lusilao-Makiese, J G; Tessier, E; Amouroux, D; Tutu, H; Chimuka, L; Weiersbye, I; Cukrowska, E M

    2016-01-01

    Total mercury (HgTOT), inorganic mercury (IHg), and methylmercury (MHg) were determined in dry season waters, sediments, and tailings from an active mine which has long history of gold exploitation. Although HgTOT in waters was generally low (0.03 to 19.60 ng L(-1)), the majority of the samples had proportions of MHg of at least 90 % of HgTOT which denotes a substantial methylation potential of the mine watersheds. Mercury was relatively high in tailing materials (up to 867 μg kg(-1)) and also in the mine sediments (up to 837 μg kg(-1)) especially in samples collected near tailing storage facilities and within a receiving water dam. Sediment profiles revealed mercury enrichment and enhanced methylation rate at deeper layers. The presence of IHg and decaying plants (organic matter) in the watersheds as well as the anoxic conditions of bulk sediments are believed to be some of the key factors favoring the mercury methylation at the site.

  10. Heavy metal pollution in soil associated with a large-scale cyanidation gold mining region in southeast of Jilin, China.

    Science.gov (United States)

    Chen, Mo; Lu, Wenxi; Hou, Zeyu; Zhang, Yu; Jiang, Xue; Wu, Jichun

    2017-01-01

    Different gold mining and smelting processes can lead to distinctive heavy metal contamination patterns and results. This work examined heavy metal pollution from a large-scale cyanidation gold mining operation, which is distinguished from artisanal and small-scale amalgamation gold mining, in Jilin Province, China. A total of 20 samples including one background sample were collected from the surface of the mining area and the tailings pond in June 2013. These samples were analyzed for heavy metal concentrations and degree of pollution as well as sources of Cr, Cu, Zn, Pb, Ni, Cd, As, and Hg. The mean concentrations of Pb, Hg, and Cu (819.67, 0.12, and 46.92 mg kg(-1), respectively) in soil samples from the gold mine area exceeded local background values. The mean Hg content was less than the first-class standard of the Environmental Quality for Soils, which suggested that the cyanidation method is helpful for reducing Hg pollution. The geochemical accumulation index and enrichment factor results indicated clear signs that enrichment was present for Pb, Cu, and Hg, with the presence of serious Pb pollution and moderate presence to none of Hg and Cu pollution. Multivariate statistical analysis showed that there were three metal sources: (1) Pb, Cd, Cu, and As came from anthropogenic sources; (2) Cr and Zn were naturally occurring; whereas (3) Hg and Ni had a mix of anthropogenic and natural sources. Moreover, the tailings dam plays an important role in intercepting the tailings. Furthermore, the potential ecological risk assessment results showed that the study area poses a potentially strong risk to the ecological health. Furthermore, Pb and Hg (due to high concentration and high toxicity, respectively) are major pollutants on the risk index, and both Pb and Hg pollution should be of great concern at the Haigou gold mines in Jilin, China.

  11. Arsenic associated with historical gold mining in the Sierra Nevada foothills: Case study and field trip guide for Empire Mine State Historic Park, California

    Science.gov (United States)

    Alpers, Charles N.; Myers, Perry A; Millsap, Daniel; Regnier, Tamsen B; Bowell, Robert J.; Alpers, Charles N.; Jamieson, Heather E.; Nordstrom, Kirk; Majzlan, Juraj

    2014-01-01

    The Empire Mine, together with other mines in the Grass Valley mining district, produced at least 21.3 million troy ounces (663 tonnes) of gold (Au) during the 1850s through the 1950s, making it the most productive hardrock Au mining district in California history (Clark 1970). The Empire Mine State Historic Park (Empire Mine SHP or EMSHP), established in 1975, provides the public with an opportunity to see many well-preserved features of the historic mining and mineral processing operations (CDPR 2014a).A legacy of Au mining at Empire Mine and elsewhere is contamination of mine wastes and associated soils, surface waters, and groundwaters with arsenic (As), mercury (Hg), lead (Pb), and other metals. At EMSHP, As has been the principal contaminant of concern and the focus of extensive remediation efforts over the past several years by the State of California, Department of Parks and Recreation (DPR) and Newmont USA, Ltd. In addition, the site is the main focus of a multidisciplinary research project on As bioavailability and bioaccessibility led by the California Department of Toxic Substances Control (DTSC) and funded by the U.S. Environmental Protection Agency’s (USEPA’s) Brownfields Program.This chapter was prepared as a guide for a field trip to EMSHP held on June 14, 2014, in conjunction with a short course on “Environmental Geochemistry, Mineralogy, and Microbiology of Arsenic” held in Nevada City, California on June 15–16, 2014. This guide contains background information on geological setting, mining history, and environmental history at EMSHP and other historical Au mining districts in the Sierra Nevada, followed by descriptions of the field trip stops.

  12. The nature of gold in the Aitik Cu-Au deposit:implications for mineral processing and mine planning

    OpenAIRE

    Sammelin, Monika

    2011-01-01

    The Aitik mine is a large Cu-Au producer in Europe with an annual production of 28 million tons of ore and a planned expansion of production to 36 million tons of ore until year 2013. Large ongoing investments are done in the mine and a new processing plant is built to manage the capacity increase. The mine is situated 15 kilometers from the town Gällivare, in northern Norrbotten, Sweden. The ore is a large porphyry type deposit with low grades of disseminated copper (0,27 %) and gold (0,16 p...

  13. Presence of glucose, xylose, and glycerol fermenting bacteria in the deep biosphere of the former Homestake gold mine, South Dakota

    Science.gov (United States)

    Eight fermentative bacterial strains were isolated from mixed enrichment cultures of a composite soil sample collected at 1.34 km depth from the former Homestake gold mine in Lead, SD, USA. Phylogenetic analysis of their 16S rRNA gene sequences revealed that these isolates were affiliated with the p...

  14. Analysis of the factors affecting the poverty in rural areas around gold mine areas in West Sumbawa Regency

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    Ibrahim

    2016-04-01

    Full Text Available West Sumbawa Regencyis one of the regencies that are rich of natural resources managed by PT. Newmont Nusa Tenggara. However, local communities around the gold mine areas have generally to date been poor. This study was aimed to (1 examine the effect of material poverty, physical weakness, isolation, vulnerability, and powerlessness on poverty, and (2 describe the distribution of rural povertybased on land slope mapsin gold mine areas in West Sumbawa Regency.This study applied a survey technique, observation, and structured interviews to collect data. The processing and analysis of data was carried out by a quantitative method using a multiple regression analysis. The results of the study showed that the factors significantly affecting the poverty among rural communities around gold mine areas were material poverty, physical weakness, isolation, vulnerability and powerlessness (R2 = 0.715. However, the mostly dominant factor affecting the poverty was powerlessness (t = 19.715. Meanwhile, the distribution of poverty based on topographic sites showed that the poverty occurred in villages with plain topography (Goa Village, terrain topography (Maluk Village, wave topography (Belo Village, and hilly topography (Sekongkang Bawah Village. The poverties occurred in all the villages were mostly affected by powerlessness with t values of 3.489, 13.921, 11.828, and 6.504, respectively. This condition was due to minimum access and communication by local communities to local government and the gold mining company of PT. Newmont Nusa Tenggara

  15. Characterization and risk of exposure to elements from artisanal gold mining operations in the Bolivian Andes.

    Science.gov (United States)

    Pavilonis, Brian; Grassman, Jean; Johnson, Glen; Diaz, Yilmael; Caravanos, Jack

    2017-04-01

    Artisanal and small-scale gold mining (ASGM) offers low-skilled workers an opportunity to elevate themselves out of poverty. However, this industry operates with little to no pollution controls and the cost to the environment and human health can be large. The objectives of this study were to measure levels of arsenic (As), manganese (Mn), cobalt (Co), lead (Pb), and mercury (Hg) in the environment and characterize health risks to miners and residents in an area with active ASGM operations. An exposure assessment was conducted at two different mining sites and a nearby village in the Bolivian Anders. The resulting measurements were then used to quantify cancerous and noncancerous health risks to children and adults working at and living near ASGM areas. Soil concentrations of As were well above background levels and showed great variations between the village and mining area. Mercury vapor levels at the two mining sites were approximately 30 times larger than the EPA reference concentration. The risk of developing non-cancerous health effects were primarily due to exposure to As and Hg. The probability of individuals developing cancer was considerably increased with adult miners having a probability of 1.3 out of 100. Cancer potential was driven by exposure to As, with de minimus cancer risk from all other elements. Based on the environmental characterization of elements in soils and Hg vapors, the risk of developing cancerous and non-cancerous health outcomes were above a level of concern based on EPA risk assessment guidance. Personal protective equipment was not worn by workers and Hg amalgam is commonly heated in workers' homes. Better education of the risks of ASGM is needed as well as simple controls to reduce exposure. Published by Elsevier Inc.

  16. Ecological and human health risks associated with abandoned gold mine tailings contaminated soil

    Science.gov (United States)

    Ngole-Jeme, Veronica Mpode; Fantke, Peter

    2017-01-01

    Gold mining is a major source of metal and metalloid emissions into the environment. Studies were carried out in Krugersdorp, South Africa, to evaluate the ecological and human health risks associated with exposure to metals and metalloids in mine tailings contaminated soils. Concentrations of arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), lead (Pb), manganese (Mn), nickel (Ni), and zinc (Zn) in soil samples from the area varied with the highest contamination factors (expressed as ratio of metal or metalloid concentration in the tailings contaminated soil to that of the control site) observed for As (3.5x102), Co (2.8x102) and Ni (1.1x102). Potential ecological risk index values for metals and metalloids determined from soil metal and metalloid concentrations and their respective risk factors were correspondingly highest for As (3.5x103) and Co (1.4x103), whereas Mn (0.6) presented the lowest ecological risk. Human health risk was assessed using Hazard Quotient (HQ), Chronic Hazard Index (CHI) and carcinogenic risk levels, where values of HQ > 1, CHI > 1 and carcinogenic risk values > 1×10−4 represent elevated risks. Values for HQ indicated high exposure-related risk for As (53.7), Cr (14.8), Ni (2.2), Zn (2.64) and Mn (1.67). Children were more at risk from heavy metal and metalloid exposure than adults. Cancer-related risks associated with metal and metalloid exposure among children were also higher than in adults with cancer risk values of 3×10−2 and 4×10−2 for As and Ni respectively among children, and 5×10−3 and 4×10−3 for As and Ni respectively among adults. There is significant potential ecological and human health risk associated with metal and metalloid exposure from contaminated soils around gold mine tailings dumps. This could be a potential contributing factor to a setback in the health of residents in informal settlements dominating this mining area as the immune systems of some of these residents are already

  17. Mercury Pollution in Soils from the Yacuambi River (Ecuadorian Amazon) as a Result of Gold Placer Mining.

    Science.gov (United States)

    López-Blanco, Charo; Collahuazo, Luis; Torres, Sandra; Chinchay, Luis; Ayala, Diana; Benítez, Paulina

    2015-09-01

    Gold mining is known to generate important economic products but also to produce several types of contamination/pollution. We report here the first data about Hg concentrations in the soils of the Yacuambi River in the Ecuadorian Amazon. We analyzed soil samples to assess the extent of contamination caused by gold placer mining in this area. Hg concentrations in soils exceeded the local background concentrations. High concentrations of Mn, As, Pb, Cr, Cu, Fe and Zn in some soil samples were probably derived from the geology of the site, which is rich in polysulfides and metamorphic rocks. Placer mining may accelerate the natural release of these elements to the environment by the exposure of the bedrock to the atmosphere. Accumulation of Hg in the river soils may be a potential source of toxicity for aquatic life and a risk to human health in the future.

  18. Selection of mercury accumulator plants for gold mine tailing contaminated soils

    Directory of Open Access Journals (Sweden)

    N Muddarisna

    2015-04-01

    Full Text Available Phytoremediation, which is more efficient with less side effects than conventional physical and chemical methods, is increasing in popularity as a remediation system. This paper provides a brief overview of developments in research and application of phytoremediation of soil contaminated with gold mine tailings containing mercury. Lindernia crustacea L., Digitaria radicosa Presl. Miq., Zingiber purpurium L, Paspalum conjugatum Berg., Cyperus kyllingia Endl., and Caladium bicolor Vent., that were selected for this study were planted in the planting media consisting of soil (70% and tailings (30% for 9 weeks. The results showed that after 9 weeks of planting, Paspalum conjugatum had growth rate, biomass production, Hg accumulation, and ratio of shoot Hg : root Hg higher than those of other plant species tested, both in the media consisted of amalgamation and cyanidation tailings. It can thus be concluded that Paspalum conjugatum is potential plant species for remediating mercury-contaminated soil.

  19. Metal(loid)s in sediment, lobster and mussel tissues near historical gold mine sites.

    Science.gov (United States)

    Walker, Tony R; Grant, Jon

    2015-12-15

    Previous studies near historical gold mining districts in Nova Scotia have identified significant enrichment of metal(loid)s in coastal marine sediments. Most of this inventory is buried below biologically active zones, although in some areas arsenic has bioaccumulated in marine biota resulting in localised bivalve shellfish closures. Isaacs Harbour is poised for future industrial development, but before potential impacts are predicted, current marine baseline conditions must be determined. To address this gap, this study established a baseline using surface sediments and biota (mussel and lobster tissues), to provide a broader picture of metal(loid)s in the marine environment. Results confirmed previous studies showing that most sediment metal(loid) concentrations still exceeded Canadian Marine Sediment Quality Guidelines, and also provided evidence of Canadian Food Inspection Agency fish tissue exceedances of arsenic in lobster and lead in mussel tissues indicating that some bioaccumulation of legacy contaminants in marine biota continues to the present day.

  20. Arsenic resistance and cycling in earthworms residing at a former gold mine in Canada.

    Science.gov (United States)

    Button, Mark; Koch, Iris; Reimer, Kenneth J

    2012-10-01

    Earthworms (Lumbricus castaneous and Dendrodrilus rubidus), their host soils and leaf litter were collected from a former gold mine with widespread arsenic (As) contamination in Nova Scotia, Canada and determined for total and speciated As. Resistance to As toxicity was investigated by measurement of DNA damage in exposed earthworm populations using the comet assay. Arsenobetaine (AB) was observed at low concentration in the earthworms but not in the host soil or leaf litter. Several different organoarsenic species were observed in the leaf litter and only inorganic As was found in the host soils. The results suggest that 1) adaptation to As toxicity in earthworms is widespread and not particular to a single species, 2) AB originates in the earthworm and not the consumed soil or leaf litter and 3) as previously hypothesised (Button et al., 2010), biotransformation of inorganic As to AB is not likely involved in the adaptation.

  1. Mercury levels in pristine and gold mining impacted aquatic ecosystems of Suriname, South America.

    Science.gov (United States)

    Ouboter, Paul E; Landburg, Gwendolyn A; Quik, Jan H M; Mol, Jan H A; van der Lugt, Frank

    2012-12-01

    Mercury levels in sediment and predatory fish were measured for 53 localities in Suriname. The average mercury level in bottom sediment surpassed the Canadian standard for sediment in most localities, except the coastal plains. Of the predatory fish, 41 % had a mercury level above the European Union standard for human consumption of 0.5 μg g(-1). Highest mercury levels were found in fish from the Brokopondo Reservoir and from the Upper Coppename River. High levels of mercury in fish in pristine areas are explained by atmospheric transportation of mercury with the northeastern trade winds followed by wet deposition. Contrary to gold mining areas, where mercury is bound to drifting sediments, in "pristine" areas the mercury is freely available for bio-accumulation and uptake. Impacts on piscivorous reptiles, birds, and mammals are unknown, but likely to be negative.

  2. Unstable Malaria Transmission in the Southern Peruvian Amazon and Its Association with Gold Mining, Madre de Dios, 2001-2012.

    Science.gov (United States)

    Sanchez, Juan F; Carnero, Andres M; Rivera, Esteban; Rosales, Luis A; Baldeviano, G Christian; Asencios, Jorge L; Edgel, Kimberly A; Vinetz, Joseph M; Lescano, Andres G

    2017-02-08

    The reemergence of malaria in the last decade in Madre de Dios, southern Peruvian Amazon basin, was accompanied by ecological, political, and socioeconomic changes related to the proliferation of illegal gold mining. We conducted a secondary analysis of passive malaria surveillance data reported by the health networks in Madre de Dios between 2001 and 2012. We calculated the number of cases of malaria by year, geographic location, intensity of illegal mining activities, and proximity of health facilities to the Peru-Brazil Interoceanic Highway. During 2001-2012, 203,773 febrile cases were identified in Madre de Dios, of which 30,811 (15.1%) were confirmed cases of malaria; all but 10 cases were due to Plasmodium vivax Cases of malaria rose rapidly between 2004 and 2007, reached 4,469 cases in 2005, and then declined after 2010 to pre-2004 levels. Health facilities located in areas of intense illegal gold mining reported 30-fold more cases than those in non-mining areas (ratio = 31.54, 95% confidence interval [CI] = 19.28, 51.60). Finally, health facilities located > 1 km from the Interoceanic Highway reported significantly more cases than health facilities within this distance (ratio = 16.20, 95% CI = 8.25, 31.80). Transmission of malaria in Madre de Dios is unstable, geographically heterogeneous, and strongly associated with illegal gold mining. These findings highlight the importance of spatially oriented interventions to control malaria in Madre de Dios, as well as the need for research on malaria transmission in illegal gold mining camps. © The American Society of Tropical Medicine and Hygiene.

  3. Assessment of heavy metal pollution risks in Yonki Reservoir environmental matrices affected by gold mining activity.

    Science.gov (United States)

    Kapia, Samuel; Rao, B K Rajashekhar; Sakulas, Harry

    2016-10-01

    This study reports the heavy metal (Hg, Cd, Cr, Cu, and Pb) contamination risks to and safety of two species of fresh water fish (tilapia, Oreochromis mossambicus and carp, Cyprinus carpio) that are farmed in the Yonki Reservoir in the Eastern Highlands of Papua New Guinea (PNG). The upper reaches of the reservoir are affected by alluvial and large-scale gold mining activities. We also assessed heavy metal levels in the surface waters and sediments and in selected aquatic plant species from the reservoir and streams that intersect the gold mining areas. The water quality was acceptable, except for the Cr concentration, which exceeded the World Health Organization (WHO) standard for water contamination. The sediments were contaminated with Cd and Cu in most of the sampling stations along the upstream waters and the reservoir. The Cd concentration in the sediments exceeded the US Environmental Protection Agency's Sediment Quality Guideline (SQG) values, and the geoaccumulation index (Igeo) values indicated heavy to extreme pollution. In addition, the Cd, Cu, and Pb concentrations in aquatic plants exceeded the WHO guidelines for these contaminants. Between the fish species, tilapia accumulated significantly higher (P < 0.05) Cu in their organ tissues than carp, confirming the bioaccumulation of some metals in the aquatic fauna. The edible muscles of the fish specimens had metal concentrations below the maximum permissible levels established by statutory guidelines. In addition, a human health risk assessment, performed using the estimated weekly intake (EWI) values, indicated that farmed fish from the Yonki Reservoir are safe for human consumption.

  4. Biodegradation Of Thiocyanate Using Microbial Consortia Cultured From Gold Mine Tailings

    Science.gov (United States)

    Moreau, J. W.; Watts, M. P.; Spurr, L. P.; Vu, H. P.

    2015-12-01

    Some bacteria possess the capability to degrade SCN-; therefore, harnessing this metabolic trait offers a biotechnological remediation strategy for SCN- produced in gold ore processing. A tailings storage facility (TSF) at a gold mine in Victoria, Australia holds large quantities of thiocyanate (SCN-) contaminated mine waste. The surface water in the TSF typically contains SCN- concentrations of >800 mg L-1, and seepage from the facility has contaminated the groundwater at the site. This study aimed to culture SCN-degrading microbes from the TSF, characterize the microbial consortia and test its operational parameters for use in a thiocyanate-degrading bioreactor. Surface samples were obtained from several locations around the TSF facility and used to inoculate medium reflective of the moderately saline and alkaline tailings water at the TSF, in the absence of organic carbon but subject to additions of phosphate and trace metals. Four microbial consortia capable of rapid SCN- degradation were successfully cultured. Sequencing of 16S rRNA genes found that the consortia were dominated by Thiobacillus species, a genus of known SCN- degraders. Lower abundances of other SCN- degraders; Sphingopyxis and Rhodobacter, were also identified. The impact of a number of geochemical conditions, including pH, temperature and SCN- concentration, upon the growth and SCN- degrading capacity of these consortia was determined. These results informed the optimization of a lab-scale thiocyanate degrading bioreactor. In summary, the cultured bacterial consortia proved effective towards SCN- degradation at the prevailing geochemical conditions of the TSF, requiring minimal nutrient additions. These consortia were dominated by genera of known autotrophic SCN- degraders. The comprehensive characterisation of these SCN- degrading consortia will provide the fundamental operational parameters required for deployment of this technique at the field scale.

  5. Geochemical distribution of trace element concentrations in the vicinity of Boroo gold mine, Selenge Province, Mongolia.

    Science.gov (United States)

    Inam, Edu; Khantotong, Supawan; Kim, Kyoung-Woong; Tumendemberel, Bulgan; Erdenetsetseg, Sugar; Puntsag, Tamir

    2011-01-01

    The environmental impacts of Boroo gold mine project in Mongolia was evaluated by chemical characterization of trace element concentrations in water, soils and tailing dam sediment samples. The results showed that concentrations of B, Cd, Ni and Se in the water samples were within the accepted levels of the Mongolia water quality standard (MNS4586: 1998). However, the concentrations of Al, As, Cu, Mn, Fe, Pb, U and Zn were higher than the maximum allowable concentration especially in the monitoring and heap leach wells. The average concentrations of As, Cd, Cu, Ni, Pb and Zn in the tailing dam sediment were 4419, 58.5, 56.0, 4.8, 20.6 and 25.7 mg/kg, respectively. Generally, arsenic and heavy metals in the soil samples were within the acceptable concentrations of the soil standard of Mongolia (MNS 5850: 2008). The chemical characterization of As solid phase in tailing dam sediment showed that the majority of As were found in the residual fraction comprising about 74% of total As. Assessing the potential risk to humans, simple bioavailability extraction test was used to estimate bioavailability of arsenic and heavy metals, and the concentrations extracted from tailing dam sediment were; 288.2 mg/kg As, 7.2 mg/kg Cd, 41.1 mg/kg Cu, 13.5 mg/kg Pb, 4.7 mg/kg Ni and 23.5 mg/kg Zn, respectively. From these results, the Boroo gold mine project has presently not significantly impacted the environment, but there is a high probability that it may act as a source of future contamination.

  6. Health and environmental assessment of mercury exposure in a gold mining community in Western Mindanao, Philippines.

    Science.gov (United States)

    Cortes-Maramba, Nelia; Reyes, Jose Paciano; Francisco-Rivera, Ana Trinidad; Akagi, Hirokatsu; Sunio, Rose; Panganiban, Lynn Crisanta

    2006-10-01

    The small-scale gold mining activities using mercury began in the late 1980s in Sibutad, Western Mindanao. It is located very near the Murcielagos Bay with tailing ponds directly discharging into bodies of water. This cross-sectional study aimed to determine the health and environmental effects of gold mining activities on the community. Residents were randomly selected and classified into two groups, namely, the directly exposed and indirectly exposed populations using a set inclusion criteria. Complete medical and laboratory examinations were performed. Environmental and biologic samples were collected for total mercury and methylmercury determinations. The results showed that the directly exposed group had significantly higher mean blood total mercury and methylmercury levels in comparison with the indirectly exposed population. Although there were no significant differences between hair total mercury and methylmercury levels, there was a trend for higher levels of these biomarkers among the directly exposed residents as compared with the unexposed group. The absence of statistically significant differences may be attributable to the small sample size. Ambient air quality monitoring for mercury exceeded the allowable levels. However, levels of mercury in drinking water and sediments were within allowable limits. Frequency of gastrointestinal complaints was significantly associated with elevated hair methylmercury levels (p=0.02). Also, there appears to be a trend towards higher blood total mercury levels and frequency of gastrointestinal complaints (p=0.09). An interesting finding in this study was the increasing incidence of elevated diastolic blood pressure with elevated hair total mercury levels (p=0.07). Mercury storage at home is a risk factor.

  7. Isotopic composition of inorganic mercury and methylmercury downstream of a historical gold mining region

    Science.gov (United States)

    Donovan, Patrick M.; Blum, Joel D.; Singer, Michael B.; Marvin-DiPasquale, Mark C.; Tsui, Martin T.K.

    2016-01-01

    We measured total mercury (THg) and monomethyl mercury (MMHg) concentrations and mercury (Hg) isotopic compositions in sediment and aquatic organisms from the Yuba River (California, USA) to identify Hg sources and biogeochemical transformations downstream of a historical gold mining region. Sediment THg concentrations and δ202Hg decreased from the upper Yuba Fan to the lower Yuba Fan and the Feather River. These results are consistent with the release of Hg during gold mining followed by downstream mixing and dilution. The Hg isotopic composition of Yuba Fan sediment (δ202Hg = −0.38 ± 0.17‰ and Δ199Hg = 0.04 ± 0.03‰; mean ± 1 SD, n = 7) provides a fingerprint of inorganic Hg (IHg) that could be methylated locally or after transport downstream. The isotopic composition of MMHg in the Yuba River food web was estimated using biota with a range of %MMHg (the percent of THg present as MMHg) and compared to IHg in sediment, algae, and the food web. The estimated δ202Hg of MMHg prior to photodegradation (−1.29 to −1.07‰) was lower than that of IHg and we suggest this is due to mass-dependent fractionation (MDF) of up to −0.9‰ between IHg and MMHg. This result is in contrast to net positive MDF (+0.4 to +0.8‰) previously observed in lakes, estuaries, coastal oceans, and forests. We hypothesize that this unique relationship could be due to differences in the extent or pathway of biotic MMHg degradation in stream environments.

  8. Isotopic Composition of Inorganic Mercury and Methylmercury Downstream of a Historical Gold Mining Region.

    Science.gov (United States)

    Donovan, Patrick M; Blum, Joel D; Singer, Michael Bliss; Marvin-DiPasquale, Mark; Tsui, Martin T K

    2016-02-16

    We measured total mercury (THg) and monomethyl mercury (MMHg) concentrations and mercury (Hg) isotopic compositions in sediment and aquatic organisms from the Yuba River (California, USA) to identify Hg sources and biogeochemical transformations downstream of a historical gold mining region. Sediment THg concentrations and δ(202)Hg decreased from the upper Yuba Fan to the lower Yuba Fan and the Feather River. These results are consistent with the release of Hg during gold mining followed by downstream mixing and dilution. The Hg isotopic composition of Yuba Fan sediment (δ(202)Hg = -0.38 ± 0.17‰ and Δ(199)Hg = 0.04 ± 0.03‰; mean ± 1 SD, n = 7) provides a fingerprint of inorganic Hg (IHg) that could be methylated locally or after transport downstream. The isotopic composition of MMHg in the Yuba River food web was estimated using biota with a range of %MMHg (the percent of THg present as MMHg) and compared to IHg in sediment, algae, and the food web. The estimated δ(202)Hg of MMHg prior to photodegradation (-1.29 to -1.07‰) was lower than that of IHg and we suggest this is due to mass-dependent fractionation (MDF) of up to -0.9‰ between IHg and MMHg. This result is in contrast to net positive MDF (+0.4 to +0.8‰) previously observed in lakes, estuaries, coastal oceans, and forests. We hypothesize that this unique relationship could be due to differences in the extent or pathway of biotic MMHg degradation in stream environments.

  9. The genetic differentiation of Colocasia esculenta growing in gold mining areas with arsenic contamination.

    Science.gov (United States)

    Boonmee, Sirilak; Neeratanaphan, Lamyai; Tanee, Tawatchai; Khamon, Prodpran

    2015-05-01

    Arsenic is a heavy metal found in contaminated gold mining areas and which can affect plant and animal species. This study aims to determine the concentration of As in the aquatic plant Colocasia esculenta as well as this plant's genetic variability. Sediment and C. esculenta samples were collected from three studied sites at the edge of a stream around a gold mine. The arsenic concentrations in sediment and C. esculenta samples were analyzed using induction coupled plasma-mass spectrometry (ICP-MS). Genetic differentiations were studied by random amplified polymorphic DNA (RAPD) with dendrogram construction and analysis of genetic similarity (S). The results showed that the arsenic concentrations in sediment and C. esculenta samples ranged from 4.547 ± 0.318 to 229.964 ± 0.978 and 0.108 ± 0.046 to 0.406 ± 0.174 mg kg(-1), respectively. To compare the samples studied to the reference site, RAPD fingerprints from 26 primers successfully produced 2301 total bands used for dendrogram construction and S value analysis. The dendrogram construction separates C. esculenta into four clusters corresponding to their sampling sites. The S values of the studied sample sites compared to the reference site are 0.676-0.779, 0.739-0.791, and 0.743-0.783 for sites 1, 2, and 3, respectively, whereas the values of the individuals within each site are as high as 0.980. These results suggest that As accumulation in aquatic plant species should be of concern because of the potential effects of As on aquatic plants as well as humans.

  10. Metal and fluid sources in a potential world-class gold deposit: El-Sid mine, Egypt

    Science.gov (United States)

    Helmy, Hassan; Zoheir, Basem

    2015-04-01

    Lode gold mineralization at the El-Sid mine area is associated with the ca. 600 Ma Fawakhir granite intrusion, which cuts the ~737 Ma ophiolite nappes in the Central Eastern Desert of Egypt. The mineralized quartz veins are hosted by ~E- and NE-trending fault/fracture sets cutting the western boundary of the intrusion and sheared ophiolites. The results of electron microprobe analyses of gold-associated hydrothermal sulfide and silicate minerals suggest that Au was mobilized alongside Ni, Co, Cr and As from the adjacent ophiolitic serpentinite. After granite emplacement, hydrothermal fluids interacted with the sheared serpentinite, leaching metals and re-depositing them in the faults/fractures and adjacent wall rock in a cyclic process. Low-salinity aqueous-carbonic fluids with significant quantities of volatile species (CO2, CH4, and N2 ± H2S) leached and transported Au from deep to shallow crustal levels. Carbon dioxide had a buffering effect on the Au-bearing hydrothermal solution, maintaining its pH within a narrow near-neutral range, where elevated gold concentration was transported by complexation with reduced magmatic sulfur in a reducing environment. Gold deposition along fault/fracture conduits in the Fawakhir granite and adjacent serpentinite resulted from interplay of pressure drop, fluctuations in oxygen and sulfur fugacities, and exsolution of the volatile phases. Infiltration of meteoric water may have contributed to the formation of the late stage gold-sulfide mineralization that formed at shallower levels during terrane uplift. Sulfidation of the Fe-rich magmatic minerals was, on the other hand, the overriding process in the wall rock as evidenced by abundant disseminated sulfides with gold inclusions. Considering the structural control by regional shear zones (fluid conduits) and the voluminous granitic and ophiolitic rocks (metal sources), a high tonnage gold deposit amenable to open pit mining at the El-Sid mine area is very likely.

  11. Seismic moment tensor resolution on a local scale: Simulated rockburst and mine-induced seismic events in the Kopanang gold mine, South Africa

    CSIR Research Space (South Africa)

    Sileny, J

    2006-08-01

    Full Text Available modelled as an isotropic explosive source. At regional distances, this inversion experiment has been performed with seismic records of a calibration blast, detonated on November 11, 1999 in the Dead Sea (S? ?LENY? and HOFSTETTER, 2002). The aim... rockburst?a blasting experiment carried out in a deep-level gold mine?was performed within a rock mass. Thus, this experiment was much more suitable for testing the resolvability of the individual source components. Several mine-induced seismic events...

  12. Mercury and Cyanide Contaminations in Gold Mine Environment and Possible Solution of Cleaning Up by Using Phytoextraction

    Directory of Open Access Journals (Sweden)

    NURIL HIDAYATI

    2009-09-01

    Full Text Available Water contamination with heavy metals, mainly mercury and cyanide (CN due to small scale of public mines and large scale of industrial mines have been in concern to residents around the area. Surveys of heavy metal contamination in aquatic environments, such as rivers and paddy fields over two gold mine areas in West Jawa were conducted and possible solution of using indigenous plants for phytoremediation was studied. The results showed that most of the rivers and other aquatic environments were affected by gold mine activities. Rivers, ponds, and paddy fields around illegal public mines were mostly contaminated by mercury in considerably high levels, such as paddy fields in two locations (Nunggul and Leuwijamang, Pongkor were contaminated up to 22.68 and 7.73 ppm of Hg, respectively. Whereas rivers located around large scale industrial mines were contaminated by CN. Possible solution of cleaning up by using green technology of phytoremediation was examined. Some plant species grew in the contaminated sites showed high tolerance and potentially effective in accumulating cyanide or mercury in their roots and above ground portions. Lindernia crustacea (L. F.M., Digitaria radicosa (Presl Miq, Paspalum conjugatum, Cyperus kyllingia accumulated 89.13, 50.93, 1.78, and 0.77 ppm of Hg, respectively. Whereas, Paspalum conjugatum, Cyperus kyllingia accumulated 16.52 and 33. 16 ppm of CN respectively.

  13. STUDY OF A FAULT DIAGNOSIS EXPERT SYSTEM FOR SYNTHETIC MINING SYSTEM HYDRAULIC SUPPORT

    Institute of Scientific and Technical Information of China (English)

    Han Yilun

    2000-01-01

    Fault diagnosis expert system for hydraulic support is studied.The system is achieved by Turbo-prolong Language, it summaries the experience of the domain expert and sets up a fault tree, knowledge base is developed by a productive rule.According to the feature of diagnosis, the system selects forward non-determination inferring and limited depth-first search strategy.It can accomplish expert diagnosis of more than 50 kinds faults in hydraulic support.

  14. Ardrea characterisation of acidophilic micro-organisms isolated from gold mines in Marmato, Colombia

    Directory of Open Access Journals (Sweden)

    Edna Judith Márquez F.

    2008-02-01

    Full Text Available Mineral bio-oxidation improves the extraction of valuable metals and also decreases the impact caused by mining waste; however, the interactions between the micro-organisms so involved are little known. Double-layer solid culture media techniques and amplified ribosomal DNA restriction enzyme analysis (Ardrea, using Eco72I, Eco24I, XcmI and BsaAI enzymes, were used for characterising four micro-organisms isolated from gold mines located in Marmato, Colombia. This work was aimed at better understanding of native acidophilic micro-organisms’ microbial interactions in mixed cultures. Iron and sulphur oxidising isolates revealed similar restriction patterns to those previously reported for Acidithiobacillus ferrooxidans; however, one of them exhibited different colony morphology compared to previously reported morphology. The iron non-oxidising isolate presented a restriction pattern agreeing with theoretical analysis of Acidithiobacillus thiooxidans database sequences. ARDREA proved to be a viable technique for differentiating between At. ferrooxidans and At. thiooxidans; in turn, it enabled checking isolates’ identity with their physiological traits and colony morphology.

  15. Injury Risk Factors in a Small-Scale Gold Mining Community in Ghana's Upper East Region.

    Science.gov (United States)

    Long, Rachel N; Sun, Kan; Neitzel, Richard L

    2015-08-01

    Occupational injury is one of many health concerns related to small-scale gold mining (ASGM), but few data exist on the subject, especially in sub-Saharan Africa. In 2011 and 2013, we examined accidents, injuries, and potential risk factors in a Ghanaian ASGM community. In 2011, 173 participants were surveyed on occupational history and health, and 22 of these were surveyed again in 2013. Injury rates were estimated at 45.5 and 38.5 injuries per 100 person-years in 2011 and in 2013, respectively; these rates far surpass those of industrialized mines in the U.S. and South Africa. Demographic and job characteristics generally were not predictive of injury risk, though there was a significant positive association with injury risk for males and smokers. Legs and knees were the most common body parts injured, and falling was the most common cause of injury. The most common type of injuries were cuts or lacerations, burns and scalds, and contusions and abrasions. Only two miners had ever received any occupational safety training, and PPE use was low. Our results suggest that injuries should be a priority area for occupational health research in ASGM.

  16. A MCDM Analysis of the Roşia Montană Gold Mining Project

    Directory of Open Access Journals (Sweden)

    Adriana Mihai

    2015-06-01

    Full Text Available The need and estimated utility for a structured analysis of the Roşia Montană gold exploitation project have been palpable in the Romanian public sphere during the last 15 years and there is a vast amount of conflicting information and opinions on the benefits and risks involved. This article provides a comprehensive decision analysis of the Roşia Montană project. Over 100 documents from the past years have been gathered regarding the Roşia Montană mining project, which cover the main official, formal and less formal documents covering the case and produced by a wide range of stakeholders. These were then analyzed while designing a multi-criteria tree including the relevant perspectives under which the most commonly discussed four alternatives were analyzed. The result of this can be translated into a valuable recommendation for the mining company and for the political decision-makers. If these stakeholders want the continuation of the project and its acceptance by civil society, the key challenge is to increase the transparency of the process and improve the credibility and legal aspects; if these aspects cannot be met, the decision-makers need to pay attention to the alternatives available for a sustainable development in the area.

  17. GOLD MINING IN IGUN IJESHA, SOUTHWEST NIGERIA: IMPACTS AND IMPLICATIONS FOR WATER QUALITY

    Directory of Open Access Journals (Sweden)

    O. O. Ayantobo

    2014-01-01

    Full Text Available This study was carried out in Igun-Ijesha, Osun State, Nigeria to determine the likely hotspots of water contamination for future treatment trials. Water quality analyses were based on physico-chemical and heavy metal parameters of surface and ground water collected from the study community. A total of thirty-eight water samples were collected between September 2012 and February 2013 and analyzed using standard procedures. Concentrations of heavy metals were determined using Atomic Absorption Spectrophotometer. Results showed that water samples within the gold mining community are contaminated and the hydrochemistry varied with seasons. The values of magnesium, turbidity, total dissolved solids, electrical conductivity and pH during the period of sampling ranged 3.1-42.1 mg/L, 0-150 NTU, 30-560 mg/L, 80-1192 µS/cm and 5.95-8.55 respectively. Chloride, nitrate, phosphate, sulphate and sodium data were within the stipulated limits set by the Nigerian Standards for Drinking Water Quality (NSDWQ. Heavy metal contents of the groundwater were generally higher than those from surface water sampled within the mining district. The values of arsenic, cadmium, chromium, copper, lead, manganese, nickel and zinc, ranged from 0.01-1.20, 0.05-0.52, 0.80-34.80, 0.09-4.30, 0.09-8.30, 0.05-3.94, 0.05-19.6 and 1.80-29.90 mg/L respectively. Most of these metals have values exceeding the international and national recommended limits. The daily intake of water in the study area poses a potential health threat from long-term exposure to heavy-metals. The study suggests that water safety plans should be developed to safeguard water resource and public health within the mining community.

  18. Review of samples of sediment, tailings, and waters adjacent to the Cactus Queen gold mine, Kern County, California

    Science.gov (United States)

    Rytuba, James J.; Kim, Christopher S.; Goldstein, Daniel N.

    2011-01-01

    The Cactus Queen Mine is located in the western Mojave Desert in Kern County, California. The Cactus Queen gold-silver (Au-Ag) deposit is similar to other Au-Ag deposits hosted in Miocene volcanic rocks that consist of silicic domes and associated flows, pyroclastic rocks, and subvolcanic intrusions. The volcanic rocks were emplaced onto a basement of Mesozoic silicic intrusive rocks. A part of the Cactus Queen Mine is located on Federal land managed by the U.S. Bureau of Land Management (BLM). Staff from the BLM initially sampled the mine area and documented elevated concentrations of arsenic (As) in tailings and sediment. BLM then requested that the U.S. Geological Survey (USGS), in collaboration with Chapman University, measure and characterize As and other geochemical constituents in sediment, tailings, and waters on the part of the mine on Federal lands. This report is made in response to the request by the BLM, the lead agency mandated to conduct a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) - Removal Site Investigation (RSI). The RSI applies to the potential removal of As-contaminated mine waste from the Cactus Queen Mine as a means of reducing As release and exposure to humans and biota. This report summarizes data obtained from field sampling of sediments, mine tailings, and surface waters at the Cactus Queen Mine on January 27, 2008. Our results provide a preliminary assessment of the sources of As and associated chemical constituents that could potentially impact humans and biota.

  19. Implementation of state-of-art mining knowledge and technologies in design and operation of a safe and efficient deep gold mine stope for 21st Century.

    CSIR Research Space (South Africa)

    Van der Merwe, JN

    2001-02-01

    Full Text Available than 15 m face advance per month, dilution and gold losses reduced by 15 % compared to adjacent stoping, consistent provision of recommended environmental conditions and finally cost effectiveness. The main areas of concern with current mining... and enhance advance per blast. • Water jet assisted scraper face cleaning. Assists with preliminary barring and dust suppression. • Gully shoulder support – constant yield force, low mass reinforced concrete packs or Fill-packs in backfilled stopes. 5...

  20. High levels of activity of bats at gold mining water bodies: implications for compliance with the International Cyanide Management Code.

    Science.gov (United States)

    Griffiths, Stephen R; Donato, David B; Coulson, Graeme; Lumsden, Linda F

    2014-06-01

    Wildlife and livestock are known to visit and interact with tailings dam and other wastewater impoundments at gold mines. When cyanide concentrations within these water bodies exceed a critical toxicity threshold, significant cyanide-related mortality events can occur in wildlife. Highly mobile taxa such as birds are particularly susceptible to cyanide toxicosis. Nocturnally active bats have similar access to uncovered wastewater impoundments as birds; however, cyanide toxicosis risks to bats remain ambiguous. This study investigated activity of bats in the airspace above two water bodies at an Australian gold mine, to assess the extent to which bats use these water bodies and hence are at potential risk of exposure to cyanide. Bat activity was present on most nights sampled during the 16-month survey period, although it was highly variable across nights and months. Therefore, despite the artificial nature of wastewater impoundments at gold mines, these structures present attractive habitats to bats. As tailings slurry and supernatant pooling within the tailings dam were consistently well below the industry protective concentration limit of 50 mg/L weak acid dissociable (WAD) cyanide, wastewater solutions stored within the tailings dam posed a minimal risk of cyanide toxicosis for wildlife, including bats. This study showed that passively recorded bat echolocation call data provides evidence of the presence and relative activity of bats above water bodies at mine sites. Furthermore, echolocation buzz calls recorded in the airspace directly above water provide indirect evidence of foraging and/or drinking. Both echolocation monitoring and systematic sampling of cyanide concentration in open wastewater impoundments can be incorporated into a gold mine risk-assessment model in order to evaluate the risk of bat exposure to cyanide. In relation to risk minimisation management practices, the most effective mechanism for preventing cyanide toxicosis to wildlife

  1. Environmental Impact of Electricity Consumption in Crushing and Grinding Processes of Traditional and Urban Gold Mining by Using Life Cycle Assessment (LCA)

    OpenAIRE

    Nur Rafidah Yahaya; Marfaiza Murad; Norhashimah Morad; Fera Fizani Ahmad Fizri

    2012-01-01

    Mining is not only an essential component of social and economic development since prehistoric time, but it also gives a large impact on our civilization. Gold is a noble metal that is highly valued. The extraction of minerals from earth is known as traditional mining. Gold also can be extracted from electronic waste or e-waste, and this new concept is called urban mining. There are many stages in traditional and urban mining process. However, in this study, the focus was on crushing and grin...

  2. Exploiting Stable Mercury Isotopic Analysis to Differentiate between Mercury Sources: Gold Mining vs. Land-Use Change (Invited)

    Science.gov (United States)

    Bergquist, B. A.; Adler Miserendino, R. A.; Guimarães, J. R.; Veiga, M.; Velasquez-López, P.; Lees, P. S.; Thibodeau, A. M.; Fernandez, L. E.

    2013-12-01

    In parts of the developing world, mercury (Hg) is used to extract gold by amalgamation during artisanal and small-scale gold mining (ASGM) and this can lead to contamination of downstream aquatic ecosystems. Differentiation between Hg from ASGM and from other sources of Hg, such as increased erosion from land cover and land use change (LCLUC), is challenging and has lead to heated debates over the dominant sources of elevated Hg in some ecosystems. Here, stable Hg isotopic analysis was applied in two aquatic ecosystems in South America: (1) the Amazonian aquatic ecosystem of Amapá, Brazil downstream of artisanal gold mining (AGM) and (2) the Puyango-Tumbes River ecosystem downstream of Portovelo-Zaruma, Ecuador, a large mining area where both AGM and small-scale gold mining (SGM) are in operation. The Hg isotopic analyses from Amapá, Brazil, do not support AGM as the source of elevated Hg in the downstream aquatic ecosystem. Instead, Hg isotopes are most consistent with the elevated Hg being from preferential migration of Hg from soil erosion, which is likely associated with land use change. Although soils are regarded as Hg sinks in the global Hg cycle, this work suggests that LCLUC can disrupt Hg stores with significant ecological consequences. In contrast in the Southwestern Andean region of Ecuador and Peru, analysis of Hg isotopes and other toxic metals (i.e., Pb, Zn, Cu), which are associated with the larger scale mining and cyanide used during SGM, demonstrate Hg used during gold mining is the predominant source of Hg downstream and can be traced far from the dominant mining area. Although it has been speculated that Hg from SGM in Ecuador was not that mobile or that Hg far downstream of SGM processing plants was from erosion due to LCLUC or from AGM taking place downstream, the isotopically heavy signature of Hg used during gold mining and elevated other metal concentrations were observed ~120 km downstream of Portovelo-Zaruma. Mercury isotopes appear

  3. Determining the radon exhalation rate from a gold mine tailings dump by measuring the gamma radiation.

    Science.gov (United States)

    Ongori, Joash N; Lindsay, Robert; Newman, Richard T; Maleka, Peane P

    2015-02-01

    The mining activities taking place in Gauteng province, South Africa have caused millions of tons of rocks to be taken from underground to be milled and processed to extract gold. The uranium bearing tailings are placed in an estimated 250 dumps covering a total area of about 7000 ha. These tailings dumps contain considerable amounts of radium and have therefore been identified as large sources of radon. The size of these dumps make traditional radon exhalation measurements time consuming and it is difficult to get representative measurements for the whole dump. In this work radon exhalation measurements from the non-operational Kloof mine dump have been performed by measuring the gamma radiation from the dump fairly accurately over an area of more than 1 km(2). Radon exhalation from the mine dump have been inferred from this by laboratory-based and in-situ gamma measurements. Thirty four soil samples were collected at depths of 30 cm and 50 cm. The weighted average activity concentrations in the soil samples were 308 ± 7 Bq kg(-1), 255 ± 5 Bq kg(-1) and 18 ± 1 Bq kg(-1) for (238)U, (40)K and (232)Th, respectively. The MEDUSA (Multi-Element Detector for Underwater Sediment Activity) γ-ray detection system was used for field measurements. The radium concentrations were then used with soil parameters to obtain the radon flux using different approaches such as the IAEA (International Atomic Energy Agency) formula. Another technique the MEDUSA Laboratory Technique (MELT) was developed to map radon exhalation based on (1) recognising that radon exhalation does not affect (40)K and (232)Th activity concentrations and (2) that the ratio of the activity concentration of the field (MEDUSA) to the laboratory (HPGe) for (238)U and (40)K or (238)U and (232)Th will give a measure of the radon exhalation at a particular location in the dump. The average, normalised radon flux was found to be 0.12 ± 0.02 Bq m(-2) s(-1) for the mine dump.

  4. Mercury pollution from the artisanal mining in Yani gold district, Northern Bolivia

    Science.gov (United States)

    Alfonso, Pura; Freixas, Anna; Bascompta, Marc; María Aranibar, Ana; Villegas, Karla; María García-Noguero, Eva; Higueras, Pablo; Cielito Saraiva, Angela

    2016-04-01

    Artisanal gold mining is the main economic activity in the Yani district, Northern Bolivia. In this area abundant orogenic gold deposits constituted by quartz veins hosted in paleozoic turbiditic series that contain either free gold or associated with pyrite. Gold is recovered in processing plants by gravimetric methods using shaking tables in several communities of this district. Previously, miners ground the mineral in ball mills together with mercury. The present study aims to evaluate the effect of mercury used in the gold recovering process to the environment and human health in the Yani district. The assessment was based on the analysis of human hair, sediments and water from the river nearby the processing plant and drinking water from the fountain that supplies these communities. 47 samples of hair from miners and other people from the Yani and Señor de Mayo communities were obtained in 2014 and 52 samples in 2015. All were analysed to evaluate the mercury exposure in these places. The results from the 2014 sampling show a wide range of Hg concentration in hair, especially in Señor de Mayo, with values up to 136 μg/g THg. However, in 2015 among the 43 residents in Señor de Mayo, 29 (67%) exhibit concentrations higher than 2 μg/g THg, with an average value of 5.36 μg/g THg. On the other hand, in Yani only 40% have concentrations above 2 μg/g THg, with an average value of 2.34 μg/g THg. The content in Hg in most of the hair samples exhibit values above the tolerable limits established by the US Environmental Protection Agency (1 μg/g Hg) and the World Health Organisation (WHO, 2 μg/g Hg). These high Hg concentrations are found not only in miners but also in the other members of the community, in spite of low fish consumption in this area. Part of the hair was analysed before and after cleaning. Usually in the second case the content of Hg is reduced, but still show high Hg levels, then probably the atmosphere is polluted with Hg and population is

  5. The effect of gold mining and processing on biogeochemical cycles in Muteh area, Isfahan province, Iran

    Science.gov (United States)

    Keshavarzi, B.; Moore, F.

    2009-04-01

    The environmental impacts of gold mining and processing on geochemical and biogeochemical cycles in Muteh region located northwest of Esfahan province and northeast of Golpaygan city is investigated. For this purpose systematic sampling was carried out in, rock, soil, water, and sediment environments along with plant, livestocks and human hair samples. Mineralogical and Petrological studies show that ore mineral such as pyrite and arsenopyrite along with fluorine-bearing minerals like tremolite, actinolite, biotite and muscovite occur in green schist, amphibolite and lucogranitic rocks in the area. The hydrochemistry of the analysed water samples indicate that As and F display the highest concentrations among the analysed elements. Indeed arsenic has the highest concentration in both topsoil and subsoil samples when compared with other potentially toxic elements. Anthropogenic activity also have it s greatest effect on increasing arsenic concentration among the analysed samples. The concentration of the majority of the analysed elements in the shoots and leaves of two local plants of the region i.e Artemesia and Penagum is higher than their concentration in the roots. Generally speaking, Artemesia has a greater tendency for bioaccumulating heavy metals. The results of cyanide analysis in soil samples show that cyanide concentration in the soils near the newly built tailing dam is much higher than that in the vicinity of the old tailing dam. The high concentration of fluorine in the drinking water of the Muteh village is the main reason of the observed dental fluorosis symptoms seen in the inhabitants. One of the two drinking water wells which is located near the metamorphic complex and supplies part of the tap water in the village, probably has the greatest impact in this regard. A decreasing trend in fluorine concentration is illustrated with increasing distance from the metamorphic complex. Measurements of As concentration in human hair specimens indicate that As

  6. Historical and Present Day Mercury Contamination From Gold Mining in Three Feeding Guilds of Bats From the Peruvian Amazon

    Science.gov (United States)

    Kumar, A.; Divoll, T.

    2014-12-01

    Miners in many countries use mercury as an amalgam to separate gold from river sediments. In the last twenty years the price of gold has risen and the number of small-scale, artisanal gold mining operations in the Amazon basin have also increased. The influx of mercury into natural river systems has detrimental consequences for the surrounding ecosystem and for organisms, particularly those at higher trophic levels. Toxic mercury levels have been shown to impair reproductive, neurological and behavioral functioning of organisms. I used bats (Chiroptera) as a mammalian model system to study mercury contamination and accumulation due to gold mining from field caught and museum collection specimens in Amazonian Perú and showed that: (1) Total mercury concentrations in Amazonian bat species have increased over time since the 1920's; (2) Bat species from sites with current active mining have higher concentrations of mercury than non-mining sites, with some species having levels exceeding those considered toxic for mammals; (3) Higher trophic levels of bats (piscivores and insectivores) bioaccumulate more mercury than bats of lower trophic levels (frugivores); (4) Bats located in present day uncontaminated sites have the same mercury levels as bats collected in the 1920's from the Amazon basin. The variety of bat feeding guilds allowed for a comparison of how mercury accumulation is affected by diet within one taxonomic order. The novel use of museum specimens allowed for a look back into the historical timeline of mercury contamination in the Amazon basin. Bats represent a new and exciting study system since, like humans, they are mammals and should therefore show similar neurochemical and behavioral responses to this toxic element.

  7. Enduring legacy of a toxic fan via episodic redistribution of California gold mining debris.

    Science.gov (United States)

    Singer, Michael Bliss; Aalto, Rolf; James, L Allan; Kilham, Nina E; Higson, John L; Ghoshal, Subhajit

    2013-11-12

    The interrelationships between hydrologically driven evolution of legacy landscapes downstream of major mining districts and the contamination of lowland ecosystems are poorly understood over centennial time scales. Here, we demonstrate within piedmont valleys of California's Sierra Nevada, through new and historical data supported by modeling, that anthropogenic fans produced by 19th century gold mining comprise an episodically persistent source of sediment-adsorbed Hg to lowlands. Within the enormous, iconic Yuba Fan, we highlight (i) an apparent shift in the relative processes of fan evolution from gradual vertical channel entrenchment to punctuated lateral erosion of fan terraces, thus enabling entrainment of large volumes of Hg-laden sediment during individual floods, and (ii) systematic intrafan redistribution and downstream progradation of fan sediment into the Central Valley, triggered by terrace erosion during increasingly long, 10-y flood events. Each major flood apparently erodes stored sediment and delivers to sensitive lowlands the equivalent of ~10-30% of the entire postmining Sierran Hg mass so far conveyed to the San Francisco Bay-Delta (SFBD). This process of protracted but episodic erosion of legacy sediment and associated Hg is likely to persist for >10(4) y. It creates, within an immense swath of river corridor well upstream of the SFBD, new contaminated floodplain surfaces primed for Hg methylation and augments/replenishes potential Hg sources to the SFBD. Anticipation, prediction, and management of toxic sediment delivery, and corresponding risks to lowland ecology and human society globally, depend on the morphodynamic stage of anthropogenic fan evolution, synergistically coupled to changing frequency of and duration extreme floods.

  8. Hypersalinity reduces the risk of cyanide toxicosis to insectivorous bats interacting with wastewater impoundments at gold mines.

    Science.gov (United States)

    Griffiths, Stephen R; Donato, David B; Lumsden, Linda F; Coulson, Graeme

    2014-01-01

    Wildlife and livestock that ingest bioavailable cyanide compounds in gold mining tailings dams are known to experience cyanide toxicosis. Elevated levels of salinity in open impoundments have been shown to prevent wildlife cyanide toxicosis by reducing drinking and foraging. This finding appears to be consistent for diurnal wildlife interacting with open impoundments, however the risks to nocturnal wildlife of cyanide exposure are unknown. We investigated the activity of insectivorous bats in the airspace above both fresh (potable to wildlife) and saline water bodies at two gold mines in the goldfields of Western Australian. During this study, cyanide-bearing solutions stored in open impoundments at both mine sites were hypersaline (range=57,000-295,000 mg/L total dissolved solids (TDS)), well above known physiological tolerance of any terrestrial vertebrate. Bats used the airspace above each water body monitored, but were more active at fresh than saline water bodies. In addition, considerably more terminal echolocation buzz calls were recorded in the airspace above fresh than saline water bodies at both mine sites. However, it was not possible to determine whether these buzz calls corresponded to foraging or drinking bouts. No drinking bouts were observed in 33 h of thermal video footage recorded at one hypersaline tailings dam, suggesting that this water is not used for drinking. There is no information on salinity tolerances of bats, but it could be assumed that bats would not tolerate salinity in drinking water at concentrations greater than those documented as toxic for saline-adapted terrestrial wildlife. Therefore, when managing wastewater impoundments at gold mines to avoid wildlife mortalities, adopting a precautionary principle, bats are unlikely to drink solutions at salinity levels ≥50,000 mg/L TDS. © 2013 Published by Elsevier Inc.

  9. The Kinematics Analysis of the Hydraulic Mine-clearing Mechanical Manipulator

    Institute of Scientific and Technical Information of China (English)

    XIE Qing-hua; DUAN Hong

    2005-01-01

    Through analyzing the kinematics of the hydraulic manipulator operating system, according to the rules for seting up the D-H coordinate system, the generalized coordinate of the manipulator system is established. The rotating and moving joints are selected from the mechanism as joint variables. Each generalized transformation matrix of joints is worked out. The kinematics equation at the finger end of the manipulator is calculated. The obverse solution for the manipulator is gained. The geometrical operating parameters and primary technical specification of the manipulator system are simulated through the computer. The simulative result has shown that the manipulator operating system meets the working task requirements. This research provides theoretical basis for optimizing structural parameters of the manipulator operating. So it also is justified the feasibility for mechanical manipulators to be used in the engineering equipment platform of the hydraulic excavator.

  10. Phytoextraction of trace elements by water hyacinth in contaminated area of gold mine tailing.

    Science.gov (United States)

    Romanova, Tamara E; Shuvaeva, Olga V; Belchenko, Ludmila A

    2016-01-01

    The ability of water hyacinth (Eichhornia crassipes) to uptake Ag, Ba, Cd, Mo, and Pb from waters in gold mine tailing area was studied. All experiments were carried out in the field conditions without using of model system. Bioconcentration (BCF) and translocation factors (TF) as well as elements accumulation by plant in different points of tailings-impacted area were evaluated. It has been shown that water hyacinth demonstrates high ability to accumulate Mo, Pb, and Ba with BCF values 24,360 ± 3600, 18,800 ± 2800 and 10,040 ± 1400, respectively and is efficient in translocation of Mo and Cd. The general trend of the plant accumulation ability in relation to the studied elements corresponds to their concentration in the medium. As the distance from tailings increases, concentration of Ag, Ba and Pb in plant decreases more clearly than that of Cd, while the amount of Mo accumulated by plant doesn't drop significantly in accordance with its concentration in water. Under the conditions of the confluence of river Ur and drainage stream Ba and Ag can be considered as potential candidates for phytomining.

  11. Relationship between localization of gold mining areas and hair mercury levels in people from Bolivar, north of Colombia.

    Science.gov (United States)

    Olivero-Verbel, Jesús; Caballero-Gallardo, Karina; Marrugo Negrete, Jose; Negrete-Marrugo, José

    2011-12-01

    Mercury (Hg) is a heavy metal that, once in the environment, is bioaccumulated and biomagnified through food chain impacting ecosystems. The aim of this study was to evaluate total Hg (T-Hg) concentrations in individuals along Cauca and Magdalena Rivers in Colombia, where most gold mining activities take place. A total of 1,328 hair samples were collected and analyzed for T-Hg using atomic absorption spectroscopy. T-Hg concentrations ranged from 0.01 to 20.14 μg/g. Greatest levels were detected in La Raya (5.27 ± 0.32 μg/g), Achi (2.44 ± 0.22 μg/g), and Montecristo (2.20 ± 0.20 μg/g), places that are located near gold mines. Concentrations decreased with the distance from main mining areas. Only 0.75% of the individuals had T-Hg levels above 10 μg/g. Men had significantly higher T-Hg levels than women, and correlation analysis revealed moderately weak but significant relationships between T-Hg and weight (R = 0.111, P mining, monitoring, and educational programs are necessary to protect health of people living near Colombian rivers.

  12. Cyanide hazards to plants and animals from gold mining and related water issues.

    Science.gov (United States)

    Eisler, Ronald; Wiemeyer, Stanley N

    2004-01-01

    Cyanide extraction of gold through milling of high-grade ores and heap leaching of low-grade ores requires cycling of millions of liters of alkaline water containing high concentrations of potentially toxic sodium cyanide (NaCN), free cyanide, and metal-cyanide complexes. Some milling operations result in tailings ponds of 150 ha and larger. Heap leach operations that spray or drip cyanide onto the flattened top of the ore heap require solution processing ponds of about 1 ha in surface area. Puddles of various sizes may occur on the top of heaps, where the highest concentrations of NaCN are found. Solution recovery channels are usually constructed at the base of leach heaps, some of which may be exposed. All these cyanide-containing water bodies are hazardous to wildlife, especially migratory waterfowl and bats, if not properly managed. Accidental spills of cyanide solutions into rivers and streams have produced massive kills of fish and other aquatic biota. Freshwater fish are the most cyanide-sensitive group of aquatic organisms tested, with high mortality documented at free cyanide concentrations >20 microg/L and adverse effects on swimming and reproduction at >5 microg/L. Exclusion from cyanide solutions or reductions of cyanide concentrations to nontoxic levels are the only certain methods of protecting terrestrial vertebrate wildlife from cyanide poisoning; a variety of exclusion/cyanide reduction techniques are presented and discussed. Additional research is recommended on (1) effects of low-level, long-term, cyanide intoxication in birds and mammals by oral and inhalation routes in the vicinity of high cyanide concentrations; (2) long-term effects of low concentrations of cyanide on aquatic biota; (3) adaptive resistance to cyanide; and (4) usefulness of various biochemical indicators of cyanide poisoning. To prevent flooding in mine open pits, and to enable earth moving on a large scale, it is often necessary to withdraw groundwater and use it for

  13. The Curse of the Gold: Discourses Surrounding the Project of the Largest Pit-mine in Europe

    Directory of Open Access Journals (Sweden)

    Istvan Egresi

    2011-11-01

    Full Text Available In 1996, a Canadian company started geological explorations in the Rosia Montana area in the Romanian Carpathians. Two years later it formed a joint-venture with a Romanian state company to exploit what is believed to be Europe´s largest gold reserves. However, as of June 2011 extraction has not started yet and it may never start due to the opposition of numerous NGO´s that have pointed out the environmental, social and economic unsustainability of this mining project. This situation is highly unusual for a country that is hungry for foreign investment especially since up until very recently the state had supported any project promising to revitalize its mining sector. This paper will investigate the changes in the discourses surrounding this mining project taking into consideration the effects of globalization and the effects of Romania´s EU membership after 2007.

  14. A First Nations-led social innovation: a moose, a gold mining company, and a policy window

    Directory of Open Access Journals (Sweden)

    Daniel D. P. McCarthy

    2014-12-01

    combined with several other factors, including: (1 the high price of gold; (2 a mining company seeking to demonstrate corporate social responsibility to repair its international reputation with indigenous peoples by supporting an innovative, local Indigenous-led initiative; and (3 a new policy context, including Supreme Court of Canada decisions and provisions in the updated Ontario Mining Act, that require meaningful consultation with indigenous peoples has led to the emergence of a indigenous peoples-led collaborative, social innovation. This policy window allowed for the formation of an unprecedented council of indigenous knowledge holders (elders and traditional practitioners to help inform mine restoration and practice as well as to foster the resurgence of traditional language and culture in local indigenous communities. Here, we document this unprecedented social change opportunity.

  15. Vertical hydraulic transport for deep sea mining: A study into flow assurance

    NARCIS (Netherlands)

    Van Wijk, J.M.

    2016-01-01

    Deep sea mining activities require excavation of material at the sea floor, transport of the material from the sea floor to the sea surface and processing of the material afterwards. One way to transport the material from the sea floor to sea surface is by means of a riser with centrifugal pump

  16. Vertical hydraulic transport for deep sea mining: A study into flow assurance

    NARCIS (Netherlands)

    Van Wijk, J.M.

    2016-01-01

    Deep sea mining activities require excavation of material at the sea floor, transport of the material from the sea floor to the sea surface and processing of the material afterwards. One way to transport the material from the sea floor to sea surface is by means of a riser with centrifugal pump boos

  17. Biochemical passive reactors for treatment of acid mine drainage: Effect of hydraulic retention time on changes in efficiency, composition of reactive mixture, and microbial activity.

    Science.gov (United States)

    Vasquez, Yaneth; Escobar, Maria C; Neculita, Carmen M; Arbeli, Ziv; Roldan, Fabio

    2016-06-01

    Biochemical passive treatment represents a promising option for the remediation of acid mine drainage. This study determined the effect of three hydraulic retention times (1, 2, and 4 days) on changes in system efficiency, reactive mixture, and microbial activity in bioreactors under upward flow conditions. Bioreactors were sacrificed in the weeks 8, 17 and 36, and the reactive mixture was sampled at the bottom, middle, and top layers. Physicochemical analyses were performed on reactive mixture post-treatment and correlated with sulfate-reducing bacteria and cellulolytic and dehydrogenase activity. All hydraulic retention times were efficient at increasing pH and alkalinity and removing sulfate (>60%) and metals (85-99% for Fe(2+) and 70-100% for Zn(2+)), except for Mn(2+). The longest hydraulic retention time (4 days) increased residual sulfides, deteriorated the quality of treated effluent and negatively impacted sulfate-reducing bacteria. Shortest hydraulic retention time (1 day) washed out biomass and increased input of dissolved oxygen in the reactors, leading to higher redox potential and decreasing metal removal efficiency. Concentrations of iron, zinc and metal sulfides were high in the bottom layer, especially with 2 day of hydraulic retention time. Sulfate-reducing bacteria, cellulolytic and dehydrogenase activity were higher in the middle layer at 4 days of hydraulic retention time. Hydraulic retention time had a strong influence on overall performance of passive reactors.

  18. Amazonian former gold mined soils as a source of methylmercury: evidence from a small scale watershed in French Guiana.

    Science.gov (United States)

    Guedron, Stephane; Grimaldi, Michel; Grimaldi, Catherine; Cossa, Daniel; Tisserand, Delphine; Charlet, Laurent

    2011-04-01

    Total mercury (HgT) and monomethylmercury (MMHg) were investigated in a tropical head watershed (1 km(2)) of French Guiana. The watershed includes a pristine area on the hill slopes and a former gold mined flat in the bottomland. Concentrations of dissolved and particulate HgT and MMHg were measured in rain, throughfall, soil water and at three points along the stream. Samples were taken in-between and during 14 storm events at the beginning and middle of the 2005 and 2006 rainy seasons. Dissolved and particulate HgT concentrations in the stream slightly increased downstream, while dissolved and particulate MMHg concentrations were low at the pristine sub-watershed outlet (median = 0.006 ng L(-1) and 1.84 ng g(-1), respectively) and sharply increased at the gold mined flat outlet (median = 0.056 ng L(-1) and 6.80 ng g(-1), respectively). Oxisols, which are dominant in the pristine area act as a sink of HgT and MMHg from rain and throughfall inputs. Hydromorphic soils in the flat are strongly contaminated with Hg (including Hg(0) droplets) and their structure has been disturbed by former gold-mining processes, leading to multiple stagnant water areas where biogeochemical conditions are favorable for methylation. In the former gold mined flat high dissolved MMHg concentrations (up to 0.8 ng L(-1)) were measured in puddles or suboxic soil pore waters, whereas high dissolved HgT concentrations were found in lower Eh conditions. Iron-reducing bacteria were suggested as the main methylators since highest concentrations for dissolved MMHg were associated with high dissolved ferrous iron concentrations. The connection between saturated areas and stagnant waters with the hydrographic network during rain events leads to the export of dissolved MMHg and HgT in stream waters, especially at the beginning of the rainy season. As both legal and illegal gold-mining continues to expand in French Guiana, an increase in dissolved and particulate MMHg emissions in the hydrographic

  19. Chemical Composition of the Tourmaline from Stratiform Tourmalinites of the Passagem de Mariana Gold Mine, Southeastern Quadrilátero Ferrífero (Minas Gerais, Brazil)

    OpenAIRE

    Gianna Maria Garda; Johann Hans Daniel Schorscher; Paulo Beljavskis; Marcos de Souza Mansueto; Margareth Sugano Navarro; Andrezza Alves Mota

    2009-01-01

    The Passagem de Mariana Mine in the southeastern part of the Quadrilátero Ferrífero, Minas Gerais, Brazil, is one ofthe oldest Brazilian gold mines. Gold is associated with stratiform tourmalinites and tourmaline-bearing quartz and carbonateveins and breccias. The highest gold contents (up to 200 g/t) have been recorded in the stratiform tourmalinites, whichbelong to the Batatal Formation (Caraça Group, Minas Supergroup). Three petrographic types of tourmaline have been defined and analyzed b...

  20. Microscopy and certification as tools for environmentally benign, mercury-free small-scale gold mining.

    Science.gov (United States)

    Hylander, Lars D; Plath, David

    2006-09-01

    Small-scale gold miners lose annually 500-700 tonnes of mercury when amalgamating gold with mercury and subsequent burning. So far, mercury-free alternatives have been demanding more skill, time, or capital investments and the interest from the miners to reduce the mercury emissions has been limited. Recent development of mercury free methods, an increasing mercury price, and increased awareness of health and environmental damages caused by mercury is changing the attitudes. This trend could be spurred by certification of gold with added value due to clean production methods. Our objectives are to present a method to distinguish gold recovered without using mercury or harmful chemicals such as cyanide. Thereby, this gold could be certified and thus obtain a higher market price. The method is based on inspection of the gold grain surfaces with a light microscope. This method separated natural gold grains from gold recovered by amalgamation or cyanidation. The method also demonstrated different characteristics of gold grains from different gold fields and a basis for a catalogue with photomicrographs of gold grains from different gold fields has been established and partly presented in this article. In conclusion, studies of gold grains with a light microscope and photo documentation is an inexpensive but reliable method to distinguish environment-friendly recovered gold, which could be used for certification to get a higher market price.

  1. Human health risk assessment of mercury vapor around artisanal small-scale gold mining area, Palu city, Central Sulawesi, Indonesia.

    Science.gov (United States)

    Nakazawa, Koyomi; Nagafuchi, Osamu; Kawakami, Tomonori; Inoue, Takanobu; Yokota, Kuriko; Serikawa, Yuka; Cyio, Basir; Elvince, Rosana

    2016-02-01

    Emissions of elemental mercury, Hg(0), from artisanal small-scale gold mining activities accounted for 37% of total global Hg(0) emissions in 2010. People who live near gold-mining areas may be exposed to high concentrations of Hg(0). Here, we assessed the human health risk due to Hg(0) exposure among residents of Palu city (Central Sulawesi Province, Indonesia). The area around the city has more than 60t of gold reserves, and the nearby Poboya area is the most active gold-mining site in Indonesia. Owing to its geography, the city experiences alternating land and sea breezes. Sampling was done over a period of 3 years (from 2010 Aug. to 2012 Dec.) intermittently with a passive sampler for Hg(0), a portable handheld mercury analyzer, and a mercury analyzer in four areas of the city and in the Poboya gold-processing area, as well as wind speeds and directions in one area of the city. The 24-h average concentration, wind speed, and wind direction data show that the ambient air in both the gold-processing area and the city was always covered by high concentration of mercury vapor. The Hg(0) concentration in the city was higher at night than in the daytime, owing to the effect of land breezes. These results indicate that the inhabitants of the city were always exposed to high concentrations of Hg(0). The average daytime point-sample Hg(0) concentrations in the city, as measured with a handheld mercury analyzer over 3 days in July 2011, ranged from 2096 to 3299ngm(-3). In comparison, the average daytime Hg(0) concentration in the Poboya gold-processing area was 12,782ngm(-3). All of these concentrations are substantially higher than the World Health Organization air-quality guideline for annual average Hg exposure (1000ngm(-3)). We used the point-sample concentrations to calculate hazard quotient ratios by means of a probabilistic risk assessment method. The results indicated that 93% of the sample population overall was at risk (hazard quotient ratio ≥1 and cut off at

  2. Occurrence, emission and ignition of combustible strata gases in Witwatersrand gold mines and Bushveld platinum mines, and means of ameliorating related ignition and explosion hazards, Part 1: literature and technical review.

    CSIR Research Space (South Africa)

    Cook, AP

    1998-10-01

    Full Text Available on different mines. Gold mines have more ignition related accidents, whereas the platinum mines have face outbursts during drilling, usually without ignition. The most common causes leading to gas accidents are changes to the ventilation, lack of testing... Plessis, 1998). It accumulates in raises and other high areas, layering in poor ventilation (Rowe, 1998), and this can lead to long tailing layers extending along the hangingwall. The pressure of gas pockets causes the face to break out (Marais, 1998...

  3. Experimental validation of a mine-wide continuous closure monitoring system as a decision making tool for gold mines.

    CSIR Research Space (South Africa)

    Malan, DF

    2003-03-01

    Full Text Available of a mine-wide continuous closure monitoring system. A RMT remote reading telltale system was modified to operate as a closure system and installed at Mponeng Mine. Unfortunately, this system did not succeed in collecting data from a large number...

  4. The future of European mining: What should our mining industry learn from the Skouries and Rosia Montana community gold conflicts

    Science.gov (United States)

    Hardy, Liam; Heller, Shaun; Faltyn, Rowan; Stefanaki, Anna; Economidou, Romina; Savin, Irina; Hood, Leo; Conway, Christopher

    2017-04-01

    The popular image of mining portrayed by media and by a majority of public opinion is a dominantly negative one. From worker's rights to environmental damages, disasters such as the Copiapó mine collapse (Chile), the acid mine drainage at Lousal (Portugal) and the Pb contamination of waters around the Tyndrum mines (Scotland) overshadow initiatives like the ICMM. Some companies receive little praise despite creating active community education and investment projects, while others simply build higher barbed wire fences and attempt to weather the protests, budgeting them into mine life assessments. This image problem, combined with the decentralised political segregation of Europe and the increased power of grass-roots protest initiatives (such as Antigold in Greece), has resulted in mining companies joining a long list of industries effected by the 'auto-protest' reaction in face of development, regardless of potential regional and national benefits, there is a pre-existing lack of trust in corporate and government powers to protect community interests. The poor management of existing licences is thus becoming a significant danger to future operations and the wider industry. Here we report on the Rosia Montana dispute (Romania) and the ongoing Skouries conflict (Greece). We then discuss how the European mining industry may need to significantly adapt its exploration and community engagement strategies to avoid future conflicts and, present a recent example of how effective suitably organised community engagement projects can be for local mining initiatives from Southern Portugal.

  5. Testing and modeling the influence of reclamation and control methods for reducing nonpoint mercury emissions associated with industrial open pit gold mines.

    Science.gov (United States)

    Miller, Matthieu B; Gustin, Mae S

    2013-06-01

    Industrial gold mining is a significant source of mercury (Hg) emission to the atmosphere. To investigate ways to reduce these emissions, reclamation and dust and mercury control methods used at open pit gold mining operations in Nevada were studied in a laboratory setting. Using this information along with field data, and building off previous work, total annual Hg emissions were estimated for two active gold mines in northern Nevada. Results showed that capping mining waste materials with a low-Hg substrate can reduce Hg emissions from 50 to nearly 100%. The spraying of typical dust control solutions often results in higher Hg emissions, especially as materials dry after application. The concentrated application of a dithiocarbamate Hg control reagent appears to reduce Hg emissions, but further testing mimicking the actual distribution of this chemical within an active leach solution is needed to make a more definitive assessment.

  6. Mathematical model of electric hydraulic and powered support control system at a plough mining face

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; HAN Xiao; SUN Jing-jing

    2008-01-01

    Given the actual working of a fully mechanized plough at a mining face, we have proposed a formula for running con-straints between powered supports and a coal plough under assumed geological conditions of the coal face and, on this basis, estab-lished an automatic control model of powered supports for the coal plough face. We introduced the working principle of the pow-ered support control system of the plough at the mining face. We established three advanced characteristics of this control system: response speed, reliability and easy maintenance of the system. As well, we briefly introduced, the principal function of primary and subordinate controllers and the realization of the communication system by a Single Bus. Ten controllers were constructed and tested in our laboratorium. The results show that the control model is practical and meets actual conditions. It provides a theoretical basis for designing a computer control system for a powered support system of a plough at a mining face.

  7. Characterization of hydraulic connections between mine shaft and caprock based on time series analysis of water level changes for the flooded Asse I salt mine in northern Germany

    Energy Technology Data Exchange (ETDEWEB)

    Brauchler, Ralf; Mettier, Ralph; Schulte, Peter [AF-Consult Switzerland AG, Baden (Switzerland); Fuehrboeter, Jens Fred [Bundesamt fuer Strahlenschutz, Salzgitter (Germany)

    2015-07-01

    In the context of safe enclosure of nuclear waste in salt formations, one of the main challenges is potential water inflow into the excavations. In this context, the hydraulic relationship between the abandoned Asse I salt mine and the salt dissolution network at the base of the caprock of the Asse salt structure in northern Germany is characterized by utilizing time series analysis of water level changes. The data base comprises a time series of water level measurements over eight years with a temporal resolution of 15 minutes (in general) and up to 2 minutes for specific intervals. The water level measurements were collected in the shaft of the flooded mine, which is filled with ground rock salt until a depth of 140 m, and a deep well, which is screened in 240 m depth at the salt dissolution zone at the base of the caprock. The distance between the well and the shaft is several hundred meters. Since the beginning of the continuous observations in the 1970s, the shaft has shown periodically abrupt declines of the water level of several meters occurring in intervals of approx. 8 to 10 years. The time series analysis consists of trend, Fourier-, autocorrelation and cross-correlation analysis. The analysis showed that during times with small water level changes the measured water level in the well and the shaft are positively correlated whereas during the abrupt water level drops in the shaft, the measured water levels between the shaft and the well are negatively correlated. A potential explanation for this behavior is that during times with small changes, the measured water levels in the well and in the shaft are influenced by the same external events with similar response times. In contrast, during the abrupt water level decline events in the shaft, a negatively correlated pressure signal is induced in the well, which supports the assumption of a direct hydraulic connection between the shaft and the well via flooded excavations and the salt dissolution network

  8. 中国金矿开采区环境汞污染%Review on Mercury Contamination in Gold Mining Areas of China

    Institute of Scientific and Technical Information of China (English)

    张刚; 王宁; 王艺; 艾建超; 肖才林; 许德玄

    2012-01-01

    Mercury(Hg)is the typical pollutant for the environment of gold environment areas.The homology between Au and Hg leads to high Hg content in the gold ores.With amalgamation as the main gold extraction method,the Hg contamination of gold mines of China is very serious.The distribution and mining,dressing and smelting of gold mines in China have been introduced and the reasons of Hg environmental pollution in the gold mine areas have been studied.Furthermore,the release of Hg in process of the Au extraction has been analyzed and the contaminations of the soil,water,air and organism in the mining area caused by Au mining have been summarized.Finally,environment management and restoration of the ecosystem of Hg pollution in the gold mine areas have been discussed.%汞是金矿区环境的特征污染物。金汞同源性导致金矿床一般汞含量偏高,且在以混汞法为代表的提金过程影响下,导致了中国金矿区严重的环境汞污染问题。本文介绍了中国金矿分布与开采及选冶概况,研究了导致金矿区环境汞污染的原因,分析了金矿石选冶过程中汞的释放,并综述了金矿开采所致矿区土壤、水体、大气、生物体中汞污染状况,最后讨论了金矿区汞污染环境管理与生态修复。

  9. Reducing Mercury Pollution from Artisanal and Small-Scale Gold Mining

    Science.gov (United States)

    To reduce airborne mercury emissions from these Gold Shops, EPA and the Argonne National Laboratory (ANL) have partnered to design a low cost, easily constructible technology called the Gold Shop Mercury Capture System (MCS).

  10. Arsenic speciation in arsenic-rich Brazilian soils from gold mining sites under anaerobic incubation

    Science.gov (United States)

    De Mello, J. W. V.; Talbott, J.L.; Scott, J.; Roy, W.R.; Stucki, J.W.

    2007-01-01

    Background. Arsenic speciation in environmental samples is essential for studying toxicity, mobility and bio-transformation of As in aquatic and terrestrial environments. Although the inorganic species As(III) and As(V) have been considered dominant in soils and sediments, organisms are able to metabolize inorganic forms of arsenic into organo-arsenic compounds. Arsenosugars and methylated As compounds can be found in terrestrial organisms, but they generally occur only as minor constituents. We investigated the dynamics of arsenic species under anaerobic conditions in soils surrounding gold mining areas from Minas Gerais State, Brazil to elucidate the arsenic biogeochemical cycle and water contamination mechanisms. Methods. Surface soil samples were collected at those sites, namely Paracatu Formation, Banded Iron Formation and Riacho dos Machados Sequence, and incubated in CaCl2 2.5 mmol L-1 suspensions under anaerobic conditions for 1, 28, 56 and 112 days. After that, suspensions were centrifuged and supernatants analyzed for soluble As species by IC-ICPMS and HPLC-ICPMS. Results. Easily exchangeable As was mainly arsenite, except when reducible manganese was present. Arsenate was mainly responsible for the increase in soluble arsenic due to the reductive dissolution of either iron or manganese in samples from the Paracatu Formation and Riacho dos Machados Sequence. On the other hand, organic species of As dominated in samples from the Banded Iron Formation during anaerobic incubation. Discussion. Results are contrary to the expectation that, in anaerobic environments, As release due to the reductive dissolution of Fe is followed by As(V) reduction to As(III). The occurrence of organo-arsenic species was also found to be significant to the dynamics of soluble arsenic, mainly in soils from the Banded Iron Formation (BIF), under our experimental conditions. Conclusions. In general, As(V) and organic As were the dominant species in solution, which is surprising

  11. Eliminating Cyanide, Reducing Heavy Metals, and Harvesting Gold from Mining Waste with Plants

    DEFF Research Database (Denmark)

    2001-01-01

    wastewater combines several benefits: cyanide is removed, plants are irrigated and fertilised. Heavy metals (including gold) are extracted by plants. Plants can be harvested and used, e.g., for energy production by burning. The ash of the plants is probaly rich in gold and a resource for further gold...

  12. Eliminating Cyanide, Reducing Heavy Metals, and Harvesting Gold from Mining Waste with Plants

    DEFF Research Database (Denmark)

    2001-01-01

    wastewater combines several benefits: cyanide is removed, plants are irrigated and fertilised. Heavy metals (including gold) are extracted by plants. Plants can be harvested and used, e.g., for energy production by burning. The ash of the plants is probaly rich in gold and a resource for further gold...

  13. Actinorhizal Alder Phytostabilization Alters Microbial Community Dynamics in Gold Mine Waste Rock from Northern Quebec: A Greenhouse Study

    Science.gov (United States)

    Callender, Katrina L.; Roy, Sébastien; Khasa, Damase P.; Whyte, Lyle G.; Greer, Charles W.

    2016-01-01

    Phytotechnologies are rapidly replacing conventional ex-situ remediation techniques as they have the added benefit of restoring aesthetic value, important in the reclamation of mine sites. Alders are pioneer species that can tolerate and proliferate in nutrient-poor, contaminated environments, largely due to symbiotic root associations with the N2-fixing bacteria, Frankia and ectomycorrhizal (ECM) fungi. In this study, we investigated the growth of two Frankia-inoculated (actinorhizal) alder species, A. crispa and A. glutinosa, in gold mine waste rock from northern Quebec. Alder species had similar survival rates and positively impacted soil quality and physico-chemical properties in similar ways, restoring soil pH to neutrality and reducing extractable metals up to two-fold, while not hyperaccumulating them into above-ground plant biomass. A. glutinosa outperformed A. crispa in terms of growth, as estimated by the seedling volume index (SVI), and root length. Pyrosequencing of the bacterial 16S rRNA gene for bacteria and the ribosomal internal transcribed spacer (ITS) region for fungi provided a comprehensive, direct characterization of microbial communities in gold mine waste rock and fine tailings. Plant- and treatment-specific shifts in soil microbial community compositions were observed in planted mine residues. Shannon diversity and the abundance of microbes involved in key ecosystem processes such as contaminant degradation (Sphingomonas, Sphingobium and Pseudomonas), metal sequestration (Brevundimonas and Caulobacter) and N2-fixation (Azotobacter, Mesorhizobium, Rhizobium and Pseudomonas) increased over time, i.e., as plants established in mine waste rock. Acetate mineralization and most probable number (MPN) assays showed that revegetation positively stimulated both bulk and rhizosphere communities, increasing microbial density (biomass increase of 2 orders of magnitude) and mineralization (five-fold). Genomic techniques proved useful in investigating

  14. Actinorhizal Alder Phytostabilization Alters Microbial Community Dynamics in Gold Mine Waste Rock from Northern Quebec: A Greenhouse Study.

    Directory of Open Access Journals (Sweden)

    Katrina L Callender

    Full Text Available Phytotechnologies are rapidly replacing conventional ex-situ remediation techniques as they have the added benefit of restoring aesthetic value, important in the reclamation of mine sites. Alders are pioneer species that can tolerate and proliferate in nutrient-poor, contaminated environments, largely due to symbiotic root associations with the N2-fixing bacteria, Frankia and ectomycorrhizal (ECM fungi. In this study, we investigated the growth of two Frankia-inoculated (actinorhizal alder species, A. crispa and A. glutinosa, in gold mine waste rock from northern Quebec. Alder species had similar survival rates and positively impacted soil quality and physico-chemical properties in similar ways, restoring soil pH to neutrality and reducing extractable metals up to two-fold, while not hyperaccumulating them into above-ground plant biomass. A. glutinosa outperformed A. crispa in terms of growth, as estimated by the seedling volume index (SVI, and root length. Pyrosequencing of the bacterial 16S rRNA gene for bacteria and the ribosomal internal transcribed spacer (ITS region for fungi provided a comprehensive, direct characterization of microbial communities in gold mine waste rock and fine tailings. Plant- and treatment-specific shifts in soil microbial community compositions were observed in planted mine residues. Shannon diversity and the abundance of microbes involved in key ecosystem processes such as contaminant degradation (Sphingomonas, Sphingobium and Pseudomonas, metal sequestration (Brevundimonas and Caulobacter and N2-fixation (Azotobacter, Mesorhizobium, Rhizobium and Pseudomonas increased over time, i.e., as plants established in mine waste rock. Acetate mineralization and most probable number (MPN assays showed that revegetation positively stimulated both bulk and rhizosphere communities, increasing microbial density (biomass increase of 2 orders of magnitude and mineralization (five-fold. Genomic techniques proved useful in

  15. Abatement of mercury pollution in the small-scale gold mining industry: restructuring the policy and research agendas.

    Science.gov (United States)

    Hilson, Gavin

    2006-06-01

    This paper critiques contemporary research and policy approaches taken toward the analysis and abatement of mercury pollution in the small-scale gold mining sector. Unmonitored releases of mercury from gold amalgamation have caused considerable environmental contamination and human health complications in rural reaches of sub-Saharan Africa, Latin America and Asia. Whilst these problems have caught the attention of the scientific community over the past 15-20 years, the research that has since been undertaken has failed to identify appropriate mitigation measures, and has done little to advance understanding of why contamination persists. Moreover, the strategies used to educate operators about the impacts of acute mercury exposure, and the technologies implemented to prevent further pollution, have been marginally effective at best. The mercury pollution problem will not be resolved until governments and donor agencies commit to carrying out research aimed at improving understanding of the dynamics of small scale gold mining communities. Acquisition of this knowledge is the key to designing and implementing appropriate support and abatement measures.

  16. [Absorption of Hg in typical farmland soils in the Linglong gold mining area].

    Science.gov (United States)

    Wang, Fei; Wang, Ming; Tang, Jing-Chun; Zhang, Lei

    2011-09-01

    This study focused on the adsorption properties of Hg in 2 typical farmland soils in the Linglong gold mining area in Yantai area of China. The adsorption-desorption of Hg(II) research result showed higher adsorption of Hg in neutral soil with the value of 201.38 microg/g than that in acid soil with the value of 156.9 microg/g. The desorption of Hg in both soils was low with neutral soil showing a higher desorption ratio (13%) than acid soil (12%). Hg(II) adsorption isotherms were well fitted by Langmuir and Freundlich equation in the acid soil, with the correlation coefficient r value of 0.995 6 and 0.982 6, respectively. Langmuir equation can best describe Hg(II) adsorption isotherm in the neutral soil and acid soil, with the r value of 0.995 6 and 0.955 9, respectively. The adsorption was a bi-phasic process which started with a fast-adsorption phase and a slow-adsorption phase. The adsorption amount and rate of Hg in the fast reaction phase were much larger than that in the slow one. The adsorption kinetic can be better fitted by Elovich equation with correlation coefficient of 0.971 4 and 0.967 2, respectively. At pH 3.0 - 5.5, the equilibrium adsorption amount of Hg(II) increased with higher pH, and then decreased when the pH reached 6.5.

  17. Cover layers to the growth of trees and shrobs over a sulfide spoil from gold mining

    Directory of Open Access Journals (Sweden)

    Igor Rodrigues de Assis

    2011-08-01

    Full Text Available This work was done at a gold mine company in Paracatu, MG, Brazil, and was conducted from March 2000 to November 2005. The substrate (spoil studied was a phillite rock which contains sulfides such as pyrite and arsenopyrite. This study aimed to evaluate the survival and growth of plant species on different combinations of substrate layers over the spoil. These layers were a cover layer and a sealing layer, both deposited over the spoil. The treatment 1 had saprolite (B1 in the sealing layer (SL and B1 with liming (B1L in the cover layer (CL. The treatment 2 had B1 in SL and B1L + soil with liming (SoL in the CL. The treatment 3 had B1 + SoL in the SL and B1L in the CL. The treatment 4 had B1 + SoL in the SL and B1L + SoL in the CL. The plant species used were Acacia farnesiana, A. holosericea, A. polyphylla, Albizia lebbeck, Clitoria fairchildiana, Flemingia sp., Mimosa artemisiana, M. bimucronata e Enterolobium contortisiliquum. Forty and 57 months after planting, collardiameter, height, and living plants were evaluated. The greatest survival rate was oobservedintreatmentwith B horizon of an Oxisoil in both layers, with 80 %. In general, M. bimucronata and A. farnesiana species showed the highest survival rate. The arsenic-content by Mehlich 3 in the cover layer ranged from 0.00 to 14.69 mg dm- 3 among treatments. The experimental results suggest that layers combinations above the sulfide substrate allow the rapid revegetation of the spoil.

  18. Mercury contamination in fish from gold mining areas in Indonesia and human health risk assessment.

    Science.gov (United States)

    Castilhos, Zuleica C; Rodrigues-Filho, Saulo; Rodrigues, Ana Paula C; Villas-Bôas, Roberto C; Siegel, Shefa; Veiga, Marcello M; Beinhoff, Christian

    2006-09-01

    This study investigates the effects on fish and assesses human health hazards from mercury released in two gold mining areas in Indonesia: Tatelu (North Sulawesi Province) and Galangan (Katingan District, Central Kalimatan Province). In Tatelu, 154 fish specimens of 10 freshwater species were collected, as well as five marine species from the fish market. The mean concentration of total mercury in muscles of freshwater fish from this area was 0.58+/-0.44 microg/g, with more than 45% of fish having Hg levels above the WHO guideline for human consumption of 0.5 microg/g. In Galangan, where 263 fish specimens of 25 species were collected, the total mercury in muscles averaged 0.25+/-0.69 microg/g. Excluding data from flooded open pits in sub-area P4, mean Hg levels in fish from Galangan were 2 to 4 times lower than 0.5 microg/g, while fewer than 10% of fish from Galangan exceeded WHO guidelines. The Hazard Quotient (HQ) was applied to both areas to determine the threat of MeHg exposure for communities in both areas. The HQ is a risk assessment indicator which defines the ratio of exposure level to a single substance in relation to a reference dose. Samples from Tatelu (excluding marine species) had an HQ above one, while those from Galangan resulted in values of 2.4 for the whole area and 9.9 for sub-area P4, pointing to potentially harmful fish consumption for the local population. By using the single-compartment model to estimate mercury levels in blood and hair from daily intake dose, sub-area P4 showed the highest levels, higher than the upper limit guideline for pregnant women, but still lower than threshold levels associated with observed clinical effects.

  19. Heavy metals in the gold mine soil of the upstream area of a metropolitan drinking water source.

    Science.gov (United States)

    Ding, Huaijian; Ji, Hongbing; Tang, Lei; Zhang, Aixing; Guo, Xinyue; Li, Cai; Gao, Yang; Briki, Mergem

    2016-02-01

    Pinggu District is adjacent to the county of Miyun, which contains the largest drinking water source of Beijing (Miyun Reservoir). The Wanzhuang gold field and tailing deposits are located in Pinggu, threatening Beijing's drinking water security. In this study, soil samples were collected from the surface of the mining area and the tailings piles and analyzed for physical and chemical properties, as well as heavy metal contents and particle size fraction to study the relationship between degree of pollution degree and particle size. Most metal concentrations in the gold mine soil samples exceeded the background levels in Beijing. The spatial distribution of As, Cd, Cu, Pb, and Zn was the same, while that of Cr and Ni was relatively similar. Trace element concentrations increased in larger particles, decreased in the 50-74 μm size fraction, and were lowest in the pollution, but moderate to no Ni, Cr, and Hg pollution. The Tucker 3 model revealed three factors for particle fractions, metals, and samples. There were two factors in model A and three factors for both the metals and samples (models B and C, respectively). The potential ecological risk index shows that most of the study areas have very high potential ecological risk, a small portion has high potential ecological risk, and only a few sampling points on the perimeter have moderate ecological risk, with higher risk closer to the mining area.

  20. ANALYSIS OF SURFACE SINK OF EXPLORATION VACANCY IN GOLD MINING AREA OF ZHAOYUAN CTIY BASED ON RS AND GIS

    Institute of Scientific and Technical Information of China (English)

    WU Quan-yuan; AN Guo-qiang; BAO Wen-dong; ZHANG Zu-lu; XU Qiu-xiao; FANG Xue-mi

    2005-01-01

    Surface sink is a main geological calamity of gold mining areas and a main factor to restrict economic sustainable development of mining zone. Based on former investigations, this article draws the environment information of surface sink of exploration vacancy in gold mining area of Zhaoyuan City, Shangdong Province by RS technology. Through spatial simulation analysis and expert diagnoses on the basis of GIS technology, the article affirms the inducement factors of the surface sink. Then using these factors as distinguishing ones the authors prognosticate the criticality of other exploration vacancies. The results indicate that the surface sink area of study area in Zhaoyuan City, has already come to 0.78km2 and it is forecasted that 0.97km2 of the exploration vacancy belongs to high danger area. Decisive measures need taking in order to prevent this crucial problem. Another 1.57km2 of the exploration vacancies belongs to middle danger area, which will sink when meeting some inducing factors, such as earthquake. Still another 1.53kmn2 of the exploration vacancies belongs to low danger area that can not lead to surface sink when meeting common inducing factors.

  1. Assessment of environmental mercury discharge at a four-year-old artisanal gold mining area on Lombok Island, Indonesia.

    Science.gov (United States)

    Krisnayanti, Baiq Dewi; Anderson, Christopher W N; Utomo, Wani Hadi; Feng, Xinbin; Handayanto, Eko; Mudarisna, Nurul; Ikram, Hadiman; Khususiah

    2012-10-26

    Indonesian artisanal and small-scale gold mining activities (ASGM) have been described for the islands of Borneo (Kalimantan) and Sulawesi. But the increased gold price over recent years has seen operations extend to the islands of Lombok and Sumbawa. For the current research, an environmental assessment was conducted across three new ASGM locations. Gold is recovered by miners through a two-stage process of whole-ore amalgamation and cyanidation. Waste (tailings) is discharged to land or sea with no concern for contaminants in the tailings. The gold grade of ore is up to 5000 mg kg(-1). The mean gold grade of the amalgamation tailings is 7 mg kg(-1), dropping to 1.2 mg kg(-1) for the cyanidation tailings. The mean mercury concentration of the amalgamation tailings is about 3000 mg kg(-1) and greater than 1600 mg kg(-1) for the cyanidation tailings. Samples of paddy rice grain collected adjacent to cyanidation tailings ponds showed methyl mercury concentrations greater than 100 ng g(-1). This is five times above the Chinese permissible level for total mercury in food crops. The mean total mercury concentration in hair of Lombok ASGM workers was greater than that in a non-exposed population; however there was no difference in methyl mercury concentration. This indicates the primary pathway of mercury exposure is inhalation of volatile mercury in the atmosphere. Future exposure may come from ingestion of methyl mercury contaminated rice where discharge of cyanide tailings to paddies continues. To protect the environment and to enhance the sustainability of ASGM, appropriate tailings management must be implemented. The gold grade of the tailings indicates that the residual value might be recoverable with appropriate technology. Ongoing research is investigating systems such as phytoextraction that might assist ASGM operators in Lombok and Sumbawa to improve their environmental performance.

  2. Water quality assessment in the Bétaré-Oya gold mining area (East-Cameroon): Multivariate Statistical Analysis approach.

    Science.gov (United States)

    Rakotondrabe, Felaniaina; Ndam Ngoupayou, Jules Remy; Mfonka, Zakari; Rasolomanana, Eddy Harilala; Nyangono Abolo, Alexis Jacob; Ako Ako, Andrew

    2018-01-01

    The influence of gold mining activities on the water quality in the Mari catchment in Bétaré-Oya (East Cameroon) was assessed in this study. Sampling was performed within the period of one hydrological year (2015 to 2016), with 22 sampling sites consisting of groundwater (06) and surface water (16). In addition to measuring the physicochemical parameters, such as pH, electrical conductivity, alkalinity, turbidity, suspended solids and CN(-), eleven major elements (Na(+), K(+), Ca(2+), Mg(2+), NH4(+), Cl(-), NO3(-), HCO3(-), SO4(2-), PO4(3-) and F(-)) and eight heavy metals (Pb, Zn, Cd, Fe, Cu, As, Mn and Cr) were also analyzed using conventional hydrochemical methods, Multivariate Statistical Analysis and the Heavy metal Pollution Index (HPI). The results showed that the water from Mari catchment and Lom River was acidic to basic (5.40water quality, except for nitrates in some wells, which was found at a concentration >50mg NO3(-)/L. This water was found as two main types: calcium magnesium bicarbonate (CaMg-HCO3), which was the most represented, and sodium bicarbonate potassium (NaK-HCO3). As for trace elements in surface water, the contents of Pb, Cd, Mn, Cr and Fe were higher than recommended by the WHO guidelines, and therefore, the surface water was unsuitable for human consumption. Three phenomena were responsible for controlling the quality of the water in the study area: hydrolysis of silicate minerals of plutono-metamorphic rocks, which constitute the geological basement of this area; vegetation and soil leaching; and mining activities. The high concentrations of TSS and trace elements found in this basin were mainly due to gold mining activities (exploration and exploitation) as well as digging of rivers beds, excavation and gold amalgamation. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. DEVELOPING AND EXPLOITING A UNIQUE DATASET FROM SOUTH AFRICAN GOLD MINES FOR SOURCE CHARACTERIZATION AND WAVE PROPAGATION

    Energy Technology Data Exchange (ETDEWEB)

    Julia, J; Nyblade, A; Gok, R; Walter, W; Linzer, L; Durrheim, R

    2009-07-06

    In this project, we are developing and exploiting a unique seismic dataset to address the characteristics of small seismic events and the associated seismic signals observed at local (< 200 km) and regional (< 2000 km) distances. The dataset is being developed using mining-induced events from three deep gold mines in South Africa recorded on in-mine networks (< 1 km) composed of tens of high-frequency sensors, a network of four broadband stations installed as part of this project at the surface around the mines (1-10 km), and a network of existing broadband seismic stations at local/regional distances (50-1000 km) from the mines. Data acquisition has now been completed and includes: (1) {approx}2 years (2007 and 2008) of continuous recording by the surface broadband array, and (2) tens of thousands of mine tremors in the -3.4 < ML < 4.4 local magnitude range. Events with positive magnitudes are generally well recorded by the surface-mine stations, while magnitudes of 3.0 and larger are seen at regional distances (up to {approx} 600 km) in high-pass filtered recordings. We have now completed the quality control of the in-mine data gathered at the three gold mines included in this project. The quality control consisted of: (1) identification and analysis of outliers among the P- and S-wave travel-time picks reported by the in-mine network operator and (2) verification of sensor orientations. The outliers have been identified through a 'Wadati filter' that searches for the largest subset of P- and S-wave travel-time picks consistent with a medium of uniform wave-speed. They have observed that outliers are generally picked at a few select stations. They have also detected that trigger times were mistakenly reported as origin times by the in-mine network operator, and corrections have been obtained from the intercept times in the Wadati diagrams. Sensor orientations have been verified through rotations into the local ray-coordinate system and, when possible

  4. Migrancy, masculine identities and AIDS: the psychosocial context of HIV transmission on the South African gold mines.

    Science.gov (United States)

    Campbell, C

    1997-07-01

    Levels of HIV infection are particularly high amongst migrant workers in sub-Saharan Africa. This paper presents a case study of one such vulnerable group of migrants-underground workers on the South African gold mines-and highlights the psychosocial context of HIV transmission in the mining setting. On the assumption that social identities serve as an important influence on peoples' sexual behaviour, the study examines the way in which miners construct their social identities within the parameters of their particular living and working conditions. It also identifies some of the key narratives used by miners to make sense of their experience in the realms of health, ill-health, HIV and sexuality. Masculinity emerged as a leading narrative in informants' accounts of their working life, health and sexuality, and the paper examines the way in which the construction of masculine identities renders miners particularly vulnerable to HIV. The implications of these findings for HIV educational interventions are discussed.

  5. Methylmercury in tailings ponds of Amazonian gold mines (French Guiana): Field observations and an experimental flocculation method for in situ remediation

    OpenAIRE

    Guédron, Stéphane; Cossa, D.; Grimaldi, Michel; Charlet, L.

    2011-01-01

    Sites of monomethylmercury (MMHg) production in Amazonian regions have been identified in hydraulic reservoirs, lake sediments and wetlands, but tailings ponds have not yet received sufficient attention for this purpose. This work evidenced high MMHg production within the water column and the interstitial water of two tailings ponds of French Guiana Au mines located; (i) in a small scale exploitation (Combat) where Hg was used for Au amalgamation, and (ii) in an industrial on-going Au mine (Y...

  6. A centennial tribute to G.K. Gilbert's Hydraulic Mining Débris in the Sierra Nevada

    Science.gov (United States)

    James, L. A.; Phillips, J. D.; Lecce, S. A.

    2017-10-01

    G.K. Gilbert's (1917) classic monograph, Hydraulic-Mining Débris in the Sierra Nevada, is described and put into the context of modern geomorphic knowledge. The emphasis here is on large-scale applied fluvial geomorphology, but other key elements-e.g., coastal geomorphology-are also briefly covered. A brief synopsis outlines key elements of the monograph, followed by discussions of highly influential aspects including the integrated watershed perspective, the extreme example of anthropogenic sedimentation, computation of a quantitative, semidistributed sediment budget, and advent of sediment-wave theory. Although Gilbert did not address concepts of equilibrium and grade in much detail, the rivers of the northwestern Sierra Nevada were highly disrupted and thrown into a condition of nonequilibrium. Therefore, concepts of equilibrium and grade-for which Gilbert's early work is often cited-are discussed. Gilbert's work is put into the context of complex nonlinear dynamics in geomorphic systems and how these concepts can be used to interpret the nonequilibrium systems described by Gilbert. Broad, basin-scale studies were common in the period, but few were as quantitative and empirically rigorous or employed such a range of methodologies as PP105. None demonstrated such an extreme case of anthropogeomorphic change.

  7. Initial growth of leguminous trees and shrubs in a cut gold mined area in Minas Gerais State, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Dias, L.E.; Campello, E.F.C.; Ribeiro, E.S. Jr.; Mello, J.W.V.

    1999-07-01

    In an opencast gold mining in Minas Gerais State, Brazil, leguminous trees and shrubs were used to revegetate an acid cut mined area. the substrate was high in pyrite content (3%) and received 50 cm of covered material in two layers: (1) insulating layer of 20 cm where clay or a mining refuse (MR) was used to prevent the pyrite oxidation, and (2) an upper layer with 30 cm formed by topsoil or topsoil + urban compost (3:1 v/v). After the application of the cover materials, planting holes were manually made spaced by 1 x 1 m. Each hole received limestone (100 g), rock phosphate (150 g), potassium chloride (45 g) and cattle manure (2 L). Fifteen leguminous species were planted an each plot (15 x 8 m), spaced by 1.0 x 1.0 m (one specie per row). Sixteen months after the planting the plants were evaluated and the results showed an effect of substrate on the plants survival, height, and diameter. The use of clay as insulating layer was better than mining refuse and the plants did not respond to the addition of urban compost to the topsoil. Among the evaluated species, Thephrosia sinapau, Erytrina verna, Dipterix alata and Stryphnodenadrum guyanensis showed a mortality rate of 100% after 16 months while Sesbania marginata, Acacaia holosericea, Mimosa pellita, Acacia crassicarpa, Acacia mangium and Acacia angustissima exhibited more adaptation capacity to the acid substrate. Analyses from the substrate showed higher exchangeable acidity (Al{sup 3+}) for the plots receiving MR as insulating layer. This study has applications for the acid mine drainage from coal mines of Brazil.

  8. Contamination from gold and platinum-group metals mining in the Gulf of Darién, Colombia

    Science.gov (United States)

    Vasquez-Bedoya, L.; Palacio Baena, J.

    2013-12-01

    Gulf of Darién, triangular southernmost extension of the Caribbean Sea, bounded by Panama on the southwest and by Colombia on the southeast and east. The Gulf is made up of 17 municipalities in the department of Choco and Antioquia. The Gulf of Darién is a geostrategic region, rich in biodiversity, known for its natural resources of minerals, oil, lumber as well as its water and fertile land. The Darién also acts as the bridge between South America and Central America and has access to the Pacific Ocean and the Caribbean Sea. The economy in the region is based mainly on agribusinesses, tourism and mining activities, mainly the 'mining of gold and platinum-group metals'. In our study we determined the degree of trace element contamination in estuarine sediment samples originated from mining activities and municipal waste water discharges of effluents on the gulf of Darién. . Surface samples were taken from 17 locations through the entire Gulf. Grain size, Corg, Ag, Al, Ca , Cr, Cu, Fe, Mg, Mn, Na, Ni, Pb and Zn concentrations were analyzed, and enrichment factors (EF) as well as geo-accumulation indices (Igeo) were calculated. Concentrations of Pb, Zn, Ni, Cu and Cr show levels that are consistent with those typically found in urbanized marine environments. EF and Igeo values revealed that the Gulf is extremely contaminated with Ag and moderately contaminated with Cr and Zn. The sources of Cr, Ag, Hg and Zn are associated with the development of mining activities in the Atrato River basin. The observed enrichment of Ag may be explained as a residue of the extraction of gold and platinum-group metals.

  9. An Assessment of Radiological Hazards from Gold Mine Tailings in the Province of Gauteng in South Africa

    Directory of Open Access Journals (Sweden)

    Caspah Kamunda

    2016-01-01

    Full Text Available Radiological hazards associated with exposure to Naturally Occurring Radionuclides Materials from gold mine tailings in the province of Gauteng in South Africa were evaluated. A comparison was made with soil samples from a control area. In this study, gamma spectroscopy was used to measure the activity concentrations of these radionuclides in 56 soil samples from the mine tailings and 10 soil samples from the control area. The average activity concentrations in Bq∙kg−1 for Uranium-238, Thorium-232, and Potassium-40 from the mine tailings were found to be 785.3 ± 13.7, 43.9 ± 1.0 and 427.0 ± 13.1, respectively. On the other hand, the average activity concentrations in Bq∙kg−1 for Uranium-238, Thorium-232, and Potassium-40 from the control area were found to be 17.0.1 ± 0.4, 22.2 ± 0.5 and 496.8 ± 15.2, respectively. Radiological hazard parameters calculated from these activity concentrations were higher than recommended safe limits. In particular, calculated average values for the external hazard (Hex and the internal hazard (Hin from the mine tailings were found to be 2.4 and 4.5. Both these values were higher than unity, posing a significant health risk to the population in the area.

  10. An Assessment of Radiological Hazards from Gold Mine Tailings in the Province of Gauteng in South Africa.

    Science.gov (United States)

    Kamunda, Caspah; Mathuthu, Manny; Madhuku, Morgan

    2016-01-18

    Radiological hazards associated with exposure to Naturally Occurring Radionuclides Materials from gold mine tailings in the province of Gauteng in South Africa were evaluated. A comparison was made with soil samples from a control area. In this study, gamma spectroscopy was used to measure the activity concentrations of these radionuclides in 56 soil samples from the mine tailings and 10 soil samples from the control area. The average activity concentrations in Bq∙kg(-1) for Uranium-238, Thorium-232, and Potassium-40 from the mine tailings were found to be 785.3 ± 13.7, 43.9 ± 1.0 and 427.0 ± 13.1, respectively. On the other hand, the average activity concentrations in Bq∙kg(-1) for Uranium-238, Thorium-232, and Potassium-40 from the control area were found to be 17.0.1 ± 0.4, 22.2 ± 0.5 and 496.8 ± 15.2, respectively. Radiological hazard parameters calculated from these activity concentrations were higher than recommended safe limits. In particular, calculated average values for the external hazard (Hex) and the internal hazard (Hin) from the mine tailings were found to be 2.4 and 4.5. Both these values were higher than unity, posing a significant health risk to the population in the area.

  11. Observational studies of the rock mass response to mining in highly-stressed gold mines in South Africa

    CSIR Research Space (South Africa)

    Ogasawara, H

    2014-09-01

    Full Text Available Kawakata, O Murakami Ritsumeikan University, Japan N Yoshimitsu The University of Tokyo, Japan AK Ward, J Wienand, P Lenegan Sibanye Gold, South Africa H Yilmaz, S Mngadi University of the Witwatersrand, South Africa PS Piper, TN Clements Groundwork...

  12. Towards a System Combining SAR and Optical Sentinel Data to Monitor Gold Mining in the Guiana Shield

    Science.gov (United States)

    Rahm, Mathieu; Lardeux, Cedric; Frison, Pierre-Louis; Bedeau, Caroline; Crabbe, Sarah; Svensson, Sara; Hardjoprajitno, Mercedes; Moe soe Let, Valentien; Miranda, Pricilla; Paloeng, Consuela; Kasanpawiro, Cindyrella; Smartt, Towana; Totaram, Jasmin; Funi, Claudia; Farias, Patrick; Lauger, Anthony

    2016-08-01

    Included in the Guiana Shield ecosystem which is one of the largest blocks of intact tropical forest worldwide, Guyana, Suriname, French Guiana and the Brazilian state of Amapá play a critical role in mitigating climate change, preserving biodiversity and regulating water of the Amazon basin. Under low pressure in the past, degradation of this fragile ecosystem is growing, especially driven by gold mining activities.The REDD+ for the Guiana Shield project developed a method involving each country in data production to monitor the impact of this activity on the forest cover and freshwater at the regional level. This paper presents the data and methodology that were used to quantify the impact on the forest cover. It discusses the results of three reference years (2001, 2008 and 2014) which confirmed the alarming expansion of gold mining in the region. Furthermore, the paper shows the results of innovative methods combining the use of optical and Synthetic Aperture Radar (SAR) satellite data on pilot sites to improve the efficiency of future monitoring.

  13. Detection and Recovery of Palladium, Gold and Cobalt Metals from the Urban Mine Using Novel Sensors/Adsorbents Designated with Nanoscale Wagon-wheel-shaped Pores

    OpenAIRE

    2015-01-01

    Developing low-cost, efficient processes for recovering and recycling palladium, gold and cobalt metals from urban mine remains a significant challenge in industrialized countries. Here, the development of optical mesosensors/adsorbents (MSAs) for efficient recognition and selective recovery of Pd(II), Au(III), and Co(II) from urban mine was achieved. A simple, general method for preparing MSAs based on using high-order mesoporous monolithic scaffolds was described. Hierarchical cubic Ia3d wa...

  14. Roof Weakening of Hydraulic Fracturing for Control of Hanging Roof in the Face End of High Gassy Coal Longwall Mining: A Case Study

    Science.gov (United States)

    Huang, Bingxiang; Wang, Youzhuang

    2016-09-01

    The occurence of hanging roof commonly arises in the face end of longwall coal mining under hard roof conditions. The sudden break and subsequent caving of a hanging roof could result in the extrusion of gas in the gob to the face, causing gas concentrations to rise sharply and to increase to over a safety-limited value. A series of linear fracturing-holes of 32 mm diameter were drilled into the roof of the entries with an anchor rig. According to the theory that the gob should be fully filled with the fragmentized falling roof rock, the drilling depth is determined as being 3 5 times the mining height if the broken expansion coefficient takes an empirical value. Considering the general extension range of cracks and the supporting form of the entryway, the spacing distance between two drilling holes is determined as being 1 2 times the crack's range of extension. Using a mounting pipe, a high pressure resistant sealing device of a small diameter-size was sent to the designated location for the high-pressure hydraulic fracturing of the roof rock. The hydraulic fracturing created the main hydro-fracturing crack and airfoil branch cracks in the interior of the roof-rock, transforming the roof structure and weakening the strength of the roof to form a weak plane which accelerated roof caving, and eventually induced the full caving in of the roof in time with the help of ground pressure. For holes deeper than 4 m, retreating hydraulic fracturing could ensure the uniformity of crack extension. Tested and applied at several mines in Shengdong Mining District, the highest ruptured water pressure was found to be 55 MPa, and the hanging roof at the face end was reduced in length from 12 m to less than 1 2 m. This technology has eliminated the risk of the extrusion of gas which has accumulated in the gob.

  15. Assessing the Environmental and Socio-Economic Impacts of Artisanal Gold Mining on the Livelihoods of Communities in the Tarkwa Nsuaem Municipality in Ghana.

    Science.gov (United States)

    Obiri, Samuel; Mattah, Precious A D; Mattah, Memuna M; Armah, Frederick A; Osae, Shiloh; Adu-kumi, Sam; Yeboah, Philip O

    2016-01-26

    Gold mining has played an important role in Ghana's economy, however the negative environmental and socio-economic effects on the host communities associated with gold mining have overshadowed these economic gains. It is within this context that this paper assessed in an integrated manner the environmental and socio-economic impacts of artisanal gold mining in the Tarkwa Nsuaem Municipality from a natural and social science perspective. The natural science group collected 200 random samples on bi-weekly basis between January to October 2013 from water bodies in the study area for analysis in line with methods outlined by the American Water Works Association, while the social science team interviewed 250 residents randomly selected for interviews on socio-economic issues associated with mining. Data from the socio-economic survey was analyzed using logistic regression with SPSS version 17. The results of the natural science investigation revealed that the levels of heavy metals in water samples from the study area in most cases exceeded GS 175-1/WHO permissible guideline values, which are in tandem with the results of inhabitants' perceptions of water quality survey (as 83% of the respondents are of the view that water bodies in the study area are polluted). This calls for cost-benefits analysis of mining before new mining leases are granted by the relevant authorities.

  16. Assessing the Environmental and Socio-Economic Impacts of Artisanal Gold Mining on the Livelihoods of Communities in the Tarkwa Nsuaem Municipality in Ghana

    Directory of Open Access Journals (Sweden)

    Samuel Obiri

    2016-01-01

    Full Text Available Gold mining has played an important role in Ghana’s economy, however the negative environmental and socio-economic effects on the host communities associated with gold mining have overshadowed these economic gains. It is within this context that this paper assessed in an integrated manner the environmental and socio-economic impacts of artisanal gold mining in the Tarkwa Nsuaem Municipality from a natural and social science perspective. The natural science group collected 200 random samples on bi-weekly basis between January to October 2013 from water bodies in the study area for analysis in line with methods outlined by the American Water Works Association, while the social science team interviewed 250 residents randomly selected for interviews on socio-economic issues associated with mining. Data from the socio-economic survey was analyzed using logistic regression with SPSS version 17. The results of the natural science investigation revealed that the levels of heavy metals in water samples from the study area in most cases exceeded GS 175-1/WHO permissible guideline values, which are in tandem with the results of inhabitants’ perceptions of water quality survey (as 83% of the respondents are of the view that water bodies in the study area are polluted. This calls for cost-benefits analysis of mining before new mining leases are granted by the relevant authorities.

  17. Co-treatment of abandoned mine drainage and Marcellus Shale flowback water for use in hydraulic fracturing.

    Science.gov (United States)

    He, Can; Zhang, Tieyuan; Vidic, Radisav D

    2016-11-01

    Flowback water generated during shale gas extraction in Pennsylvania is mostly reused for hydraulic fracturing operation. Abandoned mine drainage (AMD), one of the most widespread threats to water quality in Pennsylvania, can potentially serve as a make-up water source to enable flowback water reuse. This study demonstrated co-treatment of flowback water and AMD produced in northeastern Pennsylvania in a pilot-scale system consisting of rapid mix reactor, flocculation tank and sedimentation tank. Sulfate concentration in the finished water can be controlled at a desired level (i.e., below 100 mg/L) by adjusting the ratio of flowback water and AMD in the influent. Fe(3+) contained in the AMD can serve as a coagulant to enhance the removal of suspended solids, during which Fe(2+) is co-precipitated and the total iron is reduced to a desirable level. Solid waste generated in this process (i.e., barite) will incorporate over 99% of radium present in the flowback water, which offers the possibility to control the fate of naturally occurring radioactive materials (NORM) brought to the surface by unconventional gas extraction. Sludge recirculation in the treatment process can be used to increase the size of barite particles formed by mixing flowback water and AMD to meet specifications for use as a weighting agent in drilling fluid. This alternative management approach for NORM can be used to offset the treatment cost and promote flowback water reuse, reduce environmental impacts of AMD and reduce pressure on fresh water sources. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Groundwater Surface Water Interactions in a Gold-Mined Dredged Floodplain of the Merced River

    Science.gov (United States)

    Sullivan, L.; Conklin, M. H.; Ghezzehei, T. A.

    2012-12-01

    The Merced River, originating in the Sierra Nevada, California, drains a watershed with an area of ~3,305 km2. Merced River has been highly altered due to diversions, mechanically dredged mining, and damming. A year of groundwater-surface water interactions were studied to elucidate the hydrological connection between the Main Canal, an unlined canal that contains Merced River water flows parallel to the river with an average elevation of 89m, the highly conductive previously dredged floodplain, and the Merced River with an average elevation of 84m. Upstream of the study reach, located in an undredged portion, of the floodplain are two fish farms that have been operating for approximately 40 years. This study reach has been historically important for salmon spawning and rearing, where more than 50% of the Chinook salmon of the Merced River spawn. Currently salmon restoration is focusing gravel augmentation and adding side channel and ignoring groundwater influences. Exchanges between the hyporheic and surrounding surface, groundwater, riparian, and alluvial floodplain habitats occur over a wide range of spatial and temporal scales. Pressure transducers were installed in seven wells and four ponds located in the dredged floodplain. All wells were drilled to the Mehrten Formation, a confining layer, and screened for last 3m. These groundwater well water levels as well as the surface water elevations of the Main Canal and the Merced River were used to determine the direction of sublateral surface flows using Groundwater Vistas as a user interface for MODFLOW. The well and pond waters and seepage from the river banks were sampled for anion/cation, dissolved organic carbon, total nitrogen, total iron, and total dissolved iron concentrations to determine water sources and the possibility of suboxic water. Field analysis indicated that water in all wells and ponds exhibit low dissolved oxygen, high conductivity rates, and oxidation/reduction potentials that switched from

  19. Multielemental analysis of Migori (Southwest, Kenya) artisanal gold mine ores and sediments by EDX-ray fluorescence technique: implications of occupational exposure and environmental impact.

    Science.gov (United States)

    Odumo, O B; Mustapha, A O; Patel, J P; Angeyo, H K

    2011-05-01

    The results of heavy element profiling of the gold ores and sediments associated with the artisanal gold mining activities of the Migori gold belt of Southwestern Nyanza, Kenya, were reported in this paper. The analysis was made to assess the occupational exposure of the miners as well as to investigate the environmental impact of toxic heavy metals. Gold ores and sediments from the artisanal gold processing were sampled in four artisanal gold mining areas: Osiri A, Osiri B, Mikei and Macalder (Makalda) and analyzed for heavy elemental content using (109)Cd radioisotope excited EDXRF spectrometry technique. Analysis consisted of direct irradiating of sample pellets. The concentrations of major elements detected were: titanium (711.41-10,766.67 mg/kg); cobalt (82.65-1,010.00 mg/kg); zinc (29.90-63,210 mg/kg); arsenic (29.30-8,246.59 mg/kg); gold (14.07-73.48 mg/kg); lead (16.31-14,999.40 mg/kg) and mercury (16.10-149.93 mg/kg). The average concentration of the heavy toxic metals i.e. arsenic, lead, titanium and zinc were found to be above 50 mg/Kg as recommended by World Health Organization.

  20. Gold-silver mining districts, alteration zones, and paleolandforms in the Miocene Bodie Hills Volcanic Field, California and Nevada

    Science.gov (United States)

    Vikre, Peter G.; John, David A.; du Bray, Edward A.; Fleck, Robert J.

    2015-09-25

    The Bodie Hills is a ~40 by ~30 kilometer volcanic field that straddles the California-Nevada state boundary between Mono Lake and the East Walker River. Three precious metal mining districts and nine alteration zones are delineated in Tertiary-Quaternary volcanic and Mesozoic granitic and metamorphic rocks that comprise the volcanic field. Cumulative production from the mining districts, Bodie, Aurora, and Masonic, is 3.4 million ounces of gold and 28 million ounces of silver. Small amounts of mercury were produced from the Potato Peak, Paramount-Bald Peak, and Cinnabar Canyon-US 395 alteration zones; a native sulfur resource in the Cinnabar Canyon-US 395 alteration zone has been identified by drilling. There are no known mineral resources in the other six alteration zones, Red Wash-East Walker River, East Brawley Peak, Sawtooth Ridge, Aurora Canyon, Four Corners, and Spring Peak. The mining districts and alteration zones formed between 13.4 and 8.1 Ma in predominantly ~15–9 Ma volcanic rocks of the Bodie Hills volcanic field. Ages of hydrothermal minerals in the districts and zones are the same as, or somewhat younger than, the ages of volcanic host rocks.

  1. Application of borehole radar to South Africa’s Ultra-Deep gold mining environment

    CSIR Research Space (South Africa)

    Trickett, JC

    2000-05-01

    Full Text Available Borehole Radar has been identified as the most immediately applicable electromagnetic technique to delineate disruptions to gold reef in the South African Deepmine environment. The economically important Ventersdorp Contact Reef (VCR) has...

  2. Explosion-assisted preparation of dispersed gold-bearing different-grade ore for selective mining

    Science.gov (United States)

    Trubachev, AI; Zykov, NV

    2017-02-01

    It is found that there are transient zones (between quality and off-quality ore areas) with the respective content of useful component in an ore body, and a variant of explosive treatment of such zones before the selective mining is put forward. Practicability of two processing technologies is evaluated: processing of high-grade and low-grade ore from the transient zones and heap leaching of metals from the low-grade and impoverished ore. Open mining technology is conventional truck-and-shovel scheme, with distributed ore flows to processing plant and (or) to heap leaching, which generally enhances the mine efficiency.

  3. Goldquarryite, a new Cd-bearing phosphate mineral from the Gold Quarry mine, Eureka County, Nevada

    Science.gov (United States)

    Roberts, Andrew C.; Cooper, M.A.; Hawthorne, F.C.; Gault, Robert A.; Jensen, M.C.; Foord, E.E.

    2003-01-01

    Goldquarryite, idealized formula CuCd2Al3(PO44F2(H2O)10(H2O 2, structure-derived formula (Cu0.70???0.30??1.00(Cd1.68Ca0.32??2.00Al3 (PO44F2(H2O)10[(H2O 1.60F0.40]??2.00, is triclinic, space group P1, with unit-cell parameters derived from crystal structure: a = 6.787(1), b = 9.082(2), c = 10.113(2) A??, ?? = 101.40(1)??, ?? = 104.27(1)??, ?? = 102.51(1)??, V = 568.7(3) A??3, a:b:c: = 0.7473:1:1.1135, Z = 1. The strongest seven reflections in the X-ray powder-diffraction pattern are [d(A??)(I)(hkl)]: 9.433(100)(001); 4.726(30)(002); 3.700(30)(022); 3.173(30b)(122, 113, 120, 003); 3.010(30)(122, 212); 2.896(30)(211); 2.820(50)(022). The mineral occurs on a single specimen collected from the 5,425-foot bench, Gold Quarry mine, Eureka County, Nevada, as isolated clusters of radiating sprays of crystals and as compact parallel crystal aggregates, which are both found on and between breccia fragments. Sprays and aggregates never exceed 3 mm in longest dimension and typically average about 0.5 mm in size. Goldquarryite is a late-stage supergene mineral associated with opal, carbonate-fluorapatite and hewettite, on a host rock composed principally of brecciated and hydrothermally rounded jasperoid fragments which have been lightly cemented by late-stage silicification. Individual euhedral crystals are acicular to bladed, elongate [100], with a length-to-width ratio of approximately 20:1; the maximum size is 1.5 mm but most crystals do not exceed 0.4 mm in length. Forms are {010}, {001} major and {100} very minor. The mineral is pleochroic; translucent (masses) to transparent (crystals); very pale blue to blue-gray (crystals) or blue (masses); with a white streak and a vitreous to glassy luster. Goldquarryite is brittle, lacks cleavage, has an irregular fracture, and is nonfluorescent; hardness (Mohs') is estimated at 3-4; measured density is 2.78(1) g/cm3 (sink-float techniques using methylene iodide-acetone mixtures), calculated density is 2.81 g/cm3 (for formula and unit

  4. DEVELOPING AND EXPLOITING A UNIQUE SEISMIC DATA SET FROM SOUTH AFRICAN GOLD MINES FOR SOURCE CHARACTERIZATION AND WAVE PROPAGATION

    Energy Technology Data Exchange (ETDEWEB)

    Julia, J; Nyblade, A A; Gok, R; Walter, W R; Linzer, L; Durrheim, R

    2008-07-08

    In this project, we are developing and exploiting a unique seismic data set to address the characteristics of small seismic events and the associated seismic signals observed at local (< 200 km) and regional (< 2000 km) distances. The dataset is being developed using mining-induced events from 3 deep gold mines in South Africa recorded on inmine networks (< 1 km) comprised of tens of high-frequency sensors, a network of 4 broadband stations installed as part of this project at the surface around the mines (1-10 km), and a network of existing broadband seismic stations at local/regional distances (50-1000 km) from the mines. After 1 year of seismic monitoring of mine activity (2007), over 10,000 events in the range -3.4 < ML < 4.4 have been catalogued and recorded by the in-mine networks. Events with positive magnitudes are generally well recorded by the surface-mine stations, while magnitudes 3.0 and larger are seen at regional distances (up to {approx}600 km) in high-pass filtered recordings. We have analyzed in-mine recordings in detail at one of the South African mines (Savuka) to (i) improve on reported hypocentral locations, (ii) verify sensor orientations, and (iii) determine full moment tensor solutions. Hypocentral relocations on all catalogued events have been obtained from P- and S-wave travel-times reported by the mine network operator through an automated procedure that selects travel-times falling on Wadati lines with slopes in the 0.6-0.7 range; sensor orientations have been verified and, when possible, corrected by correlating P-, SV-, and SH-waveforms obtained from theoretical and empirical (polarization filter) rotation angles; full moment tensor solutions have been obtained by inverting P-, SV-, and SH- spectral amplitudes measured on the theoretically rotated waveforms with visually assigned polarities. The relocation procedure has revealed that origin times often necessitate a negative correction of a few tenths of second and that hypocentral

  5. 矿井液压支架插板的机械设计探讨%Mechanical Design of Mine Hydraulic Support Flapper

    Institute of Scientific and Technical Information of China (English)

    崔向东; 丁怀青

    2013-01-01

    With the development of technology of coal mine machinery, more practical and economic type of powered was developed. This article analyses the current defects of hydraulic support at the same time, proposes a new type of hydraulic SQT-6210 hydraulic support structure and focus on direct Board depicts the structure of machine theory and mechanical analysis, produced for medium and small coal enterprises to apply for future hydraulic support provides a theoretical basis.%随着煤矿机械技术的发展,更加实用和经济型的液压支架被开发出来。文章分析了当前液压支架缺陷的同时,提出了一种新型SQT-6210型液压支架的结构及前沿技术,并重点描写了该直接插板结构的机械原理及力学分析,为今后能够生产出适合中小煤矿企业适用的液压支架提供了理论基础。

  6. Mercury concentrations in water resources potentially impacted by coal-fired power stations and artisanal gold mining in Mpumalanga, South Africa

    CSIR Research Space (South Africa)

    Williams

    2010-09-01

    Full Text Available impacted by major anthropogenic mercury (Hg) sources (i.e coal-fired power stations and artisanal gold mining activities). Aqueous TotHg concentrations were found to be elevated above the global average (5.0 ng/L) in 38% of all aqueous samples, while...

  7. Advances in geophysical technologies for the exploration and safe mining of deep gold ore bodies in the Witwatersrand basin, South Africa

    CSIR Research Space (South Africa)

    Durrheim, RJ

    2013-08-01

    Full Text Available -1 Proceedings of the Twelfth Biennial Meeting of the Society for Geology Applied to Mineral Deposits, Uppsala, Sweden, 12-15 August 2013 Advances in geophysical technologies for the exploration and safe mining of deep gold ore bodies in the Witwatersrand...

  8. Influence of papermill sludge on growth of Medicago sativa, Festuca rubra and Agropyron trachycaulum in gold mine tailings: A greenhouse study

    Energy Technology Data Exchange (ETDEWEB)

    Green, Scott [Department of Botany, University of Manitoba, 505 Buller building, Winnipeg, Manitoba R3T 2N2 (Canada); Renault, Sylvie [Department of Botany, University of Manitoba, 505 Buller building, Winnipeg, Manitoba R3T 2N2 (Canada)], E-mail: renaults@cc.umanitoba.ca

    2008-02-15

    A greenhouse study was undertaken to determine the suitability of adding papermill sludge to neutral/alkaline gold mine tailings to improve the establishment of Festuca rubra, Agropyron trachycaulum and Medicago sativa. Festuca rubra root and shoot biomass and A. Trachycaulum shoot biomass were increased with papermill sludge amendment. The addition of papermill sludge and fertilizer drastically increased the shoot and root biomass of M. sativa (20-30 times) while A. trachycaulum and F. rubra showed a more moderate increase in growth. Photosynthetic pigment content of the leaves was higher in papermill sludge treatments than in the treatments without papermill sludge. The organic carbon content, macro-aggregate content and field capacity of the gold mine tailings were increased while the bulk density was decreased by the addition of papermill sludge. This study suggests that addition of papermill sludge and adequate fertilization can alleviate some of the adverse conditions of neutral/alkaline gold mine tailings. - Addition of papermill sludge and adequate fertilization of neutral gold mine tailings increased growth of Medicago sativa, Festuca rubra and Agropyron trachycaulum.

  9. Sedentary nestlings of Wood Stork as monitors of mercury contamination in the gold mining region of the Brazilian Pantanal

    Energy Technology Data Exchange (ETDEWEB)

    Nassif Del Lama, Silvia, E-mail: dsdl@ufscar.br [Laboratorio Genetica de Aves, Departamento de Genetica e Evolucao, Universidade Federal de Sao Carlos, Rodovia Washington Luis km 235, 13565-905 Sao Carlos, Sao Paulo (Brazil); Dosualdo Rocha, Cristiano [Laboratorio Genetica de Aves, Departamento de Genetica e Evolucao, Universidade Federal de Sao Carlos, Rodovia Washington Luis km 235, 13565-905 Sao Carlos, Sao Paulo (Brazil); Figueiredo Jardim, Wilson [Institute of Chemistry, State University of Campinas, P.O. Box 6154, 13083-970 Sao Paulo (Brazil); Tsai, Jo-Szu; Frederick, Peter Crawford [Department of Wildlife Ecology and Conservation, P.O. Box 110430, University of Florida, Gainesville, FL 32611 (United States)

    2011-11-15

    Sedentary organisms that are at top trophic levels allow inference about the level of local mercury contamination. We evaluated mercury contamination in feather tissue of nestling Wood Storks (Mycteria americana), sampled in different parts of the Brazilian Pantanal that were variably polluted by mercury releases from gold mining activities. Levels of mercury in feathers sampled in seven breeding colonies were determined by atomic absorption spectroscopy, and the mean value of mercury concentration was 0.557 {mu}g/g, dry weight (n=124), range 0.024-4.423 {mu}g/g. From this total sample, 21 feathers that represent 30% of nestlings collected in Porto da Fazenda and Tucum colonies, in the northern region, ranged from 1.0 to 4.43 {mu}g/g, dry weight (median value=1.87 {mu}g/g). We found significant differences among regions (H=57.342; p=0<0.05). Results suggest that permanently flooded areas, or along mainstream rivers are more contaminated by mercury than dry areas, regardless of the distance from the gold mining center, which is located in the northern Pantanal. Highest values found in nestlings feathers were similar to those found in feathers of adult birds and in tissues of adult mammals that are less sedentary and were captured in the same region of Pantanal. These findings indicate that mercury released has been biomagnified and it is present in high concentrations in tissues of top consumers. We suggest a program to monitor mercury availability in this ecosystem using sedentary life forms of top predators like Wood Storks or other piscivorous birds. - Highlights: Black-Right-Pointing-Pointer Sedentary stork nestlings were used for the first time to show local mercury contamination of Pantanal. Black-Right-Pointing-Pointer Differences were found among regions but they are not explained only by distance from the gold mining. Black-Right-Pointing-Pointer Permanently flooded areas and areas along mainstream rivers are more contaminated than dry areas. Black

  10. Mercury Pollution from Small-Scale Gold Mining Can Be Stopped by Implementing the Gravity-Borax Method--A Two-Year Follow-Up Study from Two Mining Communities in the Philippines.

    Science.gov (United States)

    Køster-Rasmussen, Rasmus; Westergaard, Maria L; Brasholt, Marie; Gutierrez, Richard; Jørs, Erik; Thomsen, Jane F

    2016-02-01

    Mercury is used globally to extract gold in artisanal and small-scale gold mining. The mercury-free gravity-borax method for gold extraction was introduced in two mining communities using mercury in the provinces Kalinga and Camarines Norte. This article describes project activities and quantitative changes in mercury consumption and analyzes the implementation with diffusion of innovations theory. Activities included miner-to-miner training; seminars for health-care workers, school teachers, and children; and involvement of community leaders. Baseline (2011) and follow-up (2013) data were gathered on mining practices and knowledge about mercury toxicology. Most miners in Kalinga converted to the gravity-borax method, whereas only a few did so in Camarines Norte. Differences in the nature of the social systems impacted the success of the implementation, and involvement of the tribal organization facilitated the shift in Kalinga. In conclusion, the gravity-borax method is a doable alternative to mercury use in artisanal and small-scale gold mining, but support from the civil society is needed.

  11. Mercury Distribution in the Processing of Jatiroto Gold Mine Wonogiri Central Java Indonesia

    Science.gov (United States)

    Fitri Yudiantoro, Dwi; Nurcholis, Muhammad; Sri Sayudi, Dewi; Abdurrachman, Mirzam; Paramita Haty, Intan; Pambudi, Wiryan; Subroborini, Arum

    2017-06-01

    The research area is one of the Wonogiri gold producer. In this region there are nearly 30 gold processing locations. This area has a steep morphology which is part of Mt. Mas. The work of the gold processing is a part time job besides for the local farmer population. To get the gold bearing rocks, are by digging holes manually around Mt. Mas, while gold processing is carried out in their homes. As a result of these activities, then identified the distribution of mercury in the surrounding settlements. Analytical methods used in this study is the measurement mercury content using Hg meter on altered rocks, soil and using XRF (X-Ray Fluorescence) for plant samples. This results of research shows that there are conducted on mercury contents in the altered rocks, soil and plants showed significant mercury contents in altered rocks, soil and plants. This proves that mercury has polluted the environment surrounding residents, both of people living in the hill down on the lower plain areas. The results of this study are expected to be used as reference to help overcome the pollution of the area.

  12. Geophysical delineation of acidity and salinity in the Central Manitoba gold mine tailings pile, Manitoba, Canada

    Science.gov (United States)

    Tycholiz, C.; Ferguson, I. J.; Sherriff, B. L.; Cordeiro, M.; Sri Ranjan, R.; Pérez-Flores, M. A.

    2016-08-01

    Surface electrical and electromagnetic geophysical methods can map enhanced electrical conductivity caused by acid mine drainage in mine tailings piles. In this case study, we investigate quantitative relationships between geophysical responses and the electrical conductivity, acidity and salinity of tailing samples at the Central Manitoba Mine tailings in Manitoba, Canada. Previous electromagnetic surveys at the site identified zones of enhanced conductivity that were hypothesized to be caused by acid mine drainage. In the present study, high-resolution EM31 and DC-resistivity measurements were made on a profile through a zone of enhanced conductivity and laboratory measurements of salinity and pH were made on saturation paste extracts from an array of tailing samples collected from the upper 2 m of tailings along the profile. Observed spatial correlation of pH and pore-fluid salinity in the tailings samples confirms that the enhanced conductivity in the Central Manitoba Mine tailings is due to acid mine drainage. Contoured cross-sections of the data indicate that the acid mine drainage is concentrated near the base of the oxidized zone in the thicker parts of the tailings pile. The zone of increased acidity extends to the surface on sloping margins causing an increase in apparent conductivity in shallow penetrating geophysical responses. The quantitative relationship between measured pH and salinity shows that the conductivity increase associated with the acid mine drainage is due only in part to conduction by ions produced from dissociation of sulfuric acid. Comparison of the observations with fluid conductivity estimates based on statistical relationships of pH and ion concentrations in water samples from across the tailings pile shows that Ca2 + and Mg2 + ions also make significant contributions to the conductivity at all values of pH and Cu2 +, Al3 + and Fe3 + ions make additional contributions at low pH. Variability in the measured conductivity at constant

  13. Preface to anthropogenic fluvial sedimentation: Centennial celebration of G.K. Gilbert's Hydraulic-Mining Débris in the Sierra Nevada

    Science.gov (United States)

    James, L. Allan; Phillips, Jonathan D.; Lecce, Scott A.

    2017-10-01

    This special issue celebrates the centennial of the publication of G.K. Gilbert's (1917) monograph, Hydraulic-Mining Débris in the Sierra Nevada, U.S. Geological Survey Professional Paper 105 (PP105). Reasons to celebrate PP105 are manifold. It was the last of four classic monographs that Gilbert wrote in a career that spanned five decades. The monograph, PP105, introduced several important concepts and provided an integrated view of watersheds that was uncommon in its day. It also provided an extreme, lucid example of anthropogenic changes and legacy sediment and how to approach such large-scale phenomena from an objective, quantitative basis.

  14. Assessment of mercury and methylmercury in water, sediment, and biota in Sulphur Creek in the vicinity of the Clyde Gold Mine and the Elgin Mercury Mine, Colusa County, California

    Science.gov (United States)

    Hothem, Roger L.; Rytuba, James J.; Brussee, Brianne E.; Goldstein, Daniel N.

    2013-01-01

    At the request of the U.S. Bureau of Land Management, we performed a study during April–July 2010 to characterize mercury (Hg), monomethyl mercury (MMeHg), and other geochemical constituents in sediment, water, and biota at the Clyde Gold Mine and the Elgin Mercury Mine, located in neighboring subwatersheds of Sulphur Creek, Colusa County, California. This study was in support of a Comprehensive Environmental Response, Compensation, and Liability Act - Removal Site Investigation. The investigation was in response to an abatement notification from the California Central Valley Regional Water Quality Control Board to evaluate the release of Hg from the Clyde and Elgin mines. Samples of water, sediment, and biota (aquatic macroinvertebrates) were collected from sites upstream and downstream from the two mine sites to evaluate the level of Hg contamination contributed by each mine to the aquatic ecosystem. Physical parameters, as well as dissolved organic carbon, total Hg (HgT), and MMeHg were analyzed in water and sediment. Other relevant geochemical constituents were analyzed in sediment, filtered water, and unfiltered water. Samples of aquatic macroinvertebrates from each mine were analyzed for HgT and MMeHg. The presence of low to moderate concentrations of HgT and MMeHg in water, sediment, and biota from the Freshwater Branch of Sulphur Creek, and the lack of significant increases in these concentrations downstream from the Clyde Mine indicated that this mine is not a significant source of Hg to the watershed during low flow conditions. Although concentrations of HgT and MMeHg were generally higher in samples of sediment and water from the Elgin Mine compared to the Clyde Mine, concentrations in comparable biota from the two mine areas were similar. It is likely that highly saline effluent from nearby hot springs contribute more Hg to the West Fork of Sulphur Creek than the mine waste material at the Elgin Mine.

  15. Isolation and Characterization of a Geobacillus thermoleovorans Strain from an Ultra-Deep South African Gold Mine

    Energy Technology Data Exchange (ETDEWEB)

    Deflaun, Mary F.; Fredrickson, Jim K.; Dong, Hailiang; Pfiffner, Susan M.; Onstott, T. C.; Balkwill, David L.; Streger, Sheryl H.; Stackebrandt, E.; Knoessen, S.; van Heerden, E.

    2007-03-08

    A thermophilic, facultative bacterium was isolated from a depth of 3.1 km below ground surface in an ultradeep gold mine in South Africa. This isolate, designated GE-7, was cultivated from pH 8.0, 600C fissure water. GE-7 grows optimally at 650C, pH 6.5 on a wide range of carbon substrates including GE-7 is a long rod-shaped bacterium (4-6 µm long x 0.5 wide) with terminal endospores and flagella, in addition to O2, can also utilize nitrate as an electron acceptor. Phylogenetic analysis of GE-7 16S rDNA sequence revealed high sequence similarity with G. thermoleovorans DSM 5366T (99.6%), however, certain phenotypic characteristics of GE-7 were distinct from this and other strains of G. thermoleovorans previously described.

  16. Sulphide bioxidation using native Acidithiobacillus ferrooxidans and thiooxidans, related acidophile strains from "El Zancudo" gold mine (Titiribí, Colombia

    Directory of Open Access Journals (Sweden)

    Diana M Ossa H

    2007-02-01

    Full Text Available This investigation was aimed at a laboratory evaluation of the action of native Acidithiobacillus ferrooxidans-and thiooxidans-related acidophile micro-organism (isolated from El Zancudo gold mine in Titiribí, Colombia on the oxidation of sulphides, mainly consisting of pyrite and arsenopyrite; sulphide concentration varied from 8% to 16% and particle size from 75 um to 106 um. pH and redox potential measurement revealed efficient oxidation for each culture over a 25-day period, reaching 1,4 pH and 600 mV redox potential. 20 g/L As and 60 g/L Fe levels were reached in solution. XRD, FTIR and SEM/EDX analysis revealed the presence of bacterial oxidation products such as jarosite and iron arsenates, as well as low and high corrosion in pyrites and arsenopyrites, respectively. Key words: chemolithotrophics, bioleaching, pyrite, arsenopyrite, applied mineralogy.

  17. Monitoring and analysis of nonlinear dynamic damage of transport roadway supported by composite hard rock materials in Linglong Gold Mine

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The study concentrates mainly on the development of failure process in composite rock mass. By use of acoustic emission(AE), convergence inspection, pressure monitoring, level measurement techniques and the modem signal analysis technology, as wellas scan electron microscopy (SEM) experiment, various aspects of nonlinear dynamic damage of composite rock mass surroundingthe transport roadway in Linglong gold mine are discussed. According to the monitoring results, the stability of the rock mass can besynthetically evaluated, and the intrinsic relation between the damage and the characteristic parameters of acoustic emission can bedetermined. The location of the damage of rock mass can also be detected based on the acoustic emission couple monitoring signals.Finally, the key factors which influence the stability of the transport roadway supported by composite hard rock materials are foundout.

  18. Buying intoformalization? State institutions and interlocked markets in African small-scale gold mining

    DEFF Research Database (Denmark)

    Fold, Niels; Jønsson, Jesper Bosse; Yankson, Paul

    2014-01-01

    . This paper argues that future research and design of policy mechanisms needs to focus on the inter-linkages of actors and material flows within the complex intertwinement of the formal and informal ASM sectors. Our point of departure is the findings on interlocked markets within the literature on rural...... dependency relations, barriers for poverty eradication and agricultural development. The paper outlines the previous debate on formalization and maps out the territorial and organizational configuration of the present ASM gold chain in Tanzania and Ghana. On this basis we maintain that state action...... is inevitable and suggest possible institutional mechanisms to set up incentives for possible formalization pathways for African ASM gold chains....

  19. Mercury in Some Lakes of Gold Mining Area of the Southern Ural

    Directory of Open Access Journals (Sweden)

    Tatsy Y. G.

    2013-04-01

    Full Text Available The mercury content in bottom sediments of Kalkan Lake, of the Uchala district, the Southern Ural. It was assumed that high concentrations of mercury in fish due to pollution of bottom sediments as a result of amalgamation at developing of gold placers. Detailed study of distribution of different elements in sediments show close association Hg with the chalcophylic elements, whose anomalies do not have technogenic nature. Association of mercury with the elements-companions of gold placers is evidence of basic contribution of natural mercury to its anomalous accumulation in sediments and fish. This is result of steady long-term natural mercury pollution.

  20. Observational study of rock mass response to mining induced seismic events and controlled blasting experiments at deep level gold mines in South Africa

    Science.gov (United States)

    Milev, A.; Durrheim, R. J.; Nakatani, M.; Yabe, Y.; Naoi, M. M.; Ogasawara, H.

    2012-12-01

    The strong ground motion generated by mining induced seismic events was studied to characterize the rock mass response and to estimate the site effect on the surface of the underground excavations. A stand-alone instruments, especially designed for recording strong ground motions, were installed underground at a number of deep level gold mines in South Africa. The instruments were recording data at the surface of the stope hangingwalls. A maximum value of 3 m/s was measured. Therefore data were compared to the data recorded in the solid rock by the mine seismic networks to determine the site response. The site response was defined as the ratio of the peak ground velocity measured at the surface of the excavations to the peak ground velocity inferred from the mine seismic data measured in the solid rocks. The site response measured at all mines studied was found to be 9 ± 3 times larger on average. In addition a number of simulated rockbursts were conducted underground in order to estimate the rock mass response when subjected to strong ground motion. The rockbursts were simulated by means of large blasts detonated in solid rock close to the sidewall of a tunnel. The numerical models used in the design of the simulated rockbursts were calibrated by small blasts taking place at each experimental site. A dense array of shock type accelerometers was installed along the blasting wall to monitor the attenuation of the strong ground motion as a function of the distance from the source. The attenuation of peak particle velocity was found to be proportional to R-1.7. In order to improve the understanding of the rock mass behaviour around deep level mining the rate of tilt was monitor and then compare to the seismic ground motion. A good correspondence between the rate of tilt and seismic ground motion was found. The rate of coseismic and aseismic tilt, as well as seismicity recorded by the mine seismic network, are approximately constant until the daily blasting time

  1. Preliminary mineralogic, fluid inclusion, and stable isotope study of the Mahd adh Dhahab gold mine, Kingdom of Saudi Arabia

    Science.gov (United States)

    Rye, Robert O.; Hall, W.E.; Cunningham, C.G.; Czamanske, G.K.; Afifi, A.M.; Stacey, J.S.

    1983-01-01

    The Mahd adh Dhahab mine, located about 280 km northeast of Jiddah, Kingdom of Saudi Arabia, has yielded more than 2 million ounces of gold from periodic production during the past 3,000 years. A new orebody on the southern side of the ancient workings, known as the South orebody, is being developed by Gold Fields-Mahd adh Dhahab Limited. A suite of samples was collected from the newly exposed orebody for preliminary mineralogic, stable isotope, fluid inclusion, and geochemical studies. The Mahd adh Dhahab deposit is in the carapace of a Proterozoic epizonal rhyolite stock that domed pyroclastic and metasedimentary rocks of the Proterozoic Halaban group. Ore of gold, silver, copper, zinc, tellurium, and lead is associated with north-trending, steeply dipping quartz veins in a zone 1,000 m long and 400 m wide. The veins include an assemblage of quartz-chlorite-pyrite-hematite-chalcopyrite-sphalerite-precious metals, which is similar to the mineral assemblage at the epithermal deposit at Creede, Colorado. The primary ore contains abundant chalcopyrite, sphalerite, and pyrite in addition to a complex precious metal assemblage. Gold and silver occur principally as minute grains of telluride minerals disseminated in quartz-chlorite-hematite and as inclusions in chalcopyrite and sphalerite. Telluride minerals include petzite, hessite, and sylvanite. Free gold is present but not abundant. All of the vein-quartz samples contained abundant, minute inclusions of both low-density, vapor-rich fluids and liquid-rich fluids. Primary fluid inclusions yielded homogenization temperatures of from 110? to 238? C. Preliminary light-stable isotope studies of the sulfide minerals and quartz showed that all of the d34S values are between 1.2 and 6.3 per mil, which is a typical range for hydrothermal sulfide minerals that derive their sulfur from an igneous source. The data-suggest that the sulfide sulfur isotope geochemistry was controlled by exchange with la large sulfur isotope

  2. [Another Dante's inferno in a gold mine during the Vargas era: Nova Lima, Minas Gerais].

    Science.gov (United States)

    Maia, Andréa Casa Nova

    2014-01-01

    This article analyzes the control strategies in place at Morro Velho mine in the Brazilian state of Minas Gerais, and the changes after the implementation of labor legislation during the Vargas administration. The diseases common amongst mine workers, silicosis and arsenicosis, are investigated through statements given by former miners and a book by an anonymous author that discusses the diseases and the power relations between employers and employees, identifying the limitations of the legislation and the workers' struggles. The book presents a striking story of how for many years the British company side-stepped laws such as the insalubrity premium, a right which other mining companies, not only of British ownership, flouted and still flout in different parts of the world.

  3. 75 FR 22469 - National Emission Standards for Hazardous Air Pollutants: Gold Mine Ore Processing and Production...

    Science.gov (United States)

    2010-04-28

    ...- 1990s. Also, a number of facilities had carbon adsorption beds to control mercury emissions on various... adsorption process, the gold loaded carbon (which also contains mercury and other constituents) is moved into... in the pregnant solution are concentrated through adsorption onto activated carbon. If mercury...

  4. Investigation into the causes of accidents on scraper systems in the gold and platinum mining sectors

    CSIR Research Space (South Africa)

    Moseme, R

    2003-11-01

    Full Text Available and cleaning operations of the scraper winch systems that require identification. This research report identifies the risk and hazards associated with scraper winch systems that may lead to potential accidents in the gold and platinum sector. The research also...

  5. Probabilistic meta-analysis of risk from the exposure to Hg in artisanal gold mining communities in Colombia.

    Science.gov (United States)

    De Miguel, Eduardo; Clavijo, Diana; Ortega, Marcelo F; Gómez, Amaia

    2014-08-01

    Colombia is one of the largest per capita mercury polluters in the world as a consequence of its artisanal gold mining activities. The severity of this problem in terms of potential health effects was evaluated by means of a probabilistic risk assessment carried out in the twelve departments (or provinces) in Colombia with the largest gold production. The two exposure pathways included in the risk assessment were inhalation of elemental Hg vapors and ingestion of fish contaminated with methyl mercury. Exposure parameters for the adult population (especially rates of fish consumption) were obtained from nation-wide surveys and concentrations of Hg in air and of methyl-mercury in fish were gathered from previous scientific studies. Fish consumption varied between departments and ranged from 0 to 0.3 kg d(-1). Average concentrations of total mercury in fish (70 data) ranged from 0.026 to 3.3 μg g(-1). A total of 550 individual measurements of Hg in workshop air (ranging from Colombia.

  6. A novel polymer inclusion membrane based method for continuous clean-up of thiocyanate from gold mine tailings water.

    Science.gov (United States)

    Cho, Youngsoo; Cattrall, Robert W; Kolev, Spas D

    2018-01-05

    Thiocyanate is present in gold mine tailings waters in concentrations up to 1000mgL(-1) and this has a serious environmental impact by not allowing water reuse in the flotation of gold ore. This significantly increases the consumption of fresh water and the amount of wastewater discharged in tailings dams. At the same time thiocyanate in tailings waters often leads to groundwater contamination. A novel continuous membrane-based method for the complete clean-up of thiocyanate in concentrations as high as 1000mgL(-1) from its aqueous solutions has been developed. It employs a flat sheet polymer inclusion membrane (PIM) of composition 70wt% PVC, 20wt% Aliquat 336 and 10wt% 1-tetradecanol which separates counter-current streams of a feed thiocyanate solution and a 1M NaNO3 receiving solution. The PIM-based system has been operated continuously for 45days with 99% separation efficiency. The volume of the receiving solution has been drastically reduced by recirculating it and continuously removing thiocyanate by precipitating it with in-situ generated Cu(I). The newly developed PIM-based thiocyanate clean-up method is environmentally friendly in terms of reagent use and inexpensive with respect to both equipment and running costs. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Disability Weights for Chronic Mercury Intoxication Resulting from Gold Mining Activities: Results from an Online Pairwise Comparisons Survey

    Directory of Open Access Journals (Sweden)

    Nadine Steckling

    2017-01-01

    Full Text Available In artisanal small-scale gold mining, mercury is used for gold-extraction, putting miners and nearby residents at risk of chronic metallic mercury vapor intoxication (CMMVI. Burden of disease (BoD analyses allow the estimation of the public health relevance of CMMVI, but until now there have been no specific CMMVI disability weights (DWs. The objective is to derive DWs for moderate and severe CMMVI. Disease-specific and generic health state descriptions of 18 diseases were used in a pairwise comparison survey. Mercury and BoD experts were invited to participate in an online survey. Data were analyzed using probit regression. Local regression was used to make the DWs comparable to the Global Burden of Disease (GBD study. Alternative survey (visual analogue scale and data analyses approaches (linear interpolation were evaluated in scenario analyses. A total of 105 participants completed the questionnaire. DWs for moderate and severe CMMVI were 0.368 (0.261–0.484 and 0.588 (0.193–0.907, respectively. Scenario analyses resulted in higher mean values. The results are limited by the sample size, group of interviewees, questionnaire extent, and lack of generally accepted health state descriptions. DWs were derived to improve the data basis of mercury-related BoD estimates, providing useful information for policy-making. Integration of the results into the GBD DWs enhances comparability.

  8. Disability Weights for Chronic Mercury Intoxication Resulting from Gold Mining Activities: Results from an Online Pairwise Comparisons Survey.

    Science.gov (United States)

    Steckling, Nadine; Devleesschauwer, Brecht; Winkelnkemper, Julia; Fischer, Florian; Ericson, Bret; Krämer, Alexander; Hornberg, Claudia; Fuller, Richard; Plass, Dietrich; Bose-O'Reilly, Stephan

    2017-01-10

    In artisanal small-scale gold mining, mercury is used for gold-extraction, putting miners and nearby residents at risk of chronic metallic mercury vapor intoxication (CMMVI). Burden of disease (BoD) analyses allow the estimation of the public health relevance of CMMVI, but until now there have been no specific CMMVI disability weights (DWs). The objective is to derive DWs for moderate and severe CMMVI. Disease-specific and generic health state descriptions of 18 diseases were used in a pairwise comparison survey. Mercury and BoD experts were invited to participate in an online survey. Data were analyzed using probit regression. Local regression was used to make the DWs comparable to the Global Burden of Disease (GBD) study. Alternative survey (visual analogue scale) and data analyses approaches (linear interpolation) were evaluated in scenario analyses. A total of 105 participants completed the questionnaire. DWs for moderate and severe CMMVI were 0.368 (0.261-0.484) and 0.588 (0.193-0.907), respectively. Scenario analyses resulted in higher mean values. The results are limited by the sample size, group of interviewees, questionnaire extent, and lack of generally accepted health state descriptions. DWs were derived to improve the data basis of mercury-related BoD estimates, providing useful information for policy-making. Integration of the results into the GBD DWs enhances comparability.

  9. Disability Weights for Chronic Mercury Intoxication Resulting from Gold Mining Activities: Results from an Online Pairwise Comparisons Survey

    Science.gov (United States)

    Steckling, Nadine; Devleesschauwer, Brecht; Winkelnkemper, Julia; Fischer, Florian; Ericson, Bret; Krämer, Alexander; Hornberg, Claudia; Fuller, Richard; Plass, Dietrich; Bose-O’Reilly, Stephan

    2017-01-01

    In artisanal small-scale gold mining, mercury is used for gold-extraction, putting miners and nearby residents at risk of chronic metallic mercury vapor intoxication (CMMVI). Burden of disease (BoD) analyses allow the estimation of the public health relevance of CMMVI, but until now there have been no specific CMMVI disability weights (DWs). The objective is to derive DWs for moderate and severe CMMVI. Disease-specific and generic health state descriptions of 18 diseases were used in a pairwise comparison survey. Mercury and BoD experts were invited to participate in an online survey. Data were analyzed using probit regression. Local regression was used to make the DWs comparable to the Global Burden of Disease (GBD) study. Alternative survey (visual analogue scale) and data analyses approaches (linear interpolation) were evaluated in scenario analyses. A total of 105 participants completed the questionnaire. DWs for moderate and severe CMMVI were 0.368 (0.261–0.484) and 0.588 (0.193–0.907), respectively. Scenario analyses resulted in higher mean values. The results are limited by the sample size, group of interviewees, questionnaire extent, and lack of generally accepted health state descriptions. DWs were derived to improve the data basis of mercury-related BoD estimates, providing useful information for policy-making. Integration of the results into the GBD DWs enhances comparability. PMID:28075395

  10. Mercury concentrations in fish from a Sierra Nevada foothill reservoir located downstream from historic gold-mining operations.

    Science.gov (United States)

    Saiki, Michael K; Martin, Barbara A; May, Thomas W; Alpers, Charles N

    2010-04-01

    This study examined mercury concentrations in whole fish from Camp Far West Reservoir, an 830-ha reservoir in northern California, USA, located downstream from lands mined for gold during and following the Gold Rush of 1848-1864. Total mercury (reported as dry weight concentrations) was highest in spotted bass (mean, 0.93 microg/g; range, 0.16-4.41 microg/g) and lower in bluegill (mean, 0.45 microg/g; range, 0.22-1.96 microg/g) and threadfin shad (0.44 microg/g; range, 0.21-1.34 microg/g). Spatial patterns for mercury in fish indicated high concentrations upstream in the Bear River arm and generally lower concentrations elsewhere, including downstream near the dam. These findings coincided with patterns exhibited by methylmercury in water and sediment, and suggested that mercury-laden inflows from the Bear River were largely responsible for contaminating the reservoir ecosystem. Maximum concentrations of mercury in all three fish species, but especially bass, were high enough to warrant concern about toxic effects in fish and consumers of fish.

  11. Size-dependent characterisation of historical gold mine wastes to examine human pathways of exposure to arsenic and other potentially toxic elements.

    Science.gov (United States)

    Martin, Rachael; Dowling, Kim; Pearce, Dora C; Florentine, Singarayer; Bennett, John W; Stopic, Attila

    2016-10-01

    Abandoned historical gold mining wastes often exist as geographically extensive, unremediated, and poorly contained deposits that contain elevated levels of As and other potentially toxic elements (PTEs). One of the key variables governing human exposure to PTEs in mine waste is particle size. By applying a size-resolved approach to mine waste characterisation, this study reports on the proportions of mine waste relevant to human exposure and mobility, as well as their corresponding PTE concentrations, in four distinct historical mine wastes from the gold province in Central Victoria, Australia. To the best of our knowledge, such a detailed investigation and comparison of historical mining wastes has not been conducted in this mining-affected region. Mass distribution analysis revealed notable proportions of waste material in the readily ingestible size fraction (≤250 µm; 36.1-75.6 %) and the dust size fraction (≤100 µm; 5.9-45.6 %), suggesting a high potential for human exposure and dust mobilisation. Common to all mine waste types were statistically significant inverse trends between particle size and levels of As and Zn. Enrichment of As in the finest investigated size fraction (≤53 µm) is of particular concern as these particles are highly susceptible to long-distance atmospheric transport. Human populations that reside in the prevailing wind direction from a mine waste deposit may be at risk of As exposure via inhalation and/or ingestion pathways. Enrichment of PTEs in the finer size fractions indicates that human health risk assessments based on bulk contaminant concentrations may underestimate potential exposure intensities.

  12. High-Resolution Mapping Using a Sub-Audio Magnetic Survey at the Comet Gold Mine, Western Australia

    Directory of Open Access Journals (Sweden)

    Piyaphong Chenrai

    2011-01-01

    Full Text Available The Comet Gold Mine in the Murchison mineral field lies within the Yilgarn Craton of Western Australia. Gold mineralization in this area is associated with a series of north-northeasterly trending structures, and has a long exploration history with some previous geophysical information. Other exploration information, such as geology and drill hole data, are integrated with the geophysical results to study the geophysical responses and generate a geophysical interpretation map. The response from the sub-audio magnetic (SAM survey was investigated over an area of 13 sq km. The SAM survey was completed using a transmitter current of 5 - 8 Amp with a 50 o/o duty cycle at 4 Hz frequency, which was considered a good instrumental setting for the Comet area. SAM anomalies were compared to results obtained from other geophysical methods and then integrated with geological data to generate a geophysical interpretation map at a 1 : 5000 scale. The new interpretation of geological units and structures at the Comet area should provide a better understanding of the geological and structural setting for mineralization in the Comet area. Our results show that the Comet Fault represents a faulted limb of the Comet fold structure that has both limbs dipping to the southeast and a plunge to the northeast. Magnetic anomalies associated with sedimentary iron formation (SIF are considered to be well correlated with some gold bearing horizons and the location of the Comet Fault, which has become more siliceous and has been altered by sulphide minerals and magnetite minerals.

  13. Investigating hydraulic connections and the origin of water in a mine tunnel using stable isotopes and hydrographs

    Science.gov (United States)

    Walton-Day, Katherine; Poeter, Eileen

    2009-01-01

    Turquoise Lake is a water-supply reservoir located north of the historic Sugarloaf Mining district near Leadville, Colorado, USA. Elevated water levels in the reservoir may increase flow of low-quality water from abandoned mine tunnels in the Sugarloaf District and degrade water quality downstream. The objective of this study was to understand the sources of water to Dinero mine drainage tunnel and evaluate whether or not there was a direct hydrologic connection between Dinero mine tunnel and Turquoise Lake from late 2002 to early 2008. This study utilized hydrograph data from nearby draining mine tunnels and the lake, and stable isotope (δ18O and δ2H) data from the lake, nearby draining mine tunnels, imported water, and springs to characterize water sources in the study area. Hydrograph results indicate that flow from the Dinero mine tunnel decreased 26% (2006) and 10% (2007) when lake elevation (above mean sea level) decreased below approximately 3004 m (approximately 9855 feet). Results of isotope analysis delineated two meteoric water lines in the study area. One line characterizes surface water and water imported to the study area from the western side of the Continental Divide. The other line characterizes groundwater including draining mine tunnels, springs, and seeps. Isotope mixing calculations indicate that water from Turquoise Lake or seasonal groundwater recharge from snowmelt represents approximately 10% or less of the water in Dinero mine tunnel. However, most of the water in Dinero mine tunnel is from deep groundwater having minimal isotopic variation. The asymmetric shape of the Dinero mine tunnel hydrograph may indicate that a limited mine pool exists behind a collapse in the tunnel and attenutates seasonal recharge. Alternatively, a conceptual model is presented (and supported with MODFLOW simulations) that is consistent with current and previous data collected in the study area, and illustrates how fluctuating lake levels change the local water

  14. Water pollution in gold mining industry: a case study in Roşia Montană district, Romania

    Science.gov (United States)

    Florea, R. M.; Stoica, A. I.; Baiulescu, G. E.; Capotă, P.

    2005-10-01

    The preliminary study of streams and rivers from the Roşia Montană area revealed that the concntration of heavy metals— Cd, Mn, Cu, Pb, and Zn—are above accepted limits. The gold extraction method is based on flotation. The most important pollution sources are mine tailings. The determinations were performed for samples collected in: April 2004, July 2004, September 2004, November 2004, February 2005 and May 2005. The highest concentrations were found for cadmium in September 2004: 0.17 mg/L; for copper in September 2004: 1.38 mg/L; for manganese in July 2004: 239.4 mg/L; for lead in May 2005: 0.54 mg/L; and for zinc in September 2004: 35.37 mg/L;. This study involved three small rivers (streams) that flow into the Mureş River and finally into the Danube River, having a great impact on human health and environmental stability in the area. In May 2005, a sample of drinking water from the mining district was also collected.

  15. Injury Risk Factors in a Small-Scale Gold Mining Community in Ghana’s Upper East Region

    Directory of Open Access Journals (Sweden)

    Rachel N. Long

    2015-07-01

    Full Text Available Occupational injury is one of many health concerns related to small-scale gold mining (ASGM, but few data exist on the subject, especially in sub-Saharan Africa. In 2011 and 2013, we examined accidents, injuries, and potential risk factors in a Ghanaian ASGM community. In 2011, 173 participants were surveyed on occupational history and health, and 22 of these were surveyed again in 2013. Injury rates were estimated at 45.5 and 38.5 injuries per 100 person-years in 2011 and in 2013, respectively; these rates far surpass those of industrialized mines in the U.S. and South Africa. Demographic and job characteristics generally were not predictive of injury risk, though there was a significant positive association with injury risk for males and smokers. Legs and knees were the most common body parts injured, and falling was the most common cause of injury. The most common type of injuries were cuts or lacerations, burns and scalds, and contusions and abrasions. Only two miners had ever received any occupational safety training, and PPE use was low. Our results suggest that injuries should be a priority area for occupational health research in ASGM.

  16. Report on the behalf of the Sustainable Development and Land Planning Commission on the bill project aiming at forbidding the exploration and exploitation of liquid or gaseous hydrocarbon mines by hydraulic fracturing, and abrogating exclusive search permits including projects using this technique; Rapport fait au nom de la Commission du Developpement Durable et de l'Amenagement du Territoire sur la proposition de Loi, visant a interdire l'exploration et l'exploitation des mines d'hydrocarbures liquides ou gazeux par fracturation hydraulique et a abroger les permis exclusifs de recherches comportant des projets ayant recours a cette technique

    Energy Technology Data Exchange (ETDEWEB)

    Havard, M.; Chanteguet, J.P.

    2011-07-01

    In a first part, this report presents the exploitation of liquid and gaseous hydrocarbons as a new gold rush, notably in Canada and in the USA where this exploitation started at the beginning of the 2000's. The authors recall that this resource has been well known for many years, present the technology applied to extract these products: a combination of vertical and horizontal drilling followed by hydraulic fracturing. Then, they outline health and environmental risks associated with hydraulic fracturing, at any stage of the process (important water supply, ground water pollution, used water treatment, use of chemical additives, impact on landscape, greenhouse gas emission). In the second part, the authors notice that France is among the most attractive countries in Europe for the projects of gas and oil companies, and outline the need to reinforce the mining and environmental legal framework. A last part reports the discussions about the bill project articles

  17. Geochemical fractions and risk assessment of trace elements in soils around Jiaojia gold mine in Shandong Province, China.

    Science.gov (United States)

    Cao, Feifei; Kong, Linghao; Yang, Liyuan; Zhang, Wei

    2015-09-01

    Soils located adjacent to the Jiaojia gold mine were sampled and analyzed to determine the degree of which they were contaminated by trace elements (Hg, As, Cd, Pb, Cu, and Zn) in Shandong Province, China. All 18 samples exhibited mean Hg, As, Cd, and Pb concentrations in excess of local background values, while the mean concentrations of Cu and Zn were below the background values. In addition, the concentrations of trace elements in gold smelter (GS) soils were higher than in the gold mine (GM) soils. The result from a modified Tessier sequential extraction procedure was that with the exception of Cu in soils near the smelter, the trace elements were predominantly associated with the residual fraction. After residual fraction, most Hg was mainly humic acid and strong organic fraction, while most As was the humic acid. Cd was associated with the water soluble, ion exchange, and carbonate fractions compared with the other trace elements. Furthermore, Cu, Pb, and Zn were more concentrated in the humic acid and Fe/Mn oxide fraction. The fractions of trace elements were affected by soil pH and Ec (Electrical conductivity). The humic acid fraction of Hg as well as the ion exchange fraction of Cd and Zn displayed negative correlations with soil pH. The strong organic fraction of Hg, the Fe/Mn oxide fraction of Cd, and the carbonate fraction of Zn were positively related to the soil Ec. The strong organic fraction and ion exchange fraction of Zn were negatively related to soil Ec. However, the ion exchange and carbonate fractions of As showed significant positive correlations with soil pH. A calculated individual availability factor (A f (i) ) is used; the values of each trace element in the soils are in the following order: Cu > Cd > Pb > Zn > As > Hg. When combined with a risk assessment code, data suggest that Hg, As, Pb, and Zn levels showed low risk for the environment, whereas Cd levels in soils adjacent to the GM and Cu levels in soils adjacent to the GS showed

  18. Integrated Assessment of Artisanal and Small-Scale Gold Mining in Ghana — Part 3: Social Sciences and Economics

    Directory of Open Access Journals (Sweden)

    Mark L. Wilson

    2015-07-01

    Full Text Available This article is one of three synthesis reports resulting from an integrated assessment (IA of artisanal and small-scale gold mining (ASGM in Ghana. Given the complexities that involve multiple drivers and diverse disciplines influencing ASGM, an IA framework was used to analyze economic, social, health, and environmental data and to co-develop evidence-based responses in collaboration with pertinent stakeholders. We look at both micro- and macro-economic processes surrounding ASGM, including causes, challenges, and consequences. At the micro-level, social and economic evidence suggests that the principal reasons whereby most people engage in ASGM involve “push” factors aimed at meeting livelihood goals. ASGM provides an important source of income for both proximate and distant communities, representing a means of survival for impoverished farmers as well as an engine for small business growth. However, miners and their families often end up in a “poverty trap” of low productivity and indebtedness, which reduce even further their economic options. At a macro level, Ghana’s ASGM activities contribute significantly to the national economy even though they are sometimes operating illegally and at a disadvantage compared to large-scale industrial mining companies. Nevertheless, complex issues of land tenure, social stability, mining regulation and taxation, and environmental degradation undermine the viability and sustainability of ASGM as a livelihood strategy. Although more research is needed to understand these complex relationships, we point to key findings and insights from social science and economics research that can guide policies and actions aimed to address the unique challenges of ASGM in Ghana and elsewhere.

  19. Integrated Assessment of Artisanal and Small-Scale Gold Mining in Ghana - Part 3: Social Sciences and Economics.

    Science.gov (United States)

    Wilson, Mark L; Renne, Elisha; Roncoli, Carla; Agyei-Baffour, Peter; Tenkorang, Emmanuel Yamoah

    2015-07-15

    This article is one of three synthesis reports resulting from an integrated assessment (IA) of artisanal and small-scale gold mining (ASGM) in Ghana. Given the complexities that involve multiple drivers and diverse disciplines influencing ASGM, an IA framework was used to analyze economic, social, health, and environmental data and to co-develop evidence-based responses in collaboration with pertinent stakeholders. We look at both micro- and macro-economic processes surrounding ASGM, including causes, challenges, and consequences. At the micro-level, social and economic evidence suggests that the principal reasons whereby most people engage in ASGM involve "push" factors aimed at meeting livelihood goals. ASGM provides an important source of income for both proximate and distant communities, representing a means of survival for impoverished farmers as well as an engine for small business growth. However, miners and their families often end up in a "poverty trap" of low productivity and indebtedness, which reduce even further their economic options. At a macro level, Ghana's ASGM activities contribute significantly to the national economy even though they are sometimes operating illegally and at a disadvantage compared to large-scale industrial mining companies. Nevertheless, complex issues of land tenure, social stability, mining regulation and taxation, and environmental degradation undermine the viability and sustainability of ASGM as a livelihood strategy. Although more research is needed to understand these complex relationships, we point to key findings and insights from social science and economics research that can guide policies and actions aimed to address the unique challenges of ASGM in Ghana and elsewhere.

  20. Soil heavy metal contamination and health risks associated with artisanal gold mining in Tongguan, Shaanxi, China.

    Science.gov (United States)

    Xiao, Ran; Wang, Shuang; Li, Ronghua; Wang, Jim J; Zhang, Zengqiang

    2017-07-01

    Soil contamination with heavy metals due to mining activities poses risks to ecological safety and human well-being. Limited studies have investigated heavy metal pollution due to artisanal mining. The present study focused on soil contamination and the health risk in villages in China with historical artisanal mining activities. Heavy metal levels in soils, tailings, cereal and vegetable crops were analyzed and health risk assessed. Additionally, a botany investigation was conducted to identify potential plants for further phytoremediation. The results showed that soils were highly contaminated by residual tailings and previous mining activities. Hg and Cd were the main pollutants in soils. The Hg and Pb concentrations in grains and some vegetables exceeded tolerance limits. Moreover, heavy metal contents in wheat grains were higher than those in maize grains, and leafy vegetables had high concentrations of metals. Ingestion of local grain-based food was the main sources of Hg, Cd, and Pb intake. Local residents had high chronic risks due to the intake of Hg and Pb, while their carcinogenic risk associated with Cd through inhalation was low. Three plants (Erigeron canadensis L., Digitaria ciliaris (Retz.) Koel., and Solanum nigrum L.) were identified as suitable species for phytoremediation. Copyright © 2017. Published by Elsevier Inc.

  1. Long-range effect of cyanide on mercury methylation in a gold mining area in southern Ecuador.

    Science.gov (United States)

    Guimaraes, Jean Remy Davée; Betancourt, Oscar; Miranda, Marcio Rodrigues; Barriga, Ramiro; Cueva, Edwin; Betancourt, Sebastián

    2011-11-01

    Small-scale gold mining in Portovelo-Zaruma, Southern Equador, performed by mercury amalgamation and cyanidation, yields 9-10 t of gold/annum, resulting in annual releases of around 0.65 t of inorganic mercury and 6000 t of sodium cyanide in the local river system. The release of sediments, cyanide, mercury, and other metals present in the ore such as lead, manganese and arsenic significantly reduces biodiversity downstream the processing plants and enriches metals in bottom sediments and biota. However, methylmercury concentrations in sediments downstream the mining area were recently found to be one order of magnitude lower than upstream or in small tributaries. In this study we investigated cyanide, bacterial activity in water and sediment and mercury methylation potentials in sediments along the Puyango river watershed, measured respectively by in-situ spectrophotometry and incubation with (3)H-leucine and (203)Hg(2+). Free cyanide was undetectable (processing plants area and was still detectable about 100 km downstream. At stations with detectable free cyanide in unfiltered water, 50% of it was dissolved and 50% associated to suspended particles. Bacterial activity and mercury methylation in sediment showed a similar spatial pattern, inverse to the one found for free cyanide in water, i.e. with significant values in pristine upstream sampling points (respectively 6.4 to 22 μgC·mg wet weight(-1)·h(-1) and 1.2 to 19% of total (203) Hg·gdry weight(-1)·day(-1)) and undetectable downstream the processing plants, returning to upstream values only in the most distant downstream stations. The data suggest that free cyanide oxidation was slower than would be expected from the high water turbulence, resulting in a long-range inhibition of bacterial activity and hence mercury methylation. The important mercury fluxes resultant from mining activities raise concerns about its biomethylation in coastal areas where many mangrove areas have been converted to shrimp

  2. Characterization of geochemical alteration halo associated with gold mineralization at the Buzwagi mine, northern Tanzania

    Science.gov (United States)

    Manya, Shukrani

    2017-05-01

    Alteration halo geochemical study was carried out along one transect at the Buzwagi mine which is found in the Neoarchaean Nzega greenstone belt of northern Tanzania. The Buzwagi mine Au mineralization is hosted in quartz veins that are cross-cutting strongly sheared and hydrothermally altered K-granites. Mineralogical studies within the shear zone reveal that sericite, silica and sulphides are the most important hydrothermal mineral assemblages responsible for Au mineralization at the Buzwagi mine. The geochemical alteration halo is characterized by the addition of Au, Cu, Fe, K, Rb, Sn, W and U to wall rocks and simultaneous removal of Na, Sr, Ba, LREE and MREE from the host rocks. The concentrations of Cu (130-870 ppm) which show strong positive correlation with Au (R2 = 0.99) are so high in the alteration halo indicating that Cu is a strong Au pathfinder at the Buzwagi mine. Owing to their immobility during the post-emplacement processes, the HFSE (Zr, Hf, Th, Ta) remained unchanged during the hydrothermal alteration process. The addition of Fe and Cu is attributed to the presence of Fe- and Cu-sulphides (pyrite, chalcopyrite and chalcocite) whereas the addition of K, Rb, Sn, W and U is a function of both primary concentrations of these elements in the host rocks as well as the subsequent strong hydrothermal alteration evidenced by sericitization and silicification which involved the destruction of feldspars into sericites). The destruction of albite and its replacement by sericite accounts for the depletion of Na, Sr (and Ba). The Buzwagi mine Au mineralization mineral association do not include the more known pathfinders like Ag, As, Sb, Bi, Te and Tl and they seem not to have played a role in the mineralization process. These elements, therefore, should not be considered as pathfinders for Au exploration purposes at a Buzwagi-like deposit.

  3. Reconnaissance study of the mining waste from the Gold Quadrilateral of the Apuseni Mountains (Romania) - data from SUSMIN project

    Science.gov (United States)

    Munteanu, Marian; Cioacă, Mihaela Elena; Ion, Daniel; Rusu, Constantin; Floria, Nelu; Maftei, Raluca; Filipciuc, Constantina; Tudor, Elena

    2015-04-01

    The Gold Quadrilateral of the Apuseni Mountains contains numerous epithermal Au-Ag deposits and porphyry Cu-Au deposits. Most mines are now closed. A reconnaissance investigation has been made on samples from the waste rock dumps at Bucium, Stănija, Valea Arsului, Ruda Barza, Larga, Haneş, Radeş-Runcu, Dealul Fetii, Valea Lungă and Caraci, and from the tailing ponds at Ţărăţel and Ribiţa (Brad mining field), Valea Săliştei and Gura Roşiei (Roşia Montană). Mercury shows the most elevated values (close to 0.8 ppm) at Ruda Barza and Haneş. Copper and Zn have contents of tens to hundreds ppm, while Pb can reach thousands ppm. Arsenic has highest values at Ruda, Haneş and Larga (150-280 ppm). Gold and silver contents vary from 0.1 ppm to 0.8 ppm and from 1 ppm to 23 ppm, respectively. For comparison, the rocks in the porphyry Cu-Au deposits at Bolcana, Bucium, Rovina, Roşia Poieni and Valea Arsului showed contents of 0.1-1.3 ppm Au, 0.2-8.5 ppm Ag, 4-278 ppm Pb, 0.2-105 ppm Te and 20-26 ppm As (Cioacă et al., 2014). The samples of sulfide-rich waste from the former processing plant at Bucium showed Te contents of 200-400 ppm. The material in the tailings ponds at Ribiţa and Ţărăţel is dominated by quartz, followed by clay minerals and gypsum ± calcite. At Valea Săliştei and Gura Roşiei, K-feldspar is dominant, followed by quartz and clay minerals. At Valea Săliştei and Gura Roşiei (> 9% K2O), potassium is significantly higher than it is at Ribiţa and Ţărăţel (< 2.5% K2O). Hg, Cu, Zn, As, Te and Bi are one order of magnitude higher at Ribiţa and Ţărăţel than they are at Valea Săliştei and Gura Roşiei. The gold content is ca. 0.3 ppm at Ţărăţel, 0.4 ppm at Valea Săliştei and Gura Roşiei and 0.8 ppm at Ribiţa. The results encourage further investigations for the assessment of the economic potential of the mining waste in the Gold Quadrilateral. This research is part of the SUSMIN project (http

  4. The risks to miners, mines, and the public posed by large seismic events in the gold mining districts of South Africa

    CSIR Research Space (South Africa)

    Durrheim, RJ

    2006-10-01

    Full Text Available with respect to mine planning and blasting schedules. The national and local monitoring networks, operated by the Council for Geoscience and mining companies, respectively, are on a par with those installed in seismically active mining districts elsewhere...

  5. Some Observations on Gold in the Weathering Profile at Garimpo Porquinho, an Artisanal Mine in the Tapajós Region, Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Sonia Maria Barros de Oliveira

    2006-03-01

    Full Text Available At Garimpo Porquinho (Tapajós Province, Brazilian Amazon gold-bearing quartz veins containing sulfides occur in anarrow zone affected by hydrothermal alteration. The artisanally mined veins are exposed in a saprolite zone extending downat least 9 m to the fresh rock and are covered by a 1 m thick residual soil. Lateral gold dispersion in the saprolite is notnoticeable whereas in the soil gold dispersion has been observed as far as 2 m from the vein. Trace metals associated with goldinclude Ag, Bi, As and Sb. Copper and lead, present in sulfides, can also indicate the presence of gold. The study of goldparticles in different levels of the profile shows that gold has been affected by weathering. In the upper levels of the profile,particles are smaller, more rounded and pitted by dissolution. Grains of primary gold containing up to 20% Ag are commonlyexhibit silver-poor rims which may penetrate deep into the grain. The interface between the Ag-poor rims and the interior isvery sharp. Such gold-rich rims likely formed by self-electrorefining of electrum grains during weathering

  6. A cross-sectional survey on knowledge and perceptions of health risks associated with arsenic and mercury contamination from artisanal gold mining in Tanzania

    Directory of Open Access Journals (Sweden)

    Charles Elias

    2013-01-01

    Full Text Available Abstract Background An estimated 0.5 to 1.5 million informal miners, of whom 30-50% are women, rely on artisanal mining for their livelihood in Tanzania. Mercury, used in the processing gold ore, and arsenic, which is a constituent of some ores, are common occupational exposures that frequently result in widespread environmental contamination. Frequently, the mining activities are conducted haphazardly without regard for environmental, occupational, or community exposure. The primary objective of this study was to assess community risk knowledge and perception of potential mercury and arsenic toxicity and/or exposure from artisanal gold mining in Rwamagasa in northwestern Tanzania. Methods A cross-sectional survey of respondents in five sub-villages in the Rwamagasa Village located in Geita District in northwestern Tanzania near Lake Victoria was conducted. This area has a history of artisanal gold mining and many of the population continue to work as miners. Using a clustered random selection approach for recruitment, a total of 160 individuals over 18 years of age completed a structured interview. Results The interviews revealed wide variations in knowledge and risk perceptions concerning mercury and arsenic exposure, with 40.6% (n=65 and 89.4% (n=143 not aware of the health effects of mercury and arsenic exposure respectively. Males were significantly more knowledgeable (n=59, 36.9% than females (n=36, 22.5% with regard to mercury (x2=3.99, px2=22.82, p= Conclusions The knowledge of individuals living in Rwamagasa, Tanzania, an area with a history of artisanal gold mining, varied widely with regard to the health hazards of mercury and arsenic. In these communities there was limited awareness of the threats to health associated with exposure to mercury and arsenic. This lack of knowledge, combined with minimal environmental monitoring and controlled waste management practices, highlights the need for health education, surveillance, and policy

  7. A cross-sectional survey on knowledge and perceptions of health risks associated with arsenic and mercury contamination from artisanal gold mining in Tanzania.

    Science.gov (United States)

    Charles, Elias; Thomas, Deborah S K; Dewey, Deborah; Davey, Mark; Ngallaba, Sospatro E; Konje, Eveline

    2013-01-25

    An estimated 0.5 to 1.5 million informal miners, of whom 30-50% are women, rely on artisanal mining for their livelihood in Tanzania. Mercury, used in the processing gold ore, and arsenic, which is a constituent of some ores, are common occupational exposures that frequently result in widespread environmental contamination. Frequently, the mining activities are conducted haphazardly without regard for environmental, occupational, or community exposure. The primary objective of this study was to assess community risk knowledge and perception of potential mercury and arsenic toxicity and/or exposure from artisanal gold mining in Rwamagasa in northwestern Tanzania. A cross-sectional survey of respondents in five sub-villages in the Rwamagasa Village located in Geita District in northwestern Tanzania near Lake Victoria was conducted. This area has a history of artisanal gold mining and many of the population continue to work as miners. Using a clustered random selection approach for recruitment, a total of 160 individuals over 18 years of age completed a structured interview. The interviews revealed wide variations in knowledge and risk perceptions concerning mercury and arsenic exposure, with 40.6% (n=65) and 89.4% (n=143) not aware of the health effects of mercury and arsenic exposure respectively. Males were significantly more knowledgeable (n=59, 36.9%) than females (n=36, 22.5%) with regard to mercury (x²=3.99, parsenic toxicity, the majority (n=10, 58.8%) were miners. The knowledge of individuals living in Rwamagasa, Tanzania, an area with a history of artisanal gold mining, varied widely with regard to the health hazards of mercury and arsenic. In these communities there was limited awareness of the threats to health associated with exposure to mercury and arsenic. This lack of knowledge, combined with minimal environmental monitoring and controlled waste management practices, highlights the need for health education, surveillance, and policy changes.

  8. Going for Gold

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    While the international gold price in February hit the highest point in 25 years at $541.20 per ounce for futures delivery, a new gold rush is sweeping across China. According to the World Gold Council, the London-based gold marketing organization funded by leading global gold mining firms, the purchase of gold products in China grew by 9 percent in the first nine

  9. Violent failure of a remnant in a deep South African gold mine

    Science.gov (United States)

    Durrheim, R. J.; Haile, A.; Roberts, M. K. C.; Schweitzer, J. K.; Spottiswoode, S. M.; Klokow, J. W.

    1998-04-01

    The violent failure of a peninsular remnant at a depth of 2300 m below surface occurred in a mine in the Carletonville Goldfield of South Africa, severely damaging a stope mining the Ventersdorp Contact Reef (VCR). At the rockburst site the VCR is 1-2 m thick with a lava hangingwall and quartzite/conglomerate footwall. The remnant had been formed as the result of a fault and `roll' encountered during mining. Observations at the rockburst site led us to conclude that the seismic event, with local magnitude of 2.1, resulted from failure of the remnant with attendant movement into the workings. The event could not be explained by a single shear slip. Two different damage mechanisms were identified. Firstly, the face and footwall on the east side of the remnant were violently ejected into the void between the original face and first line of timber packs following failure and dilation of the remnant and its foundation. Secondly, the hangingwall on the south side of the remnant fragmented and collapsed when subjected to intense seismic shaking. This response was due to the presence of a bedding-parallel fault and calcite-coated joints in the vicinity of a `roll'. The stope support system failed to contain the seismically fragmented rock.

  10. Factors Affecting Elevated Arsenic and Methyl Mercury Concentrations in Small Shield Lakes Surrounding Gold Mines near the Yellowknife, NT, (Canada) Region.

    Science.gov (United States)

    Houben, Adam James; D'Onofrio, Rebecca; Kokelj, Steven V; Blais, Jules M

    2016-01-01

    Gold mines in the Yellowknife, NT, region--in particular, the Giant Mine--operated from 1949-99, releasing 237,000 tonnes of waste arsenic trioxide (As2O3) dust, among other compounds, from gold ore extraction and roasting processes. For the first time, we show the geospatial distribution of roaster-derived emissions of several chemical species beyond the mine property on otherwise undisturbed taiga shield lakes within a 25 km radius of the mine, 11 years after its closing. Additionally, we demonstrate that underlying bedrock is not a significant source for the elevated concentrations in overlying surface waters. Aquatic arsenic (As) concentrations are well above guidelines for drinking water (10 μg/L) and protection for aquatic life (5 μg/L), ranging up to 136 μg/L in lakes within 4 km from the mine, to 2.0 μg/L in lakes 24 km away. High conversion ratios of methyl mercury were shown in lakes near the roaster stack as well, with MeHg concentrations reaching 44% of total mercury. The risk of elevated exposures by these metals is significant, as many lakes used for recreation and fishing near the City of Yellowknife are within this radius of elevated As and methyl Hg concentrations.

  11. Factors Affecting Elevated Arsenic and Methyl Mercury Concentrations in Small Shield Lakes Surrounding Gold Mines near the Yellowknife, NT, (Canada Region.

    Directory of Open Access Journals (Sweden)

    Adam James Houben

    Full Text Available Gold mines in the Yellowknife, NT, region--in particular, the Giant Mine--operated from 1949-99, releasing 237,000 tonnes of waste arsenic trioxide (As2O3 dust, among other compounds, from gold ore extraction and roasting processes. For the first time, we show the geospatial distribution of roaster-derived emissions of several chemical species beyond the mine property on otherwise undisturbed taiga shield lakes within a 25 km radius of the mine, 11 years after its closing. Additionally, we demonstrate that underlying bedrock is not a significant source for the elevated concentrations in overlying surface waters. Aquatic arsenic (As concentrations are well above guidelines for drinking water (10 μg/L and protection for aquatic life (5 μg/L, ranging up to 136 μg/L in lakes within 4 km from the mine, to 2.0 μg/L in lakes 24 km away. High conversion ratios of methyl mercury were shown in lakes near the roaster stack as well, with MeHg concentrations reaching 44% of total mercury. The risk of elevated exposures by these metals is significant, as many lakes used for recreation and fishing near the City of Yellowknife are within this radius of elevated As and methyl Hg concentrations.

  12. Occupational exposure to radon and natural gamma radiation in the La Carolina, a former gold mine in San Luis Province, Argentina.

    Science.gov (United States)

    Anjos, R M; Umisedo, N; da Silva, A A R; Estellita, L; Rizzotto, M; Yoshimura, E M; Velasco, H; Santos, A M A

    2010-02-01

    Radon and gamma radiation level measurements were carried out inside the La Carolina mine, one of the oldest gold mining camps of southern South America, which is open for touristic visits nowadays. CR-39 track-etch detectors and thermoluminescent dosimeters of natural CaF(2) and LiF TLD-100 were exposed at 14 points along the mine tunnels in order to estimate the mean (222)Rn concentration and the ambient dose equivalent during the summer season (November 2008 to February 2009). The values for the (222)Rn concentration at each monitoring site ranged from 1.8+/-0.1 kBqm(-3) to 6.0+/-0.5 kBqm(-3), with a mean value of 4.8 kBqm(-3), indicating that these measurements exceed in about three times the upper action level recommended by ICRP for workplaces. The correlations between radon and gamma radiation levels inside the mine were also investigated. Effective doses due to (222)Rn and gamma rays inside the mine were determined, resulting in negligible values to tourists. Considering the effective dose to the mine tourist guides, values exceeding 20mSv of internal contribution to the effective doses can be reached, depending on the number of working hours inside the mine.

  13. Occupational exposure to radon and natural gamma radiation in the La Carolina, a former gold mine in San Luis Province, Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Anjos, R.M., E-mail: meigikos@if.uff.b [Instituto de Fisica, Universidade Federal Fluminense, Av. Gal Milton Tavares de Souza, s/no, Gragoata, 24210-340, Niteroi, RJ (Brazil); Umisedo, N. [Instituto de Fisica, Universidade de Sao Paulo, C.P. 66318, 05315-970, Sao Paulo, SP (Brazil); Silva, A.A.R. da [Servico Especializado em Engenharia de Seguranca e Medicina do Trabalho, Departamento de Saude, Universidade de Sao Paulo, Rua da Reitoria, 109, 05508-900, Sao Paulo, SP (Brazil); Estellita, L. [Instituto de Fisica, Universidade Federal Fluminense, Av. Gal Milton Tavares de Souza, s/no, Gragoata, 24210-340, Niteroi, RJ (Brazil); Rizzotto, M. [GEA, Instituto de Matematica Aplicada San Luis (IMASL), Universidad Nacional de San Luis, Consejo Nacional de Investigaciones Cientificas y Tecnicas, Ej. de los Andes 950, D5700HHW San Luis (Argentina); Yoshimura, E.M. [Instituto de Fisica, Universidade de Sao Paulo, C.P. 66318, 05315-970, Sao Paulo, SP (Brazil); Velasco, H. [GEA, Instituto de Matematica Aplicada San Luis (IMASL), Universidad Nacional de San Luis, Consejo Nacional de Investigaciones Cientificas y Tecnicas, Ej. de los Andes 950, D5700HHW San Luis (Argentina); Santos, A.M.A. [Fundacao Jorge Duprat Figueiredo de Seguranca e Medicina do Trabalho, Fundacentro, C.P. 11484, 05499-970, Sao Paulo, SP (Brazil)

    2010-02-15

    Radon and gamma radiation level measurements were carried out inside the La Carolina mine, one of the oldest gold mining camps of southern South America, which is open for touristic visits nowadays. CR-39 track-etch detectors and thermoluminescent dosimeters of natural CaF{sub 2} and LiF TLD-100 were exposed at 14 points along the mine tunnels in order to estimate the mean {sup 222}Rn concentration and the ambient dose equivalent during the summer season (November 2008 to February 2009). The values for the {sup 222}Rn concentration at each monitoring site ranged from 1.8 +- 0.1 kBq m{sup -3} to 6.0 +- 0.5 kBq m{sup -3}, with a mean value of 4.8 kBq m{sup -3}, indicating that these measurements exceed in about three times the upper action level recommended by ICRP for workplaces. The correlations between radon and gamma radiation levels inside the mine were also investigated. Effective doses due to {sup 222}Rn and gamma rays inside the mine were determined, resulting in negligible values to tourists. Considering the effective dose to the mine tourist guides, values exceeding 20 mSv of internal contribution to the effective doses can be reached, depending on the number of working hours inside the mine.

  14. Investigating hydraulic connections and the origin of water in a mine tunnel using stable isotopes and hydrographs

    Energy Technology Data Exchange (ETDEWEB)

    Walton-Day, Katherine, E-mail: kwaltond@usgs.gov [US Geological Survey, Box 25046, MS 415, Denver, CO 80225 (United States); Poeter, Eileen [Department of Geology and Geological Engineering, Colorado School of Mines, Golden, CO 80401 (United States)

    2009-12-15

    Turquoise Lake is a water-supply reservoir located north of the historic Sugarloaf Mining district near Leadville, Colorado, USA. Elevated water levels in the reservoir may increase flow of low-quality water from abandoned mine tunnels in the Sugarloaf District and degrade water quality downstream. The objective of this study was to understand the sources of water to Dinero mine drainage tunnel and evaluate whether or not there was a direct hydrologic connection between Dinero mine tunnel and Turquoise Lake from late 2002 to early 2008. This study utilized hydrograph data from nearby draining mine tunnels and the lake, and stable isotope ({delta}{sup 18}O and {delta}{sup 2}H) data from the lake, nearby draining mine tunnels, imported water, and springs to characterize water sources in the study area. Hydrograph results indicate that flow from the Dinero mine tunnel decreased 26% (2006) and 10% (2007) when lake elevation (above mean sea level) decreased below approximately 3004 m (approximately 9855 feet). Results of isotope analysis delineated two meteoric water lines in the study area. One line characterizes surface water and water imported to the study area from the western side of the Continental Divide. The other line characterizes groundwater including draining mine tunnels, springs, and seeps. Isotope mixing calculations indicate that water from Turquoise Lake or seasonal groundwater recharge from snowmelt represents approximately 10% or less of the water in Dinero mine tunnel. However, most of the water in Dinero mine tunnel is from deep groundwater having minimal isotopic variation. The asymmetric shape of the Dinero mine tunnel hydrograph may indicate that a limited mine pool exists behind a collapse in the tunnel and attenutates seasonal recharge. Alternatively, a conceptual model is presented (and supported with MODFLOW simulations) that is consistent with current and previous data collected in the study area, and illustrates how fluctuating lake levels

  15. Mercury in soils and sediments from gold mining liabilities in Southern Amazonia

    Directory of Open Access Journals (Sweden)

    Julio Cesar Wasserman

    2007-08-01

    Full Text Available The 1980-1990 Amazonian gold rush left an enormous liability that increasingly has been substituted by developing fish aquaculture. This work aimed at the identification of the mercury levels in the environment, associated with fish farms located in the North of Mato Grosso State, Southern Amazon. Sediment and soil samples were analyzed for total organic carbon and total mercury. Results indicate that the chemical characteristics of the sediment largely depend on the management procedures of the fish pond (liming, fish food used and fish population. The soils presented relatively low concentrations when compared with other data from the literature.

  16. Application of organic matter to enhance phytoremediation of mercury contaminated soils using local plant species: a case study on small-scale gold mining locations in Banyuwangi of East Java

    OpenAIRE

    N. Muddarisna; B.C. Siahaan

    2014-01-01

    The discharge of small-scale gold mine tailing to agricultural lands at Pesanggaran village of Banyuwangi Regency caused soil degradation as indicated by reduced crop production. This soil degradation is mainly due to the toxicity of mercury contained in the tailing. The purpose of this study was to explore the potential of three local plant species, i.e. Lindernia crustacea, Digitaria radicosa, and Cyperus kyllingia for phytoremediation of agricultural land contaminated gold mine waste conta...

  17. Broadband records of earthquakes in deep gold mines and a comparison with results from SAFOD, California

    Science.gov (United States)

    McGarr, A.; Boettcher, M.; Fletcher, Joe B.; Sell, R.; Johnston, M.J.S.; Durrheim, R.; Spottiswoode, S.; Milev, A.

    2009-01-01

    For one week during September 2007, we deployed a temporary network of field recorders and accelerometers at four sites within two deep, seismically active mines. The ground-motion data, recorded at 200 samples/sec, are well suited to determining source and ground-motion parameters for the mining-induced earthquakes within and adjacent to our network. Four earthquakes with magnitudes close to 2 were recorded with high signal/noise at all four sites. Analysis of seismic moments and peak velocities, in conjunction with the results of laboratory stick-slip friction experiments, were used to estimate source processes that are key to understanding source physics and to assessing underground seismic hazard. The maximum displacements on the rupture surfaces can be estimated from the parameter Rv, where v is the peak ground velocity at a given recording site, and R is the hypocentral distance. For each earthquake, the maximum slip and seismic moment can be combined with results from laboratory friction experiments to estimate the maximum slip rate within the rupture zone. Analysis of the four M 2 earthquakes recorded during our deployment and one of special interest recorded by the in-mine seismic network in 2004 revealed maximum slips ranging from 4 to 27 mm and maximum slip rates from 1.1 to 6:3 m=sec. Applying the same analyses to an M 2.1 earthquake within a cluster of repeating earthquakes near the San Andreas Fault Observatory at Depth site, California, yielded similar results for maximum slip and slip rate, 14 mm and 4:0 m=sec.

  18. Effects of soil composition and mineralogy on the bioaccessibility of arsenic from tailings and soil in gold mine districts of Nova Scotia

    OpenAIRE

    Meunier, Louise; Walker, Stephen R; Wragg, Joanna; Parsons, Michael B.; Koch, Iris; Jamieson, Heather E; Reimer, Kenneth J.

    2010-01-01

    Bioaccessibility tests and mineralogical analyses were performed on arsenic-contaminated tailings and soils from gold mine districts of Nova Scotia, Canada, to examine the links between soil composition, mineralogy, and arsenic bioaccessibility. Arsenic bioaccessibility ranges from 0.1% to 49%. A weak correlation was observed between total and bioaccessible arsenic concentrations, and the arsenic bioaccessibility was not correlated with other elements. Bulk X-ray absorption near-edge structur...

  19. Pollution status and mercury sedimentation in small river near amalgamation and cyanidation units of Talawaan-Tatelu gold mining, North Sulawesi

    Directory of Open Access Journals (Sweden)

    T M Palapa

    2015-04-01

    Full Text Available Information Journal Help User Username Password Remember me Notifications View Subscribe / Unsubscribe Search Keyword : The activities of traditional gold mining in the region of Talawaan-Tatelu, North Minahasa regency, North Sulawesi, have been ongoing since 1998. Processing the gold in the mine consists of three stages i.e., the excavation, milling and amalgamation, and the use of cyanide tanks. Waste from the processing units which contains high mercury, generally flows directly into small rivers nearby. This study aimed to determine the pollution status and mercury sedimentation in a small river near the amalgamation and cyanidation processing units in Talawaan-Tatelu gold mining. Water and sediment samples were taken from seven stations along a small river, as many as four temporal replications (weekly. Mercury determination in water and sediments was done by using Cold Vapor Atomic Fluorescence Spectrometry. Pollution status was determined through the calculation of Hg ratio in water samples and in water quality criterion (4th class, as noted in The Indonesian Government Regulation No. 82 of 2001 on Water Quality and Water Pollution Control, while the mercury sedimentation was calculated from the ratio of mercury in water and sediment. The results showed that there are differences in the status of pollution and mercury sedimentation of seven sampling stations. Amalgamation and cyanidation processing units provide significant impact on the status of pollution (although it is categorized in contamination and mercury sedimentation along small river in the gold mining area of Talawaan-Tatelu. The downstream of this small river, Talawaan River, is the main river of the Talawaan watershed. Things that should be a concern are Talawaan rural communities living near Talawaan River who often use the water for daily needs such as bathing and washing. Risk to public health around the river can arise when the status of pollution and mercury

  20. Mapping the expansion of galamsey gold mines in the cocoa growing area of Ghana using optical remote sensing

    Science.gov (United States)

    Snapir, B.; Simms, D. M.; Waine, T. W.

    2017-06-01

    Artisanal gold mining (galamsey) and cocoa farming are essential sources of income for local populations in Ghana. Unfortunately the former poses serious threats to the environment and human health, and conflicts with cocoa farming and other livelihoods. Timely and spatially referenced information on the extent of galamsey is needed to understand and limit the negative impacts of mining. To address this, we use multi-date UK-DMC2 satellite images to map the extent and expansion of galamsey from 2011 to 2015. We map the total area of galamsey in 2013 over the cocoa growing area, using k-means clustering on a cloud-free 2013 image with strong spectral contrast between galamsey and the surrounding vegetation. We also process a pair of hazy images from 2011 and 2015 with Multivariate Alteration Detection to map the 2011-2015 galamsey expansion in a subset, labelled the change area. We use a set of visually interpreted random sample points to compute bias-corrected area estimates. We also delineate an indicative impact zone of pollution proportional to the density of galamsey, assuming a maximum radius of 10 km. In the cocoa growing area of Ghana, the estimated total area of galamsey in 2013 is 27,839 ha with an impact zone of 551,496 ha. In the change area, galamsey has more than tripled between 2011 and 2015, resulting in 603 ha of direct encroachment into protected forest reserves. Assuming the same growth rate for the rest of the cocoa growing area, the total area of galamsey in 2015 is estimated at 43,879 ha. Galamsey is developing along most of the river network (Offin, Ankobra, Birim, Anum, Tano), with downstream pollution affecting both land and water.

  1. Toxicity and metal speciation characterisation of waste water from an abandoned gold mine in tropical northern Australia.

    Science.gov (United States)

    Dam, Rick van; Hogan, Alicia; Harford, Andrew; Markich, Scott

    2008-09-01

    The decommissioned Mount Todd gold mine, located in the wet-dry tropics of northern Australia, consists of a large waste water inventory and an acid rock drainage problem, which has the potential to impact upon freshwater ecosystems of the Edith River catchment. The toxicity of retention pond 1 (RP1) water was determined using six local freshwater species (duckweed, alga, cladoceran, snail, hydra and a fish). RP1 water was very toxic to all species, with the percentage dilution of RP1 water inhibiting 10% of organism response (IC10), or lethal to 5% of individuals (LC5), ranging from 0.007 to 0.088%. The percentage dilution of RP1 water inhibiting 50% of organism response (IC50), or lethal to 50% of individuals (LC50), ranged from 0.051% to 0.58%. Based on chemical analyses and geochemical speciation modelling of the test waters, Cu, Zn and Al were the most likely toxic components at acidic dilutions (i.e. > or =1%), while Cu and Zn were the most likely toxic components at 0.1% RP1 water, where pH was 6.5. Species sensitivity distributions (SSDs) were used to predict dilutions of RP1 water that would protect or unacceptably affect the downstream aquatic ecosystems. A dilution ratio of 1 part RP1 water to 20000 parts Edith River water (0.005% RP1 water) was calculated to be required for the protection of at least 95% of species. This information can be used in conjunction with field chemical and biological data to better predict the ecological risks of RP1 waste water downstream of the Mount Todd mine.

  2. Cancer incidence and soil arsenic exposure in a historical gold mining area in Victoria, Australia: a geospatial analysis.

    Science.gov (United States)

    Pearce, Dora Claire; Dowling, Kim; Sim, Malcolm Ross

    2012-01-01

    Soil and mine waste around historical gold mining sites may have elevated arsenic concentrations. Recent evidence suggests some systemic arsenic absorption by residents in the goldfields region of Victoria, Australia. Victorian Cancer Registry and geochemical data were accessed for an ecological geographical correlation study, 1984-2003. Spatial empirical Bayes smoothing was applied when estimating standardised incidence ratios (SIRs) for cancers in 61 statistical local areas. The derived soil arsenic exposure metric ranged from 1.4 to 1857 mg/kg. Spatial autoregressive modelling detected increases in smoothed SIRs for all cancers of 0.05 (95% confidence interval (CI), 0.02-0.08) and 0.04 (0.01-0.07) per 2.7-fold increase in the natural log-transformed exposure metric for males and females, respectively, in more socioeconomically disadvantaged areas; for melanoma in males (0.05 (0.01-0.08) adjusted for disadvantage) and females (0.05 (0.02-0.09) in disadvantaged areas). Excess risks were estimated for all cancers (relative risk 1.21 (95% CI, 1.15-1.27) and 1.08 (1.03-1.14)), and melanoma (1.52 (1.25-1.85) and 1.29 (1.08-1.55)), for males and females, respectively, in disadvantaged areas in the highest quintile of the exposure metric relative to the lowest. Our findings suggest small but significant increases in past cancer risk associated with increasing soil arsenic in socioeconomically disadvantaged areas and demonstrate the robustness of this geospatial approach.

  3. Report on observations and suggestions arising out of a visit to the gold mining industry in South Africa

    CSIR Research Space (South Africa)

    Reed, JJ

    1968-02-01

    Full Text Available Following a visit to the South African mining industry and the Chambers Research Organization, the author has presented a number of observations on various aspects of mining and mining research in the Republic. These observations relate generally...

  4. Stable isotopes of nitrogen in plants of contaminated soils and sediments by an abandoned gold mine

    Science.gov (United States)

    Becerra, O. F.; Sanchez, A.; Marmolejo, A. J.; Magallanes, V. R.

    2013-05-01

    Mining industry is an economic activity which generates high ecological impact. In the mining district "El Triunfo", the concentration of potential toxic elements (PTE: As, Cd, Hg, Sb) have exceeded 50 times allowable limits. Nowadays, environmental pollution levels can be evaluated through the use of stable isotopes of N. For this, isotopic analysis of nitrogen and concentrations of metals and metalloids were considered in the area where plants are exposed (Prosopis spp., Parkinsonia spp. and Salicornia spp.) Polluted sediments were collected over 48 km of the Las Gallinas-El Hondo-El Carrizal arroyo. PTE concentrations, with a previous acidic digestion (HF, HCl, HNO3 and H2SO4) were determined by ICP-MS. As and Sb were determined by NAA. For N isotopes, obtained samples were grounded to fine powder in an agate mortar with an acetone rinse between samples then analyzed by an EA-IRMS. Results showed that plants growing on the tailings decreased their δ15N proportionally to the metal concentration in the area.

  5. Contaminação por mercúrio no Brasil: fontes industriais vs garimpo de ouro Mercury contamination in Brazil: industrial sources vs gold mining

    Directory of Open Access Journals (Sweden)

    L. D. Lacerda

    1997-04-01

    Full Text Available This paper reviews the history of Hg contamination in Brazil by characterizing and quantifying two major sources of Hg emissions to the environment: industrial sources and gold mining. Industry was responsible for nearly 100% of total Hg emissions from the late 1940's to the early 1970's, when efficient control policies were enforced, leading to a decrease in emissions. Gold mining, on the other hand was nearly insignificant as a Hg source up to the late 1970's, but presently is responsible for over 80% of total emissions. Presently, over 115 tons of Hg are released into the atmosphere in Brazil annually. Nearly 78 tons come from gold mining operations, 12 tons come from chlor-alkali industry and 25 tons come from all other industrial uses. Inputs to soils and waters however, are still unknown, due to lack of detailed data base. However, emissions from diffuse sources rather than well studied classical industrial sources are probably responsible for the major inputs of mercury to these compartments.

  6. La Balouta exhumed karst: a Roman gold-mine-derived landscape within the Las Médulas UNESCO World Heritage Site (Spain

    Directory of Open Access Journals (Sweden)

    José M. Redondo-Vega

    2015-09-01

    Full Text Available The La Balouta Valley, located in the extreme SW region of the Las Médulas Natural Monument and UNESCO World Heritage Site (León, Spain, is one of the largest gold-mining sites developed by the Romans more than 2,000 years ago when excavating a thick series of red Miocene sediments in the area. The main determining feature of the La Balouta Valley, especially if we compare it with the Sil River Valley of which it is a tributary, is its status of a non-functional valley. It is a dry paleo-valley with a flat bottom and is characterized by limited surface water runoff and the presence of small cavities, channels, and residual karst topography. Variscan structures that form the structural framework of the study area underwent long-term erosion and supported deep sediment accumulation in the area during the Miocene, reaching depths of more than 100 m. A portion of these sediments accumulated over a karst, as indicated by karst channels that exhibit total and locally partial filling with red sediments similar to those mined at Las Médulas roughly 2 km further to the east. The presence of gold particles in one of the sediment samples and the identification of several characteristics common of formations mined by the Romans lead us to deem the La Balouta Valley an ancient paleokarst that was initially fossilized by deposition of red Miocene sediments and subsequently excavated via historical mining activities, which formed its current characteristics. In La Balouta, natural and anthropogenic processes have produced a unique cultural landscape that is reflective of systematic gold mining of sediments on the NW Iberian Peninsula by the Romans.

  7. Research and Simulated Calculation of Long-distance Hydraulic-fiuid Supply System for Coal Mine%煤矿远距离供液系统仿真计算与研究

    Institute of Scientific and Technical Information of China (English)

    王俊伟; 赵利杰; 马芬芝

    2014-01-01

    In order to improve mining efficiency, reduce the amount of the Roadway Excavation,enhance the mine production safety, based on distributed parameter model, the paper make scientific researches on Long-distance Hydraulic-fiuid Supply. the AMESIM Software is used to establish Long -distance Hydraulic -fiuid supply model, then according to various situations were simulated, finally design Long -distance Hydraulic -fiuid Supply scheme. Through the research, the distance of Long -distance Hydraulic-fiuid Supply scheme for Fully-mechanized Mining Faceis 1500 meters,thatbasically meet the needs of the mining area face of my company.%为了提高回采效率,减小巷道掘进量,增强矿井生产的安全性,基于分布式参数模型,本文对工作面远距离供液技术进行研究。首先使用 AMESIM 软件建立远距离供液模型,然后针对各种情况进行仿真计算,最后设计远距离供液方案。通过研究,远距离供液方案,可以为综采工作面提供1500m 的供液距离,基本满足采区工作面的需要。

  8. Flotation Experiment Research on A Gold ore of a Gold Mine from Inner Mongolia%内蒙古某金矿石金的浮选试验研究

    Institute of Scientific and Technical Information of China (English)

    程秀峰; 周南

    2015-01-01

    The main recovering element in a ore is gold , and gold mineral is micro particle . poisonous ele-ment in a ore is less . The technology of one coarse grinding and two roughing flotation Followed by three cleanings .This technology is simple and effective . Flotation gold concentrate grade is 122 g/t and the gold recovery rate 92 .56% on the condition of crude gold grade being 19 .56g/t . This technological process pro-vides a technical basis for the development of the mine .%矿石中可回收的元素为金 ,属于微细粒金 ,有害元素砷含量较低.浮选工艺流程为一次粗磨两次粗选、三次精选.工艺流程简单有效 ,在原矿品位A u4 .20 g/t条件下 ,浮选得到金精矿金品位122 g/t ;金回收率92 .56% .为该金矿的合理开发提供了技术依据.

  9. Identification of Response Options to Artisanal and Small-Scale Gold Mining (ASGM) in Ghana via the Delphi Process

    Science.gov (United States)

    Basu, Avik; Phipps, Sean; Long, Rachel; Essegbey, George; Basu, Niladri

    2015-01-01

    The Delphi technique is a means of facilitating discussion among experts in order to develop consensus, and can be used for policy formulation. This article describes a modified Delphi approach in which 27 multi-disciplinary academics and 22 stakeholders from Ghana and North America were polled about ways to address negative effects of small-scale gold mining (ASGM) in Ghana. In early 2014, the academics, working in disciplinary groups, synthesized 17 response options based on data aggregated during an Integrated Assessment of ASGM in Ghana. The researchers participated in two rounds of Delphi polling in March and April 2014, during which 17 options were condensed into 12. Response options were rated via a 4-point Likert scale in terms of benefit (economic, environmental, and benefit to people) and feasibility (economic, social/cultural, political, and implementation). The six highest-scoring options populated a third Delphi poll, which 22 stakeholders from diverse sectors completed in April 2015. The academics and stakeholders also prioritized the response options using ranking exercises. The technique successfully gauged expert opinion on ASGM, and helped identify potential responses, policies and solutions for the sector. This is timely given that improvement to the ASGM sector is an important component within the UN Minamata Convention. PMID:26378557

  10. Trace metals associated with deep-sea tailings placement at the Batu Hijau copper-gold mine, Sumbawa, Indonesia.

    Science.gov (United States)

    Angel, Brad M; Simpson, Stuart L; Jarolimek, Chad V; Jung, Rob; Waworuntu, Jorina; Batterham, Grant

    2013-08-15

    The Batu Hijau copper-gold mine on the island of Sumbawa, Indonesia operates a deep-sea tailings placement (DSTP) facility to dispose of the tailings within the offshore Senunu Canyon. The concentrations of trace metals in tailings, waters, and sediments from locations in the vicinity of the DSTP were determined during surveys in 2004 and 2009. In coastal and deep seawater samples from Alas Strait and the South Coast of Sumbawa, the dissolved concentrations of Ag, As, Cd, Cr, Hg, Pb and Zn were in the sub μg/L range. Dissolved copper concentrations ranged from 0.05 to 0.65 μg/L for all depths at these sites. Dissolved copper concentrations were the highest in the bottom-water from within the tailings plume inside Senunu Canyon, with up to 6.5 μg Cu/L measured in close proximity to the tailings discharge. In general, the concentrations of dissolved and particulate metals were similar in 2004 and 2009. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Integrated Assessment of Artisanal and Small-Scale Gold Mining in Ghana—Part 2: Natural Sciences Review

    Directory of Open Access Journals (Sweden)

    Mozhgon Rajaee

    2015-07-01

    Full Text Available This paper is one of three synthesis documents produced via an integrated assessment (IA that aims to increase understanding of artisanal and small-scale gold mining (ASGM in Ghana. Given the complexities surrounding ASGM, an integrated assessment (IA framework was utilized to analyze socio-economic, health, and environmental data, and co-develop evidence-based responses with stakeholders. This paper focuses on the causes, status, trends, and consequences of ecological issues related to ASGM activity in Ghana. It reviews dozens of studies and thousands of samples to document evidence of heavy metals contamination in ecological media across Ghana. Soil and water mercury concentrations were generally lower than guideline values, but sediment mercury concentrations surpassed guideline values in 64% of samples. Arsenic, cadmium, and lead exceeded guideline values in 67%, 17%, and 24% of water samples, respectively. Other water quality parameters near ASGM sites show impairment, with some samples exceeding guidelines for acidity, turbidity, and nitrates. Additional ASGM-related stressors on environmental quality and ecosystem services include deforestation, land degradation, biodiversity loss, legacy contamination, and potential linkages to climate change. Though more research is needed to further elucidate the long-term impacts of ASGM on the environment, the plausible consequences of ecological damages should guide policies and actions to address the unique challenges posed by ASGM.

  12. Thermostable hemicellulases of a bacterium, Geobacillus sp. DC3, isolated from the former Homestake gold mine in Lead, South Dakota.

    Science.gov (United States)

    Bergdale, Terran E; Hughes, Stephen R; Bang, Sookie S

    2014-04-01

    A thermophilic strain, Geobacillus sp. DC3, capable of producing hemicellulolytic enzymes was isolated from the 1.5-km depth of the former Homestake gold mine in Lead, South Dakota. The DC3 strain expressed a high level of extracellular endoxylanase at 39.5 U/mg protein with additional hemicellulases including β-xylosidase (0.209 U/mg) and arabinofuranosidase (0.230 U/mg), after the bacterium was grown in xylan for 24 h. Partially purified DC3 endoxylanase exhibited a molecular mass of approximately 43 kDa according to zymography with an optimal pH of 7 and optimal temperature of 70 °C. The kinetic constants, K m and V max, were 13.8 mg/mL and 77.5 μmol xylose/min·mg xylan, respectively. The endoxylanase was highly stable and maintained 70 % of its original activity after 16 h incubation at 70 °C. The thermostable properties and presence of three different hemicellulases of Geobacillus sp. DC3 strain support its potential application for industrial hydrolysis of renewable biomass such as lignocelluloses.

  13. Integrated Assessment of Artisanal and Small-Scale Gold Mining in Ghana—Part 1: Human Health Review

    Directory of Open Access Journals (Sweden)

    Niladri Basu

    2015-05-01

    Full Text Available This report is one of three synthesis documents produced via an integrated assessment (IA that aims to increase understanding of artisanal and small-scale gold mining (ASGM in Ghana. Given the complexities surrounding ASGM, an IA framework was utilized to analyze economic, social, health, and environmental data, and co-develop evidence-based responses with pertinent stakeholders. The current analysis focuses on the health of ASGM miners and community members, and synthesizes extant data from the literature as well as co-authors’ recent findings regarding the causes, status, trends, and consequences of ASGM in Ghana. The results provide evidence from across multiple Ghanaian ASGM sites that document relatively high exposures to mercury and other heavy metals, occupational injuries and noise exposure. The work also reviews limited data on psychosocial health, nutrition, cardiovascular and respiratory health, sexual health, and water and sanitation. Taken together, the findings provide a thorough overview of human health issues in Ghanaian ASGM communities. Though more research is needed to further elucidate the relationships between ASGM and health outcomes, the existing research on plausible health consequences of ASGM should guide policies and actions to better address the unique challenges of ASGM in Ghana and potentially elsewhere.

  14. Advances in life cycle assessment and emergy evaluation with case studies in gold mining and pineapple production

    Science.gov (United States)

    Ingwersen, Wesley W.

    Life cycle assessment (LCA) is an internationally standardized framework for assessing the environmental impacts of products that is rapidly evolving to improve understanding and quantification of how complex product systems depend upon and affect the environment. This dissertation contributes to that evolution through the development of new methods for measuring impacts, estimating the uncertainty of impacts, and measuring ranges of environmental performance, with a focus on product systems in non-OECD countries that have not been well characterized. The integration of a measure of total energy use, emergy, is demonstrated in an LCA of gold from the Yanacocha mine in Peru in the second chapter. A model for estimating the accuracy of emergy results is proposed in the following chapter. The fourth chapter presents a template for LCA-based quantification of the range of environmental performance for tropical agricultural products using the example of fresh pineapple production for export in Costa Rica that can be used to create product labels with environmental information. The final chapter synthesizes how each methodological contribution will together improve the science of measuring product environmental performance.

  15. Phylogenetic evidence of noteworthy microflora from the subsurface of the former Homestake gold mine, Lead, South Dakota

    Science.gov (United States)

    Waddell, Evan J.; Elliott, Terran J.; Sani, Rajesh K.; Vahrenkamp, Jefferey M.; Roggenthen, William M.; Anderson, Cynthia M.; Bang, Sookie S.

    2013-01-01

    Molecular characterization of subsurface microbial communities in the former Homestake gold mine, South Dakota, was carried out by 16S rDNA sequence analysis using a water sample and a weathered soil–like sample. Geochemical analyses indicated that both samples were high in sulfur, rich in nitrogen and salt, but with significantly different metal concentrations. Microbial diversity comparisons unexpectedly revealed three distinct operational taxonomic units (OTUs) belonging to the archaeal phylum Thaumarchaeota typically identified from marine environments, and one OTU to a potentially novel phylum that falls sister to Thaumarchaeota. To our knowledge this is only the second report of Thaumarchaeota in a terrestrial environment. The majority of the clones from Archaea sequence libraries fell into two closely related OTUs and grouped most closely to an ammonia–oxidizing, carbon–fixing and halophilic thaumarchaeote genus, Nitrosopumilus. The two samples showed neither Euryarchaeota nor Crenarchaeota members that were often identified from other subsurface terrestrial ecosystems. Bacteria OTUs containing the highest percentage of sequences were related to sulfur-oxidizing bacteria of the orders Chromatiales and Thiotrichales. Community members of Bacteria from individual Homestake ecosystems were heterogeneous and distinctive to each community with unique phylotypes identified within each sample. PMID:20662386

  16. Identification of Response Options to Artisanal and Small-Scale Gold Mining (ASGM in Ghana via the Delphi Process

    Directory of Open Access Journals (Sweden)

    Avik Basu

    2015-09-01

    Full Text Available The Delphi technique is a means of facilitating discussion among experts in order to develop consensus, and can be used for policy formulation. This article describes a modified Delphi approach in which 27 multi-disciplinary academics and 22 stakeholders from Ghana and North America were polled about ways to address negative effects of small-scale gold mining (ASGM in Ghana. In early 2014, the academics, working in disciplinary groups, synthesized 17 response options based on data aggregated during an Integrated Assessment of ASGM in Ghana. The researchers participated in two rounds of Delphi polling in March and April 2014, during which 17 options were condensed into 12. Response options were rated via a 4-point Likert scale in terms of benefit (economic, environmental, and benefit to people and feasibility (economic, social/cultural, political, and implementation. The six highest-scoring options populated a third Delphi poll, which 22 stakeholders from diverse sectors completed in April 2015. The academics and stakeholders also prioritized the response options using ranking exercises. The technique successfully gauged expert opinion on ASGM, and helped identify potential responses, policies and solutions for the sector. This is timely given that improvement to the ASGM sector is an important component within the UN Minamata Convention.

  17. Design and construction of a prototype of hydraulic generator for study and development of control strategies for electric power generation in underground mines

    Directory of Open Access Journals (Sweden)

    Fabián Higuera

    2013-12-01

    Full Text Available This paper presents the design and control of a hydraulic generator to produce energy in the underground mine EL UVO of the company Paz del Río S.A., taking advantage the water flows that are generated in the exploitation of iron ore. The generator is constituted of a Pelton wheel which receives water through a servo valve, and it is connected to a DC generator. It was developed a discrete controller by algebraic methods for controlling the servo valve with the aim of achieving a constant flow of water to the Pelton wheel, allowing a constant voltage generation.

  18. Mining

    Directory of Open Access Journals (Sweden)

    Khairullah Khan

    2014-09-01

    Full Text Available Opinion mining is an interesting area of research because of its applications in various fields. Collecting opinions of people about products and about social and political events and problems through the Web is becoming increasingly popular every day. The opinions of users are helpful for the public and for stakeholders when making certain decisions. Opinion mining is a way to retrieve information through search engines, Web blogs and social networks. Because of the huge number of reviews in the form of unstructured text, it is impossible to summarize the information manually. Accordingly, efficient computational methods are needed for mining and summarizing the reviews from corpuses and Web documents. This study presents a systematic literature survey regarding the computational techniques, models and algorithms for mining opinion components from unstructured reviews.

  19. Estimation of groundwater flow directions and the tensor of hydraulic conductivity in crystalline massif rocks using information from surface structural geology and mining exploration boreholes

    Science.gov (United States)

    Florez, C.; Romero, M. A.; Ramirez, M. I.; Monsalve, G.

    2013-05-01

    In the elaboration of a hydrogeological conceptual model in regions of mining exploration where there is significant presence of crystalline massif rocks., the influence of physical and geometrical properties of rock discontinuities must be evaluated. We present the results of a structural analysis of rock discontinuities in a region of the Central Cordillera of Colombia (The upper and middle Bermellon Basin) in order to establish its hydrogeological characteristics for the improvement of the conceptual hydrogeological model for the region. The geology of the study area consists of schists with quartz and mica and porphyritic rocks, in a region of high slopes with a nearly 10 m thick weathered layer. The main objective of this research is to infer the preferential flow directions of groundwater and to estimate the tensor of potential hydraulic conductivity by using surface information and avoiding the use of wells and packer tests. The first step of our methodology is an analysis of drainage directions to detect patterns of structural controls in the run-off; after a field campaign of structural data recollection, where we compile information of strike, dip, continuity, spacing, roughness, aperture and frequency, we built equal area hydro-structural polar diagrams that indicate the potential directions for groundwater flow. These results are confronted with records of Rock Quality Designation (RQD) that have been systematically taken from several mining exploration boreholes in the area of study. By using all this information we estimate the potential tensor of hydraulic conductivity from a cubic law, obtaining the three principal directions with conductivities of the order of 10-5 and 10-6 m/s; the more conductive joint family has a NE strike with a nearly vertical dip.

  20. Human exposure and risk assessment associated with mercury contamination in artisanal gold mining areas in the Brazilian Amazon.

    Science.gov (United States)

    Castilhos, Zuleica; Rodrigues-Filho, Saulo; Cesar, Ricardo; Rodrigues, Ana Paula; Villas-Bôas, Roberto; de Jesus, Iracina; Lima, Marcelo; Faial, Kleber; Miranda, Antônio; Brabo, Edilson; Beinhoff, Christian; Santos, Elisabeth

    2015-08-01

    Mercury (Hg) contamination is an issue of concern in the Amazon region due to potential health effects associated with Hg exposure in artisanal gold mining areas. The study presents a human health risk assessment associated with Hg vapor inhalation and MeHg-contaminated fish ingestion, as well as Hg determination in urine, blood, and hair, of human populations (about 325 miners and 321 non-miners) from two gold mining areas in the Brazilian Amazon (São Chico and Creporizinho, Pará State). In São Chico and Creporizinho, 73 fish specimens of 13 freshwater species, and 161 specimens of 11 species, were collected for total Hg determination, respectively. The hazard quotient (HQ) is a risk indicator which defines the ratio of the exposure level and the toxicological reference dose and was applied to determine the threat of MeHg exposure. The mean Hg concentrations in fish from São Chico and Creporizinho were 0.83 ± 0.43 and 0.36 ± 0.33 μg/g, respectively. More than 60 and 22 % of fish collected in São Chico and Creporizinho, respectively, were above the Hg limit (0.5 μg/g) recommended by WHO for human consumption. For all sampling sites, HQ resulted from 1.5 to 28.5, except for the reference area. In Creporizinho, the values of HQ are close to 2 for most sites, whereas in São Chico, there is a hot spot of MeHg contamination in fish (A2-São Chico Reservoir) with the highest risk level (HQ = 28) associated with its human consumption. Mean Hg concentrations in urine, blood, and hair samples indicated that the miners group (in São Chico: urine = 17.37 μg/L; blood = 27.74 μg/L; hair = 4.50 μg/g and in Creporizinho: urine = 13.75 μg/L; blood = 25.23 μg/L; hair: 4.58 μg/g) was more exposed to mercury compared to non-miners (in São Chico: urine = 5.73 μg/L; blood = 16.50 μg/L; hair = 3.16 μg/g and in Creporizinho: urine = 3.91 μg/L; blood = 21.04 μg/L, hair = 1.88 μg/g). These high Hg levels (found

  1. Rapid plant-cover establishment on gold mine tailings in southern New Zealand: glasshouse screening trials.

    Science.gov (United States)

    Schroeder, K; Rufaut, C G; Smith, C; Mains, D; Craw, D

    2005-01-01

    The use of a short-term vegetation cover to temporarily control the negative environmental effects of inactive tailings ponds is notfrequently practiced during operational mining, but could have some merit This article reports on a glasshouse trial designed to examine some of the issues associated with short-term vegetation: fast germination of a high proportion of seed, the ability of seedlings to survive in unamended substrates, and potentially toxic substrate. Five nonindigenous plant species were tested--barley (Hordeum vulgare), rye corn (Secale cereale), Italian ryegrass (Lolium multifiorum), red clover (Trifolium pratense), and lucerne (Medicago sativa)--in five different types of substrate: unamended tailings, tailings and fertilizer, tailings and greenwaste, biosolid-blend compost, and local topsoil. The nutrient and heavy metal status (As, Cu, Cd, Ni, Pb) of each substrate type was determined Plant species performance was monitored over 14 wk Substrate metal concentrations were low except for As, which was elevated in all substrate types. Plants in unamended tailings grew less vigorously than plants in tailings and compost or in topsoil. Plant performance in tailings and fertiliser was greatly suppressed following a high fertilization rate. Metal uptake in plants was highest for As (0.4-77 mg kg(-1) DW) and Cu (5.3-50.3 mg kg(-1) DW). Future field trials are necessary to authenticate findings, but barley and rye corn are promising species for a short-term tailings cover.

  2. Phytostabilization of gold mine tailings, New Zealand. Part 1: Plant establishment in alkaline saline substrate.

    Science.gov (United States)

    Mains, D; Craw, D; Rufaut, C G; Smith, C M S

    2006-01-01

    Tailings from the Macraes mine, southern New Zealand, are prone to wind erosion. Use of a vegetation cover for physical stabilization is one potential solution to this environmental problem. This study used field trials contained in lysimeters to 1), test the ability of different plant species to grow in un/amended tailings and 2), provide background information on the nutrient and chemical content of waters in tailings. Barley (Hordeum vulgare), blue lupin (Lupinus angustifolius), and rye corn (Secale cereale) were trialed, using Superphosphate fertilizer and sewage sludge as amendments. Rye corn grew well in fertilizer-amended tailings, but poorly in unamended tailings; barley growth was similar in amended and unamended tailings; blue lupins grew poorly overall The tailings had alkaline pH (7-8.5) and water rapidly (< 1 mo) interacted with the tailings to become strongly saline. Minor acid generation was neutralized by calcite, with associated release of calcium and carbonate ions. Leachate waters were supersaturated with respect to calcite and dolomite. Dissolved sodium concentrations were up to 1000 mg L(-1), but elevated Ca2+ calcium and Mg2+ ensured that sodicity was lower than plant-toxic levels. Rye corn is a potentially useful plant for rapid phytostabilization of tailings, with only minor phosphate amendment required.

  3. EQUILIBRIO HIDRÁULICO EN SISTEMAS DE BOMBEO MINERO: ESTUDIO DE CASO HYDRAULIC BALANCE ON MINE PUMPING SYSTEMS: A CASE STUDY

    Directory of Open Access Journals (Sweden)

    Luis Enrique Ortiz Vidal

    2010-12-01

    Full Text Available Fue evaluada la influencia del uso de los métodos de Hazen-Williams y Darcy-Weisbach en el establecimiento del equilibrio hidráulico para un sistema de bombeo minero. Empresas mineras con actividad subterránea hacen uso de estaciones de bombeo para evacuar el agua, producto de la profundización de sus labores. Proyectistas y vendedores de equipos de bombeo usan diferentes expresiones para la estimación de la pérdida de carga total del sistema, parámetro importante para la determinación del equilibrio hidráulico. El presente estudio tiene como objetivo analizar y validar la aplicación de algunas de estas expresiones para un sistema de bombeo minero. Las principales características del estudio de caso son: caudal de agua de 1.350 l/s; tuberías de acero y HDPE de 16 in y 18 in de diámetro, respectivamente; longitud total de la tubería de 2.900 m; y una altura geodésica de 230 m. Los cálculos fueron realizados con los métodos ya mencionados teniendo las expresiones de Haaland, Swamee-Jain y Churchill como factores de fricción. Los resultados obtenidos fueron comparados con los medidos en campo, teniéndose una desviación máxima del sistema de 28,6% y 3,1% para la pérdida de carga y Hman total, respectivamente.This study evaluates the influence of the Hazen-Williams and Darcy-Weisbach methods on the hydraulic balance of a mine pumping system. Underground mining sompanies use pumping stations for evacuate the produced water. Designers and equipment sellers use different expressions to estimate the head loss. This study analyzes and validates the implementation of some of these expressions to a mine pumping system. The features of the case study are: water flow rate of 1350 l/s, steel and HDPE diameter pipes of 16in. and 18in., respectively. The total pipe length is 2900m, and the hydraulic height difference is 230 m. The calculations were performed by the above-mention methods, taking the expressions of Haaland, Swamee-Jain and

  4. Mineral mining installation

    Energy Technology Data Exchange (ETDEWEB)

    Plevak, L.; Weirich, W.

    1982-04-20

    A longwall mineral mining installation has a longwall conveyor and a plurality of roof support units positioned side-by-side at the goaf side of the conveyor. The hydraulic appliances of the roof support units, such as their hydraulic props, hydraulic advance rams and hydraulic control valves, are supplied with pressurized hydraulic fluid from hydraulic supply lines which run along the goaf side of the conveyor. A plurality of flat, platelike intermediate members are provided at the goaf side of the conveyor. These intermediate members are formed with internal ducts for feeding the hydraulic fluid from the supply lines to the hydraulic appliances of the roof support units.

  5. The Association between Noise, Cortisol and Heart Rate in a Small-Scale Gold Mining Community—A Pilot Study

    Directory of Open Access Journals (Sweden)

    Allyson Green

    2015-08-01

    Full Text Available We performed a cross-sectional pilot study on salivary cortisol, heart rate, and personal noise exposures in a small-scale gold mining village in northeastern Ghana in 2013. Cortisol level changes between morning and evening among participants showed a relatively low decline in cortisol through the day (−1.44 ± 4.27 nmol/L, n = 18, a pattern consistent with chronic stress. A multiple linear regression, adjusting for age, sex, smoking status, and time between samples indicated a significant increase of 0.25 nmol/L cortisol from afternoon to evening per 1 dBA increase in equivalent continuous noise exposure (Leq over that period (95% CI: 0.08–0.42, Adj R2 = 0.502, n = 17. A mixed effect linear regression model adjusting for age and sex indicated a significant increase of 0.29 heart beats per minute (BPM for every 1 dB increase in Leq. Using standard deviations (SDs as measures of variation, and adjusting for age and sex over the sampling period, we found that a 1 dBA increase in noise variation over time (Leq SD was associated with a 0.5 BPM increase in heart rate SD (95% CI: 0.04–−0.9, Adj. R2 = 0.229, n = 16. Noise levels were consistently high, with 24-hour average Leq exposures ranging from 56.9 to 92.0 dBA, with a mean daily Leq of 82.2 ± 7.3 dBA (mean monitoring duration 22.1 ± 1.9 hours, n = 22. Ninety-five percent of participants had 24-hour average Leq noise levels over the 70 dBA World health Organization (WHO guideline level for prevention of hearing loss. These findings suggest that small-scale mining communities may face multiple, potentially additive health risks that are not yet well documented, including hearing loss and cardiovascular effects of stress and noise.

  6. 高速矿井架空人车液压系统的设计与分析%Design and Analysis of Hydraulic System for High-speed Coal-mining Manned-ropeway

    Institute of Scientific and Technical Information of China (English)

    李锐; 侯友夫

    2012-01-01

    设计一种高速矿井架空人车液压系统的主回路以及制动回路,采用电液比例技术实现系统软启动、软制动以及调速.分析矿井架空人车在启动、制动、调速等不同工况下,液压系统各元器件的动作要求和控制机制,为高速矿井架空人车液压系统的选择提供了参考.%A kind of main loop and braking loop were designed for high-speed coal-mining manned-ropeway hydraulic system. Electro-hydraulic proportional technology was adopted to realize soft start, soft brake and speed regulation. The motion requirements and controlling mechanism of each component in coal-mining manned-ropeway hydraulic system were analyzed when the system was starting, braking or speed regulation. It provides reference for design of high-speed coal-mining manned-ropeway hydraulic system.

  7. The Tree-Ring Mercury Record of Gold Mining in the Klondike, Central Yukon Territory

    Science.gov (United States)

    Clackett, S.; Porter, T. J.; Lehnherr, I.

    2016-12-01

    Mercury (Hg) is an atmospherically mixed pollutant of global concern with the potential to become toxic methyl-Hg (MeHg) is some environments. Accurate projections of future health impacts caused by Hg pollution will partly depend on changes in the atmospheric Hg pool, but knowledge of natural Hg variability is limited by a lack of long term monitoring data, which precludes a robust analysis of how it may evolve in the future. Natural archives such as lake sediments, ice cores and tree-rings have the potential to fill this knowledge gap. Tree-rings may be ideally suited for this purpose since they are annually resolved, they span multiple centuries in some areas, and cover large portions of the Earth's surface. Few studies have evaluated tree-ring Hg, and generally agree tree-rings are a passive archive for local Hg emissions. However, further studies are needed to validate this hypothesis. An ideal site to test this proxy is Bear Creek in the Klondike where the Hg amalgamation method was used during the period 1918-1966 to recover fine gold from placer ore. Gaseous Hg was lost to the local environment during operations, as is confirmed by high soil Hg concentrations at the site today. Local trees would have been exposed to the elevated Hg emissions. We measured tree-ring Hg at Bear Creek to determine if historical Hg trends are preserved. Our preliminary results from a single tree reveal that: (1) peak tree-ring Hg coincides with Bear Creek operations; (2) the lowest tree-ring Hg is observed during the pre-industrial control period (1870-1880); and (3) post-Bear Creek operations (1970-2010) coincides with intermediate tree-ring Hg levels, presumably due to higher Hg global backgrounds in recent decades. Additional trees are being analysed to determine if this result is robust, and will provide important insights on the reliability of this proxy for reconstructing long-term atmospheric Hg at local and potentially broader spatial scales.

  8. Application of Geophysical and Geochemical Prospecting in Hayden Gold Mine%物化探工作在海登金矿勘探中的应用

    Institute of Scientific and Technical Information of China (English)

    杨恺; 李华

    2014-01-01

    海登金矿位于澳大利亚西澳大利亚州佛雷斯特尼亚绿岩带,属于澳洲三级金成矿远景区。综合矿区地质特征、地球物理特征、地球化学特征,圈出异常靶区。通过槽探验证,确定了化探靶区具有直接找矿意义,为本地区寻找石英脉型金矿提供了依据。%The Hayden gold mine is located in the Forrestania greenstone belt in Western Australia State, Australia belongs to third class gold metallogenic prospects. Through mine area geological, geophysical and geochemical characteristics integration has delineat⁃ed anomalous target areas. Through trenching verification has determined that the geochemical anomalous target areas have direct pros⁃pecting significance, thus provided basis for quartz vein typed gold ore deposit prospecting.

  9. Land Use, Water Quality, and Incidence of Buruli Ulcer in Gold-Mining Regions of Ghana

    Science.gov (United States)

    Hagarty, J.; Voegborlo, R.; Smithwick, E. A.; Singha, K.

    2011-12-01

    , thus highlighting that the problems are likely largely surface water based. Analyses of rainfall data collected from eleven stations throughout Ghana show that patterns of annual rainfall do not vary greatly between Buruli-endemic and non-endemic areas, suggesting that normal rainfall patterns do not affect incidence of disease, and that event-based precipitation may be a driving factor for the onset of Buruli ulcer. Analysis of localized soil and water chemistry is ongoing, with samples collected from mining pits, farms, rivers, ponds, swamps, and wells in our five communities within Ghana.

  10. Fate of process solution cyanide and nitrate at three nevada gold mines inferred from stable carbon and nitrogen isotope measurements

    Science.gov (United States)

    Johnson, C.A.; Grimes, D.J.; Rye, R.O.

    2000-01-01

    Stable isotope methods have been used to identify the mechanisms responsible for cyanide consumption at three heap-leach operations that process Carlin-type gold ores in Nevada, U.S.A. The reagent cyanide had ??15N values ranging from -5 to -2??? and ??13C values from -60 to -35???. The wide ??13C range reflects the use by different suppliers of isotopically distinct natural-gas feedstocks and indicates that isotopes may be useful in environmental studies where there is a need to trace cyanide sources. In heap-leach circuits displaying from 5 to 98% consumption of cyanide, barren-solution and pregnant-solution cyanide were isotopically indistinguishable. The similarity is inconsistent with cyanide loss predominantly by HCN offgassing (a process that in laboratory experiments caused substantial isotopic changes), but it is consistent with cyanide retention within the heaps as solids, a process that caused minimal isotopic changes in laboratory simulations, or with cyanide oxidation, which also appears to cause minimal changes. In many pregnant solutions cyanide was carried entirely as metal complexes, which is consistent with ferrocyanides having precipitated or cyanocomplexes having been adsorbed within the heaps. It is inferred that gaseous cyanide emissions from operations of this type are less important than has generally been thought and that the dissolution or desorption kinetics of solid species is an important control on cyanide elution when the spent heaps undergo rinsing. Nitrate, nitrite and ammonium had ??15N values of 1-16???. The data reflect isotopic fractionation during ammonia offgassing or denitrification of nitrate - particularly in reclaim ponds - but do not indicate the extent to which nitrate is derived from cyanide or from explosive residues. ?? The Institution of Mining and Metallurgy 2000.

  11. Natural radioactivity levels in soils, rocks and water at a mining concession of Perseus gold mine and surrounding towns in Central Region of Ghana.

    Science.gov (United States)

    Faanu, A; Adukpo, O K; Tettey-Larbi, L; Lawluvi, H; Kpeglo, D O; Darko, E O; Emi-Reynolds, G; Awudu, R A; Kansaana, C; Amoah, P A; Efa, A O; Ibrahim, A D; Agyeman, B; Kpodzro, R; Agyeman, L

    2016-01-01

    Levels of naturally occurring radioactive materials prior to processing of gold ore within and around the new eastern concession area of Perseus Mining (Ghana) Limited were carried out to ascertain the baseline radioactivity levels. The study was based on situ measurements of external gamma dose rate at 1 m above ground level as well as laboratory analysis by direct gamma spectrometry to quantify the radionuclides of interest namely; (238)U, (232)Th and (40)K in soil, rock, ore samples and gross alpha/beta analysis in water samples. The average absorbed dose rate in air at 1 m above sampling point using a radiation survey metre was determined to be 0.08 ± 0.02 μGyh(-1) with a corresponding average annual effective dose calculated to be 0.093 ± 0.028 mSv. The average activity concentrations of (238)U, (232)Th, and (40)K in the soil, rock, and ore samples were 65.1 ± 2.2, 71.8 ± 2.2 and 1168.3 Bqkg(-1) respectively resulting in an average annual effective dose of 0.91 ± 0.32 mSv. The average Radium equivalent activity value was 257.8 ± 62.4 Bqkg(-1) in the range of 136.6-340.2 Bqkg(-1). The average values of external and internal indices were 0.7 ± 0.2 and 0.9 ± 0.2 respectively. The average gross alpha and gross beta activity concentrations in the water samples were determined to be 0.0032 ± 0.0024 and 0.0338 ± 0.0083 Bql(-1) respectively. The total annual effective dose from the pathways considered for this study (gamma ray from the soil, rock and ore samples as well as doses determined from the gross alpha/beta activity concentration in water samples) was calculated to be 0.918 mSv. The results obtained in this study shows that the radiation levels are within the natural background radiation levels found in literature and compare well with similar studies for other countries and the total annual effective dose is below the ICRP recommended level of 1 mSv for public exposure control.

  12. Application of sintered plate dust collector in gold mines%烧结板除尘器在黄金矿山的应用

    Institute of Scientific and Technical Information of China (English)

    郑民; 轩慎英; 刘刚

    2016-01-01

    It is always difficult for gold mine to collect dust .Inner Mongolia Pacific Mining Corporation Limited first applies sintered plate dust collectors in the crashing stage during the second phase of expansion project .The sin-tered plate dust collector occupies less space and is reliable with good dust collection effect and lower vent gas concen -tration.The paper based on technical characteristics of dust collection process and performance test results focused on the technical and economical analysis of the application of sintered plate dust collector ,expecting to provide reference of the dust collection process for gold mines .%黄金生产中的除尘问题一直受到黄金矿山企业的关注.内蒙古太平矿业有限公司二期扩建项目首次在选矿厂破碎工段采用了烧结板除尘器,其设备占地面积小、运行可靠、除尘效果好、尾气质量浓度低于排放标准.该文结合除尘工艺技术特点以及设备性能测试结果,重点对烧结板除尘器的应用进行了技术与经济分析,以期为类似黄金矿山企业除尘工艺提供参考.

  13. Developing a generic model of the initial review process for a gold mine shaft business unit / Theunis Christoffel Meyer

    OpenAIRE

    Meyer, Theunis Christoffel

    2003-01-01

    South Africa is one of the world's foremost mining nations and mining and its associated industries continue to form the cornerstone of the country's economy. However, the mining industry has, by its very nature, the potential to endanger human health and safety, as well as the physical environment. Consequently, mining will always contend with major environmental challenges and remain under constant public pressure to demonstrate its commitment to responsible environmental man...

  14. Mineral Processing Experimental Study on A Gold Mine from Gansu%甘肃某金矿选矿试验研究

    Institute of Scientific and Technical Information of China (English)

    张远宁; 李福兰

    2016-01-01

    甘肃某金矿,金主要是以独立自然金,少量银金矿赋存,与黄铁矿、方铅矿、闪锌矿等硫化矿伴生。采用单一浮选的原则工艺流程就可以获得合格的金精矿,将原矿磨至⁃0.074 mm占75%,经两次粗选、一次扫选产出尾矿,两次精选产出金精矿的工艺流程。添加碳酸钠、丁基黄药和2#油三种药剂。闭路试验获得了金精矿金品位178.85 g/t、金回收率93.95%的较好选矿指标。试验指标良好,为现场生产提供了技术依据。%Gold in a gold mine from Gansu Province was mainly independent native gold, with a small amount of silver gold associated with pyrite, galena and sphalerite. Qualified gold concentrate can be obtained by simple flotation process. The ore was ground to 75% ⁃0.074 mm, followed with two stages of roughing, one scavenging, and two stages of concentrating. So⁃dium carbonate, butyl xanthate and pine oil were used in the flotation. Grade of the gold concentrate form closed circuit test was 178.85 g / t, with a recovery rate of 93.95%. This test index was good, which can provide the technical basis for the field production.

  15. Assessment of Hg contamination and exposure to miners and schoolchildren at a small-scale gold mining and recovery operation in Thailand.

    Science.gov (United States)

    Umbangtalad, S; Parkpian, P; Visvanathan, C; Delaune, R D; Jugsujinda, A

    2007-12-01

    Gold extracted by Hg-amalgamation process, which can cause both health and environmental problems, is widespread in South East Asia including Myanmar, Laos, Cambodia, and Thailand. Small-scale gold mining operations have been carried out since the year 2000 in Phanom Pha District, Phichit Province, Thailand. Since no data is available for evaluating Hg exposure, an investigation of mercury (Hg) contamination and exposure assessment was carried out at this mine site. Environmental monitoring illustrated the total Hg in water was as high as 4 microg/l while Hg in sediment ranged between 102 to 325 microg/kg dry weight. Both Hg deposition from the air (1.28 microg/100 cm(2)/day) and concentration in surface soil (20,960 microg/kg dry weight) were elevated in the area of amalgamation. The potential of Hg exposure to miners as well as to schoolchildren was assessed. The concentrations of Hg in urine of 79 miners who were directly (group I) or indirectly (group II) involved in the gold recovery operation were 32.02 and 20.04 microg/g creatinine, respectively, which did not exceed regulatory limits (35 microg/g creatinine). Hair Hg levels in both groups (group I and group II) also were not significantly higher than the non-exposed group. In terms of risk factors, gender and nature of food preparation and consumption were the two significant variables influencing the concentration of Hg in urine of miners (P < 0.05). A hazard quotient (HQ) was estimated based on the inorganic Hg exposure of individual miners. The HQ values of group I were in a range 16 to 218 times higher than the safety level set as 1. By comparison the group II HQ index was very low (0.03-0.39). The miners in group I who worked and ate food from this area experienced potentially high exposure to Hg associated with the mining process. In a second Hg exposure assessment, a group of 59 schoolchildren who attended an elementary school near the gold mine site was evaluated for Hg exposure. A slightly higher

  16. Raman and micro-thermometric investigation of the fluid inclusions in quartz in a gold-rich formation from Lepaguare mining district (Honduras, Central America)

    Science.gov (United States)

    Bersani, D.; Salvioli-Mariani, E.; Mattioli, M.; Menichetti, M.; Lottici, P. P.

    2009-08-01

    Fluid inclusions in the quartz crystals present in gold-rich veins from central Honduras have been studied by means of micro-thermometry and micro-Raman spectroscopy in order to provide information on the physico-chemical conditions and chemical composition of the mineralizing fluids. The use of a confocal micro-Raman apparatus allowed to obtain information on the fluid composition, in particular on the gas phase, minimizing the contributions of the host matrix to the Raman signal. The samples studied were collected from an area (Lepaguare mining district, Northern-Central Honduras) rich in ore deposits due to the Cenozoic magmatic activity, where the gold and sulphide mineralization is connected with a system of quartz veins (few decimetres thick) occurring in low-grade metamorphic rocks and produced by hydrothermal fluids. The quartz crystals present in the gold-rich veins often contain fluid inclusions. Four types of fluid inclusions have been observed, but their assemblage in the same clusters and fracture systems, as well as their comparable salinity and homogenization data, suggest that they have the same origin. Micro-thermometry and Raman spectroscopy provide a composition of the mineralizing fluids attributable to the system H 2O-NaCl-KCl-CO 2-CH 4, with temperature and pressure intervals of 210-413 °C and 1050-3850 bar, respectively. These data agree with an epigenetic origin of the gold deposit (depth < 6 km) related to granitoid or granodiorite intrusions associated to orogenic environments.

  17. Raman and micro-thermometric investigation of the fluid inclusions in quartz in a gold-rich formation from Lepaguare mining district (Honduras, Central America).

    Science.gov (United States)

    Bersani, D; Salvioli-Mariani, E; Mattioli, M; Menichetti, M; Lottici, P P

    2009-08-01

    Fluid inclusions in the quartz crystals present in gold-rich veins from central Honduras have been studied by means of micro-thermometry and micro-Raman spectroscopy in order to provide information on the physico-chemical conditions and chemical composition of the mineralizing fluids. The use of a confocal micro-Raman apparatus allowed to obtain information on the fluid composition, in particular on the gas phase, minimizing the contributions of the host matrix to the Raman signal. The samples studied were collected from an area (Lepaguare mining district, Northern-Central Honduras) rich in ore deposits due to the Cenozoic magmatic activity, where the gold and sulphide mineralization is connected with a system of quartz veins (few decimetres thick) occurring in low-grade metamorphic rocks and produced by hydrothermal fluids. The quartz crystals present in the gold-rich veins often contain fluid inclusions. Four types of fluid inclusions have been observed, but their assemblage in the same clusters and fracture systems, as well as their comparable salinity and homogenization data, suggest that they have the same origin. Micro-thermometry and Raman spectroscopy provide a composition of the mineralizing fluids attributable to the system H(2)O-NaCl-KCl-CO(2)-CH(4), with temperature and pressure intervals of 210-413 degrees C and 1050-3850 bar, respectively. These data agree with an epigenetic origin of the gold deposit (depth < 6 km) related to granitoid or granodiorite intrusions associated to orogenic environments.

  18. 平硐深溜井技术在紫金山金矿的应用%Application of Adit Deep Chute in Zijinshan Gold Mine

    Institute of Scientific and Technical Information of China (English)

    李瑞祥

    2011-01-01

    针对紫金山金矿储量大、品位低、溜井深、粉矿含量高、矿石处理量大的特点以及年降雨量达1600mm的影响,主要介绍了紫金山金矿露天采场8条深溜井设计、施工、堵塞处理技术等,在此基础上提出了溜井安全高效运行的技术措施,并对平硐溜井技术进行了经济分析与评价.平硐溜井技术在紫金山金矿的安全、高效应用,大大地降低了运输成本,取得了很好的经济效益和社会效益.%In view of the features of large reserves, low grade, deep chute, high level of fine ore, and large capacity in Zijinshan Gold Mine, and together with the impact of 1600 mm annual rainfall, the design, construction, congestion handling technology for eight deep chutes are introduced in Zijinshan open pit gold mine. Based on this, the technical measures for safe and high efficient operation of the chute are proposed, and the economic analysis and evaluation on the adit chute technique are made. The application of the adit chute in safety and high efficiency in Zijinshan gold mine greatly reduce the transportation costs, with good economic and social benefits achieved.

  19. Gold in Modern Economy

    Directory of Open Access Journals (Sweden)

    Boryshkevych Olena V.

    2014-01-01

    Full Text Available The article studies the role of gold in modern economy. It analyses dynamics and modern state of the gold market. It studies volumes of contracts in exchange and off-exchange markets. In order to reveal changes of key features of the gold market, it focuses on the study of gold demand volumes, studies volumes and geographical changes in the world gold mining, and analyses volumes of monetary gold of central banks and its share in gold and currency reserves. It analyses price fluctuations in the gold market during 1968 – 2013 and identifies main factors that determine the gold price. It identifies interconnection between the state of the gold market and financial markets of countries. The study showed that namely geopolitical and economic instability restricts the spectrum of financial assets for investing and gold is not only a safe investment object but also a profitable one.

  20. Phytoremediation of Gold Mine Tailings Amended with Iron-Coated and Uncoated Rice Husk Ash by Vetiver Grass (Vetiveria zizanioides (Linn.) Nash)

    OpenAIRE

    Tariq, F. S.; Samsuri, A. W.; D. S. Karam; Aris, A. Z.

    2016-01-01

    This study was undertaken to determine the effects of rice husk ash (RHA) and iron-coated rice husk ash (Fe-RHA) on phytoavailability of As, Cd, Cr, Cu, Mn, Pb, and Zn to vetiver grass grown in gold mine tailings amended with either RHA or Fe-RHA at 0%, 5%, 10%, and 20% (w/w). The results showed that the RHA amended tailings recorded higher concentration of As in the shoot and the root and higher concentration of Cr and Mn in the root compared to the untreated tailings which was used as a con...

  1. Phytoremediation of Gold Mine Tailings Amended with Iron-Coated and Uncoated Rice Husk Ash by Vetiver Grass (Vetiveria zizanioides (Linn.) Nash)

    OpenAIRE

    Tariq, F. S.; Samsuri, A. W.; Karam, D. S.; Aris, A. Z.

    2016-01-01

    This study was undertaken to determine the effects of rice husk ash (RHA) and iron-coated rice husk ash (Fe-RHA) on phytoavailability of As, Cd, Cr, Cu, Mn, Pb, and Zn to vetiver grass grown in gold mine tailings amended with either RHA or Fe-RHA at 0%, 5%, 10%, and 20% (w/w). The results showed that the RHA amended tailings recorded higher concentration of As in the shoot and the root and higher concentration of Cr and Mn in the root compared to the untreated tailings which was used as a con...

  2. Using native epiphytic ferns to estimate the atmospheric mercury levels in a small-scale gold mining area of West Java, Indonesia.

    Science.gov (United States)

    Kono, Yuriko; Rahajoe, Joeni S; Hidayati, Nuril; Kodamatani, Hitoshi; Tomiyasu, Takashi

    2012-09-01

    Mercury pollution is caused by artisanal and small-scale gold mining (ASGM) operations along the Cikaniki River (West Java, Indonesia). The atmosphere is one of the primary media through which mercury can disperse. In this study, atmospheric mercury levels are estimated using the native epiphytic fern Asplenium nidus complex (A. nidus) as a biomonitor; these estimates shed light on the atmospheric dispersion of mercury released during mining. Samples were collected from 8 sites along the Cikaniki Basin during September-November, 2008 and September-November, 2009. The A. nidus fronds that were attached to tree trunks 1-3m above the ground were collected and measured for total mercury concentration using cold vapor atomic absorption spectrometry (CVAAS) after acid-digestion. The atmospheric mercury was collected using porous gold collectors, and the concentrations were determined using double-amalgam CVAAS. The highest atmospheric mercury concentration, 1.8 × 10(3) ± 1.6 × 10(3) ngm(-3), was observed at the mining hot spot, and the lowest concentration of mercury, 5.6 ± 2.0 ngm(-3), was observed at the remote site from the Cikaniki River in 2009. The mercury concentrations in A. nidus were higher at the mining village (5.4 × 10(3) ± 1.6 × 10(3) ngg(-1)) than at the remote site (70 ± 30 ngg(-1)). The distribution of mercury in A. nidus was similar to that in the atmosphere; a significant correlation was observed between the mercury concentrations in the air and in A. nidus (r=0.895, P<0.001, n=14). The mercury levels in the atmosphere can be estimated from the mercury concentration in A. nidus using a regression equation: log (Hg(A.nidu)/ngg(-1))=0.740 log (Hg(Air)/ngm (-3)) - 1.324.

  3. 节约集约在黄金矿山中的实践%Application of economical and intensive development strategies on gold mines

    Institute of Scientific and Technical Information of China (English)

    赵景刚

    2013-01-01

      The paper takes Hexi gold mine for an example and illustrates the necessity and urgency for gold mines to implement economical and intensive development strategies .In the practice,the strategies mainly include establis-hing specific management systems ,innovating techniques according to mining conditions ,perfecting filling technology and filling systems,expanding safety investment,improving resources utilization,optimizing processing techniques,ex-tending exploration to increase reserves ,lowering indexes to make full use of resources at hand and recovering compre-hensively with least waste of useful materials .These 8 measures significantly increased economic benefits gained by mines and are referential to others.%  以河西金矿为例,阐述了黄金矿山实现节约集约的重要性和紧迫性。河西金矿在节约集约的实践中主要采取“建章立制,精细管理;科研创新,因矿施法;改进充填工艺,完善充填系统;加大安全投入,提高资源利用;优化选矿工艺,提高选矿回收率;探矿增储,有效开发;降低指标,变废为宝;综合回收,吃干榨净”八大措施,使矿山取得了显著的经济效益,值得借鉴。

  4. The Mt. Diwata study on the Philippines 1999--assessing mercury intoxication of the population by small scale gold mining.

    Science.gov (United States)

    Drasch, G; Böse-O'Reilly, S; Beinhoff, C; Roider, G; Maydl, S

    2001-02-21

    The region of Diwalwal, dominated by Mt. Diwata, is a gold rush area on Mindanao (Philippines) where approximately 15000 people live. The fertile plain of Monkayo is situated downstream, where people grow crops such as rice and bananas; locally caught fish is eaten frequently. The ore is dug in small-scale mines and ground to a powder by ball-mills while still in Diwalwal. The gold is then extracted by adding liquid mercury (Hg), forming gold-amalgam. To separate the gold from the Hg, in most cases the amalgam is simply heated in the open by blow-torches. A high external Hg burden of the local population must be assumed. To evaluate the internal Hg burden of the population and the extent of possible negative health effects, 323 volunteers from Mt. Diwalwal, Monkayo and a control group from Davao were examined by a questionnaire, neurological examination and neuro-psychological testing. Blood, urine and hair samples were taken from each participant and analyzed for total Hg. A statistical evaluation was possible for 102 workers (occupationally Hg burdened ball-millers and amalgam-smelters), 63 other inhabitants from Mt. Diwata ('only' exposed from the environment), 100 persons, living downstream in Monkayo, and 42 inhabitants of Davao (serving as controls). The large volume of data was reduced to yes/no decisions. Alcohol as a possible bias factor was excluded (level of alcohol consumption and type, see Section 4.4). Each factor with a statistically significant difference of at least one exposed group to the control group was included in a medical score (0-21 points). In each of the exposed groups this score was significantly worse than in the control group (median control, 3; downstream, 9; Mt. Diwata, non-occupational exposed, 6; Hg workers, 10). In comparison to the surprisingly high Hg concentration in blood (median, 9.0 microg/l; max, 31.3) and in hair (2.65 microg/g; max, 34.7) of the control group, only the workers show elevated levels: Hg-blood median 11

  5. Distribution of total mercury and methylmercury around the small-scale gold mining area along the Cikaniki River, Bogor, Indonesia.

    Science.gov (United States)

    Tomiyasu, Takashi; Kodamatani, Hitoshi; Hamada, Yuriko Kono; Matsuyama, Akito; Imura, Ryusuke; Taniguchi, Yoko; Hidayati, Nuril; Rahajoe, Joeni Setijo

    2017-01-01

    This study investigates the distribution of total mercury (T-Hg) and methylmercury (MeHg) in the soil and water around the artisanal and small-scale gold mining (ASGM) area along the Cikaniki River, West Java, Indonesia. The concentration of T-Hg and MeHg in the forest soil ranged from 0.07 to 16.7 mg kg(-1) and from Mercury deposited on the soil surface can be trapped and retained by organic matter and subjected to methylation. The slope of the line obtained for the T-Hg vs. TOC plot became larger near the ASGM villages, implying a higher rate of mercury deposition in these areas. In contrast, the plots of MeHg vs. TOC fell along the same trend line regardless of the distance from the ASGM village. Organic carbon content may be a predominant factor in controlling MeHg formation in forest soils. The T-Hg concentration in the river water ranged from 0.40 to 9.6 μg L(-1). River water used for irrigation can prove to be a source of mercury for the paddy fields. The concentrations of Hg(0) and Hg(2+) in river water showed similar variations as that observed for the T-Hg concentration. The highest Hg(0) concentration of 3.2 μg L(-1) can be attributed to the waste inflow from work sites. The presence of Hg(0) in river water can become a source of mercury present in the atmosphere along the river. MeHg concentration in the river water was found to be 0.004-0.14% of T-Hg concentration, which was considerably lower than the concentrations of other Hg species. However, MeHg comprised approximately 0.2% of the T-Hg in paddy field soil. Mercury deposited from the atmosphere and the river water can be subjected to methylation. Paddy fields are very important ecosystems; therefore, the effect of MeHg on these ecosystems and human beings should be further investigated.

  6. Developing and Exploiting a Unique Dataset from South African Gold Mines for Source Characterization and Wave Propagation

    Science.gov (United States)

    2010-09-01

    mechanisms of mine-related seismicity, Savuka mine, South Africa, Bull. Seism . Soc. Am. 99: 2801–2814. Mayeda, K. (2003). Stable and transportable...regional magnitudes based on coda-derived moment-rate spectra, Bull. Seism . Soc. Am. 93: 224–239. Menke, W. (1989). Geophysical Data Analysis...Bull. Seism . Soc. Am. 19: 1579–1582. McGarr, A. (1992b). Moment tensors of ten Witwatersrand mine tremors, Pure Appl. Geophys. 139: 781–800

  7. 盘区宽进路机械化充填采矿法在焦家金矿寺庄矿区的应用%Application of mechanized back filling mining method with wide panel access in Sizhuang mining area of Jiaojia gold mine

    Institute of Scientific and Technical Information of China (English)

    董金奎; 周士霖; 张忠辉; 邱俊刚; 司呈斌

    2012-01-01

    According to the conditions of the Sizhuang mining area of Jiaojia gold mine,considering with the economical,safe,and efficient mining,Sizhuang mining area,on the basis of upwards horizontal cut-and-fill mining method,the mining method was changed into the wide panel access mechanized back filling mining method with wide panel accesses.The paper introduces corresponding configuration of this modified mining method,structure parameters,as well as stoping and back filling process.The practical application proved that this mechanized back filling mining method with wide panel access possesses higher safety,higher production capacity,etc.,and meets the mine production requirements,meanwhile provides referable experiences for mines with similar conditions,domestic and a-broad.%根据焦家金矿寺庄矿区开采技术条件,综合考虑经济效益与安全高效开采,寺庄矿区在上向水平分层充填采矿法的基础上对采矿方法改进为盘区宽进路机械化充填采矿法.文中介绍了盘区宽进路机械化充填采矿法采场布置、结构参数以及回采、充填工艺过程.生产实际应用表明,盘区宽进路机械化充填采矿法具有安全性高、生产能力大等优点,满足了矿山生产要求,同时也为国内外同类开采条件矿山提供了可借鉴的经验.

  8. Detection and Recovery of Palladium, Gold and Cobalt Metals from the Urban Mine Using Novel Sensors/Adsorbents Designated with Nanoscale Wagon-wheel-shaped Pores.

    Science.gov (United States)

    El-Safty, Sherif A; Shenashen, Mohamed A; Sakai, Masaru; Elshehy, Emad; Halada, Kohmei

    2015-12-06

    Developing low-cost, efficient processes for recovering and recycling palladium, gold and cobalt metals from urban mine remains a significant challenge in industrialized countries. Here, the development of optical mesosensors/adsorbents (MSAs) for efficient recognition and selective recovery of Pd(II), Au(III), and Co(II) from urban mine was achieved. A simple, general method for preparing MSAs based on using high-order mesoporous monolithic scaffolds was described. Hierarchical cubic Ia3d wagon-wheel-shaped MSAs were fabricated by anchoring chelating agents (colorants) into three-dimensional pores and micrometric particle surfaces of the mesoporous monolithic scaffolds. Findings show, for the first time, evidence of controlled optical recognition of Pd(II), Au(III), and Co(II) ions and a highly selective system for recovery of Pd(II) ions (up to ~95%) in ores and industrial wastes. Furthermore, the controlled assessment processes described herein involve evaluation of intrinsic properties (e.g., visual signal change, long-term stability, adsorption efficiency, extraordinary sensitivity, selectivity, and reusability); thus, expensive, sophisticated instruments are not required. Results show evidence that MSAs will attract worldwide attention as a promising technological means of recovering and recycling palladium, gold and cobalt metals.

  9. Mining for Gold

    Science.gov (United States)

    Bigenho, Chris

    2009-01-01

    In this article, the author introduces the world of RSS (Real Simple Syndication or Rich Site Summary), one of the least used and understood of all the Web 2.0 tools. RSS technology has two parts: (1) feeds; and (2) aggregators. RSS feeds use a special type of HTML known as XML. Each feed is defined with channel tags, which contain specific…

  10. 整体顶梁机采组合液压支架的应用研究%Applied research on the hydraulic support with the integrated roof timber in shiqiao coal mine

    Institute of Scientific and Technical Information of China (English)

    郭斌; 李传磊

    2015-01-01

    为了提高矿井采煤机械化程度,通过调研及选型计算,最终确定选用ZH2600/22/32Z(Q)和ZH3200/22/32Z(Q)型整体顶梁机采组合液压支架作为采煤工作面的支护装备,提高了矿井安全保障程度。%in order to adapt to the increased mechanization of coal mine, through the investigation and selection calculation, select ZH2600/22/32Z (Q) and ZH3200/22/32Z (Q) hydraulic support with integrated roof timber as mine working face support, improve mine safety guarantee degree.

  11. 甘肃阳山金矿坑道涌水分析%An analysis on water gushing yield of Yangshan gold mine, Gansu

    Institute of Scientific and Technical Information of China (English)

    李石桥; 孙彬; 朱斌; 李创造

    2012-01-01

    阳山金矿区地下水类型主要有第四系孔隙水、层状岩类基岩裂隙水、块状岩类基岩裂隙水及构造带脉状裂隙水4种类型,坑道内涌水岩层主要为炭质千枚岩夹灰岩及斜长花岗斑岩,充水来源为第四系松散堆积层及地表浅部节理裂隙发育带,过水通道则主要为岩石节理裂隙,涌水量的大小受岩性及裂隙发育程度的影响,较大的涌水对坑道施工及将来的采矿产生不利影响,文章通过比拟法对矿坑涌水量进行预测,并对SM3坑道涌水问题的影响及矿坑水利用提出了建议.%The groundwater type Yangshan gold deposit the are mostly Quaternary System pore water, bedrock fissured water and structure nervation fissured water. Water gushing yield terrane in sap is char phyllite nip limestone and granite-porphyry. The origin of water is Quaternary System accumulate material and fissure in terrane, the alleyway is fissure. The lithology and develop degree of fissure will infection Water gushing yield. The large water gushing yield is disadvantage in sap construction or the gold mine mining. The text get across method of assimilate forecast the water gushing yield , at one time bring forward advice of the problem in water gushing yield and exploitation of mine water.

  12. Detection of mining-induced fractures around a stope in Ezulwini gold mine, South Africa, by using AE events with similar waveforms

    CSIR Research Space (South Africa)

    Moriya, H

    2012-11-01

    Full Text Available m to 500m across at depths about 1000m from surface where vertical stress is dominant and significantly enhanced. Panels (mining faces) are typically 30m across and 1-2m high. By daily blasting, the panels advance at a rate of about 10m per month... typically, causing stress perturbation and generating cracks. AE monitoring was performed during mining operations, using 6 three-component accelerometers and 24 single-component AE sensors installed in a volume measuring 95 m N–S, 50 m E–W, and 30 m...

  13. Manganese and Mercury Levels in Water, Sediments, and Children Living Near Gold-Mining Areas of the Nangaritza River Basin, Ecuadorian Amazon.

    Science.gov (United States)

    González-Merizalde, Max V; Menezes-Filho, José A; Cruz-Erazo, Claudia Teresa; Bermeo-Flores, Santos Amable; Sánchez-Castillo, María Obdulia; Hernández-Bonilla, David; Mora, Abrahan

    2016-08-01

    Artisanal and small-scale gold-mining activities performed in mountain areas of the Southern Ecuadorian Amazon have incorporated several heavy metals into the aquatic systems, thus increasing the risk of exposure in populations living in adjacent zones. Therefore, the objective of this study was to evaluate the contamination levels of mercury (Hg) and manganese (Mn) in several rivers of the Nangaritza River basin and assess the exposure in school-aged children residing near the gold-mining zones. River water and sediment samples were collected from a highly contaminated (HEx) and a moderately contaminated (MEx) zones. Hair Mn (MnH) and urinary Hg (HgU) levels were determined in school-aged children living in both zones. High concentrations of dissolved Mn were found in river waters of the HEx zone (between 2660 and 3990 µg l(-1)); however, Hg levels, in general, were lower than the detection limit (DL; <1.0 µg l(-1)). Similarly, Mn levels in sediments were also increased (3090 to 4086 µg g(-1)). Median values of MnH in children of the HEx and MEx zones were 5.5 and 3.4 µg g(-1), respectively, whereas the median values of HgU concentrations in children living in the HEx and MEx zones were 4.4 and 0.62 µg g-creat(-1), respectively. Statistically significant differences were observed between both biomarkers in children from the HEx and MEx zones. In addition, boys presented significantly greater MnH levels in both zones. The greater MnH values were found in children living in alluvial areas, whereas children living in the high mountain areas, where some ore-processing plants are located close to or inside houses and schools, had the greater HgU concentrations. In summary, the data reported in this paper highlights that artisanal and small-scale gold-mining activities can not only produce mercurial contamination, that can also release other heavy metals (such as Mn) that may pose a risk to human health.

  14. Feasibility of Applying Clean Development Mechanism and GHGs Emission Reductions in the Gold Mining Industry: A Case of Thailand

    OpenAIRE

    2015-01-01

    There is presently overwhelming scientific consensus that global climate change is indeed occurring, and that human activities are the primary driver. An increasingly resource and carbon constrained world will continue to pose formidable challenges to major industries, including mining. Understanding the implications of climate change mitigation for the mining industry, however, remains limited. This paper presents the results of a feasibility study on the implementation of a clean developmen...

  15. Establishment of SATREPS experimental sites in South African gold mines to monitor phenomena associated with earthquake nucleation and rupture

    CSIR Research Space (South Africa)

    Durrheim, RJ

    2012-03-01

    Full Text Available nucleation and rupture R.J. Durrheim SATREPS*, CSIR Centre for Mining Innovation, South Africa; and University of the Witwatersrand, South Africa H. Ogasawara SATREPS*, Ritsumeikan University, Japan M. Nakatani SATREPS*, Earthquake Research Institute... J. Wienand KDC Goldfields, South Africa P. Lenegan Goldfields, South Africa A.M. Milev SATREPS*, CSIR Centre for Mining Innovation, South Africa O. Murakami SATREPS*, Ritsumeikan University, Japan N. Yoshimitsu Ritsumeikan University, Japan...

  16. Distribution of Artisanal and Small-Scale Gold Mining in the Tapajós River Basin (Brazilian Amazon over the Past 40 Years and Relationship with Water Siltation

    Directory of Open Access Journals (Sweden)

    Felipe de Lucia Lobo

    2016-07-01

    Full Text Available An innovative remote sensing approach that combines land-use change and water quality information is proposed in order to investigate if Artisanal and Small-scale Gold Mining (ASGM area extension is associated with water siltation in the Tapajós River Basin (Brazil, containing the largest small-scale gold mining district in the world. Taking advantage of a 40-year period of the multi-satellite imagery archive, the objective of this paper is to build a normalized time-series in order to evaluate the influence of temporal mining expansion on the water siltation data (TSS, Total Suspended Solids concentration derived from previous research. The methodological approach was set to deliver a full characterization of the ASGM expansion from its initial stages in the early 1970s to the present. First, based on IRS/LISSIII images acquired in 2012, the historical Landsat image database (1973–2001 was corrected for radiometric and atmospheric effects using dark vegetation as reference to create a normalized time-series. Next, a complete update of the mining areas distribution in 2012 derived from the TerraClass Project (an official land-use classification for the Brazilian Amazon was conducted having IRS/LISSIII as the base map with the support of auxiliary data and vector editing. Once the ASGM in 2012 was quantified (261.7 km2 and validated with photos, a reverse classification of ASGM in 2001 (171.7 km2, 1993 (166.3 km2, 1984 (47.5 km2, and 1973 (15.4 km2 with the use of Landsat archives was applied. This procedure relies on the assumption that ASGM changes in the land cover are severe and remain detectable from satellite sensors for decades. The mining expansion area over time was then combined with the (TSS data retrieved from the same atmospherically corrected satellite imagery based on the literature. In terms of gold mining expansion and water siltation effects, four main periods of ASGM activities were identified in the study area: (i 1958

  17. Comparative study on bryophytes of Carlin gold mine and non-gold field area in Nipu, Guizhou%贵州泥堡卡林型金矿区与非金矿区苔藓植物比较研究

    Institute of Scientific and Technical Information of China (English)

    黄文琥; 张朝晖

    2008-01-01

    首次报道了贵州普安县泥堡村韭菜烂滩的卡林型金矿区和非金矿区的苔藓.记录了泥堡韭菜烂滩卡林型金矿生苔藓3科8属15种,非金矿生苔藓9科15属20种.通过比较我们得到韭菜烂滩卡林型金矿区和泥堡非金矿区苔藓的相似性系数为11.4%.这表明这两个生境下的苔藓组成差异极大.在这个地区有13种苔藓植物(包括异芽丝瓜藓Pohlia leucostoma、卵蒴丝瓜藓P.proligera、长蒴藓Trematodon longicollis等)只生长在卡林型金矿上,这表明有一些苔藓植物适应卡林型金矿这种基质.也许,在泥堡地区某些苔藓植物的分布与卡林型金矿存在一定的关系.%In this paper,the bryophytes both on Carlin gold mine and non-gold field area of Jiueailantan in Nipu Vil- lage of Pu'an County in Guizhou Province were reported for the first time. 15 speciea belonging to 8 genera of 3 fami- lies were found on the Carlin gold mine of Jiucailantan, and 20 species belonging to 15 genera of 9 families on non-gold field area in Nipu. Through comparison, the similarity coefficient of species level was 11.4% between the two sample sites in Nipu. It showed the distinct diversity on bryophytes of Carlin gold mine and non-gold field area. Among these bryophytes, 13 species of them (Pohlia leucostoma, P. proligera, Trematodon longicollis, etc. ) only grew on Carlin gold mine, indicating that some bryophytes adapted to the substrate of Carlin gold mine, and there were some relations between bryophytes and Carlin gold mine distribution in Nipu area.

  18. Related assemblages of sulphate-reducing bacteria associated with ultradeep gold mines of South Africa and deep basalt aquifers of Washington State.

    Science.gov (United States)

    Baker, Brett J; Moser, Duane P; MacGregor, Barbara J; Fishbain, Susan; Wagner, Michael; Fry, Norman K; Jackson, Brad; Speolstra, Nico; Loos, Steffen; Takai, Ken; Lollar, Barbara Sherwood; Fredrickson, Jim; Balkwill, David; Onstott, Tullis C; Wimpee, Charles F; Stahl, David A

    2003-04-01

    We characterized the diversity of sulphate-reducing bacteria (SRB) associated with South African gold mine boreholes and deep aquifer systems in Washington State, USA. Sterile cartridges filled with crushed country rock were installed on two hydrologically isolated and chemically distinct sites at depths of 3.2 and 2.7 km below the land surface (kmbls) to allow development of biofilms. Enrichments of sulphate-reducing chemolithotrophic (H2) and organotrophic (lactate) bacteria were established from each site under both meso- and thermophilic conditions. Dissimilatory sulphite reductase (Dsr) and 16S ribosomal RNA (rRNA) genes amplified from DNA extracted from the cartridges were most closely related to the Gram-positive species Desulfotomaculum thermosapovorans and Desulfotomaculum geothermicum, or affiliated with a novel deeply branching clade. The dsr sequences recovered from the Washington State deep aquifer systems affiliated closely with the South African sequences, suggesting that Gram-positive sulphate-reducing bacteria are widely distributed in the deep subsurface.

  19. Isolation and characterization of the heavy metal resistant bacteria CCNWRS33-2 isolated from root nodule of Lespedeza cuneata in gold mine tailings in China

    Energy Technology Data Exchange (ETDEWEB)

    Wei Gehong [College of Life Science, Shaanxi Key Laboratory of Molecular Biology for Agriculture, Northwest A and F University, Yangling Shaanxi 712100 (China)], E-mail: weigehong@yahoo.com.cn; Fan Lianmei; Zhu Wenfei; Fu Yunyun; Yu Jianfu; Tang Ming [College of Life Science, Shaanxi Key Laboratory of Molecular Biology for Agriculture, Northwest A and F University, Yangling Shaanxi 712100 (China)

    2009-02-15

    A total of 108 strains of bacteria were isolated from root nodules of wild legumes growing in gold mine tailings in northwest of China and were tested for heavy metal resistance. The results showed that the bacterial strain CCNWRS33-2 isolated from Lespedeza cuneata was highly resistant to copper, cadmium, lead and zinc. The strain had a relatively high mean specific growth rate under each heavy metal stress test and exhibited a high degree of bioaccumulation ability. The partial sequence of the copper resistance gene copA was amplified from the strain and a sequence comparison with our Cu-resistant PCR fragment showed a high homology with Cu-resistant genes from other bacteria. Phylogenetic analysis based on the 16S rRNA gene sequence showed that CCNWRS33-2 belongs to the Rhizobium-Agrobacterium branch and it had 98.9% similarity to Agrobactrium tumefaciens LMG196.

  20. Discussion on reason of 20 placer gold mine workers with pulmonary fibrosis%砂金矿工人肺纤维化20例原因探讨

    Institute of Scientific and Technical Information of China (English)

    张显军

    2013-01-01

    目的:探讨甘肃省白银地区砂金矿工人肺纤维化形成原因,为防治提供科学依据。方法选取2003~2012年在我院临床确诊为肺纤维化的20例住院砂金矿工人进行临床特点与职业场所卫生状况相关性探讨。结果20例患者来自7家不同矿井,但职业场所卫生状况相似,均为自私营企业,普遍存在乱采滥挖现象,主要采用打竖井和打隆道的方式开矿。均使用柴油机作为动力,工作过程中矿井内烟雾、粉尘浓度很高,站在几米以外的人无法看见,检测了职业场所二氧化硫(SO2)、二氧化氮(NO2)、总悬浮颗粒物(TSP)和可吸入颗粒物(PM10)浓度,均超过国家制定标准。20例患者均有明显的呼吸系统症状,主要表现为咳嗽、咳痰、胸闷、胸痛、进行性呼吸困难、乏力等。体征有低氧血症、杵状指、爆裂音(velcro啰音)等。胸片表现:两肺尖至肺底为不对称性、弥漫性、斑片状、云雾状模糊的实变影,以中上肺显著。肺的内、中、外带均被病变累及。病灶互相融合呈磨玻璃样改变,在阴影间可见广泛的粗细网状影和纤维索条影。部分患者合并有气胸。结论白银地区砂金矿工人接触粉尘中含有柴油机尾气烟雾,游离二氧化硅等,吸入高浓度柴油机尾气烟雾是引起肺纤维化的主要原因。%Objective To explore the cause of pulmonary fibrosis of workers who laboured in placer gold mine in Baiyin region of Gansu province in order to provide the scientific basis for prevention and treatment. Methods The correlation between clinical characteristics and health status of workplace of 20 hospitalized placer gold mine workers with pulmonary fibrosis diagnosed in our hospital from 2003 to 2012 were explored. Results Although 20 patients came from seven different mines, their health status of workplace were similar. These mines belonged to private enterprise, and

  1. Mercury Concentrations in Fish and Sediment within Streams are Influenced by Watershed and Landscape Variables including Historical Gold Mining in the Sierra Nevada, California

    Science.gov (United States)

    Alpers, C. N.; Yee, J. L.; Ackerman, J. T.; Orlando, J. L.; Slotton, D. G.; Marvin-DiPasquale, M. C.

    2015-12-01

    We compiled available data on total mercury (THg) and methylmercury (MeHg) concentrations in fish tissue and streambed sediment from stream sites in the Sierra Nevada, California, to assess whether spatial data, including information on historical mining, can be used to make robust predictions of fish fillet tissue THg concentrations. A total of 1,271 fish from five species collected at 103 sites during 1980-2012 were used for the modeling effort: 210 brown trout, 710 rainbow trout, 79 Sacramento pikeminnow, 93 Sacramento sucker, and 179 smallmouth bass. Sediment data were used from 73 sites, including 106 analyses of THg and 77 analyses of MeHg. The dataset included 391 fish (mostly rainbow trout) and 28 sediment samples collected explicitly for this study during 2011-12. Spatial data on historical mining included the USGS Mineral Resources Data System and publicly available maps and satellite photos showing the areas of hydraulic mine pits and other placer mines. Modeling was done using multivariate linear regression and multi-model inference using Akaike Information Criteria. Results indicate that fish THg, accounting for species and length, can be predicted using geospatial data on mining history together with other landscape characteristics including land use/land cover. A model requiring only geospatial data, with an R2 value of 0.61, predicted fish THg correctly with respect to over-or-under 0.2 μg/g wet weight (a California regulatory threshold) for 108 of 121 (89 %) size-species combinations tested. Data for THg in streambed sediment did not improve the geospatial-only model. However, data for sediment MeHg, loss on ignition (organic content), and percent of sediment less than 0.063 mm resulted in a slightly improved model, with an R2 value of 0.63. It is anticipated that these models will be useful to the State of California and others to predict areas where mercury concentrations in fish are likely to exceed regulatory criteria.

  2. The environmental and geomorphological impacts of historical gold mining in the Ohinemuri and Waihou river catchments, Coromandel, New Zealand

    Science.gov (United States)

    Clement, Alastair J. H.; Nováková, Tereza; Hudson-Edwards, Karen A.; Fuller, Ian C.; Macklin, Mark G.; Fox, Elizabeth G.; Zapico, Ignacio

    2017-10-01

    Between 1875 and 1955 approximately 250,000 Mg yr- 1 of mercury-, arsenic-, and cyanide-contaminated mine tailings were discharged directly into the Ohinemuri River and its tributaries, in the Coromandel Region, North Island, New Zealand. A devastating flood on 14 January 1907 deposited large amounts of mine waste across the floodplain of the Ohinemuri and Waihou rivers in the vicinity of the township of Paeroa. The 1907 mine-waste flood deposit was located as a dirty yellow silt in cores and floodplain profiles, with a thickness ranging from 0.15-0.50 m. Geochemical analysis of the mine waste shows elevated concentrations of Pb ( 200-570 mg kg- 1) and As ( 30-80 mg kg- 1), compared to early Holocene background concentrations (Pb environmental event. The mine-waste material remains in the floodplain today, representing a sizable legacy store of contaminant metals and metalloids that pose a long-term risk to the Ohinemuri and Waihou ecosystems.

  3. Characterization of iron- and sulphide mineral-oxidizing moderately thermophilic acidophilic bacteria from an Indonesian auto-heating copper mine waste heap and a deep South African gold mine.

    Science.gov (United States)

    Kinnunen, Päivi H-M; Puhakka, Jaakko A

    2004-10-01

    Iron- and chalcopyrite-oxidizing enrichment cultures were obtained at 50 degrees C from acidic, high-temperature, copper/gold mine environments in Indonesia and South Africa. Over 90% copper yield was obtained from chalcopyrite concentrate with the Indonesian enrichment in 3 months with 2% solids concentration, when pH was maintained at around 2. Neither addition of silver cations nor an enhanced nutrient concentration influenced chalcopyrite leaching. Excision and sequencing of bands from denaturing gradient gel electrophoresis of the amplified partial 16S rRNA gene showed that the enrichment cultures from different environments in South Africa and Indonesia were very simple, and similar. Chalcopyrite concentrate supported a simpler and different community than Fe2+. The members of the enrichment cultures were closely related to Sulfobacillus yellowstonensis and Sulfobacillus acidophilus.

  4. 整体顶梁组合悬移液压支架在鹤煤二矿的应用%Application of Integrated Roof Timber Combined Suspension Hydraulic Support at Hemei No.2 Coal Mine

    Institute of Scientific and Technical Information of China (English)

    张军义; 王俊生

    2011-01-01

    This article presents the application of zh 1600/16/24z integrated roof timber combined suspension hydraulic supports at Hemei No. 2 coal mine. This type of support overrun normal top coal caving hydraulic supports by multiple advantages such as less investment, lowers cost and convenience installation and removal.%本文叙述了ZH1600/16/24Z整体顶梁组合悬移液压支架在鹤煤二矿的应用。与普通放顶煤液压支架相比,具有投资少、费用低、安装撤除方便等优点。

  5. Joining the Gold Rush

    Institute of Scientific and Technical Information of China (English)

    LIU BO

    2006-01-01

    @@ Flush with advanced technology and large amounts of capital, overseas mining firms are carving a place in the Chinese gold industry Dozens of Western mining companies, particularly those from Canada, are making the journey into the kind of remote corners in China that other overseas investors shy away from. What are they looking for? The answer is one of the most precious substances on the planet: gold.

  6. Gold mining on Mayan-Mam territory: social unravelling, discord and distress in the Western highlands of Guatemala.

    Science.gov (United States)

    Caxaj, C Susana; Berman, Helene; Varcoe, Colleen; Ray, Susan L; Restoulec, Jean-Paul

    2014-06-01

    This article examines the influence of a large-scale mining operation on the health of the community of San Miguel Ixtahuacán, Guatemala. An anti-colonial narrative approach informed by participatory action research principles was employed. Data collection included focus groups and one-on-one interviews from August to November of 2011. Over this period, we interviewed 15 Mam Mayan men and 41 women (n = 56) between the ages of 18 and 64 including health care workers, educators, spiritual leaders, agricultural workers and previous mine employees from 13 villages within the municipality. Participants' accounts pointed to community health experiences of social unravelling characterized by overlapping narratives of a climate of fear and discord and embodied expressions of distress. These findings reveal the interconnected mechanisms by which local mining operations influenced the health of the community, specifically, by introducing new threats to the safety and mental wellbeing of local residents.

  7. Alteration Information Extraction by Applying Synthesis Processing Techniques to Landsat ETM+Data: Case Study of Zhaoyuan Gold Mines,Shandong Province, China

    Institute of Scientific and Technical Information of China (English)

    Liu Fujiang; Wu Xincai; Sun Huashan; Guo Yan

    2007-01-01

    Satellite remote sensing data are usually used to analyze the spatial distribution pattern of geological structures and generally serve as a significant means for the identification of alteration zones. Based on the Landsat Enhanced Thematic Mapper (ETM+) data, which have better spectral resolution (8 bands) and spatial resolution (15 m in PAN band), the synthesis processing techniques were presented to fulfill alteration information extraction: data preparation, vegetation indices and band ratios, and expert classifier-based classification. These techniques have been implemented in the MapGIS-RSP software (version 1.0), developed by the Wuhan Zondy Cyber Technology Co., Ltd,China. In the study area application of extracting alteration information in the Zhaoyuan (招远) gold mines, Shandong (山东) Province, China, several hydorthermally altered zones (included two new sites) were found after satellite imagery interpretation coupled with field surveys. It is concluded that these synthesis processing techniques are useful approaches and are applicable to a wide range of gold-mineralized alteration information extraction.

  8. Impacts of Artisanal and Small-Scale Gold Mining (ASGM on Environment and Human Health of Gorontalo Utara Regency, Gorontalo Province, Indonesia

    Directory of Open Access Journals (Sweden)

    Yayu Indriati Arifin

    2015-04-01

    Full Text Available Mercury concentrations in the environment (river sediments and fish and in the hair of artisanal gold miners and inhabitants of the Gorontalo Utara Regency were determined in order to understand the status of contamination, sources and their impacts on human health. Mercury concentrations in the sediments along the Wubudu and Anggrek rivers are already above the tolerable level declared safe by the World Health Organization (WHO. Meanwhile, commonly consumed fish, such as snapper, have mercury levels above the threshold limit (0.5 μg/g. The mean mercury concentrations in the hair of a group of inhabitants from Anggrek and Sumalata are higher than those in hair from control group (the inhabitants of Monano, Tolinggula and Kwandang. The mean mercury concentration in the hair of female inhabitants is higher than that in the hair of male inhabitants in each group. Neurological examinations were performed on 44 participants of artisanal and small-scale gold mining (ASGM miners and inhabitants of Anggrek and Sumalata. From the 12 investigated symptoms, four common symptoms were already observed among the participants, namely, bluish gums, Babinski reflex, labial reflex and tremor.

  9. 长山壕金矿静态吸附槽结构探讨%Discussion on structure of static adsorption tank at Changshanhao gold mine

    Institute of Scientific and Technical Information of China (English)

    李志远; 孙中建; 黄易周

    2013-01-01

    活性炭吸附是氰化提金工艺的重要组成部分,吸附槽结构对活性炭吸附效果影响甚大。以长山壕金矿为例,详细叙述了“夹层板+高频筛”和“蘑菇头层”吸附槽结构设计及工作原理,通过活性炭静态吸附工业应用效果及对比表明,“蘑菇头层”吸附槽创新地应用“蘑菇头”结构,解决了活性炭静态吸附中的炭层松散和贵液处理能力问题,且结构简单,值得借鉴。%Gold adsorption by activated carbon is an important part of oxidation gold extraction process .The struc-ture of adsorption tank has significant effects on activated carbon .The paper ,with Changshanhao gold mine as an ex-ample ,in detail introduced the structural design and working mechanism of “sandwich plate+high frequency screen+mushroom head layer” structure .Through industrial application test of static adsorption by activated carbon and com -parison ,it concludes that the “mushroom head” structure solved the problems like loose carbon layers and bad pre-cious solution treatment during the process of static adsorption .The structure is easy to go and worth referring to .

  10. 78 FR 4165 - Notice of Availability of the Draft Environmental Impact Statement for the Arturo Mine Project...

    Science.gov (United States)

    2013-01-18

    ...: Barrick-Dee Mining Venture Inc., proposes to develop the Arturo Mine Project by expansion of the existing open-pit Dee Gold Mine which is currently in closure and reclamation. The Dee Gold Mine is 45...

  11. Effects of soil composition and mineralogy on the bioaccessibility of arsenic from tailings and soil in gold mine districts of Nova Scotia.

    Science.gov (United States)

    Meunier, Louise; Walker, Stephen R; Wragg, Joanna; Parsons, Michael B; Koch, Iris; Jamieson, Heather E; Reimer, Kenneth J

    2010-04-01

    Bioaccessibility tests and mineralogical analyses were performed on arsenic-contaminated tailings and soils from gold mine districts of Nova Scotia, Canada, to examine the links between soil composition, mineralogy, and arsenic bioaccessibility. Arsenic bioaccessibility ranges from 0.1% to 49%. A weak correlation was observed between total and bioaccessible arsenic concentrations, and the arsenic bioaccessibility was not correlated with other elements. Bulk X-ray absorption near-edge structure analysis shows arsenic in these near-surface samples is mainly in the pentavalent form, indicating that most of the arsenopyrite (As(1-)) originally present in the tailings and soils has been oxidized during weathering reactions. Detailed mineralogical analyses of individual samples have identified up to seven arsenic species, the relative proportions of which appear to affect arsenic bioaccessibility. The highest arsenic bioaccessibility (up to 49%) is associated with the presence of calcium-iron arsenate. Samples containing arsenic predominantly as arsenopyrite or scorodite have the lowest bioaccessibility (iron arsenates and arsenic-bearing iron(oxy)hydroxides) are associated with intermediate bioaccessibility (1 to 10%). The presence of a more soluble arsenic phase, even at low concentrations, results in increased arsenic bioaccessibility from the mixed arsenic phases associated with tailings and mine-impacted soils.

  12. River transport of mercury from artisanal and small-scale gold mining and risks for dietary mercury exposure in Madre de Dios, Peru.

    Science.gov (United States)

    Diringer, Sarah E; Feingold, Beth J; Ortiz, Ernesto J; Gallis, John A; Araújo-Flores, Julio M; Berky, Axel; Pan, William K Y; Hsu-Kim, Heileen

    2015-02-01

    Artisanal and small-scale gold mining (ASGM) is a major contributor to deforestation and the largest anthropogenic source of atmospheric mercury worldwide. Despite significant information on the direct health impacts of mercury to ASGM miners, the impact of mercury contamination on downstream communities has not been well characterized, particularly in Peru's Madre de Dios region. In this area, ASGM has increased significantly since 2000 and has led to substantial political and social controversy. This research examined the spatial distribution and transport of mercury through the Madre de Dios River with distance from ASGM activity. This study also characterized risks for dietary mercury exposure to local residents who depend on fish from the river. River sediment, suspended solids from the water column, and fish samples were collected in 2013 at 62 sites near 17 communities over a 560 km stretch of the Madre de Dios River and its major tributaries. In areas downstream of known ASGM activity, mercury concentrations in sediment, suspended solids, and fish within the Madre de Dios River were elevated relative to locations upstream of mining. Fish tissue mercury concentrations were observed at levels representing a public health threat, with greater than one-third of carnivorous fish exceeding the international health standard of 0.5 mg kg(-1). This study demonstrates that communities located hundreds of kilometers downstream of ASGM activity, including children and indigenous populations who may not be involved in mining, are at risk of dietary mercury exposure that exceed acceptable body burdens. This report represents the first systematic study of the region to aid policy decision-making related to ASGM activities in Peru.

  13. Identifying Predictors of Arsenic Bioavailability in Low-Sulfide, Quartz-Hosted Gold Deposits: Case Study at the Empire Mine State Historic Park, CA, USA

    Science.gov (United States)

    Foster, A. L.; Alpers, C. N.; Burlak Regnier, T.; Blum, A.; Petersen, E. U.; Basta, N. T.; Whitacre, S.; Casteel, S. W.; Kim, C. S.

    2016-12-01

    Introduction: This study addressed a need to identify geochemical and mineralogical parameters that are significantly correlated with arsenic bioavailability at historically-mined, low-sulfide, quartz-hosted ("lode") gold deposits. The study location was the Empire Mine State Historic Park (EMSHP), a site that is typical of many lode deposits in California in that arsenic is a primary contaminant of concern. Methods: A total of 25 large-volume sediment/mine waste samples were collected from sites in the EMSHP, homogenized, and dry sieved (solid-phase chemistry (XRF; n = 25); (4) quantitative mineralogy (n =25); (5) Bulk As- and iron (Fe) speciation (synchrotron X-ray absorption spectroscopy, XAS, n =19); (6) point-based micron-scale composition (electron microprobe, n =12); and (7) micron-scale mineralogical and compositional mapping (QEMSCAN, n = 12). The matrix of bivariate correlations among these datasets was evaluated using a cutoff criterion for significance of p < 0.05. Results:Arsenic bioavailability was positively and significantly correlated with the abundance of Fe (hydr)oxide, the relative abundance of As-bearing hydroxide and As concentration in Fe hydroxide (datasets 4, 5, and 6, respectively). The relative abundance of As associated with Al-bearing secondary minerals (determined by As-XAS) was also positively and significantly correlated with datasets (1) and (2), but the correlation quality was lower. The relative abundance of other arsenic-bearing secondary minerals (e.g., jarosite, calcium arsenate, arseniosiderite) as determined by As XAS had positive correlations with bioaccessibility and/or bioavailability, but the correlations were not statistically significant. We ascribe this result to the fact that these phases only occurred in a few samples, whereas As- bearing Fe (hydr)oxide occurrence was ubiquitous. Highly negative and significant correlations were also observed between the abundance of arsenic-bearing sulfide minerals (datasets 4, 5

  14. Environmental arsenic contamination and its health effects in a historic gold mining area of the Mangalur greenstone belt of Northeastern Karnataka, India.

    Science.gov (United States)

    Chakraborti, Dipankar; Rahman, Mohammad Mahmudur; Murrill, Matthew; Das, Reshmi; Siddayya; Patil, S G; Sarkar, Atanu; Dadapeer, H J; Yendigeri, Saeed; Ahmed, Rishad; Das, Kusal K

    2013-11-15

    This report summarizes recent findings of environmental arsenic (As) contamination and the consequent health effects in a community located near historic gold mining activities in the Mangalur greenstone belt of Karnataka, India. Arsenic contents in water, hair, nail, soil and food were measured by FI-HG-AAS. Elemental analyses of soils were determined by ICP-MS (inductively coupled plasma-mass spectrometry). Of 59 tube-well water samples, 79% had As above 10 μg L(-1) (maximum 303 μg L(-1)). Of 12 topsoil samples, six were found to contain As greater than 2000 mg kg(-1) possibly indicating the impact of mine tailings on the area. All hair and nail samples collected from 171 residents contained elevated As. Arsenical skin lesions were observed among 58.6% of a total 181 screened individuals. Histopathological analysis of puncture biopsies of suspected arsenical dermatological symptoms confirmed the diagnosis in three out of four patients. Based on the time-course of As-like symptoms reported by the community as well as the presence of overt arsenicosis, it is hypothesized that the primary route of exposure in the study area was via contaminated groundwater; however, the identified high As content in residential soil could also be a significant source of As exposure via ingestion. Additional studies are required to determine the extent as well as the relative contribution of geologic and anthropogenic factors in environmental As contamination in the region. This study report is to our knowledge one of the first to describe overt arsenicosis in this region of Karnataka, India as well as more broadly an area with underlying greenstone geology and historic mining activity. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Rock mass response to strong ground motion generated by mining induced seismic events and blasting observed at the surface of the excavations in deep level gold mines in South Africa

    Science.gov (United States)

    Milev, Alexander; Durrheim, Ray; Ogasawara, Hiroshi

    2014-05-01

    The strong ground motion generated by mining induced seismic events was studied to characterize the rock mass response and to estimate the site effect on the surface of the underground excavations. A stand-alone instruments, especially designed for recording strong ground motions, were installed underground at a number of deep level gold mines in South Africa. The instruments were recording data at the surface of the stope hangingwalls. A maximum value of 3 m/s was measured. Therefore data were compared to the data recorded in the solid rock by the mine seismic networks to determine the site response. The site response was defined as the ratio of the peak ground velocity measured at the surface of the excavations to the peak ground velocity inferred from the mine seismic data measured in the solid rocks. The site response measured at all mines studied was found to be 9 ± 3 times larger on average. A number of simulated rockbursts were conducted underground in order to estimate the rock mass response when subjected to extreme ground motion and derive the attenuation factors in near field. The rockbursts were simulated by means of large blasts detonated in solid rock close to the sidewall of a tunnel. The numerical models used in the design of the simulated rockbursts were calibrated by small blasts taking place at each experimental site. A dense array of shock type accelerometers was installed along the blasting wall to monitor the attenuation of the strong ground motion as a function of the distance from the source. The attenuation of the ground motion was found to be proportional to the distance from the source following R^-1.1 & R^-1.7 for compact rock and R^-3.1 & R^-3.4 for more fractured rock close to the surface of the tunnel. In addition the ground motion was compared to the quasi-static deformations taking place around the underground excavations. The quasi-static deformations were measured by means of strain, tilt and closure. A good correspondence

  16. Autotrophic biofilm development on superficial samples of the gold-silver mine tailings, Valenciana (Mexico): pioneers in tailings remediation?

    Science.gov (United States)

    García-Meza, Jessica Viridiana

    2008-01-01

    We report the results of long term bio-assays on microorganism colonization of mine tailings samples, taken from the Valenciana mine tailings (Guanajuato, Mexico), under stable laboratory conditions (humidity, temperature, light exposure). In order to identify the main metabolic groups of the potentially colonizing microorganisms and the implications of their growth on the main tailing's characteristics related to biological succession, organic matter (OM) content, cationic exchange capacity (CEC), and pH values were measured as the colonization took place. We observe that photosynthetic biofilms (cyanobacteria, green algae, and diatoms) successfully colonize the mine tailings samples as pioneers; moreover, bacteria, yeast and fungi were also identified. Biofilm colonization significantly improved the OM contents, whereas the pH value is not modified during the entire observed colonization process. The results suggest that biofilms are useful during the first steps of the mine tailings remediation. This is the first report of microalgae and cyanobacteria grown of on tailings samples obtained from a semiarid region.

  17. Role of illumination in reducing risk to health and safety in South African gold and platinum mines

    CSIR Research Space (South Africa)

    Rushworth, AM

    2001-11-01

    Full Text Available This report provides a source of information that is designed to allow direct and effective action to be taken at both corporate and individual mine level to improve the visual working environment. This should, in turn, lead to improved safety and a...

  18. Self-Directed Work Teams in a Post-Apartheid Gold Mine: Perspectives from the Rock Face.

    Science.gov (United States)

    Phatkathi, Timothy Sizwe

    2002-01-01

    A participant-observation study in a South African mining company that used self directed work team training identified organizational constraints that hindered training effectiveness: lack of materials, machinery breakdown, decentralized budget, and imposed standards. Miners more often used improvisation and initiative to solve daily problems,…

  19. Seismic risks posed by mine flooding

    CSIR Research Space (South Africa)

    Goldbach, OD

    2009-09-01

    Full Text Available Many South African gold mines will flood when they close, as the groundwater will gradually fill the mining voids. Preliminary investigations have shown that flooding of mines can generate increased levels of seismicity. Examples are given...

  20. Modeling of gold production in Malaysia

    Science.gov (United States)

    Muda, Nora; Ainuddeen, Nasihah Rasyiqah; Ismail, Hamizun; Umor, Mohd Rozi

    2013-04-01

    This study was conducted to identify the main factors that contribute to the gold production and hence determine the factors that affect to the development of the mining industry in Malaysia. An econometric approach was used by performing the cointegration analysis among the factors to determine the existence of long term relationship between the gold prices, the number of gold mines, the number of workers in gold mines and the gold production. The study continued with the Granger analysis to determine the relationship between factors and gold production. Results have found that there are long term relationship between price, gold production and number of employees. Granger causality analysis shows that there is only one way relationship between the number of employees with gold production in Malaysia and the number of gold mines in Malaysia.

  1. Application of Pipe Network Hydraulic Calculation Theory in Mine Well Water Supply System Improvement%管网水力计算理论在矿井供水系统改造中的运用

    Institute of Scientific and Technical Information of China (English)

    季雅宙

    2013-01-01

    Coal mine safety rules show: we must establish and improve dustproof and water supply system in the mine well. Based on the comprehensive study and analysis on the status of water supply system in Tangshan Mining Company Tieyi District and the reconstruction plan of water supply system, this paper used the pipe network hydraulic calculation theory to calculate the existing and new water supply system to build and improve the dustproof and water supply system and ensure safety of mine.%  煤矿安全规程规定:矿井必须建立完善的防尘供水系统。本文通过对唐山矿业公司铁一区供水系统的现状及下步供水系统改造计划的综合研究、分析,利用管网水力计算理论对铁一区生产区域现有和新建供水系统进行计算校核,确保铁一区建立完善的防尘供水系统,保证矿井的安全生产。

  2. 甘肃省玉门市大锅底坑金矿地质特征%Featuress of Daguodikeng Gold Mine in Gansu Yumenshi

    Institute of Scientific and Technical Information of China (English)

    张英凯

    2015-01-01

    Daguodikeng's gold mine is located in the ditch systems integration group rock group Geer Mo:mainly by a dark metamorphic gneiss , schist ancient crystalline basement , the original rock is sandwiched with features and volcanic activity has the characteristics of marine flysch deposition metamorphic rocks .Gold mineralization occurs in the body as the Cambri-an System in the ditch group Geer Mo chlorite schist rock group .Ore vein-like, lenticular output , along strike and have a tendency to shrink the expansion slot , pinch feature reproduction .Structural alteration in foliated volcanic basin develop-ment and other show in the closing stages , squeezing effect early overlay with seam-bit transformation , so that the occur-rence of sedimentary rocks and tough , brittle deformation, strongly foliated development zone , the Gold Point and ductile-brittle Gold shear structural alteration related to lithology .%大锅底坑金矿位于中寒系统中统格尔莫沟群中岩组。主要由一套深变质的片麻岩、片岩组成古老的结晶基底,其原岩是夹有具火山活动特征和具有复理石特征的海相沉积变质岩系。金矿化体赋存于为寒武系中统格尔莫沟群中岩组绿泥石片岩。矿体呈脉状、透镜状产出,沿走向及倾向都具膨胀狭缩、尖灭再现的特征。构造蚀变岩中片理化发育等表明在火山盆地闭合阶段,挤压作用对早期含矿层位叠加改造,使沉积岩系发生韧、脆性变形,发育强烈的片理化带,该金矿点是与韧脆性剪切作用有关的构造蚀变岩性金矿。

  3. A ground electromagnetic survey used to map sulfides and acid sulfate ground waters at the abandoned Cabin Branch Mine, Prince William Forest Park, northern Virginia gold-pyrite belt

    Science.gov (United States)

    Wynn, Jeffrey C.

    2000-01-01

    INTRODUCTION AND BACKGROUND: Prince William Forest Park is situated at the northeastern end of the Virginia Gold-Pyrite belt northwest of the town of Dumfries, VA. The U. S. Marine Corps Reservation at Quantico borders the park on the west and south, and occupies part of the same watershed. Two abandoned mines are found within the park: the Cabin Branch pyrite mine, a historic source of acid mine drainage, and the Greenwood gold mine, a source of mercury contamination. Both are within the watershed of Quantico Creek (Fig.1). The Cabin Branch mine (also known as the Dumfries mine) lies about 2.4 km northwest of the town of Dumfries. It exploited a 300 meter-long, lens-shaped body of massive sulfide ore hosted by metamorphosed volcanic rocks; during its history over 200,000 tons of ore were extracted and processed locally. The site became part of the National Capitol Region of the National Park Service in 1940 and is currently managed by the National Park Service. In 1995 the National Park Service, in cooperation with the Virginia Department of Mines, Minerals, and Energy reclaimed the Cabin Branch site. The Virginia Gold-Pyrite belt, also known as the central Virginia volcanic-plutonic belt, is host to numerous abandoned metal mines (Pavlides and others, 1982), including the Cabin Branch deposit. The belt itself extends from its northern terminus near Cabin Branch, about 50 km south of Washington, D.C., approximately 175 km to the southwest into central Virginia. It is underlain by metamorphosed volcanic and clastic (non-carbonate) sedimentary rocks, originally deposited approximately 460 million years ago during the Ordovician Period (Horton and others, 1998). Three kinds of deposits are found in the belt: volcanic-associated massive sulfide deposits, low-sulfide quartz-gold vein deposits, and gold placer deposits. The massive sulfide deposits such as Cabin Branch were historically mined for their sulfur, copper, zinc, and lead contents, but also yielded byproduct

  4. Drilling into seismogenic zones of M2.0 - M5.5 earthquakes in deep South African gold mines (DSeis)

    Science.gov (United States)

    Ogasawara, Hiroshi; Durrheim, Raymond; Yabe, Yasuo; Ito, Takatoshi; van Aswegen, Gerrie; Cichowicz, Artur; Onstott, Tullis; Kieft, Tom; Boettcher, Margaret; Wiemer, Stefan; Ziegler, Martin; Janssen, Christoph; Shapiro, Serge; Gupta, Harsh; Dight, Phil

    2016-04-01

    Several times a year, mining-induced earthquakes with magnitudes equal to or larger than 2 take place only a few tens of meters away from active workings in South African gold mines at depths of up to 3.4 km. The largest event recorded in mining regions, a M5.5 earthquake, took place near Orkney, South Africa on 5 August 2014, with the upper edge of the activated fault being only some hundred meters below the nearest mine workings (3.0 km depth). This is one of the rare events for which detailed seismological data are available, both from surface and underground seismometers and strainmeters, allowing for a detailed seismological analysis and comparison with in-situ observed data. Therefore, this earthquake calls for drilling to investigate the seismogenic zones before aftershocks diminish. Such a project will have a significantly better spatial coverage (including nuclei of ruptures, strong motion sources, asperities, and rupture edges) than drilling in seismogenic zones of natural large earthquakes and will be possible with a lower risk and at much smaller costs. In seismogenic zones in a critical state of stress, it is difficult to delineate reliably the local spatial variation in both directions and magnitudes of principal stresses (3D full stress tensor) reliably. However, we have overcome this problem. We are able to numerically model stress better than before, enabling us to orient boreholes so that the chance of stress-induced damage during stress measurement is minimized, and enabling us to measure the full 3D stress tensor successively in a hole within reasonable time even when stresses are as large as those expected in seismogenic zones. Better recovery of cores with less stress-induced damage during drilling is also feasible. These will allow us to address key scientific questions in earthquake science and associated deep biosphere activities which have remained elusive. We held a 4-day workshop sponsored by ICDP and Ritsumeikan University in October

  5. Mercury Levels in Human Hair and Farmed Fish near Artisanal and Small-Scale Gold Mining Communities in the Madre de Dios River Basin, Peru.

    Science.gov (United States)

    Langeland, Aubrey L; Hardin, Rebecca D; Neitzel, Richard L

    2017-03-14

    Artisanal and small-scale gold mining (ASGM) has been an important source of income for communities in the Madre de Dios River Basin in Peru for hundreds of years. However, in recent decades, the scale of ASGM activities in the region has increased dramatically, and exposures to a variety of occupational and environmental hazards related to ASGM, including mercury, are becoming more widespread. The aims of our study were to: (1) examine patterns in the total hair mercury level of human participants in several communities in the region and compare these results to the 2.2 µg/g total hair mercury level equivalent to the World Health Organization (WHO) Expert Committee of Food Additives (JECFA)'s Provisional Tolerable Weekly Intake (PTWI); and (2), to measure the mercury levels of paco (Piaractus brachypomus) fish raised in local aquaculture ponds, in order to compare these levels to the EPA Fish Tissue Residue Criterion of 0.3 µg Hg/g fish (wet weight). We collected hair samples from 80 participants in four communities (one control and three where ASGM activities occurred) in the region, and collected 111 samples from fish raised in 24 local aquaculture farms. We then analyzed the samples for total mercury. Total mercury levels in hair were statistically significantly higher in the mining communities than in the control community, and increased with increasing geodesic distance from the Madre de Dios headwaters, did not differ by sex, and frequently exceeded the reference level. Regression analyses indicated that higher hair mercury levels were associated with residence in ASGM communities. The analysis of paco fish samples found no samples that exceeded the EPA tissue residue criterion. Collectively, these results align with other recent studies showing that ASGM activities are associated with elevated human mercury exposure. The fish farmed through the relatively new process of aquaculture in ASGM areas appeared to have little potential to contribute to human

  6. Mercury Levels in Human Hair and Farmed Fish near Artisanal and Small-Scale Gold Mining Communities in the Madre de Dios River Basin, Peru

    Science.gov (United States)

    Langeland, Aubrey L.; Hardin, Rebecca D.; Neitzel, Richard L.

    2017-01-01

    Artisanal and small-scale gold mining (ASGM) has been an important source of income for communities in the Madre de Dios River Basin in Peru for hundreds of years. However, in recent decades, the scale of ASGM activities in the region has increased dramatically, and exposures to a variety of occupational and environmental hazards related to ASGM, including mercury, are becoming more widespread. The aims of our study were to: (1) examine patterns in the total hair mercury level of human participants in several communities in the region and compare these results to the 2.2 µg/g total hair mercury level equivalent to the World Health Organization (WHO) Expert Committee of Food Additives (JECFA)’s Provisional Tolerable Weekly Intake (PTWI); and (2), to measure the mercury levels of paco (Piaractus brachypomus) fish raised in local aquaculture ponds, in order to compare these levels to the EPA Fish Tissue Residue Criterion of 0.3 µg Hg/g fish (wet weight). We collected hair samples from 80 participants in four communities (one control and three where ASGM activities occurred) in the region, and collected 111 samples from fish raised in 24 local aquaculture farms. We then analyzed the samples for total mercury. Total mercury levels in hair were statistically significantly higher in the mining communities than in the control community, and increased with increasing geodesic distance from the Madre de Dios headwaters, did not differ by sex, and frequently exceeded the reference level. Regression analyses indicated that higher hair mercury levels were associated with residence in ASGM communities. The analysis of paco fish samples found no samples that exceeded the EPA tissue residue criterion. Collectively, these results align with other recent studies showing that ASGM activities are associated with elevated human mercury exposure. The fish farmed through the relatively new process of aquaculture in ASGM areas appeared to have little potential to contribute to human

  7. 新疆某金矿地质环境影响程度分析及防治对策%Analysis of impact on geological environment of one gold mine in Xinjiang and its countermeasures

    Institute of Scientific and Technical Information of China (English)

    张紫昭; 程文瑜; 刘军

    2014-01-01

    新疆某金矿为中型矿山,2014年将采用地下开采方式。针对该金矿开采后对地质环境的影响程度,选取地质灾害、含水层破坏、地形地貌景观破坏和土地资源破坏4个指标分析了各矿建设施和破坏土地单元对地质环境的影响程度,采用快速聚类分析法将各评价单元划分为三类,即严重区、较严重区和较轻区,最后提出了矿山地质环境防治措施。%One medium-sized gold mine in Xinjiang is about to transmit to underground mining methods in 2014. This paper selects four indicators for analyzing the gold mining impact on the geological environment ,including geolog-ical disasters ,aquifer breakage ,landforms and landscape devastation and land resource destruction .The degree of im-pact of different kinds of mine constructions have on the geological environment in the mine construction and land units is analyzed .These evaluation units are divided into three categories by quick clustering analysis ,namely severe area , less severe areas and and light areas .Then this paper proposes countermeasures .

  8. Ardrea characterisation of acidophilic micro-organisms isolated from gold mines in Marmato, Colombia Caracterización por Ardrea de microorganismos acidófilos aislados en minas de oro de Marmato, Colombia

    OpenAIRE

    Osorio E. Victor Manuel; Márquez G. Marco; Márquez F. Edna Judith

    2007-01-01

    Mineral bio-oxidation improves the extraction of valuable metals and also decreases the impact caused by mining waste; however, the interactions between the micro-organisms so involved are little known. Double-layer solid culture media techniques and amplified ribosomal DNA restriction enzyme analysis (Ardrea), using Eco72I, Eco24I, XcmI and BsaAI enzymes, were used for characterising four micro-organisms isolated from gold mines located in Marmato, Colombia. This work was aimed at better und...

  9. Assessment of nanofiltration and reverse osmosis potentialities to recover metals, sulfuric acid, and recycled water from acid gold mining effluent.

    Science.gov (United States)

    Ricci, Bárbara C; Ferreira, Carolina D; Marques, Larissa S; Martins, Sofia S; Amaral, Míriam C S

    This work assessed the potential of nanofiltration (NF) and reverse osmosis (RO) to treat acid streams contaminated with metals, such as effluent from the pressure oxidation process (POX) used in refractory gold ore processing. NF and RO were evaluated in terms of rejections of sulfuric acid and metals. Regarding NF, high sulfuric acid permeation (∼100%), was observed, while metals were retained with high efficiencies (∼90%), whereas RO led to high acid rejections (<88%) when conducted in pH values higher than 1. Thus, sequential use of NF and RO was proved to be a promising treatment for sulfuric acid solutions contaminated by metals, such as POX effluent. In this context, a purified acid stream could be recovered in NF permeate, which could be further concentrated in RO. Recovered acid stream could be reused in the gold ore processing or commercialized. A metal-enriched stream could be also recovered in NF retentate and transferred to a subsequent metal recovery stage. In addition, considering the high acid rejection obtained through the proposed system, RO permeate could be used as recycling water.

  10. Mapping Supergene/Hypogene Alteration Signatures with Landsat ETM+ Data:Paishanlou Gold Mine, Liaoning Province, China

    Institute of Scientific and Technical Information of China (English)

    Malogo J M Kongola; Wang Ende

    2005-01-01

    Noise-removal routines (destriping) were performed on Landsat ETM+ data as adjustments for atmospheric and distortion factors, prior to further image enhancement and interpretation. The image enhancement techniques were contrast stretching, density slicing, spatial filtering, Fourier analysis, brightness inversion, band combinations, and band ratioing. It has been revealed that, owing to the presence of gossans at Paishanlou, the mixture of iron oxide and clay minerals affects the spectral reflectance in satellite data. The mineral and hydrothermal composite images with band ratios 5/7+5/4+3/1 RGB and 5/7+3/1+4/3 RGB, respectively, yielded the best results for their sensitivity to lithologic variables, and lack of statistical redundancy. Ratio 3/1 clearly highlighted ferric (Fe3+) iron; 5/4 depicted ferrous (Fe2+) iron, and 5/7 depicted clays, carbonates, and hydroxyl-bearing minerals. Vegetation was also successfully discriminated by ratio 5/7. Finally, coupled with field surveys, petrographical and geochemical data, the observed anomalies led to the discovery of three new sites, which are gold-mineralized. The prime objective of this study was to map supergene and/or hypogene signatures in the gold-mineralized areas using Landsat ETM+ data at Paishanlou.

  11. Mercury content in wetland rice soil and water of two different seasons at small-scale gold mine processing areas

    Directory of Open Access Journals (Sweden)

    T. Sugianti

    2016-04-01

    Full Text Available This study was aimed to identify the impact of small-scale gold processing activities on mercury content in wetland rice soil and water during the rainy and first dry seasons in Central Lombok and West Lombok Districts. The method used for this study was survey method. Measurement of mercury levels in water samples was conducted at Agro Bogor Centre using SNI 6989.77: 2011 methods. The data was collected and processed in a simple statistic presented descriptively, in order to obtain information. Results of the study showed that mercury content soils in the rainy season exceeded the threshold of 0.005 ppm, while in the first dry season the mercury content in soil decreased, but it was still above the threshold value permitted. The contents of mercury in water samples in the rainy season and the first dry season were still at a safe point that was less than 0.05 ppm. The wetland rice soil and water had been polluted with mercury, although the mercury content in the water was still below the threshold, but the accumulation of mercury that could have been absorbed by the plants are of particular concerns. The decrease of mercury content in soil in dry season was due to lack of gold processing activities.

  12. Using remote sensing techniques and field-based structural analysis to explore new gold and associated mineral sites around Al-Hajar mine, Asir terrane, Arabian Shield

    Science.gov (United States)

    Sonbul, Abdullah R.; El-Shafei, Mohamed K.; Bishta, Adel Z.

    2016-05-01

    Modern earth resource satellites provide huge amounts of digital imagery at different resolutions. These satellite imageries are considered one of the most significant sources of data for mineral exploration. Image processing techniques were applied to the exposed rocks around the Al-Aqiq area of the Asir terrane in the southern part of the Arabian Shield. The area under study has two sub-parallel N-S trending metamorphic belts of green-schist facies. The first belt is located southeast of Al-Aqiq, where the Al-Hajar Gold Mine is situated. It is essentially composed of metavolcanics and metasedimentary rocks, and it is intruded by different plutonic rocks of primarily diorite, syenite and porphyritic granite. The second belt is located northwest of Al-Aqiq, and it is composed of metavolcanics and metasedimentary rocks and is intruded by granite bodies. The current study aimed to distinguish the lithological units, detect and map the alteration zones, and extract the major fault lineaments around the Al-Hajar gold prospect. Digital satellite imageries, including Landsat 7 ETM + multispectral and panchromatic and SPOT-5 were used in addition to field verification. Areas with similar spectral signatures to the prospect were identified in the nearby metamorphic belt; it was considered as a target area and was inspected in the field. The relationships between the alteration zones, the mineral deposits and the structural elements were used to locate the ore-bearing zones in the subsurface. The metasedimentary units of the target area showed a dextral-ductile shearing top-to-the-north and the presence of dominant mineralized quartz vein-system. The area to the north of the Al-Hajar prospect showed also sub-parallel shear zones along which different types of alterations were detected. Field-based criteria such as hydrothermal breccia, jasper, iron gossans and porphyritic granite strongly indicate the presence of porphyry-type ore deposits in Al-Hajar metamorphic belt that

  13. Initial report on drilling into seismogenic zones of M2.0 - M5.5 earthquakes from deep South African gold mines (DSeis)

    Science.gov (United States)

    Ogasawara, Hiroshi; Durrheim, Raymond; Yabe, Yasuo; Ito, Takatoshi; van Aswegen, Gerrie; Grobbelaar, Michelle; Funato, Akio; Ishida, Akimasa; Ogasawara, Hiroyuki; Mngadi, Siyanda; Manzi, Musa; Ziegler, Martin; Ward, Tony; Moyer, Pamela; Boettcher, Margaret; Ellsworth, Bill; Liebenberg, Bennie; Wechsler, Neta; Onstott, Tullis; Berset, Nicolas

    2017-04-01

    The International Continental Scientific Drilling Program (ICDP) approved our proposal (Ogasawara et al., EGU 2016) to drill into and around seismogenic zones where critically stressed faults initiated ruptures at depth. The drilling targets include four ruptures equivalent to M2.0, 2.8, 3.5, and 5.5 that dynamically and quasi-statically evolved in 2.9 Ga hard rock in the Witwatersrand basin, South Africa. Major advantages of our drilling locations are the large quantity and high-quality of existing data from dense seismic arrays both on surface and near-field underground in three deep South African gold mines. Additionally, the great depths (1.0 to 3.3 km from surface) to collar holes reduce drilling costs significantly and enable a larger number of holes to be drilled. Flexibility in drilling direction will also allow us to minimize damage in borehole or drilled cores. With the ICDP funds, we will conduct full-core drilling of 16 holes with drilling ranges from 50 to 750 m to recover both materials and fractures in and around the seismogenic zones, followed by core and borehole logging. Additional in-hole monitoring at close proximity will be supported by co-mingled funds and will follow the ICDP drilling. Expected magnitudes of maximum shear stress are several tens of MPa. We have established an overcoring procedure to measure 3D-stress state for adverse underground working conditions so as not to interfere with mining operations. This procedure was optimized based on the Compact Conic-ended Borehole Overcoring (CCBO) technique (ISRM suggested; Sugawara and Obara, 1999). Funato and Ito (2016 IJRMMS) developed a diametrical core deformation analysis (DCDA) method to measure differential stress using only drilled core by assuming diametrical change with roll angles caused by elastic in-axisymmetrical expansion during drilling. A gold mine has already drilled a hole to intersect the hypocenter of a 2016 M3.5 earthquake and carried out the CCBO stress measurement in

  14. Geochemical Assessment of the Impact of Mine Tailings Reclamation on the Quality of Soils at AngloGold Concession, Obuasi, Ghana

    Directory of Open Access Journals (Sweden)

    Enoch Boateng

    2012-04-01

    Full Text Available This study assessed the geochemical impact of mine tailings reclamation on the quality of soils from the AngloGold Concession, Obuasi, Ghana. Soil samples from mine tailings reclamation sites were evaluated for the concentrations of plant nutrients and trace metals. Contaminations of trace metals, using geochemical pollution indices were used to assess possible effects on agriculture and livelihoods. The average pH ranges from 7.6 to 8.4 at the ex-tailing sites whiles the control site is 6.0. Organic carbon and nitrogen levels at the extailings site are low due to topsoil loss. Average available P and K levels were low or very low; i.e., <20 and <40 mg/kg, respectively at both ex-tailing and control sites. Average EC values as well as individual values of all the soils were less than 2 dS/m, while average ESP and individual soil values were less than 15%, indicating that the soils are non saline. Average ECEC levels, contributed by Ca and Mg, are medium at the ex-tailing sites but low at the control sites. The concentrations of arsenic (As, copper (Cu, lead (Pb and zinc (Zn were compared to their respective background concentrations to calculate their contamination factors and geo-accumulation indices at all the examined areas. Average concentration values for As are consistently high; presenting the highest value of 426.67 mg/kg at Area 3 and the least of 72.03 mg/kg at the control site, above the Netherlands soil/sediment intervention guideline value of 55 mg/kg for remediation. Furthermore, estimates from the geochemical evaluations indicated that As contamination was very high and therefore poses a threat to agricultural land use as well as general environmental quality.

  15. Application of organic matter to enhance phytoremediation of mercury contaminated soils using local plant species: a case study on small-scale gold mining locations in Banyuwangi of East Java

    Directory of Open Access Journals (Sweden)

    N. Muddarisna

    2014-10-01

    Full Text Available The discharge of small-scale gold mine tailing to agricultural lands at Pesanggaran village of Banyuwangi Regency caused soil degradation as indicated by reduced crop production. This soil degradation is mainly due to the toxicity of mercury contained in the tailing. The purpose of this study was to explore the potential of three local plant species, i.e. Lindernia crustacea, Digitaria radicosa, and Cyperus kyllingia for phytoremediation of agricultural land contaminated gold mine waste containing mercury, and its influence on the growth of maize. Six treatments (three plant species, and two levels of organic matter application were arranged in a randomized block design with three replicates. Maize was grown on soil after phytoremediation for 8 weeks. The results showed that among the three plant species tested, Cyperus kyllingia was the potential candidate plant species for phytoremediation of soil contaminated with gold mine tailing containing mercury because of its ability to accumulate mercury from 32.06 to 73.90 mg / kg of soil in 60 days. Phytoremediation of mercury contaminated soil using Cyperus kyllingia using increased maize yield by 126% compared to that the biomass yield of maize grown on soil without phytoremediation. Induce phytoremediation needs to be carried out to accelerate the process of remediation of mercury contaminated soils

  16. Coating Quality Control and Management of Hydraulic Drill on Coal Mine%浅谈煤矿用液压钻机涂装质量的控制与管理

    Institute of Scientific and Technical Information of China (English)

    王伟

    2012-01-01

    煤矿用液压钻机是我国综采工作面及普采工作面的主要钻进设备,已成为矿井安全防爆、瓦斯抽排的主要钻孔设备,随着煤矿钻机市场的蓬勃发展,机械性能不再是产品推广与展示的唯一标准.对钻机涂装的外观质量和防护性能提出了更高的要求.一直以来,钻机涂装多采用刷涂或露天喷涂,涂装工艺水平落后,生产环境恶劣,缺乏有效管理,涂装质量无法得到保证.文章介绍通过对工艺体系、质量分级、原材料控制、人员培训等多方面实施有效地控制与管理,使得煤矿用液压钻机外观涂装质量上一个新的台阶.%Hydraulic drill on coal mine is the main drilling equipment used in fully mechanized working face and conventional mining face, and has become the main drilling equipment for mine anti-explosion safety and gas suction and emission. Along with the vigorous development of coal mine drill market, mechanical performance is no longer the only standard for product promotion and display. And put higher demand on drill coating quality and protective performance. Drill coating has been used painting brush or open coating, and coating process level lags behind, the production conditions is poor, and lacks of effective management, the quality of coating cannot be guaranteed. This paper puts the effective control and management in the process system, quality grading, raw materials control, and personnel training, making the coating level of hydraulic drill on coal mine upgrade.

  17. 煤矿井下车载液压绞车的设计与实验研究%Design and experimental research of vehicle-mounted hydraulic winch in underground coal mine

    Institute of Scientific and Technical Information of China (English)

    潘成杰

    2016-01-01

    According to the structure and performance characteristics of the underground shovel plate carrier used in the coal mine, a U-shaped arrangement of vehicle-mounted hydraulic winch was designed. Under the control of the driving unit integrated by the rotary reducer and the POSI-STOP type anti-drag locking device, the vehicle hydraulic winch driven by the underground shovel plate carrier's hydraulic system could transfer power to the lateral arrangement transmission reducer. Meanwhile, through the application of a new type material rope made from ultra-high molecular weight polyethylene (UHMWPE) and aramid fiber, the inapplicability and the insecurity problems of steel wire rope used in the situation of small curvature radius roller were solved fundamentally. To acquire technical parameters of the vehicle hydraulic winch, the dynamometer tests under various sustained load were carried out with hydraulic test bed and transmission test bed. As a result, the structural correctness of the hydraulic winch's design and the thermal equilibrium of each element were proved.%针对煤矿井下铲板式搬运车的结构和性能特点设计了一种U型布置方式的车载液压绞车,该绞车以铲板式搬运车液压系统为动力源,通过集成了回转减速器、 P OSI-STOP 型反拖自锁装置为一体的驱动控制单元将动力传递给侧向布置传动减速箱,在经过小半径滚筒卷扬超高分子量聚乙烯+芳纶材料的缆绳代替传统钢丝绳实现工作输出,解决了钢丝绳不能应用于较小曲力半径滚筒上的问题和使用安全性问题。通过液压试验台和传动试验台对该绞车进行各种持续负载工况的测功平台试验,以获得绞车的各种技术参数,从而验证绞车结构、设计的合理性和绞车各部位的热平衡。

  18. The dragon on the gold: myths and realities for data mining in biomedicine and biotechnology using digital and molecular libraries.

    Science.gov (United States)

    Robson, Barry

    2004-01-01

    To develop bioscience and personalized medicine in the post-genomic era, the biggest problem may be how to extract knowledge from the rich libraries of biomedical data. A particular dragon protects the gold therein: the dragon is the "curse of dimensionality" and its formidable fire weapon, which is burning researchers, is the "combinatorial explosion". This arises because many genomic, proteomic, clinical, and lifestyle factors may interact that cannot necessarily be considered on a simple pairwise or additive basis. A suggested theoretical solution--or at least "road map" that ameliorates management of these problems--borrows from several disciplines. It is undertaken also in the hope might also lead to research with broader impact on several unresolved issues in biotechnology: conversely, mathematical understanding of processes involving molecular libraries, such as cDNA libraries and DNA in the living cell itself, may open the opportunities to use biotechnology to construct nanotechnological storage and query systems.

  19. Biodegradation of free cyanide by bacterial species isolated from cyanide-contaminated artisanal gold mining catchment area in Burkina Faso.

    Science.gov (United States)

    Razanamahandry, Lovasoa Christine; Andrianisa, Harinaivo Anderson; Karoui, Hela; Kouakou, Koffi Marcelin; Yacouba, Hamma

    2016-08-01

    Soil and water samples were collected from a watershed in Burkina Faso where illegal artisanal gold extraction using cyanidation occurs. The samples were used to evaluate cyanide contamination and the presence of cyanide degrading bacteria (CDB). Free cyanide (F-CN) was detected in all samples, with concentrations varying from 0.023 to 0.9 mg kg(-1), and 0.7-23 μg L(-1) in the soil and water samples, respectively. Potential CDB also were present in the samples. To test the effective F-CN degradation capacity of the isolated CDB species, the species were cultivated in growth media containing 40, 60 or 80 mg F-CN L(-1), with or without nutrients, at pH 9.5 and at room temperature. More than 95% of F-CN was degraded within 25 h, and F-CN degradation was associated with bacterial growth and ammonium production. However, initial concentrations of F-CN higher than 100 mg L(-1) inhibited bacterial growth and cyanide degradation. Abiotic tests showed that less than 3% of F-CN was removed by volatilization. Thus, the degradation of F-CN occurred predominately by biological mechanisms, and such mechanisms are recommended for remediation of contaminated soil and water. The bacteria consortium used in the experiment described above exist in a Sahelian climate, which is characterized by a long hot and dry season. Because the bacteria are already adapted to the local climate conditions and show the potential for cyanide biodegradation, further applicability to other contaminated areas in West Africa, where illegal gold cyanidation is widespread, should be explored. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. 综采工作面液压支架集控系统设计研究%Design of hydraulic support system for hydraulic support in fully mechanized mining face

    Institute of Scientific and Technical Information of China (English)

    唐鹏

    2015-01-01

    In view of the present stage of our country's domestic hydraulic support control system has the problem of poor real-time, low reliability and low degree of automation. This paper designs the hydraulic support system of hydraulic support in the fully mechanized working face, and introduces the hardware and software design of the system. The system has high real-time performance, stable communication, high degree of integration, and can meet the requirements of the establishment of high efifciency fully mechanized coal face.%针对现阶段我国的国产液压支架控制系统有实时性差、可靠性低、自动化程度较低等问题,设计了综采工作面液压支架集控系统,该文介绍了该系统硬件组成与软件设计,分析了液压支架集控的实现过程。该系统实时性高,通信稳定,集控程度高,能满足建立高产高效综采工作面的要求。

  1. Hydraulic structures

    CERN Document Server

    Chen, Sheng-Hong

    2015-01-01

    This book discusses in detail the planning, design, construction and management of hydraulic structures, covering dams, spillways, tunnels, cut slopes, sluices, water intake and measuring works, ship locks and lifts, as well as fish ways. Particular attention is paid to considerations concerning the environment, hydrology, geology and materials etc. in the planning and design of hydraulic projects. It also considers the type selection, profile configuration, stress/stability calibration and engineering countermeasures, flood releasing arrangements and scouring protection, operation and maintenance etc. for a variety of specific hydraulic structures. The book is primarily intended for engineers, undergraduate and graduate students in the field of civil and hydraulic engineering who are faced with the challenges of extending our understanding of hydraulic structures ranging from traditional to groundbreaking, as well as designing, constructing and managing safe, durable hydraulic structures that are economical ...

  2. Phytoremediation of Gold Mine Tailings Amended with Iron-Coated and Uncoated Rice Husk Ash by Vetiver Grass (Vetiveria zizanioides (Linn. Nash

    Directory of Open Access Journals (Sweden)

    F. S. Tariq

    2016-01-01

    Full Text Available This study was undertaken to determine the effects of rice husk ash (RHA and iron-coated rice husk ash (Fe-RHA on phytoavailability of As, Cd, Cr, Cu, Mn, Pb, and Zn to vetiver grass grown in gold mine tailings amended with either RHA or Fe-RHA at 0%, 5%, 10%, and 20% (w/w. The results showed that the RHA amended tailings recorded higher concentration of As in the shoot and the root and higher concentration of Cr and Mn in the root compared to the untreated tailings which was used as a control. The biological accumulation coefficient (BAC and bioconcentration factor (BCF values of the vetiver grass for As and Zn increased with RHA application rate but the biological transfer coefficient (BTC values of As and Zn were decreased. In Fe-RHA amended samples, As concentration in the shoot and root concentrations of Cd and Zn were significantly higher compared to the control. The Fe-RHA treated samples had lower BAC and BTC values for As and Zn than the control. However, the BCF values for those elements were higher than the control. The concentration of Pb was not detected in any of the samples.

  3. Spatial distribution of mercury and arsenic levels in water, soil and cassava plants in a community with long history of gold mining in Tanzania.

    Science.gov (United States)

    Nyanza, Elias C; Dewey, Deborah; Thomas, Deborah S K; Davey, Mark; Ngallaba, Sospatro E

    2014-12-01

    This study examined the spatial distribution of total mercury (THg) and total arsenic (TAs) in water, soil and cassava (Manihot esculenta) (leaves and roots) samples taken from areas in Rwamagasa village in northwestern Tanzania where daily living activities occur in close proximity to extensive artisanal and small scale gold mining. Results indicated that 33.3 % of the water sources had THg levels above the WHO guideline of 1.0 µg/L for safe drinking water, and 12.5 % had TAs levels above 10 µg/L. Cassava leaves were found to have higher THg (ranging from 8.3 to 167 µg/kg) and TAs (ranging from 60 to 1,120 µg/kg) levels than cassava roots, which ranged between 1.2-8.3 µg/kg for THg and 25-310 µg/kg for TAs. Concentrations of THg and TAs in soil samples ranged between 5.8-1,759 and 183-20,298 µg/kg, respectively. Both THg and TAs were found to be distributed throughout Rwamagasa village.

  4. LEVELS OF STATE REGULATION OF THE LEGAL STATUS OF THE DISPLACED PERSONS IN THE GOLD MINING INDUSTRY OF THE USSR (1930-1950

    Directory of Open Access Journals (Sweden)

    Kochegarova Elena Danilovna

    2013-04-01

    Full Text Available Repressive policy of the Soviet state remains one of the actual problems of Russian historical science. The peculiarities of the legal status of displaced persons, their contribution to the socio-economic development of certain regions, the use of labor by industry and government agencies deserve more attention. Purpose The purpose of this work is the analysis of public policy at different levels and reconstruction of the mechanism of development, adoption and implementation of government decisions in the employment of special group in the gold mining industry. Methodology The dialectical approach is a methodological basis of the research and was implemented through the principles of historicism, scientism, objectivity. Results General thrust of the state policy is determined by the directive of the central, regional and local authorities have particularized or duplicated relevant legal documents at higher levels. Dynamics of changes in the legal status of the displaced persons determined mutually exclusive trends: 1 the weakening or removal of restrictions, 2 toughening control. Priority in decisions belonged Party committees at all levels of management, while the real power had repressive authorities. The practical implementation of government decisions at the local level distorted and was adjusted based on personal or group interests. Practical implications The results can be used for further scientific development of the problem of forced migration.

  5. Mercury resistance in bacterial strains isolated from tailing ponds in a gold mining area near El Callao (Bolívar State, Venezuela).

    Science.gov (United States)

    Ball, María Mercedes; Carrero, Pablo; Castro, David; Yarzábal, Luis Andrés

    2007-02-01

    Bacterial resistance to mercury (Hg) was investigated in strains isolated from Hg-contaminated tailing ponds located in the gold mining area of El Callao (Bolívar State, Venezuela). High frequencies of resistance were detected to both inorganic-Hg and organomercurials among these strains. A broad range of resistance levels was observed when determining minimal inhibitory concentrations of Hg(2+). Some strains were able to grow in liquid medium containing 25 muM: Hg(2+), whereas others grew at 300 muM: Hg(2+). Of 190 Hg-resistant strains tested, 58.2% were additionally shown to be resistant to ampicillin (40 mg/L), 33.3% to chloramphenicol (30 mg/L), 24.9% to streptomycin (30 mg/L), 23.3% to tetracycline (30 mg/L), and 1.6% to kanamycin (30 mg/L). Furthermore, we found that 20% of the Hg-resistant strains were simultaneously resistant to as many as four of these antibiotics, at the concentrations tested. The presence of large plasmids in 62.9% of 53 Hg-resistant strains screened prompted us to investigate the horizontal transfer of resistance determinants. Mating experiments were performed using Escherichia coli and Pseudomonas aeruginosa as recipient strains. The results obtained confirmed that indigenous Hg-resistant bacteria colonizing the tailing ponds can effectively transfer the phenotype to potentially pathogenic species.

  6. Gold Mining in Ecuador: A Cross-Sectional Assessment of Mercury in Urine and Medical Symptoms in Miners from Portovelo/Zaruma

    Directory of Open Access Journals (Sweden)

    Paul Schutzmeier

    2016-12-01

    Full Text Available Mercury is a toxic metal and is used in small scale gold mining. In Portovelo, Ecuador, mercury has been an environmental and health problem for decades. The target of this study was to assess the mercury concentration in the urine of miners from Portovelo/Zaruma to establish a prevalence of high values. Eight hundred and sixty-five (865 urine samples were collected and analysed for their mercury content, using cold vapor atom absorption spectroscopy. The prevalence of high mercury values (>25 μg/L was estimated. Forty-four (44 miners with mercury levels >15 μg/L filled in a questionnaire for characteristics and possible confounders, and were examined for intoxication symptoms to establish the ten points medical score sum. The median urine value was 1.8 μg/L; 78.3% of miners were below 7 μg/L and were not at risk of an intoxication, whereas 5.9% of miners exceeded the limit of 25 μg/L and were probable to experience intoxication symptoms. The medical score sum had a range of 2 to 8 points with a median of 6. The low prevalence of high mercury concentrations shows that the politics and techniques to eliminate the use of mercury are being successfully implemented. Further studies are needed to identify factors enabling this process.

  7. Effect of arbuscular mycorrhizal fungi on the potential of three wild plant species for phytoextraction of mercury from small-scale gold mine tailings

    Directory of Open Access Journals (Sweden)

    A. Fiqri

    2016-04-01

    Full Text Available A study that was aimed to explore the effects of arbuscular mycorrhizal (AM fungi inoculation on the potential of wild plant species (Paspalum conjugatum, Cyperus kyllingia, and Lindernia crustacea for phytoextraction of mercury from small-scale gold mine tailings was conducted in a glasshouse. Each of the plant seedlings was planted in a plastic pot containing 10 kg of planting medium (mixture of tailings and compost; 50%: 50% by weight. Treatments tested were three plant species and doses of AM fungi inoculation, i.e. 0 and 30 spores/plant. At harvest of 63 days, plant shoot and root were analyzed for mercury concentration. The remaining planting media in the pots were used for growing maize for 84 days. The results showed that the most potential plant species for phytoextraction of mercury was Paspalum conjugatum, while the most mercury tolerant plant was Cyperus kyllingia. Without AM fungi inoculation, the highest accumulation of mercury (44.87 mg/kg was found in the root of Paspalum conjugatum. If AM fungi were inoculated, the highest accumulation of mercury (56.30 mg/kg was also found in the shoot of Paspalum conjugatum. Results of the second experiment proved that the growth and biomass production of maize after mycophytoextraction by the plant species were higher than those of maize grown on media without mycophytoextraction of mercury.

  8. Gold Mining in Ecuador: A Cross-Sectional Assessment of Mercury in Urine and Medical Symptoms in Miners from Portovelo/Zaruma.

    Science.gov (United States)

    Schutzmeier, Paul; Berger, Ursula; Bose-O'Reilly, Stephan

    2016-12-30

    Mercury is a toxic metal and is used in small scale gold mining. In Portovelo, Ecuador, mercury has been an environmental and health problem for decades. The target of this study was to assess the mercury concentration in the urine of miners from Portovelo/Zaruma to establish a prevalence of high values. Eight hundred and sixty-five (865) urine samples were collected and analysed for their mercury content, using cold vapor atom absorption spectroscopy. The prevalence of high mercury values (>25 μg/L) was estimated. Forty-four (44) miners with mercury levels >15 μg/L filled in a questionnaire for characteristics and possible confounders, and were examined for intoxication symptoms to establish the ten points medical score sum. The median urine value was 1.8 μg/L; 78.3% of miners were below 7 μg/L and were not at risk of an intoxication, whereas 5.9% of miners exceeded the limit of 25 μg/L and were probable to experience intoxication symptoms. The medical score sum had a range of 2 to 8 points with a median of 6. The low prevalence of high mercury concentrations shows that the politics and techniques to eliminate the use of mercury are being successfully implemented. Further studies are needed to identify factors enabling this process.

  9. HYDRAULIC SERVO

    Science.gov (United States)

    Wiegand, D.E.

    1962-05-01

    A hydraulic servo is designed in which a small pressure difference produced at two orifices by an electrically operated flapper arm in a constantly flowing hydraulic loop is hydraulically amplified by two constant flow pumps, two additional orifices, and three unconnected ball pistons. Two of the pistons are of one size and operate against the additional orifices, and the third piston is of a different size and operates between and against the first two pistons. (AEC)

  10. Tuberculosis control in South African gold mines: mathematical modeling of a trial of community-wide isoniazid preventive therapy.

    Science.gov (United States)

    Vynnycky, Emilia; Sumner, Tom; Fielding, Katherine L; Lewis, James J; Cox, Andrew P; Hayes, Richard J; Corbett, Elizabeth L; Churchyard, Gavin J; Grant, Alison D; White, Richard G

    2015-04-15

    A recent major cluster randomized trial of screening, active disease treatment, and mass isoniazid preventive therapy for 9 months during 2006-2011 among South African gold miners showed reduced individual-level tuberculosis incidence but no detectable population-level impact. We fitted a dynamic mathematical model to trial data and explored 1) factors contributing to the lack of population-level impact, 2) the best-achievable impact if all implementation characteristics were increased to the highest level achieved during the trial ("optimized intervention"), and 3) how tuberculosis might be better controlled with additional interventions (improving diagnostics, reducing treatment delay, providing isoniazid preventive therapy continuously to human immunodeficiency virus-positive people, or scaling up antiretroviral treatment coverage) individually and in combination. We found the following: 1) The model suggests that a small proportion of latent infections among human immunodeficiency virus-positive people were cured, which could have been a key factor explaining the lack of detectable population-level impact. 2) The optimized implementation increased impact by only 10%. 3) Implementing additional interventions individually and in combination led to up to 30% and 75% reductions, respectively, in tuberculosis incidence after 10 years. Tuberculosis control requires a combination prevention approach, including health systems strengthening to minimize treatment delay, improving diagnostics, increased antiretroviral treatment coverage, and effective preventive treatment regimens.

  11. Testing on Sub-step Caving and Long -wall Controlling Blasting Mining Method at Yinan Gold Mine%沂南金矿分步放顶阶段长壁控爆连续采矿法试验研究

    Institute of Scientific and Technical Information of China (English)

    万记龙; 张洪波; 武传利

    2014-01-01

    Based on the inclined thin and thickness orebody at the 101 stope at Yinan Gold Mine , the sub -step caving and long -wall controlling blasting mining method was tested and applied . By applying the sub-step caving and continuous mining method , the underground pressure of stope was transferred to goaf . In this paper , the characteristic of mining method was introduced to mining development , slot and stoping method . T he mining method is suitable to the inclined thin and thickness orebody of the 101 stope , w hich is meaningful to safety and efficient of similar mines .%以沂南金矿金场矿区101号缓倾斜薄及中厚矿体为工程背景,开展了分步放顶阶段长壁控爆连续采矿新方法的试验及应用。采用连续开采方式,并相应的对采空区采用分步放顶卸压。详细论述了该方案特征及采准、切割、回采工艺。该采矿技术工业试验效果良好,对类似矿山的安全高效开采具有一定的借鉴与指导意义。

  12. Analysis of the Decision-making of Investment of a Gold Mining Project Based on Monte Carlo Method%基于蒙特卡罗方法的某金矿项目投资决策分析

    Institute of Scientific and Technical Information of China (English)

    程国江

    2016-01-01

    在传统折现现金流法的基础上,采用蒙特卡罗方法,对某金矿项目前期投资决策涉及的4个关键不确定因素(资源量、投资、成本及金价)进行了分析,得出了项目的内部收益率、净现值和投资回收期的分布情况,表明该金矿项目有较好的抗风险能力。该分析方法对于解决复杂多因素影响下建设项目的前期投资决策问题有较好的参考价值。%Based on the the traditional discounted cash flow analysis method,the four key uncertain factors (resources,investment,cost and gold price)related to the decision-making of investment of a gold mining project are analyzed in detail by adopting the Monte Carlo method.The distribution of internal rate of return,net present value and pay back period show that the gold mining project has a good ability to re-sist risks.The analysis method of the paper has good application value to solve decision-making for the in-vestment of gold mining project under the influence of many complicated factors in the early stage.

  13. Geochemical characterization of water, sediment, and biota affected by mercury contamination and acidic drainage from historical gold mining, Greenhorn Creek, Nevada County, California, 1999-2001

    Science.gov (United States)

    Alpers, Charles N.; Hunerlach, Michael P.; May, Jason T.; Hothem, Roger L.; Taylor, Howard E.; Antweiler, Ronald C.; De Wild, John F.; Lawler, David A.

    2005-01-01

    In 1999, the U.S. Geological Survey (USGS) initiated studies of mercury and methylmercury occurrence, transformation, and transport in the Bear River and Yuba River watersheds of the northwestern Sierra Nevada. Because these watersheds were affected by large-scale, historical gold extraction using mercury amalgamation beginning in the 1850s, they were selected for a pilot study of mercury transport by the USGS and other cooperating agencies. This report presents data on methylmercury (MeHg) and total mercury (THg) concentrations in water, bed sediment, invertebrates, and frogs collected at 40 stations during 1999-2001 in the Greenhorn Creek drainage, a major tributary to Bear River. Results document several mercury contamination ?hot spots? that represent potential targets for ongoing and future remediation efforts at abandoned mine sites in the study area. Water-quality samples were collected one or more times at each of 29 stations. The concentrations of total mercury in 45 unfiltered water samples ranged from 0.80 to 153,000 nanograms per liter (ng/L); the median was 9.6 ng/L. Total mercury concentrations in filtered water (41 samples) ranged from less than 0.3 to 8,000 ng/L; the median was 2.7 ng/L. Concentrations of methylmercury in the unfiltered water (40 samples) ranged from less than 0.04 to 9.1 ng/L; the median was 0.07 ng/L. Methylmercury in filtered water (13 samples) ranged from less than 0.04 to 0.27 ng/L; the median was 0.04 ng/L. Acidic drainage with pH values as low as 3.4 was encountered in some of the mined areas. Elevated concentrations of aluminum, cadmium, copper, iron, manganese, nickel, and zinc were found at several stations, especially in the more acidic water samples. Total mercury concentrations in sediment were determined by laboratory and field methods. Total mercury concentrations (determined by laboratory methods) in ten samples from eight stations ranged from about 0.0044 to 12 ?g/g (microgram per gram, equivalent to parts per

  14. Design and Application of Valve Controlled Speed Regulating Hydraulic Coupling in Wutongzhuang Mine%阀控调速型液力偶合器在梧桐庄矿的设计及应用

    Institute of Scientific and Technical Information of China (English)

    李永苏

    2012-01-01

    According to the design and project practices of the belt conveyor in a dip of No. 4 mining block in Wutongzhuang Mine, the paper had a discussion on the factors considered in the driving method selection of the powerful belt conveyor under the complicated per- formances. A detail comparison and selection was conducted on the advantages and disadvantages of the CST, valve controlled speed regu- lating hydraulic coupling and frequency converted control soft driving modes available applied at home and abroad. The paper held that the valve controlled speed regulating hydraulic coupling could meet the driving requirements of the large power, long distance and complicated belt conveyor. The practices showed that the control start accelerated speed, start torque, automatic power balance, heat radiation and others were excellent.%根据对梧桐庄矿四采区下山带式输送机的设计和工程实践,探讨了复杂工况下强力带式输送机驱动方式选择时应考虑的因素;对现阶段国内外主要使用的CST、阀控调速型液力偶合器、变频调速3种软驱动方式的优缺点进行了详细比选;认为阀控调速型液力偶合器可以满足大功率、长距离、复杂带式输送机驱动要求,实践证明其在控制启动加速度和启动力矩、自动功率平衡、散热等方面表现优良。

  15. Mining Review

    Science.gov (United States)

    ,

    2013-01-01

    In 2012, the estimated value of mineral production increased in the United States for the third consecutive year. Production and prices increased for most industrial mineral commodities mined in the United States. While production for most metals remained relatively unchanged, with the notable exception of gold, the prices for most metals declined. Minerals remained fundamental to the U.S. economy, contributing to the real gross domestic product (GDP) at several levels, including mining, processing and manufacturing finished products. Minerals’ contribution to the GDP increased for the second consecutive year.

  16. Phage based green chemistry for gold ion reduction and gold retrieval.

    Science.gov (United States)

    Setyawati, Magdiel I; Xie, Jianping; Leong, David T

    2014-01-22

    The gold mining industry has taken its toll on the environment, triggering the development of more environmentally benign processes to alleviate the waste load release. Here, we demonstrate the use of bacteriophages (phages) for biosorption and bioreduction of gold ions from aqueous solution, which potentially can be applied to remediate gold ions from gold mining waste effluent. Phage has shown a remarkably efficient sorption of gold ions with a maximum gold adsorption capacity of 571 mg gold/g dry weight phage. The product of this phage mediated process is gold nanocrystals with the size of 30-630 nm. Biosorption and bioreduction processes are mediated by the ionic and covalent interaction between gold ions and the reducing groups on the phage protein coat. The strategy offers a simple, ecofriendly and feasible option to recover of gold ions to form readily recoverable products of gold nanoparticles within 24 h.

  17. Technology of load-sensitivity used in the hydraulic system of an all-hydraulic core rig

    Institute of Scientific and Technical Information of China (English)

    XIN De-zhong; CHEN Song-ling; WANG Qing-feng

    2009-01-01

    The existing hydraulic system always have problems of temperature rise, run-ning stability and anti-interference of the implementation components, reliability of hydrau-lic components, maintenance difficulties, and other issues. With high efficiency, energy saving, reliability, easy operating, stable running, anti-interference ability, and other ad-vantages, the load-sensitive hydraulic system is more suitable for coal mine all-hydraulic core rig. Therefore, for the technical development of the coal mine all-hydraulic core rig, the load-sensitive technology employed by the rig should be of great significance.

  18. Structure, alteration, and geochemistry of the Charlotte quartz vein stockwork, Mt Charlotte gold mine, Kalgoorlie, Australia: time constraints, down-plunge zonation, and fluid source

    Science.gov (United States)

    Mueller, Andreas G.

    2015-02-01

    The Kalgoorlie district in the Archean Yilgarn Craton, Western Australia, comprises two world-class gold deposits: Mt Charlotte (144 t Au produced to 2013) in the northwest and the Golden Mile (1,670 t Au) in the southeast. Both occur in a folded greenschist-facies gabbro sill adjacent to the Golden Mile Fault (D2) in propylitic alteration associated with porphyry dikes. At Mt Charlotte, a shear array of fault-fill veins within the Golden Mile Fault indicates sinistral strike-slip during Golden Mile-type pyrite-telluride mineralization. The pipe-shaped Charlotte quartz vein stockwork, mined in bulk more than 1 km down plunge, is separated in time by barren D3 thrusts from Golden Mile mineralization and alteration, and occurs between two dextral strike-slip faults (D4). Movement on these faults generated an organized network of extension and shear fractures opened during the subsequent infiltration of high-pressure H2S-rich fluid at 2,655 ± 13 Ma (U-Pb xenotime). Gold was deposited during wall rock sulphidation in overlapping vein selvages zoned from deep albite-pyrrhotite (3 g/t Au) to upper muscovite-pyrite assemblages (5 g/t Au bulk grade). Chlorite and fluid inclusion thermometry indicate that this kilometre-scale zonation is due to fluid cooling from 410-440 °C at the base to 350-360 °C at the top of the orebody, while the greenstone terrane remained at 250 °C ambient temperature and at 300 MPa lithostatic pressure. The opened fractures filled with barren quartz and scheelite during the retrograde stage (300 °C) of the hydrothermal event. During fracture sealing, fluid flux was periodically restricted at the lower D3 thrust. Cycles of high and low up-flow, represented by juvenile H2O-CO2 and evolved H2O-CO2-CH4 fluid, respectively, are recorded by the REE and Sr isotope compositions of scheelite oscillatory zones. The temperature gradient measured in the vein stockwork points to a hot (>600 °C) fluid source 2-4 km below the mine workings, and several

  19. 三山岛金矿提高破碎处理能力的研究与实践%Research and Practice of Improving Crushing Processing Ability of Sanshandao Gold Mine

    Institute of Scientific and Technical Information of China (English)

    赵在超; 王建平; 蔡有国

    2015-01-01

    对三山岛金矿破碎系统进行优化改造,提出多项改造方案,结合三山岛金矿发展规划,优化方案比较,本着投资少,建设周期短等因素,选择合适的改造方案,同时达到提高碎矿单位处理能力,缩短碎矿时间,降低碎矿电耗,降低碎矿粒度,提高选矿处理能力,增加黄金产量,降低生产成本的目的。%Multidirectional reconstruction scheme was proposed to reform the crushing system of Sanshandao Gold Mine. Combined with the development planning of Sanshandao Gold Mine and compared with different scheme, the low investment and short construction cycle scheme was choosed. The scheme can achieve the purpose of improving the crushing processing ability, shortening the crushing time, reducing crushing power consumption, improving the beneficiation processing ability, improving the gold output, reducing the producing cost.

  20. Hydraulic conduction system for an underground mineral mining plant, particularly a sliding plough equipment. Hydraulisches Leitungssystem fuer eine untertaegige Mineralgewinnungsanlage, insbesondere Gleithobelanlage

    Energy Technology Data Exchange (ETDEWEB)

    Dettmers, M.; Weirich, W.

    1983-01-05

    A hydraulic conduction system for a sling plough equipment assuring an utmost uniform pressure of the inner conveying trace to the coal face is described. The high-pressure main has a pressure of 300 to 400 bar. The low-pressure main is dimensioned in such a way that it exhibits a pressure drop restricted to about 5 bar at a conveying quantity of about 60 l/min and a pressure level between 100 and 200 bar. (HGOE).

  1. The application of ETM to the exploration of Beiya gold mine%基于ETM数据的北衙地区找矿应用效果

    Institute of Scientific and Technical Information of China (English)

    杨剑; 薛廉; 张景华

    2015-01-01

    遥感技术能以较低的成本快速地提供更多更有效的地质异常信息,提高工作效率,降低风险[1]。在分析云南省北衙金矿远景区区域地质背景和控矿规律的基础上,通过目视解译的方法对该区的区域地质进行了解译,并对该区域进行详细的定量分析以及蚀变异常的光谱反映特征提取。从ETM影像中利用相关方法提取了与矿区有关的羟基、铁染异常信息,解译效果良好,划分了找矿远景区。%Remote sensing technology is quite an effectively to lower costs ,provide more abnormal geological information quickly,improve work efficiency and reduce the risk.Based on analysis of gold far scenic area and ore controlling regularity in the geological background of Beiya in Yunnan province ,interpretation can be obtained through visual of regional geology,the analysis and alteration can be achieved from spectra of detailed quantitative anomaly characteristics.From the ETM images u-sing extraction and mining related method of hydroxyl,iron related with abnormal information,interpretation of good effect, divided the prospecting area.

  2. Basic hydraulics

    CERN Document Server

    Smith, P D

    1982-01-01

    BASIC Hydraulics aims to help students both to become proficient in the BASIC programming language by actually using the language in an important field of engineering and to use computing as a means of mastering the subject of hydraulics. The book begins with a summary of the technique of computing in BASIC together with comments and listing of the main commands and statements. Subsequent chapters introduce the fundamental concepts and appropriate governing equations. Topics covered include principles of fluid mechanics; flow in pipes, pipe networks and open channels; hydraulic machinery;

  3. Application of Suspended Hydraulic Support in Steep Seam Mining%悬移液压支架在急倾斜煤层开采中的应用

    Institute of Scientific and Technical Information of China (English)

    黄世坤

    2011-01-01

    The traditional steep seaming mining consumed timber a lot(whether false-inclined flexible shield mining method or block caving).The study adopted the suspended support-wall mining,which hardly consumes wood except roadway maintenance.The caving technology was simplified and consumption fell.Compared with the traditional mining,recovery rate increased above 85%.The method was also improved and was used in steep seams which achieved great benefits.%急倾斜煤层传统的开采方法(无论是伪倾斜柔性掩护支架采煤法,还是落垛采煤法)其木料消耗巨大。文章通过采用悬移支架壁式采煤法,除巷道维修外几乎不消耗木料,并简化了回采工艺、降低了工耗;它与传统采煤法相比,回采率大大提高,可达到85%以上。马家沟矿经对悬移支架壁式采煤法的改进和优化,取得了成功经验;并在急倾斜煤层开采中推广和应用,取得了可观效益。

  4. Heterogeneity of malaria prevalence in alluvial gold mining areas in Northern Mato Grosso State, Brazil Heterogeneidade da prevalência de malária em garimpos do norte de Mato Grosso, Brasil

    Directory of Open Access Journals (Sweden)

    Alisson Flávio Barbieri

    2007-12-01

    Full Text Available This paper analyzes factors affecting the risk of malaria among individuals working in wildcat gold mining camps (garimpos in northern Mato Grosso State in the Brazilian Amazon. Historically, such mining camps have the locations with the highest malaria prevalence in the Brazilian Amazon. However, little attention has focused on understanding the disease from the internal perspective of the mining camps themselves, such as the mining population's characteristics and its spatial organization. This paper adopts a stepwise logistic model to identify spatial, occupational-exposure, and cultural factors that affect malaria prevalence. According to the results, differences among individuals working and/or living in the gold mining areas could produce different exposure to the disease and thus to different risk of malaria prevalence. Understanding these differences may provide an important tool for identifying risk profiles in the gold mining and related population and for informing programs for prevention and treatment of malaria in the Amazon.O artigo analisa fatores que afetam o risco de malária entre garimpeiros de ouro no norte de Mato Grosso, Brasil. Historicamente, os garimpos apresentam a maior prevalência de malária da Amazônia Legal brasileira. Entretanto, até o momento houve pouca investigação no sentido de compreender a doença desde a perspectiva interna dos próprios garimpos, ou seja, através das características da população garimpeira e da sua organização espacial. O artigo adota um modelo logístico stepwise para identificar fatores territoriais, culturais e de exposição ocupacional que afetam a prevalência da malária. Com base nos resultados, diferenças entre indivíduos que trabalham e/ou vivem nas áreas de garimpo poderiam produzir variações na exposição à doença, levando a um risco diferenciado de prevalência de malária. A compreensão dessas diferenças pode representar uma ferramenta importante para

  5. Rushing for gold

    DEFF Research Database (Denmark)

    Jønsson, Jesper Bosse; Bryceson, Deborah Fahy

    2009-01-01

    African rural dwellers have faced depressed economic prospects for several decades. Now, in a number of mineral-rich countries, multiple discoveries of gold and precious stones have attracted large numbers of prospective small-scale miners. While their 'rush' to, and activities within, mining sit...... affluent than the others, suggesting that movement can be rewarding for those willing to 'try their luck' with the hard work and social networking demands of mining another site....

  6. Mercury Bioaccumulation on Tadpoles of a Gold Mining Zone in Dagua River, Buenaventura, Valle del Cauca, Colombia

    Directory of Open Access Journals (Sweden)

    Oscar Dario Hernandez Cordoba

    2013-06-01

    Full Text Available Amphibians, particularly larval stages, are strongly sensitive to pollutants, so they have become useful indicators to assesshow different human activities affect ecosystems. In this way, tadpoles were used as bioindicators in the Medio Dagua zone,in Zaragoza town, where mining has released pollutants into the Dagua River (mostly heavy metals. Using spectrophotometry by cold vapor atomic absorption, we measured total mercury concentrations in tadpoles of five species, with a sediment sample for each animal sample as an environment reference. The study was realized in two areas with different intervention levels, we report mercury concentration ranges from 0.07 to 0.24 μg/g for high impact zone and from 0.07 to 0.17μg/g for unknown impact zone, these levels do not exceed set limits used by local environmental authorities, however, is evident that bioaccumulation processes are developing in the area because organisms concentrations were always higher than those of the environment, in fact, significantly different (MW Utest, p = 0.001 therefore we propose the implementation ofbiomonitoring and bioremediation programs in the area,taking in consideration that tadpoles species used here, weremainly first order consumers, and when their mercuryconcentrations are incorporated into the food chain, thesecontaminant loads will produce biomagnification processes.  Bioacumulación de mercurio en larvas de anuros en la zona afectada por la minería de oro en el Río Dagua, Buenaventura, Valle del Cauca. Los anfibios, particularmente en sus estados larvales, tienen una gran sensibilidad  a la concentración de contaminantes; por lo que se han convertido en una herramienta indicadora para evaluar cómo las diferentes actividades humanas afectan  los ecosistemas acuáticos. Debido a esto se utilizaron larvas de anuros como bioindicadores en la zona del medio Dagua, en Zaragoza, donde la actividad minera, ha liberado contaminantes al río Dagua (Metales

  7. Hydraulic Structures

    Data.gov (United States)

    Department of Homeland Security — This table is required whenever hydraulic structures are shown in the flood profile. It is also required if levees are shown on the FIRM, channels containing the...

  8. Characterization of Hydrogen and Oxygen Isotope in Taojinchong Gold Mine in Mid-xuefeng Mts.%雪峰山中段淘金冲金矿床氢氧同位素特征

    Institute of Scientific and Technical Information of China (English)

    李剑; 宋泽友; 马小双; 陈新跃

    2015-01-01

    The gold rush hydrogen and oxygen isotopes in quartz of gold mine geological characteristics and main metallogenic stage composition of, to the gold rush gold source of ore-forming lfuid are discussed. Research shows that the gold rush gold deposit ore-forming lfuid δ DH20‰ values ranged from-97‰ to -44‰, δ 18OH20‰ value between -2.04‰ to +8.92‰, the mineralization phase I and II stage of ore-forming lfuid mainly to magmatic water and metamorphic water mixed, stage III with the gradual opening of the metallogenic environment, temperature and pressure reduction, precipitation gradually accounted for dominance.%本文通过对淘金冲金矿区地质特征和主成矿阶段石英氢氧同位素组成研究,对淘金冲金矿成矿流体来源进行了探讨。研究结果显示淘金冲金矿床成矿流体δDH20‰值介于-97‰~-44‰,δ18OH20‰值介于-2.04‰~+8.92‰,成矿期第Ⅰ阶段及第Ⅱ阶段成矿流体以岩浆水和变质水混合为主,第Ⅲ阶段随着成矿环境逐渐开放,温度压力降低,大气降水逐渐占主导地位。

  9. Enhancing the safety and efficiency of the driving gear of coal mining machinery by using water as a hydraulic fluid and enhancing the reliability of scraper-chain conveyors; Erhoehung der Sicherheit und Leistungsfaehigkeit der Antriebstechnik von Arbeitsmaschinen durch Verwendung von Wasserhydraulik sowie Erhoehung der Zuverlaessigkeit der Kettenkratzerfoerderer

    Energy Technology Data Exchange (ETDEWEB)

    Reichel, J.; Boeing, R.; Graetz, A.; Loehning, H.D.; Plum, D.

    1997-12-31

    The objective pursued is to increasingly use water or high water-content fluids as a substitute for other hydraulic fluids in driving gear of mining machinery. The state of the art of the technology is represented only by individual solutions achieved for given purposes which are not suitable for other applications, let alone for coal mining machinery. The research project was to identify hydraulic components that will permit the use of water or watery substances as a hydraulic fluid in mining applications. The components have been found and further developed, and finally systems with linear and rotatory drives have been tested at various test facilities in order to derive information on the system behaviour of pressurized fluids and machinery components and their suitability for coal mining applications. (orig./CB) [Deutsch] In der untertaegigen Antriebstechnik sollen vermehrt Wasser und wasserhaltige Fluessigkeiten eingesetzt werden. Der Stand der Technik fuehrt bei der Anwendung von Wasserhydraulik immer wieder nur Einzelloesungen auf, die nicht allgemein und insbesondere im Steinkohlenbergbau angewendet werden koennen. Im Rahmen dieses Forschungsvorhabens wurden fuer die Wasserhydraulik geeignete Komponenten untersucht, weiterentwickelt und schliesslich Systeme mit linearen und rotatorischen Antrieben auf verschiedenen Pruefstaenden erprobt, um Aussagen ueber das Systemverhalten von Druckfluessigkeit und Bauelementen fuer Bergbauanwendungen zu bekommen. (orig./MSK)

  10. Study on Professional Training in the Gold Mining Industryunder Market economy-Practice in Personnel Training in China NationalGold Group Corporation%市场化环境下中国黄金行业人才培养探索——中国黄金集团公司人才培养实践分享

    Institute of Scientific and Technical Information of China (English)

    王旭; 安丰玲

    2012-01-01

    随着黄金产品市场化和矿权市场化以及外资的进入,中国黄金行业已不是一个封闭的行业,这就需要人才的积极开拓创新以适应市场变化.已经市场化的黄金行业,企业战略目标的实现越来越重视人力资源战略在企业竞争优势或竞争力获取、发挥中所表现出的核心作用.通过战略性的人力资源管理,保持人才优势,持续地进行战略人力资源的开发,加强员工的培训,提升员工的素质,最终达到增强企业竞争力、实现企业战略规划的目的.因此,如何建立基于未来战略发展的人力资源培养体系已成为黄金行业参与市场竞争的关键要素,结合中国黄金集团公司人才培养与管理体系建设之实践,探索黄金行业人才培养新模式.%With the marketization of gold and mineral right as well as the introduction of foreign capital,gold mining industry has been no longer an enclosed business,which gives rise to a need for comprehensive human resources exploration in order to meet the changing market.To achieve their strategic target under a marketized gold mining industry,companies pay more and more attention to the core role of HR in corporate competitive edge or acquirement and functioning of the competitive strength.By strategic HR management,i.e.,to keep talent advantages,carry out continues strategic HR development,reinforce employee training,and improve employees quality,the objectives of enhancing enterprise competitive strength and achieving strategic plan will be finally realized.Therefore,how to build a HR development system in view of future strategic development is a key factor for gold mining firms to participate market competition.The paper explores the new ways of personnel development in the gold mining industry,with the practice in HR management and system construction in China National Cold Croup Corporation.

  11. 基于3D CAD MineStar 软件的胶东大尹格庄金矿三维数字实体模型的建立%The Buildup of the 3D Entity Model Based on the Software of 3D CAD MineStar in Dayin’gezhuang Gold Deposit,Jiaodong Region

    Institute of Scientific and Technical Information of China (English)

    孙书彬; 吴洋; 姜新吉; 张瑞忠

    2015-01-01

    Based on analyzing the character of 3D CAD MineStar software,applying AotoCAD software as well as aided design software for 3D mine,according to actual situation of the mine,entity model with 3D digital mock-up for geology and mine system at the Dayin’gezhuang gold mine was established,which had improved the information,production intelligent and automation level,production intelligence information and automation level.Moreover,it is meaningful and can provide significant direction for improving the speed and precision of the prospecting,mining quantity computation,aided design and safety management.%在分析3D CAD MineStar 软件特点的基础上,结合矿山实际情况,应用 AutoCAD 软件和三维矿山辅助设计软件 MineStar,建立了大尹格庄金矿的三维数字地质实体模型和采矿系统实体模型。三维数字实体模型的建立提高了大尹格庄金矿的信息化、生产智能化和自动化水平,对于建设大尹格庄金矿数字矿山平台,提高探矿和矿量计算的速度与精度、辅助设计和安全管理等具有重要的经济价值和指导意义。

  12. Effective Method for Finding the Lead-zinc and Gold-Preponderant Mines in Fengtai Area%陕西凤太地区寻找优势矿种铅锌金的有效方法

    Institute of Scientific and Technical Information of China (English)

    陈明寿; 武晓迪; 温深文; 陈二虎; 张选固

    2015-01-01

    Fengtai area is our important region focused on the lead-zinc and gold, ant it is also a hot spot district for see-king the lead-zinc and gold which have the big potential and good condition for prospecting the lead-zinc and gold deposits. Here we accumulated a lot of experiences and moral in searching for the deeply-burried lead-zinc and gold, and also make a significant breakthrough.The most effective method for prospecting the deeply-burried lead-zinc mines is make a deeper investigation and proceed in an orderly ways along the ore body, mineralized stratum, mineral-controlled anticline.Here in Fengtai area three gold mines had been explored in forty years, they are Taibai, Sifang and Pangjiahe gold deposits.The measured gold resources in accumulative total is nearly 200 tons.These three gold mines were found by the clue of geochem-ical anormals.The effective method for gold-finding is geochemical secondary halo scanning in first, and geochemical dis-persion trains check when find the normals in second, and confirm with geochemical primary halo in third, and verify with geochemical method in the end.These four steps can achieve the purpose of ore prospecting which have the characteristic s of less-investment, operate quickly and easy-to-accomplish steps.%凤太地区是我省重要的铅锌金矿集中区,也是寻找铅锌金矿的热点地区,具备有寻找铅锌金矿的潜力和条件. 在寻找深部隐伏铅锌矿和金矿方面积累了大量的经验和教训,也取得了重大突破. 寻找隐伏铅锌矿最有效的方法就是沿着矿体、含矿地层、控矿背斜顺藤摸瓜循序渐进. 凤太地区近四十年左右的时间找了三个金矿(太白金矿、四方金矿(也叫八卦庙金矿)、庞家河金矿) ,累计探明黄金资源量近200 t,三大金矿的发现都是化探异常提供的线索. 找金矿的有效方法,先用化探次生晕扫面,有异常再用化探分散检查定位,再用化探原生晕地化剖面进行检查确

  13. Kensington Mine Area Baseline Contaminants Study, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Hardrock mining for gold and other metals is proposed for the Kensington Mine, located on Lynn Canal in Southeast Alaska, approximately 45 miles north of Juneau. The...

  14. 花岗岩矿区水力岩土侵蚀研究初探--以福建省安溪县铁峰山花岗岩矿区为例%Initial Study on the Hydraulic Rock-soil Erosion in the Granite Mine Area-Taking the Tiefeng Mountain Granite Mine of Anxi County as the Example

    Institute of Scientific and Technical Information of China (English)

    林强

    2014-01-01

    以安溪县铁峰山花岗岩矿区为例,以集水区为单元,选取具有代表性的矿点作为研究对象,采用调查分析法、标桩法和侵蚀沟体积量算转换法进行矿区水力岩土侵蚀的研究。结果表明:①花岗岩矿区由于其自身的特点,水力岩土侵蚀以溅蚀、面蚀、沟蚀等形式体现,其土壤侵蚀强度多达到强烈甚至极强烈以上。②由于矿渣的阻滞作用,降雨后土壤多呈泥浆状溅散。雨滴的溅蚀使得土壤多呈现鳞片状侵蚀,降雨过后部分地表土层产生板结。③从研究区面蚀和沟蚀情况看,水力岩土侵蚀多达到极强烈以上侵蚀,且受坡长、坡度、堆体颗粒组成、有无植被覆盖、堆倒年限等因素的综合影响。%Taking the Tiefeng Mountain Granite Mine of Anxi County as the example , it was selected the representa-tive mine site for study based on the catchment as the unit .The study was conducted on the hydraulic rock -soil ero-sion in the mine area in accordance with the methods of investigation , standard stake and measurement conversion of e-rosion gully volume, respectively.The results showed that 1) because of own characteristics , hydraulic rock-soil ero-sion appeared in the forms of sputtering , sheet erosion and gully erosion with the erosion strength reached strong or ex-treme strong;2) due to the retardation of the slag , soil after raining sprayed as muddy .The sputtering erosion of the rain drop made the soil appeared the scaled erosion , that some top soil layers were hardened after raining;3) from the sheet erosion and gully erosion status in the study area , it was found that the hydraulic rock -soil erosion reached ex-treme strength and affected by the factors of the slope length and degree , the particle composition , vegetation cover and mound collapse years, etc.

  15. How a masculine work ethic and economic circumstances affect uptake of HIV treatment: experiences of men from an artisanal gold mining community in rural eastern Uganda

    Directory of Open Access Journals (Sweden)

    Janet Seeley

    2012-06-01

    Full Text Available Background: Current data from Uganda indicate that, compared to women, men are under-represented in HIV treatment, seek treatment later and have a higher mortality while on antiretroviral therapy (ART. By focusing on a masculine work ethic as one of the most predominant expressions of masculinity, this study explores why for some men HIV treatment enhances their masculinity while for others it undermines masculine work identity, leading them to discontinue the treatment. Methods: Participant observation and 26 in-depth interviews with men were conducted in a gold mining village in Eastern Uganda between August 2009 and August 2010. Interviewees included men who were taking HIV treatment, who had discontinued treatment, who suspected HIV infection but had not sought testing, or who had other symptoms unrelated to HIV infection. Results: Many participants reported spending large proportions of their income, alleviating symptoms prior to confirming their HIV infection. This seriously undermined their sense of masculinity gained from providing for their families. Disclosing HIV diagnosis and treatment to employers and work colleagues could reduce job offers and/or collaborative work, as colleagues feared working with “ill” people. Drug side-effects affected work, leading some men to discontinue the treatment. Despite being on ART, some men believed their health remained fragile, leading them to opt out of hard work, contradicting their reputation as hard workers. However, some men on treatment talked about “resurrecting” due to ART and linked their current abilities to work again to good adherence. For some men, it was work colleagues who suggested testing and treatment-seeking following symptoms. Conclusions: The central role of a work ethic in expressing masculinity can both encourage and discourage men's treatment-seeking for AIDS. HIV testing and treatment may be sought in order to improve health and get back to work, thereby in the

  16. Geophagy practices and the content of chemical elements in the soil eaten by pregnant women in artisanal and small scale gold mining communities in Tanzania.

    Science.gov (United States)

    Nyanza, Elias C; Joseph, Mary; Premji, Shahirose S; Thomas, Deborah Sk; Mannion, Cynthia

    2014-04-15

    Geophagy, a form of pica, is the deliberate consumption of soil and is relatively common across Sub-Saharan Africa. In Tanzania, pregnant women commonly eat soil sticks sold in the market (pemba), soil from walls of houses, termite mounds, and ground soil (kichuguu). The present study examined geophagy practices of pregnant women in a gold mining area of Geita District in northwestern Tanzania, and also examined the potential for exposure to chemical elements by testing soil samples. We conducted a cross sectional study using a convenience sample of 340 pregnant women, ranging in age from 15-49 years, who attended six government antenatal clinics in the Geita District, Tanzania. Structured interviews were conducted in June-August, 2012, to understand geophagy practices. In addition, soil samples taken from sources identified by pregnant women practicing geophagy were analysed for mineral element content. Geophagy was reported by 155 (45.6%) pregnant women with 85 (54.8%) initiating the practice in the first trimester. A total of 101 (65%) pregnant women reported eating soil 2 to 3 times per day while 20 (13%) ate soil more than 3 times per day. Of 155 pregnant women 107 (69%) bought pemba from local shops, while 48 (31%) consumed ground soil kichuguu. The estimated mean quantity of soil consumed from pemba was 62.5 grams/day. Arsenic, chromium, copper, iron, manganese, nickel and zinc levels were found in both pemba and kichuguu samples. Cadmium and mercury were found only in the kichuguu samples. Based on daily intake estimates, arsenic, copper and manganese for kichuguu and copper and manganese for pemba samples exceed the oral Minimum Risk Levels designated by the U.S. Agency for Toxic Substance and Disease Registry. Almost 50% of participants practiced geophagy in Geita District consistent with other reports from Africa. Both pemba and kichuguu contained chemical elements at varying concentration, mostly above MRLs. As such, pregnant women who eat soil in Geita

  17. 矿用牵引机车电液控制系统的设计与研究%Design and study of electro-hydraulic control system for mine-used traction locomotives

    Institute of Scientific and Technical Information of China (English)

    徐莉萍; 郑永光; 任德志

    2011-01-01

    According to the requirements of the traction locomotive proposed by long-tunneled construction, a kind of electro-hydraulic control system for mine-used traction locomotives is designed. The control system adopts PID intelligent control algorithm to adjust the displacement of variable pump and variable motor intelligently, so as to make the output rotary speed to reach the given one. In addition, the model of the electro hydraulic control system is built with simulation software AMEsim, and relevant parameters are optimized and dynamic control simulation is accomplished. The simulation and experiment results show that the system accurately, quickly and stably adjusts the rotary speed.%针对长大隧道施工对牵引机车的要求,设计了牵引机车电控液驱控制系统.该控制系统采用PID智能控制算法分别对变量泵和变量马达的排量进行智能调节,使输出转速达到设定转速.运用AMEsim液压仿真软件平台对牵引机车电液控制系统进行建模,并对相关参数进行优化设计,实现动态控制仿真.对控制系统进行了仿真和试验,结果表明,其能够准确、快速、平稳地对转速进行调节.

  18. Study of Relation Between Ground Stress and Rock cap and Mine Workings Firmness of Gold Mine%某岩金矿山地应力、覆盖岩层与井巷稳固性的关系研究

    Institute of Scientific and Technical Information of China (English)

    姚香; 宋世生; 郭明春

    2009-01-01

    介绍了我国南方某黄金矿山采用无底柱分段崩落采矿法,对在开采生产中所遇到的各方面围岩稳固性问题,即矿床开采技术条件、地应力、覆盖岩层与井巷稳固性的关系进行了分析研究,以便于在今后矿山生产中,掌握并应用其规律,达到安全、高效、经济地开发矿产资源之目的.%The problems of surrounding rock firmness occurred in mining when pillar-free sublevel caving mining method was used in a gold mine in the South of China. The relations between mining technical conditions, ground stress and rock cap of deposit and mine workings firmness were analyzed so that related laws could be grasped and applied to develop mineral resources in a safe, high efficient and economic way in production in future.

  19. Experimental study on gold extraction by resin-in-pulp method in Dongxi gold mine and its production practice%东溪金矿树脂矿浆法提金工艺试验研究与生产实践

    Institute of Scientific and Technical Information of China (English)

    韩春国

    2013-01-01

    The paper stated that production practice of resin-in-pulp (RIP) method for the extraction of gold and demonstrated the effective performance of NK 884 resin in adsorbing gold and silver. The practice proved RIP to be better choice than the previous CIP method for Dongxi gold mine. The gold leaching rate is increased by 1. 01 % adsorption rate 0. 77 % ; technical indexes of silver are more significantly improved with leaching rate increased by 8. 34 % and adsorption rate by 28.43 % .%论述了树脂矿浆法提金工艺的生产实践过程,验证了NK884型树脂对金、银所具有的良好吸附性能.生产实践表明,对东溪金矿而言,树脂矿浆法优于其原有的炭浆法.其中,金的浸出率提高1.01%,吸附率提高0.77%;银的技术指标提高更为显著,浸出率提高8.34%,吸附率提高28.43%.

  20. A Novel Method for Borehole Blockage Removal and Experimental Study on a Hydraulic Self-Propelled Nozzle in Underground Coal Mines

    Directory of Open Access Journals (Sweden)

    Zhaolong Ge

    2016-08-01

    Full Text Available When coal bed methane (CBM drainage boreholes cross fractured, soft, or water-swelling strata, they collapse and block frequently. Borehole blockages result in a rapid decrease in CBM extraction ability, which leads to a reduction in CBM output and threatens coal mine safety production. To solve these problems, a novel method that uses a self-propelled water-jet nozzle to dredge blocked boreholes in coal seams has been proposed on the basis of the existing technology. Based on a theoretical analysis of the reason for borehole caving and the theory of blockage removal, we optimized the nozzle inlet pressure and selected an appropriate high-pressure resin pipe. A field experiment on the blockage removal of blocked CBM drainage boreholes using the proposed method was run in the Fengchun coal mine, Qijiang, Chongqing, southwest China. In this field trial, the time spent to unblock a borehole varied between 18.52 and 34.98 min, which is much shorter than using a drilling rig. After blockage removal, the average pure volume of the methane drainage of a single borehole was increased from 0.03 L/min to ~1.91–7.30 L/min, and the methane drainage concentration of a single borehole increased from 5% to ~44%–85%. The extraction effect increased significantly.

  1. Design and Study of the Hydraulic Control System for Mine Traction Locomotive%矿用牵引机车液压控制系统的设计与研究

    Institute of Scientific and Technical Information of China (English)

    郑永光

    2014-01-01

    This paper analyzed the working principle of mine traction locomotive and designed the hydraulic control system for mine traction locomotive according to the long tunnel construction of traction locomotive requested. It ad-opted intelligent control algorithm of the RBF neural network self-tuning PID to adjust the displacement of variable pump and variable motor intelligently to make rotational speed output reach rotational speed given. It was modeled by applying co-simulation software of AMESim/simulink. The relevant parameters were been optimized. The dy-namic control co-simulation was accomplished. Through the co-simulation and experiments, the results show that it can accurately, quickly and stablely adjust rotational speed.%针对长大隧道施工对牵引机车的要求,分析了矿用牵引机车行走驱动的工作原理并设计了矿用牵引机车液压控制系统,该控制系统采用RBF神经网络自整定PID控制算法分别对变量泵和变量马达的排量智能调节,使输出转速达到给定的转速。运用AMESim/simulink液压联合仿真软件平台对矿用牵引机车液压控制系统进行建模,并对相关参数进行优化设计,实现了动态仿真。通过对其液压控制系统进行联合仿真和试验,结果表明,其能够准确、快速、平稳地对转速进行调节。

  2. 新城金矿深部热环境分析及围岩温度测试%Analysis on Deep Thermal Environment and Temperature Measurement of Surrounding Rock in Xincheng Gold Mine

    Institute of Scientific and Technical Information of China (English)

    刘凯; 朱兆文; 朱万成; 刘洪磊; 侯晨

    2016-01-01

    随着开采深度的增加,新城金矿已经进入深部开采阶段,逐步面临高温热害问题。鉴于此,开展地下深部热环境分析,分析矿区主要热源及其形成机理,应用工程热力学手段量测不同开采深度下巷道风流温度、湿度以及风速等环境因素。采用深孔测量法测定不同深度的围岩温度,研究地温梯度变化规律。测试结果表明,巷道风温、水温均随着开采深度的增加而增大,主要生产中段相对湿度在80% RH以上,矿区恒温带温度为23℃,正常地温梯度为0.018℃/m,调热圈半径为17~18 m。该结果为有效控制井下作业场所的热环境状况以及热害防治研究提供了基础数据。%With the increase of mining depth,Xincheng Gold Mine has entered the stage of deep mining,and is gradually facing with the problem of high temperature stress. In this regard,an analysis of deep underground thermal environment was conducted,the main heat sources and the formation mechanism in the mining area were analyzed,environmental factors such as air temperature,humidity and wind speed of different mining depths of roadways were measured by means of Engineering Ther-modynamics. The temperature of surrounding rock in different depths was determined by Deep Hole Measurement Method and the variation regularity of geothermal gradient was studied. Test results show that the air temperature and water temperature of the roadways increase with the increasing of mining depth,the relative humidity of main mining levels are above 80% RH,the temperature of underground constant temperature zone in the mine area is 23 ℃, the normal geothermal gradient is 0. 018 ℃/m,and the radius of heat adjustment circle is 17~18 m,all these will provide basic data for the effective control of thermal environment conditions in underground workplaces and the prevention and treatment of thermal hazard.

  3. 架线式电动轮汽车在长山壕金矿设计中的应用%Application of line-powered electric trolleys in the design of Changshanhao Gold Mine

    Institute of Scientific and Technical Information of China (English)

    王君

    2016-01-01

    随着露天采矿技术的发展以及人们节能环保意识的提高,架线式电动轮汽车在国外大型露天矿、水电建设等大型土石方工程中被越来越多的应用.以长山壕金矿为工程背景,从技术和经济层面对架线式电动轮汽车在大型露天矿山的应用情况进行详细分析,工程应用不仅可提高汽车运输能力及设备使用寿命,还可显著降低运输成本,新增投资返本仅0.72 a,生产每年提高经济利润1.05亿元,经济效益显著.%With the improvement of open-pit mining technology and the growing awareness of energy conservation and green mining, the application of line-powered electric trolleys in large-scale open-pit mine, utility infrastructure and such earth and rock engineering are becoming more common.The paper takes Changshanhao Gold Mine as the re-search subject,and analyzes their application status in large-scale open-pit mines technically and economically.It turns out that the application will not only improve the transportation capability and the service life of equipment,also it can significantly reduce the cost.It takes only 0.72 a to make up for the investment and make profits,increasing a signifi-cant profit of 1.05 ×108 yuan per year.

  4. Effects of Quebracho Tannin on Recovery of Colloidal Gold from ...

    African Journals Online (AJOL)

    Michael

    2015-06-01

    Jun 1, 2015 ... Gold from Bioleached Wash Liquor”, Ghana Mining Journal, Vol. 15, No ... paper considered effects of Quebracho Tannin (QT) on recovery of gold from the oxidized flotation .... partial precipitation of iron which can help reduce.

  5. 多金属金矿氢氧化钠焙烧热力学研究%Thermodynamics study of sodium hydroxide roasting in a poly-metallic gold mine

    Institute of Scientific and Technical Information of China (English)

    王瑞祥; 曾斌; 余攀; 毛继勇; 谢博毅; 王志刚; 阮建国

    2013-01-01

    Roasting is an effective pre-treatment technology to improve gold and silver recovery rate for poly-metallic gold mine. ΔG0T-T function of the main chemical reaction during NaOH roasting process in the poly-metallic gold mine by thermodynamic calculations. ΔG0T-T is drawn accordingly. Thermodynamics calculation results show that NaOH roasting lowers the generating chances of copper ferrite, zinc ferrite, zinc silicate and lead silicate, whose binding forces to Au and Ag decreases accordingly. The appropriate temperature of roasting sodium hydroxide is higher than 834.33 K.%焙烧是一种提高多金属金矿中金、银回收率的有效预处理方法,通过热力学计算,得到了多金属金矿NaOH焙烧过程主要化学反应的△G0T-T函数,并绘制了△G0T-T图.热力学分析结果表明NaOH焙烧能降低CuO· Fe2O3、ZnO·Fe2O3、PbO· SiO2、2ZnO·SiO2的生成几率,从而降低了以上物质对Au、Ag的包裹作用.多金属金矿NaOH焙烧的适宜温度为T≥834.33 K.

  6. 煤矿井下穿层水力压裂钻孔布置优化分析及应用%Optimization Analysis on Hydraulic Fracturing Crossing Borehole Layout and Its Application in Coal Mine

    Institute of Scientific and Technical Information of China (English)

    李栋; 郭臣业; 覃乐; 黄昌文; 唐育德; 周小林

    2015-01-01

    为解决重庆地区低透气性松软煤层瓦斯抽采的难题,提出煤矿井下穿层水力压裂技术,分析得出其增透主要是高压水在煤体裂隙尖端产生拉应力增高区促使原始裂隙扩展、次生裂隙形成的过程,借助数值模拟对不同孔距的穿层水力压裂煤体塑性破坏区随注入高压水压力的变化规律进行研究,得到重庆逢春煤矿7号煤层起裂压力为33~35 MPa,而延伸压力略低于起裂压力,拟合出不同孔径下水力压裂有效范围与注入高压水压力的指数曲线,并将研究成果应用于该矿底板巷瓦斯抽采工程. 结果表明:水力压裂后煤层在走向、倾向上单孔压裂有效范围分别达到60 m和50 m,煤层透气性系数提高195~370倍,瓦斯抽采纯量提高3. 5倍,瓦斯抽采浓度提高5倍.%To resolve the problem of gas drainage difficulty in soft coal seam with low permeability in Chongqing area, a new technology by hydraulic fracturing across coal seams was proposed, it was concluded from the analysis that the process of the permeability enhancement included the original crack expansion and the secondary crack formation in the tensile stress concentration area produced at the crack tip. Study was made on the variation law of the plastic failure zone of the coal body by hydraulic fracturing across seams with the pressure of the injected high-pressure water with the help of numerical simulation. It was found that the fracture initiation pressure of No. 7 coal seam in Fengchun Coal Mine was 33 ~35 MPa and the extension pressure was slightly lower than the initiation pressure. The exponential curve of the hydraulic fracturing radius and the injection pressure was fitted out, which was applied to gas pre-drainage engineering in a floor roadway. The application results showed that the effective range of hydraulic fracturing along the strike and inclination respectively reached 60 m and 50 m, the permeability of coal seam raised by 195 ~370 times

  7. Mercury bioaccumulation in fish in a region affected by historic gold mining; the South Yuba River, Deer Creek, and Bear River watersheds, California, 1999

    Science.gov (United States)

    May, Jason T.; Hothem, Roger L.; Alpers, Charles N.; Law, Matthew A.

    2000-01-01

    Mercury that was used historically for gold recovery in mining areas of the Sierra Nevada continues to enter local and downstream water bodies, including the Sacramento Delta and the San Francisco Bay of northern California. Methylmercury is of particular concern because it is the most prevalent form of mercury in fish and is a potent neurotoxin that bioaccumulates at successive trophic levels within food webs. In April 1999, the U.S. Geological Survey, in cooperation with several other agencies the Forest Service (U.S. Department of Agriculture), the Bureau of Land Management, the U.S. Environmental Protection Agency, the California State Water Resources Control Board, and the Nevada County Resource Conservation District began a pilot investigation to characterize the occurrence and distribution of mercury in water, sediment, and biota in the South Yuba River, Deer Creek, and Bear River watersheds of California. Biological samples consisted of semi-aquatic and aquatic insects, amphibians, bird eggs, and fish. Fish were collected from 5 reservoirs and 14 stream sites during August through October 1999 to assess the distribution of mercury in these watersheds. Fish that were collected from reservoirs included top trophic level predators (black basses, Micropterus spp.) intermediate trophic level predators [sunfish (blue gill, Lepomis macrochirus; green sunfish, Lepomis cyanellus; and black crappie, Poxomis nigromaculatus)] and benthic omnivores (channel catfish, Ictularus punctatus). At stream sites, the species collected were upper trophic level salmonids (brown trout, Salmo trutta) and upper-to-intermediate trophic level salmonids (rainbow trout, Oncorhynchus mykiss). Boneless and skinless fillet portions from 161 fish were analyzed for total mercury; 131 samples were individual fish,