WorldWideScience

Sample records for african gold mines

  1. 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.

  2. Gold-Mining

    DEFF Research Database (Denmark)

    Raaballe, J.; Grundy, B.D.

    2002-01-01

    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......  Based on standard option pricing arguments and assumptions (including no convenience yield and sustainable property rights), we will not observe operating gold mines. We find that asymmetric information on the reserves in the gold mine is a necessary and sufficient condition for the existence...... 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...

  3. 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....

  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. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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…

  12. 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.

  13. Occupational lung disease in the South African mining industry: research and policy implementation.

    Science.gov (United States)

    Murray, Jill; Davies, Tony; Rees, David

    2011-01-01

    South African miners face an epidemic of occupational lung diseases. Despite a plethora of research on the mining industry, and the gold mining industry in particular, research impact (including disease surveillance) on policy implementation and occupational health systems performance lags. We describe the gold mining environment, and research on silicosis, tuberculosis, HIV and AIDS, and compensation for occupational disease including initiatives to influence policy and thus reduce dust levels and disease. As these have been largely unsuccessful, we identify possible impediments, some common to other low- and middle-income countries, to the translation of research findings and policy initiatives into effective interventions.

  14. 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.

  15. 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.

  16. Perceptions and attitudes of batswana mineworkers towards the South African gold mines, with special reference to living and working conditions, legal issues and trade unions.

    OpenAIRE

    Molamu L; Molokomme A; Somolekae G

    1987-01-01

    Includes texts of "Charter of Rights for Migrant Workers in Southern Africa", "Charter of Rights for Migrant Workers" (South African Catholic Bishops Conference) and "National Union of Mineworkers Miners' Bill of Rights".

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

    DEFF Research Database (Denmark)

    Bach, Lis; Asmund, Gert; Søndergaard, Jens

    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...... 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...

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

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

    DEFF Research Database (Denmark)

    Bach, Lis; Birch Larsen, Morten

    the monitoring in 2014, the area has been without any activity. The mining company Angel Mining Gold A/S closed its gold production in November 2013 where after the Nalunaq area was affected by decommissioning and restoration until August 2014. The gold was extracted by chemical extraction with cyanide (carbon...... 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...

  5. 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.

  6. Occupational respiratory diseases in the South African mining industry

    Directory of Open Access Journals (Sweden)

    Gill Nelson

    2013-01-01

    Full Text Available Background: Crystalline silica and asbestos are common minerals that occur throughout South Africa, exposure to either causes respiratory disease. Most studies on silicosis in South Africa have been cross-sectional and long-term trends have not been reported. Although much research has been conducted on the health effects of silica dust and asbestos fibre in the gold-mining and asbestos-mining sectors, little is known about their health effects in other mining sectors. Objective: The aims of this thesis were to describe silicosis trends in gold miners over three decades, and to explore the potential for diamond mine workers to develop asbestos-related diseases and platinum mine workers to develop silicosis. Methods: Mine workers for the three sub-studies were identified from a mine worker autopsy database at the National Institute for Occupational Health. Results: From 1975 to 2007, the proportions of white and black gold mine workers with silicosis increased from 18 to 22% and from 3 to 32% respectively. Cases of diamond and platinum mine workers with asbestos-related diseases and silicosis, respectively, were also identified. Conclusion: The trends in silicosis in gold miners at autopsy clearly demonstrate the failure of the gold mines to adequately control dust and prevent occupational respiratory disease. The two case series of diamond and platinum mine workers contribute to the evidence for the risk of asbestos-related diseases in diamond mine workers and silicosis in platinum mine workers, respectively. The absence of reliable environmental dust measurements and incomplete work history records impedes occupational health research in South Africa because it is difficult to identify and/or validate sources of dust exposure that may be associated with occupational respiratory disease.

  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. 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.

  9. 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

  10. 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.

  11. 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

  12. 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...

  13. Contribution of "Women's Gold" to West African livelihoods

    DEFF Research Database (Denmark)

    Pouliot, Mariéve

    2012-01-01

    Contribution of ``Women's Gold'' to West African Livelihoods: The Case of Shea ( Vitellaria paradoxa ) in Burkina Faso. This paper (i) quantifies the contribution that Vitellaria paradoxa makes to the total income of rural households belonging to different economic groups in two areas of Burkina ...... not be considered as a remedy to poverty but instead as a way for households to diversify their livelihood strategy and decrease their vulnerability to food insecurity and climate variability....

  14. 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.

  15. 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.

  16. Assay and analytical practice in the South African mining industry

    Energy Technology Data Exchange (ETDEWEB)

    Lenahan, W.C.; Murray-Smith, R. de L.

    1986-01-01

    Contains chapters with the following titles: laboratory design; the preparation of mine samples; the furnace room; balances and mass measurement; the fire assay; sampling and the preparation of samples from metallurgical plants; the determination of gold in cyanide solutions; particle size analysis; the analysis of uranium prospecting, mining and extraction plant samples; the assay of gold bullion and some associated methods of analysis, special methods for the assay of complex materials and geological prospecting samples; the analysis of mine air; pH and electrometric measurement; the treatment and analysis of water and effluents; the sample preparation; analysis and testing of coal (and coke); the analysis of miscellaneous mine materials; the determination of base metals in ores and related materials; the determination of platinum group metals; the analysis of cyanide solutions; the determination of sulphur in ores and related materials; statistical control of analytical practice.

  17. 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.

  18. 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.

  19. 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...

  20. 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.

  1. 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

  2. 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....

  3. 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

  4. African Mining, Gender and Local Employment

    Science.gov (United States)

    Tolonen, A.; Kotsadam, A.

    2014-12-01

    Access to employment improves women's lives and is listed among the top five priorities for promoting gender equality in the 2012 World Development Report. This paper addresses this issue by exploring women's labor market opportunities in Africa within one very important and growing sector: extractive industries. Africa's opportunities are being transformed by new discoveries of natural resources and their rising prices, and the mining sector is the main recipient of foreign direct investment in Sub-Saharan Africa. Whether the discovery of natural resources is a blessing or a curse to a country's citizens is a contentious issue, and natural resource dependence has been linked to negative outcomes at the national level such as environmental degradation, conflict, elite capture of rents and low female labor force participation. Natural resource extraction has been argued to be a hindrance to women's labor market participation by increasing reservation wages and by decreasing market demand for female labor. We perform the first cross-national study testing these hypotheses with micro-data. To do this we combine survey data on 500,000 women in Sub-Saharan Africa with geo-coded data on 900 large-scale mines (see Figure 1). We treat mine openings and mine closings as natural experiments to explore local labor market changes. Industrial mines generate local structural shifts. Subsistence farming becomes less important for both men and women. However, men shift to skilled manual labor, and women shift to service sector jobs. This contradicts the hypothesis that natural resource extraction is detrimental to women, by not providing them with new job opportunities. However, in support of the hypothesis, women decrease their labor market participation more than men do. A back-of-the-envelope calculation estimates that 90,000 women across Africa benefit from service sector jobs as a direct result of industrial mining in their communities, but 280,000 women leave the labor force

  5. 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...

  6. Overview of the South African mine health and safety standardization and regulation systems

    Institute of Scientific and Technical Information of China (English)

    LI Zhong-xue; LI Jia-jie; LI Cui-ping; LIU Shuang-yue

    2008-01-01

    Outlined the South African mine health and safety regulatory framework, including the roles of government, tripartite council, service agencies, mine enterprises,rescue stations and workers unions, analyzed the institutional structures of South African mine health and safety standardization, including the South African standard and specification systems and standard development processes, and characterized the South African mine health and safety standardization and regulation systems. Intended to provide some suggestions for the transformation and improvement of mine health and safety standardization and regulation systems in China or in similar situations.

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. The role of conflict minerals, artisanal mining, and informal trading networks in African intrastate and regional conflicts

    Science.gov (United States)

    Chirico, Peter G.; Malpeli, Katherine C.

    2014-01-01

    The relationship between natural resources and armed conflict gained public and political attention in the 1990s, when it became evident that the mining and trading of diamonds were connected with brutal rebellions in several African nations. Easily extracted resources such as alluvial diamonds and gold have been and continue to be exploited by rebel groups to fund their activities. Artisanal and small-scale miners operating under a quasi-legal status often mine these mineral deposits. While many African countries have legalized artisanal mining and established flow chains through which production is intended to travel, informal trading networks frequently emerge in which miners seek to evade taxes and fees by selling to unauthorized buyers. These networks have the potential to become international in scope, with actors operating in multiple countries. The lack of government control over the artisanal mining sector and the prominence of informal trade networks can have severe social, political, and economic consequences. In the past, mineral extraction fuelled violent civil wars in Sierra Leone, Liberia, and Angola, and it continues to do so today in several other countries. The significant influence of the informal network that surrounds artisanal mining is therefore an important security concern that can extend across borders and have far-reaching impacts.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. [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.

  3. 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...

  4. 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:...

  5. 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

  6. 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.

  7. 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).

  8. 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

  9. 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.

  10. 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...

  11. 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...

  12. 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.

  13. 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.

  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. 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

  16. 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

  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. 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.

  1. 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...

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. Beyond the biomedical and behavioural: towards an integrated approach to HIV prevention in the southern African mining industry.

    Science.gov (United States)

    Campbell, C; Williams, B

    1999-06-01

    While migrant labour is believed to play an important role in the dynamics of HIV-transmission in many of the countries of southern Africa, little has been written about the way in which HIV/AIDS has been dealt with in the industrial settings in which many migrant workers are employed. This paper takes the gold mining industry in the countries of the Southern African Development Community (SADC) as a case study. While many mines made substantial efforts to establish HIV-prevention programmes relatively early on in the epidemic, these appear to have had little impact. The paper analyses the response of key players in the mining industry, in the interests of highlighting the limitations of the way in which both managements and trade unions have responded to HIV. It will be argued that the energy that has been devoted either to biomedical or behavioural prevention programmes or to human rights issues has served to obscure the social and developmental dimensions of HIV-transmission. This argument is supported by means of a case study which seeks to highlight the complexity of the dynamics of disease transmission in this context, a complexity which is not reflected in individualistic responses. An account is given of a new intervention which seeks to develop a more integrated approach to HIV management in an industrial setting.

  8. 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.

  9. Deciphering the prokaryotic community and metabolisms in South African deep-mine biofilms through antibody microarrays and graph theory.

    Directory of Open Access Journals (Sweden)

    Yolanda Blanco

    Full Text Available In the South African deep mines, a variety of biofilms growing in mine corridor walls as water seeps from intersections or from fractures represents excellent proxies for deep-subsurface environments. However, they may be greatly affected by the oxygen inputs through the galleries of mining activities. As a consequence, the interaction between the anaerobic water coming out from the walls with the oxygen inputs creates new conditions that support rich microbial communities. The inherent difficulties for sampling these delicate habitats, together with transport and storage conditions may alter the community features and composition. Therefore, the development of in situ monitoring methods would be desirable for quick evaluation of the microbial community. In this work, we report the usefulness of an antibody-microarray (EMChip66 immunoassay for a quick check of the microbial diversity of biofilms located at 1.3 km below surface within the Beatrix deep gold mine (South Africa. In addition, a deconvolution method, previously described and used for environmental monitoring, based on graph theory and applied on antibody cross-reactivity was used to interpret the immunoassay results. The results were corroborated and further expanded by 16S rRNA gene sequencing analysis. Both culture-independent techniques coincided in detecting features related to aerobic sulfur-oxidizers, aerobic chemoorganotrophic Alphaproteobacteria and metanotrophic Gammaproteobacteria. 16S rRNA gene sequencing detected phylotypes related to nitrate-reducers and anaerobic sulfur-oxidizers, whereas the EMChip66 detected immunological features from methanogens and sulfate-reducers. The results reveal a diverse microbial community with syntrophic metabolisms both anaerobic (fermentation, methanogenesis, sulphate and nitrate reduction and aerobic (methanotrophy, sulphur oxidation. The presence of oxygen-scavenging microbes might indicate that the system is modified by the artificial

  10. 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...

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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....

  20. 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.

  1. 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.

  2. 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.

  3. 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...

  4. 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.

  5. 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

  6. 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.

  7. Managing trauma in the South African mining industry.

    Science.gov (United States)

    Maiden, R Paul

    2005-01-01

    Deep sub-surface mining is one of South Africa s leading industries. It is also one of the most dangerous. While safety is maintained as much as possible to minimize cave-ins and other accidents, underground tremors and earthquakes are commonplace and unpredictable and usually involve life threatening injuries and loss of life. Crisis intervention and trauma management are essential to helping workers cope with mining accidents. This article describes the trauma management program developed by the employee assistance program at the Chamber of Mines in South Africa to respond to workplace accidents.

  8. 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...

  9. Removal of sulphates from South African mine water using coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Madzivire, G.; Petrik, L.F. [Western Cape Univ., Bellville (South Africa). Dept. of Chemistry; Gitari, W.M. [Cape Peninsula Univ. of Technology, Cape Town (South Africa). Dept. of Chemistry; Ojumu, T.V. [Cape Peninsula Univ. of Technology, Cape Town (South Africa). Dept. of Chemical Engineering; Misheer, N. [Eskom, Johannesburg (South Africa). Dept. of Research and Innovation

    2010-07-01

    This study investigated the use of alkaline fly ash (FA) produced by South African power stations as a means of neutralizing acid mine drainage South African mines. The mine water has circumneutral pH, low concentrations of iron (Fe) and aluminium (Al), and is rich in calcium (Ca), magnesium (Mg), and sulfate (SO{sub 4}{sup 2-}). The FA was used to remove SO{sub 4}{sup 2-} from the mine water. A geochemical modelling tool was used to investigate the effect of Fe and Al on sulphate removal from NMD when reacted with FA. The study also investigated the mineral phases responsible for the removal of sulphates, Fe, Al and Mn from mine water samples. The samples were analyzed by inductively-coupled plasma-atomic emission mass spectrometry and ion chromatography for cations and anions. Results of the geochemical modelling study showed that the removal of sulphates, Mg, Mn, Al and Fe was significantly influenced by the final pH of the water. When mine water pH was raised to greater than 6, 8, 9, and 11, approximately 100 percent of Al, Fe, Mn and Mg were removed. 7 refs., 6 figs.

  10. [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.

  11. Advances in dust control technology on South African underground coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Belle, B.K.; Du Plessis, J. [CSIR: Miningtek, Pretoria (South Africa)

    2001-07-01

    Despite the much-heralded arrival of the new millennium, improving mine health and safety remains an enormous challenge. Considerable progress with environmental (dust and methane) control in South African mines has indeed been made but it remains a matter of great concern to all parties, i.e. mine management, labor and the government. The introduction of the 1997 Directive on dust exposure and mine ventilation was a milestone for the South African coal mining industry in improving health and safety standards. These stricter guidelines and the latest dust control technologies are beneficial not only in the long-term health perspective, but also to in terms of controlling methane and coal dust explosions (high-risk) in the short term. Over the past two years, CSIR: Miningtek personnel developed new dust control systems through various Safety In Mines Research Advisory Committee (SIMRAC) funded projects and successfully implemented them in underground coal mines. Currently, it can be confidently claimed that the new and proven dust control systems are being effectively operated in more than 80% of the bord and pillar sections in South Africa. This paper highlights the critical components of the new dust control systems evaluated underground, viz., the half-curtain system, the retrofitted hood system, the double scrubber system and the integrated hood system for continuous miners, and the road header dust control system. The status of wet head dust control systems and the challenges facing high seam longwall mines are also presented in the paper. The relative effectiveness of various dust control systems are discussed and the relevant test results are given in the paper. It concludes with a discussion of the progress made and challenges facing the coal mining industry in reducing workers' exposure to respirable dust. 11 refs., 5 figs.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. The assessment of functional work capacity in the South African mining industry.

    Science.gov (United States)

    Hofmann, Tia-Mari; Kielblock, Johan

    2007-01-01

    Overall physical work fitness is a prerequisite in numerous industries. Apart from improved productivity, it remains fundamental with regards to the maintenance of good health and safety. To address worker fitness in the mining industry, AngloGold Ashanti and Anglo Platinum Mining Houses developed a Functional Work Capacity (FWC) test battery. The FWC test battery consists of 19 work simulations representing the required functional work capacity to cope with all types of physical work tasks and work environments in the mining industry. This assessment tool is not only used to evaluate injured or medically affected workers for alternative placement but also to ensure that the new employee is placed in a job matching his physical capacity. This paper reviews the design process and application of the FWC test battery in the mining industry.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  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. 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.

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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..

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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.

  15. 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)

  16. Environmental Management Practices and Firm Performance in a South African Mining Firm

    Directory of Open Access Journals (Sweden)

    Gibson Nyirenda

    2013-09-01

    Full Text Available This paper examines the impact of environmental management practices on the financial performance of a South African mining firm. The major aim of this paper is to investigate whether such practices have a close relationship with the mining firm’s financial performance (represented by return on equity [ROE]. The approach is a case study of a South African mining firm listed under the socially responsible index (SRI of the Johannesburg Stock Exchange (JSE. It uses Green-Steel sa (pseudonym used in place of the real name as a case study. Using multiple regression statistics, the return on equity of Green-Steel sa is regressed on three environmental management practices of Green- Steel (carbon reduction, energy efficiency, and water usage. The result shows there is no significant relationship between the variables and this lends credence to information gathered from Green-Steel environmental reports that Green-Steel’s environmental management practices are driven mostly by a desire to abide by regulations and also by a moral obligation to use environmental management practices to mitigate climate change impact.

  17. 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

  18. 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".

  19. 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.

  20. 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.

  1. 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.

  2. 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...

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

    Directory of Open Access Journals (Sweden)

    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

  4. 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...

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Research vulnerability: an illustrative case study from the South African mining industry.

    Science.gov (United States)

    Horn, Lyn

    2007-12-01

    The concept of 'vulnerability' is well established within the realm of research ethics and most ethical guidelines include a section on 'vulnerable populations'. However, the term 'vulnerability', used within a human research context, has received a lot of negative publicity recently and has been described as being simultaneously 'too broad' and 'too narrow'. The aim of the paper is to explore the concept of research vulnerability by using a detailed case study - that of mineworkers in post-apartheid South Africa. In particular, the usefulness of Kipnis's taxonomy of research vulnerability will be examined. In recent years the volume of clinical research on human subjects in South Africa has increased significantly. The HIV and TB pandemics have contributed to this increase. These epidemics have impacted negatively on the mining industry; and mining companies have become increasingly interested in research initiatives that address these problems. This case study explores the potential research vulnerability of mineworkers in the context of the South African mining industry and examines measures that can reduce this vulnerability.

  4. The South African coal mining industry: A need for a more efficient and collaborative supply chain

    Directory of Open Access Journals (Sweden)

    David Pooe

    2011-11-01

    Full Text Available It is estimated that about two-thirds of global coal is used for power generation and that, in the next 20 years, over 70% of the demand for coal will come from China and India. Coal accounts for approximately 41% of the world's electricity generation. Demand for thermal coal is influenced by factors that include availability, prices of competing products such as oil, gas and nuclear power, and the demand for electricity. The aim of this article is to provide an exposition of supply chain dynamics within the South African coal mining industry and to argue for a more efficient and collaborative supply chain. The authors attempt to investigate at local and global level, the current trends pertaining to the level of reserves, production and consumption of coal. The article further demonstrates the shortcomings of current logistics in meeting the demand for coal in both domestic and export markets. The article draws from secondary data sourced from academic papers, government and agency documents in the exposition of the coal mining supply chain. The paper concludes by recommending the need for a scientific study on supply chain constraints facing the coal mining industry in South Africa.

  5. 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.

  6. 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.

  7. 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...

  8. 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

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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 sites...... are increasingly being noted, there is little analysis of miners' mobility patterns and material outcomes. In this article, on the basis of a sample survey and interviews at two gold-mining sites in Tanzania, we probe when and why miners leave one site in favour of another. Our findings indicate that movement...... is often 'rushed' but rarely rash. Whereas movement to the first site may be an adventure, movement to subsequent sites is calculated with knowledge of the many risks entailed. Miners spend considerable time at each site before migrating onwards. Those with the highest site mobility tend to be more...

  15. 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.

  16. 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

  17. 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.

  18. 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...

  19. 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.

  20. 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

  1. 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.

  2. 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。

  3. 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...

  4. 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

  5. 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.

  6. 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

  7. [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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Investigation of the acid mine drainage potential of the Kopanang rock dump, Vaal Reefs / Charl Labuschagne

    OpenAIRE

    Labuschagne, Charl

    2008-01-01

    The Kopanang rock dump is one of several rock dumps in the Vaal Reefs gold mining area that may have an impact on the surface and groundwater quality. Few Acid Mine Drainage (AMD) studies exist on rock dumps in the South African gold industry due to the overwhelming acid generation from slime dams. Due to the existence of sulfide minerals in the Kopanang rock dump, there is a possibility that acid generation can occur, depending on the mineralogical composition of the ...

  13. Rock drills used in South African mines: a comparative study of noise and vibration levels

    Energy Technology Data Exchange (ETDEWEB)

    J.I. Phillips; P.S. Heyns; G. Nelson [National Health Laboratory Service, Johannesburg (South Africa). National Institute for Occupational Health

    2007-07-01

    The study compared the noise and vibration levels associated with three hand-held rock drills (pneumatic, hydraulic and electric) currently used in South African mines, and a prototype acoustically shielded self-propelled rock drill. Equivalent A-weighted sound pressure levels were recorded on a geometrical grid, using Rion NL-11 and NL-14 sound level meters. Vibration measurements were conducted on the pneumatic, hydraulic and electric drills in accordance with the ISO 5349-1 (2001) international standard on human exposure to hand-transmitted vibration, using a Brel and Kjaer UA0894 hand adaptor. PCB Piezo accelerometers were used to measure vibration in three orthogonal directions. No vibration measurements were conducted on the self-propelled drill. All four drills emitted noise exceeding 85 dB(A). The pneumatic drill reached levels of up to 114 dB(A), while the shielded self-propelled drill almost complied with the 85 dB(A) 8 h exposure limit. Vibration levels of up to 31 m s{sup -2} were recorded. These levels greatly exceed recommended and legislated levels. Significant engineering advances will need to be made in the manufacture of rock drills to impact on noise induced hearing loss and hand arm vibration syndrome. Isolating the operator from the drill, as for the self-propelled drill, addresses the problems of both vibration and noise exposure, and is a possible direction for future development.

  14. 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.

  15. 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.

  16. 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.

  17. Exploring the challenges associated with the greening of supply chains in the South African manganese and phosphate mining industry

    Directory of Open Access Journals (Sweden)

    R.I. David Pooe

    2014-03-01

    Full Text Available As with most mining activities, the mining of manganese and phosphate has serious consequences for the environment. Despite a largely adequate and progressive framework for environmental governance developed since 1994, few mines have integrated systems into their supply chain processes to minimise environmental risks and ensure the achievement of acceptable standards. Indeed, few mines have been able to implement green supply chain management (GrSCM. The purpose of this article was to explore challenges related to the implementation of GrSCM and to provide insight into how GrSCM can be implemented in the South African manganese and phosphate industry. This article reported findings of a qualitative study involving interviews with 12 participants from the manganese and phosphate industry in South Africa. Purposive sampling techniques were used. Emerging from the study were six themes, all of which were identified as key challenges in the implementation of GrSCM in the manganese and phosphate mining industry. From the findings, these challenges include the operationalisation of environmental issues, lack of collaboration and knowledge sharing, proper application of monitoring and control systems,lack of clear policy and legislative direction, the cost of implementing GrSCM practices, and the need for strong leadership and management of change. On the basis of the literature reviewed and empirical findings, conclusions were drawn and policy and management recommendations were accordingly made.

  18. 大功率激电在寻找金矿中的应用%Application of Large-power IP Method in Gold Mine Prospecting

    Institute of Scientific and Technical Information of China (English)

    杨培胜; 胡明科

    2013-01-01

    本文以甘肃省某矿区大功率激电寻找金矿为实例,介绍了激电扫面、测深的工作原理和方法,并取得了很好的效果,对寻找金矿有一定的借鉴意义。%Taking a mining area in Gansu as an example of using large-power IP to find the gold mine, this paper introduces the IP scanning and IP sounding principle and method, and obtains a good effect, have certain reference significance to look for gold.

  19. 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.

  20. 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...

  1. Large Scale Screening of Southern African Plant Extracts for the Green Synthesis of Gold Nanoparticles Using Microtitre-Plate Method

    Directory of Open Access Journals (Sweden)

    Abdulrahman M. Elbagory

    2016-11-01

    Full Text Available The preparation of gold nanoparticles (AuNPs involves a variety of chemical and physical methods. These methods use toxic and environmentally harmful chemicals. Consequently, the synthesis of AuNPs using green chemistry has been under investigation to develop eco-friendly nanoparticles. One approach to achieve this is the use of plant-derived phytochemicals that are capable of reducing gold ions to produce AuNPs. The aim of this study was to implement a facile microtitre-plate method to screen a large number of aqueous plant extracts to determine the optimum concentration (OC for the bio-synthesis of the AuNPs. Several AuNPs of different sizes and shapes were successfully synthesized and characterized from 17 South African plants. The characterization was done using Ultra Violet-Visible Spectroscopy, Dynamic Light Scattering, High Resolution Transmission Electron Microscopy and Energy-Dispersive X-ray Spectroscopy. We also studied the effects of temperature on the synthesis of the AuNPs and showed that changes in temperatures affect the size and dispersity of the generated AuNPs. We also evaluated the stability of the synthesized AuNPs and showed that some of them are stable in biological buffer solutions.

  2. 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.

  3. 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.

  4. 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.

  5. Geology of the world-class Kiaka polyphase gold deposit, West African Craton, Burkina Faso

    Science.gov (United States)

    Fontaine, Arnaud; Eglinger, Aurélien; Ada, Koumangdiwè; André-Mayer, Anne-Sylvie; Reisberg, Laurie; Siebenaller, Luc; Le Mignot, Elodie; Ganne, Jérôme; Poujol, Marc

    2017-02-01

    The Kiaka gold deposit is a major resource in West Africa, with measured and indicated resources of 124 Mt at 1.09 g/t Au (3.9 Moz) and inferred resources of 27 Mt at 0.83 g/t Au (0.8 Moz). Located within the Manga-Fada N'Gourma greenstone and plutonic belt in south of the Burkina Faso, the deposit is hosted by a metamorphosed volcano-sedimentary sequence of lithic-, quartz-biotite metagreywackes, aluminosilicate-bearing metapelites and garnet-orthopyroxene-bearing schists and volcanic units. Structural observations indicate four local deformation events: DK1, DK2 and DK3 and DK4. Respectively, these events are linked to regional D1 E-W compression, D2 NW-SE compression and lastly, D3- and D4-related reactivations along D2 shear zones. The S2 foliation and D2 shear zones are developed during lower amphibolite facies metamorphism whereas retrogression occurs during D3-4 reactivations along these shear zones at upper greenschist facies conditions. The emplacement of a dioritic intrusion, dated at 2140 ± 7 Ma (Concordia U-Pb age on magmatic zircon), is interpreted to be contemporaneous with sinistral displacement along mineralized, NE-trending D2 shear zones. The intersection of these shears zones and the Markoye shear zone (dextral-reverse D1 and sinistral-reverse D2 reactivations) controlled the final geometry of the host rocks and the ore zones. Four subparallel elongated ore bodies are mainly hosted within D2-related shear zones and some are developed in an apparent axial plane of a F2 isoclinal fold. Detailed petrographic studies have identified two main types of hydrothermal alteration associated with two stages of gold mineralization. The stage (1) corresponds to replacement zones with biotite and clinozoisite during the D2 event associated with pyrrhotite ± pyrite, chalcopyrite (disseminated gold stage). The stage (2) occurs during reactivations of the D2-related auriferous shear zones (vein stage) and is characterized by diopside ± actinolite D3 veins and

  6. 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.

  7. 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

  8. 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.

  9. 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 (

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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...

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. [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.

  5. 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.

  6. An empirical study on the critical success factors of small to medium sized projects in a South African mining company

    Directory of Open Access Journals (Sweden)

    Du Randt, Francois Jean

    2014-08-01

    Full Text Available Projects that fail, for whatever reason, can impact negatively on society, organisations, and other stakeholders. A number of researchers have identified various critical success factors (CSFs that can influence the outcome and success of a project. This research therefore aims to determine the CSFs that influence various success measures of small- to medium-sized projects at a South African mining company, Exxaro Resources’ Grootegeluk Coal Mine. Other objectives of this research include determining the extent of the impacts of these CSFs on the different success measures of a project. The investigation suggests that there are correlations among CSFs, and that certain factors impact the outcome of projects far more than others. This research finds that the single most important CSF for small- to medium-sized projects is the selection of a competent project manager. The competent project manager is characterised by a group of interrelated CSF factors: good leadership, commitment, and learning from past experiences. Based on the research results, other CSFs are discussed and explored in order for recommendations to be made on how this mining company, and possibly other organisations, can achieve greater project success.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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

  14. Emergence of Drug-Resistant Tuberculosis at a South African Mine

    Centers for Disease Control (CDC) Podcasts

    2010-03-03

    This podcast describes the emergence of increasingly drug resistant tuberculosis at a mine in South Africa. CDC’s Dr. Dixie Snider discusses the outbreak and some of the reasons it may have occurred, despite the existence of a well-functioning TB control program at the mine.  Created: 3/3/2010 by Emerging Infectious Diseases.   Date Released: 3/3/2010.

  15. Hazards identified and the need for health risk assessment in the South African mining industry.

    Science.gov (United States)

    Utembe, W; Faustman, E M; Matatiele, P; Gulumian, M

    2015-12-01

    Although mining plays a prominent role in the economy of South Africa, it is associated with many chemical hazards. Exposure to dust from mining can lead to many pathological effects depending on mineralogical composition, size, shape and levels and duration of exposure. Mining and processing of minerals also result in occupational exposure to toxic substances such as platinum, chromium, vanadium, manganese, mercury, cyanide and diesel particulate. South Africa has set occupational exposure limits (OELs) for some hazards, but mine workers are still at a risk. Since the hazard posed by a mineral depends on its physiochemical properties, it is recommended that South Africa should not simply adopt OELs from other countries but rather set her own standards based on local toxicity studies. The limits should take into account the issue of mixtures to which workers could be exposed as well as the health status of the workers. The mining industry is also a source of contamination of the environment, due inter alia to the large areas of tailings dams and dumps left behind. Therefore, there is need to develop guidelines for safe land-uses of contaminated lands after mine closure.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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...

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 广西某金矿工艺矿物学研究%Process Mineralogy Study of a Gold Mine in Guangxi Province

    Institute of Scientific and Technical Information of China (English)

    许霞; 苏敬韧

    2016-01-01

    The process mineralogy study of a gold mine in guangxi province shows that the gold mineral occurs mainly as native gold and is primarily hosted in pyrite, chalcopyrite, pyrrhotite and so on. Copper mineral mainly occurs in the form of chalcopryrite with few quantities of covellite. The findings of the study provide a basis for developing a reasonable metallurgical process.%对广西某矿区矿石的工艺矿物学研究表明,金以自然金为主,主要的载金矿物为黄铁矿、黄铜矿、磁黄铁矿等,铜主要以黄铜矿形式产出,有极少的铜蓝。该项研究成果为制定合理的选冶工艺提供了依据。

  8. 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.

  9. 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.

  10. 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.

  11. Computed tomographic anatomy of the heads of blue-and-gold macaws (Ara ararauna), African grey parrots (Psittacus erithacus), and monk parakeets (Myiopsitta monachus).

    Science.gov (United States)

    Veladiano, Irene A; Banzato, Tommaso; Bellini, Luca; Montani, Alessandro; Catania, Salvatore; Zotti, Alessandro

    2016-12-01

    OBJECTIVE To create an atlas of the normal CT anatomy of the head of blue-and-gold macaws (Ara ararauna), African grey parrots (Psittacus erithacus), and monk parakeets (Myiopsitta monachus). ANIMALS 3 blue-and-gold macaws, 5 African grey parrots, and 6 monk parakeets and cadavers of 4 adult blue-and-gold macaws, 4 adult African grey parrots, and 7 monk parakeets. PROCEDURES Contrast-enhanced CT imaging of the head of the live birds was performed with a 4-multidetector-row CT scanner. Cadaveric specimens were stored at -20°C until completely frozen, and each head was then sliced at 5-mm intervals to create reference cross sections. Frozen cross sections were cleaned with water and photographed on both sides. Anatomic structures within each head were identified with the aid of the available literature, labeled first on anatomic photographs, and then matched to and labeled on corresponding CT images. The best CT reconstruction filter, window width, and window level for obtaining diagnostic images of each structure were also identified. RESULTS Most of the clinically relevant structures of the head were identified in both the cross-sectional photographs and corresponding CT images. Optimal visibility of the bony structures was achieved via CT with a standard soft tissue filter and pulmonary window. The use of contrast medium allowed a thorough evaluation of the soft tissues. CONCLUSIONS AND CLINICAL RELEVANCE The labeled CT images and photographs of anatomic structures of the heads of common pet parrot species created in this study may be useful as an atlas to aid interpretation of images obtained with any imaging modality.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. Seismic risk mitigation in deep level South African mines by state of the art underground monitoring - Joint South African and Japanese study

    Science.gov (United States)

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

    2012-04-01

    Two underground sites in a deep level gold mine in South Africa were instrumented by the Council for Scientific and Industrial Research (CSIR) with tilt meters and seismic monitors. One of the sites was also instrumented by JApanese-German Underground Acoustic emission Research in South Africa (JAGUARS) with a small network, approximately 40m span, of eight Acoustic Emission (AE) sensors. The rate of tilt, defined as quasi-static deformations, and the seismic ground motion, defined as dynamic deformations, were analysed in order to understand the rock mass behavior around deep level mining. In addition the high frequency AE events recorded at hypocentral distances of about 50m located at 3300m below the surface were analysed. A good correspondence between the dynamic and quasi-static deformations 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, which takes place from about 19:30 until shortly before 21:00. During the blasting time and the subsequent seismic events the coseismic and aseismic tilt shows a rapid increase.Much of the quasi-static deformation, however, occurs independently of the seismic events and was described as 'slow' or aseismic events. During the monitoring period a seismic event with MW 2.2 occurred in the vicinity of the instrumented site. This event was recorded by both the CSIR integrated monitoring system and JAGUARS acoustic emotion network. The tilt changes associated with this event showed a well pronounced after-tilt. The aftershock activities were also well recorded by the acoustic emission and the mine seismic networks. More than 21,000 AE aftershocks were located in the first 150 hours after the main event. Using the distribution of the AE events the position of the fault in the source area was successfully delineated. The distribution of the AE events following the main shock was related to after tilt in order to

  1. AN ANALYSIS OF MAINTENANCE PERFORMANCE SYSTEMS IN THE SOUTH AFRICAN MINING INDUSTRY

    Directory of Open Access Journals (Sweden)

    Kotze, R. L. M.

    2012-11-01

    Full Text Available The measurement of performance is an essential part of the management process. The planning function usually defines the goals and objectives for the business enterprise or division of the enterprise. The control function should monitor the performance measures and establish corrective action if actual performance deviates significantly from planned performance. Maintenance performance measurement is therefore essential to ensure that maintenance objectives are achieved, and that maintenance adds value for the company. The objective of this paper is to discuss the findings of a project that investigated aspects of the maintenance performance system of a number of mining companies in South Africa. The findings of a survey indicated that maintenance performance management is not yet used to its full potential in the mining industry.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. 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...

  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(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.

  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 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.

  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. 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...

  20. 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。

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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…

  6. 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.

  7. 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.

  8. The management of heat flow in deep mines

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Horst [Montanuniv. Leoben (Austria). Dept. Mineral Resources and Petroleum Engineering

    2013-04-15

    With the ever-increasing depth of mines, the management of heat has become a key issue for their design and operation. There are two main sources of heat: heat transfer from the rock mass into the mine workings and heat associated with mining operations. The principles of heat transfer from the rock mass are discussed and basic relationships presented. Sources of heat linked to mining operations are discussed. It is shown that in deep-level mines, heat transfer from the rock mass accounts more than 75 % of total mine heat load. In highly mechanized coal mines, heat from the use of mining machinery is also significant. Some models of heat flow prediction for deep gold mines are presented. It is shown that in the case of deep mines, control of heat flow is more important than increasing refrigeration capacity. Examples of heat flow management methods are given. Furthermore, the paper deals with the effects of heat on the human body and mine cooling strategies for deep mines. In detail the effects of heat on a worker are examined, heat stress and heat tolerance discussed and methods of assessing heat stress in different mining situations presented. Experiences from deep South African gold mines highlight the adverse effects of heat stress environment on safety and labour productivity. The principal methods of cooling of deep and ultra deep mines are discussed. It is shown that auto-compression of ventilation air is a deciding factor governing the choice of surface or underground cooling of ventilation air. In the case of deep and ultra deep mines, the use of chilled service water and ice slurry has shown to be the most cost effective means of mine cooling. In the case of ice slurry as cooling medium advantage is taken of the latent heat of ice which significantly reduces the amount of water required for mine cooling and hence the cost of pumping the water to surface. Cooling strategies for moderately deep, deep and ultra deep mines are discussed. Examples of cooling

  9. 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...

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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...

  18. 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 .

  19. 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.

  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. 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.

  2. 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

  3. Observational Studies of Earthquake Preparation and Generation to Mitigate Seismic Risks in Mines

    Science.gov (United States)

    Durrheim, R. J.; Ogasawara, H.; Nakatani, M.; Milev, A.; Cichowicz, A.; Kawakata, H.; Yabe, Y.; Murakami, O.; Naoi, M. M.; Moriya, H.; Satoh, T.

    2011-12-01

    We provide a status report on a 5-year project to monitor in-situ fault instability and strong motion in South African gold mines. The project has two main aims: (1) To learn more about earthquake preparation and generation mechanisms by deploying dense arrays of high-sensitivity sensors within rock volumes where mining is likely to induce significant seismic activity. (2) To upgrade the South African national surface seismic network in the mining districts. This knowledge will contribute to efforts to upgrade schemes of seismic hazard assessment and to limit and mitigate the seismic risks in deep mines. As of 31 July 2011, 46 boreholes totalling 1.9 km in length had been drilled at project sites at Ezulwini, Moab-Khotsong and Driefontein gold mines. Several dozen more holes are still to be drilled. Acoustic emission sensors, strain- and tiltmeters, and controlled seismic sources are being installed to monitor the deformation of the rock mass, the accumulation of damage during the preparation phase, and changes in dynamic stress as the rupture front propagates. These data will be integrated with measurements of stope closure, stope strong motion, seismic data recorded by the mine-wide network, and stress modelling. Preliminary results will be reported at AGU meeting. The project is endorsed by the Japan Science and Technology Agency (JST), Japan International Cooperation Agency (JICA) and the South African government. It is funded by the JST-JICA program for Science and Technology Research Partnership for Sustainable development (SATREPS, the Council for Scientific and Industrial Research (CSIR), the Council for Geoscience, the University of the Witwatersrand and the Department of Science and Technology. The contributions of Seismogen CC, OHMS Ltd, AnglogoldAshanti Rock Engineering Applied Research Group, First Uranium, the Gold Fields Seismic Department and the Institute of Mine Seismology are gratefully acknowledged.

  4. 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.

  5. Central African Republic.

    Science.gov (United States)

    1989-11-01

    The Central African Republic contains 242,000 square miles, which rolling terrain almost 2000 feet above sea level. The climate is tropical, and it has a population of 2.8 million people with a 2.5% growth rate. There are more than 80 ethnic groups including Baya 34%, Banda 28%, Sara 10%, Mandja 9%, Mboum 9%, and M'Baka 7%. The religions are traditional African 35%, protestant 25%, Roman Catholic 25%, and Muslim 15%, and the languages are French and Sangho. The infant mortality rate is 143/1000, with expectancy at 49 years and a 40% literacy rate. The work force of 1 million is 70% agricultural, industry 6% and commerce and service 6% and government 3%. The government consists of a president assisted by cabinet ministers and a single party. Natural resources include diamonds, uranium, timber, gold, and oil, and major industries are beverages, textiles, and soap. Agricultural products feature coffee, cotton, peanuts, tobacco, food crops and livestock. Most of the population live in rural areas and most of the 80 ethnic groups have their own language. This is one of the world's least developed countries, with a per capita income of $375/year. The main problems with development are the poor transportation infrastructure, and the weak internal and international marketing systems. The US and various international organizations have aided in agriculture development, health programs, and family planning. US investment is mainly in diamond and gold mining, and although oil drilling has been successful it is not economically feasible at current prices.

  6. 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。

  7. 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

  8. 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 .

  9. 内蒙长山壕金矿矿石工艺矿物学研究%Process mineralogy study on ores from Changshanhao gold mine in Inner Mongolia

    Institute of Scientific and Technical Information of China (English)

    祁玉海; 王艳; 高歌

    2012-01-01

    长山壕金矿是低品位、高吨位的特大型金矿.工艺矿物学研究的重点是查明金矿物在矿石中赋存状态、嵌布特征等工艺特性;同时,对矿石物质组成及超出显微镜分辨能力的次显微金,采用扫描电镜进行系统研究,特别是对氰化浸渣中金流失状态的确定,将金的流失控制在合理范围内.矿石的工艺矿物学研究为选矿试验工艺流程和条件的选择确定提供了依据.选矿试验获得了较好的指标,金的氰化浸出率达93.62%.%Changshanhao gold mine is a super-large gold mine with low grades and high tonnage. The key points in this process mineralogy work are to find out such process characteristics as the occurrence state and dissemination features of gold bearing minerals and meanwhile SEM (scanning electron microscope ) is used to systematically study sub - micro gold that is beyond scanning limits of microscopes, especially the gold loss conditions in cyanide leaching slag, to control gold loss to a reasonable rate. The process mineralogy study provided basis for the selection of experimental flowsheet and conditions of mineral processing. The tests gained satisfactory technical indexes and the cyanide leaching rate of gold reached 93.62 %.

  10. 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

  11. 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...

  12. "But This Story of Mine Is Not Unique": A Review of Research on African American Children's Literature

    Science.gov (United States)

    Brooks, Wanda; McNair, Jonda C.

    2009-01-01

    This article provides a review of research on African American children's literature by synthesizing the growing body of textual and reader response research conducted across the past several decades. The literature presented in this article cuts across the disciplines of education as well as English and library science. Using the selective…

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. Stars of the terrestrial deep subsurface: a novel 'star-shaped' bacterial morphotype from a South African platinum mine.

    Science.gov (United States)

    Wanger, G; Onstott, T C; Southam, G

    2008-06-01

    We study structure and function. Credit of course, goes to TJB, for it is from him that I inherited the habit of personifying bacteria and attempting to think like a bacterium, to better understand what they do. This work has taken us to wonderful places such as Yellowstone National Park, The Canadian Arctic, Australia, and the deep subsurface in the Republic of South Africa, the subject of this manuscript. From their perspective, why they do what they do is simple, to live. How they do it, is more challenging for us to understand, so it is something that we continue to work on. The marvel of bacteria is something that I, in turn, try to pass on to my students where I hope it will find fertile ground and provide as much enjoyment as it has given me - G. Southam. A biofilm (mine-slime) collected from the Northam Platinum mine in the Republic of South Africa contained a new bacterial morphotype. Mine-slimes are generally considered to be microbiologically compromised, subsurface samples due to the likelihood of contamination from the mining environment. However, careful examination of this biofilm demonstrated that it possessed a diverse bacterial population that included organisms that are consistent with the deep subsurface, suggesting that mine-slimes represent an underutilized, 'natural' bacterial enrichment. Using scanning and transmission electron microscopy, a novel, branching, filamentous, star-shape bacterium (in cross section) has been found, adding a new bacterial morphotype and strategy that bacteria have demonstrated to increase their surface area to volume ratio.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 中国金矿深部开挖中的岩爆预报与控制%PREDICTION AND CONTROL OF ROCKBURST DURING DEEP EXCAVATION OF A GOLD MINE IN CHINA

    Institute of Scientific and Technical Information of China (English)

    章光; 陈静曦; 胡斌

    2003-01-01

    The studies of prediction and control of rockburst are presented during deep excavation in a gold mine in China Firstly, thestress-relief method is used to obtain a vast amount of data about initial geostress. Secondly, 3D FEM analyses of large scale areperformed to find out the law of geostress distribution at various excavation levels of the mining area. At the same time, as an equallyimportant measure, six typical kinds of rock blocks are sampled for the experimental study of rockburst tendency. According to thesynthesized results of the theoretical and testing results, the methods of brittleness coefficient, brittle index and stress, and so on, areadopted. Finally, the evaluation on the possibility of rockbursts is given that may take place at the deep mining area and some effectivemeasures are put forward to prevent and control the rockburst.

  9. Geochemistry of some deep gold mine waters from the western portion of the Witwatersrand Basin, South Africa

    Science.gov (United States)

    Duane, M. J.; Pigozzi, G.; Harris, C.

    1997-02-01

    A suite of 12 mine water samples within the Witwatersrand Basin (South Africa) were analysed for trace element concentrations, strontium isotopic composition and stable isotopes (O and H). Chemical profiles for four Au mines (Western Deep Levels, Vaal Reefs, Freddies and President Steyn) are used to infer origin, chemical and isotopic evolution of the brines and for comparison with basement brines from other Precambrian areas. Systematic relationships are observed between {87Sr}/{86Sr} and {1}/{Sr} : two major mixing trends are required to explain the range of very radiogenic end-members. Possible end-members for the two components could be (1) {87Sr}/{86Sr} = 0.7251 , Sr concentration = 0.12 mg l -1 from a Vaal Reefs compartment and {87Sr}/{86Sr} = 0.7694 , Sr = 39.3 mg l -1 from a Freddies compartment. (2) {87Sr}/{86Sr} = 0.7251 , Sr = 0.12 mg l -1 (as above) with a {87Sr}/{86Sr} = 0.7404 , Sr = 745 mg l -1 from Western Deep Levels. Strontium isotope ratios range above those expected for present-day seawater and are even higher than some locally-derived low Rb minerals from the Precambrian basement. The brines acquired radiogenic 87Sr through interaction with granitic basement (Kaapvaal Craton), shales of the Central Rand Group (in particular Ventersdorp Contact Reef), siliclastics within the West Rand Group and particularly with dolomites from the overlying Transvaal Supergroup. In order to obtain their multielement and radiogenic isotope signatures the meteoric waters descended through fractured rocks between the main dykes and faults (example: Oberholzer and Bank Dyke at Western Deep Levels). They slowly interacted with Au bearing conglomerates and quartzites of the West Rand Group. The inverse relationship between Sr isotope composition and precious/heavy metal concentration suggests fluid/rock interaction within the shales and volcanics of the Ventersdsorp Contact Reef (high in Au and total organic carbon [TOC], less radiogenic strontium composition by

  10. 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.

  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. Paediatric pharmacovigilance: use of pharmacovigilance data mining algorithms for signal detection in a safety dataset of a paediatric clinical study conducted in seven African countries.

    Directory of Open Access Journals (Sweden)

    Dan K Kajungu

    Full Text Available BACKGROUND: Pharmacovigilance programmes monitor and help ensuring the safe use of medicines which is critical to the success of public health programmes. The commonest method used for discovering previously unknown safety risks is spontaneous notifications. In this study we examine the use of data mining algorithms to identify signals from adverse events reported in a phase IIIb/IV clinical trial evaluating the efficacy and safety of several Artemisinin-based combination therapies (ACTs for treatment of uncomplicated malaria in African children. METHODS: We used paediatric safety data from a multi-site, multi-country clinical study conducted in seven African countries (Burkina Faso, Gabon, Nigeria, Rwanda, Uganda, Zambia, and Mozambique. Each site compared three out of four ACTs, namely amodiaquine-artesunate (ASAQ, dihydroartemisinin-piperaquine (DHAPQ, artemether-lumefantrine (AL or chlorproguanil/dapsone and artesunate (CD+A. We examine two pharmacovigilance signal detection methods, namely proportional reporting ratio and Bayesian Confidence Propagation Neural Network on the clinical safety dataset. RESULTS: Among the 4,116 children (6-59 months old enrolled and followed up for 28 days post treatment, a total of 6,238 adverse events were reported resulting into 346 drug-event combinations. Nine signals were generated both by proportional reporting ratio and Bayesian Confidence Propagation Neural Network. A review of the manufacturer package leaflets, an online Multi-Drug Symptom/Interaction Checker (DoubleCheckMD and further by therapeutic area experts reduced the number of signals to five. The ranking of some drug-adverse reaction pairs on the basis of their signal index differed between the two methods. CONCLUSIONS: Our two data mining methods were equally able to generate suspected signals using the pooled safety data from a phase IIIb/IV clinical trial. This analysis demonstrated the possibility of utilising clinical studies safety data

  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. 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.

  15. A longitudinal study of the indicators and factors for successful six sigma deployment in the South African mining industry

    Directory of Open Access Journals (Sweden)

    Keeley, A. L.

    2013-05-01

    Full Text Available The Six Sigma deployment methodology is known for its results in operational excellence associated with improved business practices. Organisations worldwide have shown significantly reduced costs and increased profits when successfully deploying Six Sigma. This paper reports a longitudinal study of a set of indicators and success factors for Six Sigma deployment, using Lonmin PLC, a mining company in South Africa, as a case. The results suggest a shift of indicators from heartfelt personal involvement in 2006 to a mechanistic performance-based culture in 2010. Practical recommendations are made regarding the nine success factor components to be included during Six Sigma deployment

  16. 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.

  17. Coseismic and aseismic deformations of the rock mass around deep level mining in South Africa - Joint South African and Japanese study

    Science.gov (United States)

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

    2010-12-01

    Two underground sites in a deep level gold mine in South Africa were instrumented by the Council for Scientific and Industrial Research (CSIR) with tilt meters and seismic monitors. One of the sites was also instrumented by JApanese-German Underground Acoustic emission Research in South Africa (JAGUARS) with a small network, approx. 40 m span, of eight Acoustic Emission (AE) sensors. The rate of tilt, defined as quasi-static deformations, and the seismic ground motion, defined as dynamic deformations, were analysed in order to understand the rock mass behavior around deep level mining. In addition the high frequency AE events recorded at hypocentral distances of about 50m were analysed. This was the first implementation of high frequency AE events at such a great depth (3300m below the surface). A good correspondence between the dynamic and quasi-static deformations 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, which takes place from about 19:30 until shortly before 21:00. During the blasting time and the subsequent seismic events the coseismic and aseismic tilt shows a rapid increase indicated by a rapid change of the tilt during the seismic event. Much of the quasi-static deformation, however, occurs independently of the seismic events and was described as ‘slow’ or aseismic events. During the monitoring period a seismic event with MW 1.9 (2.1) occurred in the vicinity of the instrumented site. This event was recorded by both the CSIR integrated monitoring system and JAGUARS acoustic emotion network. The tilt changes associated with this event showed a well pronounced after-tilt. More than 21,000 AE aftershocks were located in the first 150 hours after the main event. Using the distribution of the AE events the position of the fault in the source area was successfully delineated. The distribution of the AE events following the main shock

  18. 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.

  19. 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.

  20. 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

  1. 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。

  2. 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

  3. 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.

  4. 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

  5. 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...

  6. 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。

  7. 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

  8. 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%.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. The mining industry of the 21st century

    OpenAIRE

    2014-01-01

    The mining industry has been a significant contributor to the South African economy for over 100 years and it currently contributes 18% to the economy. The richest city in Africa, the City of Johannesburg was built on the backbone of the mining industry. If the mining industry was to collapse, the South African economy will trail behind Nigeria. One distinguishing factor about the Mining Industry in South Africa is that it relies quite extensively on labour. In this regard, the mining industr...

  14. 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, and the remaining 30 fish were combined into 10 composite samples of three fish each of the same species and size class. Mercury concentrations in samples of black basses

  15. Xinjiang’s First Specialized Gold Refining Enterprise Started Production

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>On September 28,Xinjiang Xingta Mining In- dustry Co Ltd,a company invested and con- structed by Shandong Zhaojin Mining Industry Company Limited,held its ceremony for com- pletion and start of production.This is the fourth gold mining project invested and built by Zhaojin in Xinjiang alter Tuoli County Zhaojin Beijiang Mining Co Ltd,Aletai Zhen- gyuan International Mining Co Ltd,and Zhao- jin Kunhe Mining Co Ltd.Its completion for

  16. Post-mining safety implementations and environmental aspects of abandoned mine sites in Limousin. 2006 status (and perspectives 2007); Mises en securite en apres-mine et aspects environnementaux des anciens sites miniers en Limousin. Bilan 2006 (et perspectives 2007)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This document summarizes the actions carried out in 2006 at some French abandoned mine sites: 1 - safety implementations and risks abatement in the framework of post-mining actions: coal mines of Ahun (23) and Argentat (19), antimony mines of Biard (87); 2 - remedial actions at the tin/tungsten mine of Puy-les-Vignes (87) and at the gold mine of Chatelet (23); 3 - 2007 post-mining perspectives; 4 - environmental aspects of abandoned mine sites: gold mines of Chatelet (23), Cheni and Bourneix (87), uranium mines of Haute-Vienne (expertise, control of effluents, financial warranties about tailings storage sites maintenance). (J.S.)

  17. Eastern China Geological and Mining Organization for Nonferrous Metals Becomes the Controlling Shareholder of the Boka Gold Deposit with 400-ton Future Reserves

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The Eastern China Geological and Mining Or- ganization for Nonferrous Metals recently ac- quired all of the former foreign-enterprise- owned shares,becoming the controlling share- holder of the deposit.Crowned as a "world-

  18. Caracterização da mineração aurífera em Faina, Goiás, em um contexto ambiental histórico e atual Caracterization of gold mining in Faina, Goiás, Brazil, in a historical and an actual environmental context

    Directory of Open Access Journals (Sweden)

    Marcos Pedro da Silva

    2008-01-01

    Full Text Available Faz-se, por meio de uma abordagem ambiental histórico-dialética, a caracterização dos processos auríferos desenvolvidos no município de Faina, Goiás. São analisadas três atividades: mineração escrava, mineração de dragagem e mineração industrial. Evidenciou-se que a exploração por dragagem tem um maior poder impactante. Sobretudo, a mineração aurífera em Faina contribuiu para a história ambiental local e para o resgate dessa no Brasil.We have analysed the three main processes of gold mining - slave mining, dredging and industrial gold mining -, by means of an environmental historical-dialectic approach in the municipality of Faina, in the Brazilian State of Goias State. The data showed that dredging had the greatest environmental impact on the area. The gold mining activities in Faina strongly contributed to the environmental history of the municipality and to the memory of this type of mining in Brazil.

  19. Laizhou to Build the World’s Largest Gold Industrial Base

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>Shandong Gold Group will invest RMB 35 billion to build a gold industrial base in Laizhou and gear up its 9 major gold industrial chain projects. The group’s gold output value is expected to top RMB 50 billion and reach RMB 100 billion by 2015.Laizhou boasts abundant gold reserves,and is China’s gold mining & dressing and refining base with the highest industrial concentration and the greatest scale. In June 2012,Shandong Gold Group and Laizhou

  20. Discussion on the proposals to reduce costs and increase benefits in new gold mines in China%中国新建黄金矿山项目降本增效途径的探讨

    Institute of Scientific and Technical Information of China (English)

    朱丽苹

    2009-01-01

    通过对近几年中国新建黄金矿山投入及产出调查、统计分析,针对目前中国黄金矿山建设项目的现状,用财务评价、不确定因素分析等方法,对新建、待建黄金矿山项目建立降本增效分析模型,寻找降本增效的途径.%By investigation and statistical analysis on the input and output of the new gold mines in China, and aiming at the relevant construction status, with financial evaluation and uncertainty factor analysis method, an analysis model for reducing costs and increasing benefits is established in order to find the proposals for cost saving.

  1. Biosorption of As (III) by non-living biomass of an arsenic-hypertolerant Bacillus cereus strain SZ2 isolated from a gold mining environment: equilibrium and kinetic study.

    Science.gov (United States)

    Mohd Bahari, Zaratulnur; Ali Hamood Altowayti, Wahid; Ibrahim, Zaharah; Jaafar, Jafariah; Shahir, Shafinaz

    2013-12-01

    The ability of non-living biomass of an arsenic-hypertolerant Bacillus cereus strain SZ2 isolated from a gold mining environment to adsorb As (III) from aqueous solution in batch experiments was investigated as a function of contact time, initial As (III) concentration, pH, temperature and biomass dosage. Langmuir model fitted the equilibrium data better in comparison to Freundlich isotherm. The maximum biosorption capacity of the sorbent, as obtained from the Langmuir isotherm, was 153.41 mg/g. The sorption kinetic of As (III) biosorption followed well the pseudo-second-order rate equation. The Fourier transform infrared spectroscopy analysis indicated the involvement of hydroxyl, amide and amine groups in As (III) biosorption process. Field emission scanning electron microscopy-energy dispersive X-ray analysis of the non-living B. cereus SZ2 biomass demonstrated distinct cell morphological changes with significant amounts of As adsorbed onto the cells compared to non-treated cells. Desorption of 94 % As (III) was achieved at acidic pH 1 showing the capability of non-living biomass B. cereus SZ2 as potential biosorbent in removal of As (III) from arsenic-contaminated mining effluent.

  2. Pertumbuhan Semai Gmelina dengan Berbagai Dosis Pupuk Kompos pada Media Tanah Bekas Tambang Emas (Growth of Gmelina Seedling with Various Compost Fertilizer in Ex-Gold Mining Land Media

    Directory of Open Access Journals (Sweden)

    Basuki Wasis

    2011-07-01

    Full Text Available Mining activities could have negative impacts on the environment if the tailings produced were not processedproperly. Non-economic tailing is a composite of various minerals (heavy metal with sandy texture. Environmentalimpacts that might occur as a result of poor processing of tailings is a disruption of natural ecosystems asindicated by a decline in quality and productivity of the environment as a result of changes in soil morphologyand physical properties, chemical, and biological properties. One vegetative technique that could be applied torehabilitate degraded land is re-vegetation with the application of fertilizer. Compost could improve the physicalproperties, chemical, and biological properties of soil. Compost was also an agent of bioremediation so thattoxic heavy metals elements in growing medium could be eliminated or reduced. The experimental design usedin this study was Completely Randomized Design with compost applications consisting of 4 levels of treatmentwith each level of treatment consisting of 3 replications, each replication consisted of one gmelina seedling.Research showed that the application of compost would significantly affect the growth of gmelina’s height, butnot significantly affected the diameter growth. Single-dose effect of 30 g of compost would significantly affect theseedling’s height. The combination of planting and fertilizing glemina using compost could be recommended inan effort to reclaim land of ex-gold mining.Keywords: tailing, bioremediation agent, compost fertilizer, gmelina, growth of seedling

  3. Global demand for gold is another threat for tropical forests

    Science.gov (United States)

    Alvarez-Berríos, Nora L.; Aide, T. Mitchell

    2015-01-01

    The current global gold rush, driven by increasing consumption in developing countries and uncertainty in financial markets, is an increasing threat for tropical ecosystems. Gold mining causes significant alteration to the environment, yet mining is often overlooked in deforestation analyses because it occupies relatively small areas. As a result, we lack a comprehensive assessment of the spatial extent of gold mining impacts on tropical forests. In this study, we provide a regional assessment of gold mining deforestation in the tropical moist forest biome of South America. Specifically, we analyzed the patterns of forest change in gold mining sites between 2001 and 2013, and evaluated the proximity of gold mining deforestation to protected areas (PAs). The forest cover maps were produced using the Land Mapper web application and images from the MODIS satellite MOD13Q1 vegetation indices 250 m product. Annual maps of forest cover were used to model the incremental change in forest in ˜1600 potential gold mining sites between 2001-2006 and 2007-2013. Approximately 1680 km2 of tropical moist forest was lost in these mining sites between 2001 and 2013. Deforestation was significantly higher during the 2007-2013 period, and this was associated with the increase in global demand for gold after the international financial crisis. More than 90% of the deforestation occurred in four major hotspots: Guianan moist forest ecoregion (41%), Southwest Amazon moist forest ecoregion (28%), Tapajós-Xingú moist forest ecoregion (11%), and Magdalena Valley montane forest and Magdalena-Urabá moist forest ecoregions (9%). In addition, some of the more active zones of gold mining deforestation occurred inside or within 10 km of ˜32 PAs. There is an urgent need to understand the ecological and social impacts of gold mining because it is an important cause of deforestation in the most remote forests in South America, and the impacts, particularly in aquatic systems, spread well

  4. Effects of a small-scale, abandoned gold mine on the geochemistry of fine stream-bed and floodplain sediments in the Horsefly River watershed, British Columbia, Canada

    NARCIS (Netherlands)

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

    2014-01-01

    Mining is known to be a major source of metal contamination for fluvial systems worldwide. Monitoring and understanding the effects on downstream water and sediment quality is essential for its management and to mitigate against detrimental environmental impacts. This study aimed to examine the effe

  5. Arsenic, Zinc, and Aluminium Removal from Gold Mine Wastewater Effluents and Accumulation by Submerged Aquatic Plants (Cabomba piauhyensis, Egeria densa, and Hydrilla verticillata

    Directory of Open Access Journals (Sweden)

    Ahmad Farid Abu Bakar

    2013-01-01

    Full Text Available The potential of three submerged aquatic plant species (Cabomba piauhyensis, Egeria densa, and Hydrilla verticillata to be used for As, Al, and Zn phytoremediation was tested. The plants were exposed for 14 days under hydroponic conditions to mine waste water effluents in order to assess the suitability of the aquatic plants to remediate elevated multi-metals concentrations in mine waste water. The results show that the E. densa and H. verticillata are able to accumulate high amount of arsenic (95.2% and zinc (93.7% and resulted in a decrease of arsenic and zinc in the ambient water. On the other hand, C. piauhyensis shows remarkable aluminium accumulation in plant biomass (83.8% compared to the other tested plants. The ability of these plants to accumulate the studied metals and survive throughout the experiment demonstrates the potential of these plants to remediate metal enriched water especially for mine drainage effluent. Among the three tested aquatic plants, H. verticillata was found to be the most applicable (84.5% and suitable plant species to phytoremediate elevated metals and metalloid in mine related waste water.

  6. Arsenic, zinc, and aluminium removal from gold mine wastewater effluents and accumulation by submerged aquatic plants (Cabomba piauhyensis, Egeria densa, and Hydrilla verticillata).

    Science.gov (United States)

    Abu Bakar, Ahmad Farid; Yusoff, Ismail; Fatt, Ng Tham; Othman, Faridah; Ashraf, Muhammad Aqeel

    2013-01-01

    The potential of three submerged aquatic plant species (Cabomba piauhyensis, Egeria densa, and Hydrilla verticillata) to be used for As, Al, and Zn phytoremediation was tested. The plants were exposed for 14 days under hydroponic conditions to mine waste water effluents in order to assess the suitability of the aquatic plants to remediate elevated multi-metals concentrations in mine waste water. The results show that the E. densa and H. verticillata are able to accumulate high amount of arsenic (95.2%) and zinc (93.7%) and resulted in a decrease of arsenic and zinc in the ambient water. On the other hand, C. piauhyensis shows remarkable aluminium accumulation in plant biomass (83.8%) compared to the other tested plants. The ability of these plants to accumulate the studied metals and survive throughout the experiment demonstrates the potential of these plants to remediate metal enriched water especially for mine drainage effluent. Among the three tested aquatic plants, H. verticillata was found to be the most applicable (84.5%) and suitable plant species to phytoremediate elevated metals and metalloid in mine related waste water.

  7. Analysis of the Transport and Fate of Metals Released From the Gold King Mine in the Animas and San Juan Rivers

    Science.gov (United States)

    This project’s objectives were to provide analysis of water quality following the release of acid mine drainage in the Animas and San Juan Rivers in a timely manner to 1) generate a comprehensive picture of the plume at the river system level, 2) help inform future monitoring eff...

  8. 新技术、新设备在三山岛金矿新立选矿厂的研究与应用%Research and Application of New Technology and Equipment in Xinli Concen-trating Mill of Sanshandao Gold Mine

    Institute of Scientific and Technical Information of China (English)

    杨守斌; 谢敏雄; 王宝胜; 王楠

    2013-01-01

    三山岛金矿新立8000 t/d选矿厂采用HP500圆锥破碎机、高压辊磨机以及大型球磨机MQY5.5×8.5 m和KYF-1600大型浮选机等新型选矿设备,为矿山的稳定生产提供了有力的保障,选矿自动化控制的应用更是达到了生产过程集中操作的目的。三山岛金矿新立选矿厂致力打造现代化、智能化的一流选矿工程。%Xinli 8 000 t/d concetrating mill of Sanshandao gold mine adopts HP500 gyratory crusher,high pressure roller mill,new equipments of the biggest ball grinding mill MQY5.5*8.5m in gold mine and the large flotation machine KYF-1600 and so on.New equipments and technology provide guarantee to stedy production of mine, automation control in beneficiation reaches the goal of intensive production process.Xinli concetrating mill of Sanshandao gold mine devotes to build a morden and intelligentized top-rangking programme of beneficiation.

  9. 某金矿氰化工艺贫液磨矿改造%Cyanidation Lean Liquid Grinding Process Transformation of a Gold Mine

    Institute of Scientific and Technical Information of China (English)

    徐爱章; 赵卫忠; 任向军; 王治方

    2014-01-01

    某金矿氰化段因处理量增大造成氰渣品位升高,金银回收率降低,经过讨论验证将准备作业改变为精矿压滤-贫液调浆-磨矿-脱药后进入浸出等后续作业。精矿在再磨过程中边磨边浸,经实践表明改造后金精矿进入浸出作业前金银浸出率达到70%左右,通过强化浸出不仅减少了氰化钠耗量,而且提高了0.24%浸出率。%Due to the treatment capacity's increasing, the cyanide slag grade of a cyanide section has increased, and gold and silver recovery rate has decreased. Through the discussion and verification, preparation operation is changed into the subsequent operations such as concentrate filter-lean liquid paste-grinding and leaching into removal of drugs. In the grinding process concentrate is milling and leaching. The practice proves that before gold concentrate leaches into the operation, the gold and silver leaching rate reached about 70%after transformation, by strengthening leaching it not only reduced the consumption of sodium cyanide, but also improved the leaching rate by 0.24%.

  10. An Outbreak of Lymphocutaneous Sporotrichosis among Mine-Workers in South Africa.

    Directory of Open Access Journals (Sweden)

    Nelesh P Govender

    2015-09-01

    Full Text Available The largest outbreak of sporotrichosis occurred between 1938 and 1947 in the gold mines of Witwatersrand in South Africa. Here, we describe an outbreak of lymphocutaneous sporotrichosis that was investigated in a South African gold mine in 2011.Employees working at a reopened section of the mine were recruited for a descriptive cross-sectional study. Informed consent was sought for interview, clinical examination and medical record review. Specimens were collected from participants with active or partially-healed lymphocutaneous lesions. Environmental samples were collected from underground mine levels. Sporothrix isolates were identified by sequencing of the internal transcribed spacer region of the ribosomal gene and the nuclear calmodulin gene.Of 87 male miners, 81 (93% were interviewed and examined, of whom 29 (36% had skin lesions; specimens were collected from 17 (59%. Sporotrichosis was laboratory-confirmed among 10 patients and seven had clinically-compatible lesions. Of 42 miners with known HIV status, 11 (26% were HIV-infected. No cases of disseminated disease were detected. Participants with ≤ 3 years' mining experience had a four times greater odds of developing sporotrichosis than those who had been employed for >3 years (adjusted OR 4.0, 95% CI 1.2-13.1. Isolates from 8 patients were identified as Sporothrix schenckii sensu stricto by calmodulin gene sequencing while environmental isolates were identified as Sporothrix mexicana.S. schenckii sensu stricto was identified as the causative pathogen. Although genetically distinct species were isolated from clinical and environmental sources, it is likely that the source was contaminated soil and untreated wood underground. No cases occurred following recommendations to close sections of the mine, treat timber and encourage consistent use of personal protective equipment. Sporotrichosis is a potentially re-emerging disease where traditional, rather than heavily mechanised, mining

  11. An Outbreak of Lymphocutaneous Sporotrichosis among Mine-Workers in South Africa

    Science.gov (United States)

    Govender, Nelesh P.; Maphanga, Tsidiso G.; Zulu, Thokozile G.; Patel, Jaymati; Walaza, Sibongile; Jacobs, Charlene; Ebonwu, Joy I.; Ntuli, Sindile; Naicker, Serisha D.; Thomas, Juno

    2015-01-01

    Background The largest outbreak of sporotrichosis occurred between 1938 and 1947 in the gold mines of Witwatersrand in South Africa. Here, we describe an outbreak of lymphocutaneous sporotrichosis that was investigated in a South African gold mine in 2011. Methodology Employees working at a reopened section of the mine were recruited for a descriptive cross-sectional study. Informed consent was sought for interview, clinical examination and medical record review. Specimens were collected from participants with active or partially-healed lymphocutaneous lesions. Environmental samples were collected from underground mine levels. Sporothrix isolates were identified by sequencing of the internal transcribed spacer region of the ribosomal gene and the nuclear calmodulin gene. Principal Findings Of 87 male miners, 81 (93%) were interviewed and examined, of whom 29 (36%) had skin lesions; specimens were collected from 17 (59%). Sporotrichosis was laboratory-confirmed among 10 patients and seven had clinically-compatible lesions. Of 42 miners with known HIV status, 11 (26%) were HIV-infected. No cases of disseminated disease were detected. Participants with ≤3 years’ mining experience had a four times greater odds of developing sporotrichosis than those who had been employed for >3 years (adjusted OR 4.0, 95% CI 1.2–13.1). Isolates from 8 patients were identified as Sporothrix schenckii sensu stricto by calmodulin gene sequencing while environmental isolates were identified as Sporothrix mexicana. Conclusions/Significance S. schenckii sensu stricto was identified as the causative pathogen. Although genetically distinct species were isolated from clinical and environmental sources, it is likely that the source was contaminated soil and untreated wood underground. No cases occurred following recommendations to close sections of the mine, treat timber and encourage consistent use of personal protective equipment. Sporotrichosis is a potentially re-emerging disease where

  12. Uses of the potassium permanganate to eliminate copper cyanide from waste water resulting from a lixiviation plant in a gold mine (II): Pilot plant experiences; Aplicacion del permanganato potasico para la eliminacion de cianuros de cobre en aguas residuales de la planta de lixiviacion en una mina de oro (II): Ensayos en planta piloto

    Energy Technology Data Exchange (ETDEWEB)

    Sancho, J. P.; Fernandez, B.; Ayala, J.; Gracia, M. P.; Lavandeira, A.

    2011-07-01

    The search for a detoxification treatment of the wastewater generated during industrial processes, has been a constant for all companies in general and for gold mining in particular, whose wastewater generally contains high concentrations of cyanide compounds with high toxicity. In the previous research work, developed in the laboratory, the efficacy of potassium permanganate as an oxidizing agent for cyanidic wastewater, from a gold hydrometallurgical plant, has been demonstrated, achieving the destruction of copper cyanide complexes present in solution and the subsequent metal removal by precipitation as hydroxide. This paper presents the conclusions obtained after the implementation of the process developed in the laboratory, at pilot-plant scale. (Author) 30 refs.

  13. New game - new rules: mining in the democratic South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Motlatsi, J. [National Union of Mineworkers (South Africa)

    1995-12-31

    Discusses the eight areas identified by the South African Union of Mineworkers as requiring new rules to improve safety and conditions in the South African mining industry. The areas are: improved health and safety; the elimination of racism; fair wages; decent living conditions; proper training; care for workers and areas affected by the downscaling of mining; development of an economically viable mining sector; and a mining sector run on a humane and participatory manner.

  14. Youth in Tanzania's urbanizing mining settlements: Prospecting a mineralized future

    OpenAIRE

    Bryceson, Deborah Fahy

    2014-01-01

    Over the last fifteen years many African countries have experienced a mining take-off. Mining activities have bifurcated into two sectors: large-scale, capital-intensive production generating the bulk of the exported minerals, and small-scale, labour-intensive artisanal mining, which, at present, is catalyzing far greater immediate primary, secondary and tertiary employment opportunities for unskilled African labourers. Youth residing in mining settlements, have a large vested interest in the...

  15. 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.

  16. 大兴安岭废弃金矿樟子松人工林生长规律的研究1)%Research on Growth Law of Pinus sylvestris Plantation at Discarded Gold Mine in Daxing’anling

    Institute of Scientific and Technical Information of China (English)

    崔崧; 魏嵩; 王承义

    2012-01-01

      This research investigated the grow th indexes of Pinus sylvestris plantation in gold de-posit slash in Guliku on the Daxing ’anling Jiagedaqi Forestry Bureau ,and obtained the grow th law of Pinus sylvestris plantation planted in discarded gold mine .The conclusions were as fol-lows:Pinus sylvestris plantation’s height grow th was influenced by the environmental factors significantly ,annul growth present increasing year by year ;Pinus sylvestris plantation’s diame-ter grow th effected by environmental factors showed no obvious rule ;forest at the edge of Pinus sylvestris crown not grow well ;Pinus sylvestris plantation freeze injuried by monsoon climate was very obvious ,and the main wind at winter damaged the branches severely .%  通过对大兴安岭加格达奇林业局古利库经营所管区内金矿迹地樟子松人工林的生长指标进行了调查,明确了废弃金矿樟子松人工林的生长规律。结论如下:樟子松树高生长受环境因子的影响显著,年生长量呈现逐年递增的趋势;樟子松地径生长受环境因子影响未表现出明显规律;林缘处樟子松冠幅生长较差;樟子松人工林受季风性带来的冻害影响非常明显,冬季主风向一侧的枝条冻害严重。

  17. Integration and M&A of Gold Enterprises are Expected to Pick Up Speed

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    As the bulk commodity market"kept falling",it forced many industries into predicament.The reporter learned at the"2015 China Gold and Precious Metal Summit"that,because gold price hovered at low level,the estimated value of gold resources and mines dropped sharply,many gold related listed companies also lost

  18. Transfer Rates of 238U and 232Th for E. globulus, A. mearnsii, H. filipendula and Hazardous Effects of the Usage of Medicinal Plants From Around Gold Mine Dump Environs

    Directory of Open Access Journals (Sweden)

    Victor M. Tshivhase

    2015-12-01

    Full Text Available Medicinal plant consumption can be a source of human exposure to radioactive elements such as 238U and 232Th, which can lead to internal radiation doses. The uptake of 238U and 232Th from soils to the leaf samples of three different medicinal plant species (Eucalyptus globulus, Acacia mearnsii and Hyparrhenia filipendula from the purlieu of the Princess gold mine dump, an abandoned contaminated tailings storage site (TSS, located at longitude 27°55′00″E and latitude 26°09′30″S in Davidsonville (Roodepoort, west of Johannesburg, South Africa was measured. This was done using ICP-MS spectrometry and substantial differences were observed in the soil-plant transfer factor (TF values between these radionuclides. The plant species E. globulus exhibited the highest uptake of 238U, with an average TF of 3.97, while that of H. filipendula was 0.01 and the lowest TF of 0.15 × 10−2 was measured for A. mearnsii. However, in the case of 232Th, the highest average TF was observed for A. mearnsii (0.29, followed by E. globulus (0.10 and lowest was measured for H. filipendula (0.27 × 10−2. The ratio of TF average value i.e., 238U to 232Th in the soil-plant leaves was 38.05 for E. globulus, 0.01 for A. mearnsii and 4.38 for H. filipendula.

  19. Transfer Rates of ²³⁸U and ²³²Th for E. globulus, A. mearnsii, H. filipendula and Hazardous Effects of the Usage of Medicinal Plants From Around Gold Mine Dump Environs.

    Science.gov (United States)

    Tshivhase, Victor M; Njinga, Raymond L; Mathuthu, Manny; Dlamini, Thulani C

    2015-12-10

    Medicinal plant consumption can be a source of human exposure to radioactive elements such as (238)U and (232)Th, which can lead to internal radiation doses. The uptake of (238)U and (232)Th from soils to the leaf samples of three different medicinal plant species (Eucalyptus globulus, Acacia mearnsii and Hyparrhenia filipendula) from the purlieu of the Princess gold mine dump, an abandoned contaminated tailings storage site (TSS), located at longitude 27°55'00″E and latitude 26°09'30″S in Davidsonville (Roodepoort, west of Johannesburg, South Africa) was measured. This was done using ICP-MS spectrometry and substantial differences were observed in the soil-plant transfer factor (TF) values between these radionuclides. The plant species E. globulus exhibited the highest uptake of (238)U, with an average TF of 3.97, while that of H. filipendula was 0.01 and the lowest TF of 0.15 × 10(-2) was measured for A. mearnsii. However, in the case of (232)Th, the highest average TF was observed for A. mearnsii (0.29), followed by E. globulus (0.10) and lowest was measured for H. filipendula (0.27 × 10(-2)). The ratio of TF average value i.e., (238)U to (232)Th in the soil-plant leaves was 38.05 for E. globulus, 0.01 for A. mearnsii and 4.38 for H. filipendula.

  20. Industrial test on cyclonic-static micro-bubble floatation column in a certain gold mine%旋流-静态微泡浮选柱在某金矿的工业试验

    Institute of Scientific and Technical Information of China (English)

    孙永峰; 曹亦俊; 刘洋; 董洁; 廖寅飞; 邹文杰

    2011-01-01

    通过工业分流条件试验,研究了旋流-静态微泡浮选柱在山东某金矿应用的最佳工艺条件参数.试验结果表明:用浮选柱的一次粗选、一次精选工艺流程与生产中用浮选机的一次粗选、二次精选、二次扫选的工艺流程相比,在尾矿品位接近的情况下,精矿品位可提高12.69g/t.%In industrial condition test, the optimal processing condition parameters for cyclonic-static micro-bubble flotation column are studied in a certain gold mine in Shandong. Tests results show that with the flotation column flowsheet of once roughing flotation, once cleaning floatation, and the floatation machine flowsheet of once roughing flotation, twice cleaning floatation and twice scavenging floatation, the concentrate grade of the former one is 12. 69g/ t higher, when the grades of tailings are similar.

  1. 振动给矿机在河台金矿选矿厂的改造与设计%Reformation and design of vibrofeeder in Hetai gold mine ore processing plant

    Institute of Scientific and Technical Information of China (English)

    刘晓春

    2013-01-01

    针对河台金矿选矿厂原矿仓至颚式破碎机使用板式给矿机存在的一些问题,提出了选矿厂给矿改造方案.详述了改造方案的设备选型及技术参数的设计计算过程.河台金矿选矿厂振动给矿机替代板式给矿机技术改造实践表明,技术改造提高了选矿处理能力40%,给矿均匀,且对颚式破碎机工况冲击小,维护维修简易,能耗低,取得了很好的应用效果.%A reformation design was put forward in light of the problems occurring in the plate feeder of jaw crusher. The equipment selection and technical parameters calculation process were introduced in detail. The replacement of plate feeder by vibrofeeder in the processing plant of Hetai gold mine results in a 40 % increased treatment capability. Besides, the feeder consumes less energy, feeds evenly, doing little impact to the crusher, and is convenient for maintenance, achieving good application outcome.

  2. Understanding the Social Context of the ASGM Sector in Ghana: A Qualitative Description of the Demographic, Health, and Nutritional Characteristics of a Small-Scale Gold Mining Community in Ghana.

    Science.gov (United States)

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

    2015-10-12

    This descriptive paper describes factors related to demographics and health in an artisanal and small-scale gold mining (ASGM) community in Ghana's Upper East Region. Participants (n = 114) were surveyed in 2010 and 2011, adapting questions from the established national Demographic Health Survey (DHS) on factors such as population characteristics, infrastructure, amenities, education, employment, maternal and child health, and diet. In the study community, some indicators of household wealth (e.g., radios, mobile phones, refrigerators) are more common than elsewhere in Ghana, yet basic infrastructure (e.g., cement flooring, sanitation systems) and access to safe water supplies are lacking. Risk factors for poor respiratory health, such as cooking with biomass fuel smoke and smoking tobacco, are common. Certain metrics of maternal and child health are comparable to other areas of Ghana (e.g., frequency of antenatal care), whereas others (e.g., antenatal care from a skilled provider) show deficiencies. Residents surveyed do not appear to lack key micronutrients, but report lower fruit and vegetable consumption than other rural areas. The results enable a better understanding of community demographics, health, and nutrition, and underscore the need for better demographic and health surveillance and data collection across ASGM communities to inform effective policies and programs for improving miner and community health.

  3. Understanding the Social Context of the ASGM Sector in Ghana: A Qualitative Description of the Demographic, Health, and Nutritional Characteristics of a Small-Scale Gold Mining Community in Ghana

    Directory of Open Access Journals (Sweden)

    Rachel N. Long

    2015-10-01

    Full Text Available This descriptive paper describes factors related to demographics and health in an artisanal and small-scale gold mining (ASGM community in Ghana’s Upper East Region. Participants (n = 114 were surveyed in 2010 and 2011, adapting questions from the established national Demographic Health Survey (DHS on factors such as population characteristics, infrastructure, amenities, education, employment, maternal and child health, and diet. In the study community, some indicators of household wealth (e.g., radios, mobile phones, refrigerators are more common than elsewhere in Ghana, yet basic infrastructure (e.g., cement flooring, sanitation systems and access to safe water supplies are lacking. Risk factors for poor respiratory health, such as cooking with biomass fuel smoke and smoking tobacco, are common. Certain metrics of maternal and child health are comparable to other areas of Ghana (e.g., frequency of antenatal care, whereas others (e.g., antenatal care from a skilled provider show deficiencies. Residents surveyed do not appear to lack key micronutrients, but report lower fruit and vegetable consumption than other rural areas. The results enable a better understanding of community demographics, health, and nutrition, and underscore the need for better demographic and health surveillance and data collection across ASGM communities to inform effective policies and programs for improving miner and community health.

  4. 某金矿尾矿用作水泥混合材的试验研究%Experiment study on gold tailings utilization as cement admixture from one gold mine

    Institute of Scientific and Technical Information of China (English)

    谭明洋; 吕宪俊; 姜梅芬; 吴蓬

    2015-01-01

    The experiment study on gold tailings used as cement admixture is conducted by mechanical activation method.The result shows that activity index of the tailings increased with the specific surface area within a certain range.When the specific surface area reached about 400 m2/kg,the activity index reached 65 %,and changed little after 500 m2/kg.The test of pozzolanicity has been identified unacceptable,the pozzolanic feature of the tailings is un-qualified so that they can't be used as pozzolanic materials.By the EDS,it is seen in the microscale analysis that the gold tailings partly participate in the hydration reaction.Furthermore,when the tailings were added less than 20 %,ce-ment of 42.5R grade would be prepared.While the addition is less than 30%,cement of 32.5R grade would be gen-erated,of which the stability,coagulation time met ordinary Portland cement standards.%采用机械活化的方法对某金矿尾矿用作水泥混合材进行了试验研究。其研究结果表明:比表面积在一定的范围内,尾矿的活性指数随着尾矿比表面积的增大而提高;当尾矿粉磨至比表面积为400 m2/kg时尾矿的活性指数已达到65%,当尾矿粉磨至比表面积为500 m2/kg后尾矿的活性指数几乎不再发生变化。通过火山灰性试验发现,该金矿尾矿的火山灰性不合格,因此不属于火山灰质混合材;利用电子探针对尾矿水泥净浆微观形貌分析发现,尾矿参与了部分水化反应;通过进一步研究发现,尾矿掺量在20%以内其强度满足42.5R等级水泥强度要求,掺量在30%以内其强度满足32.5 R等级水泥要求,其安定性、凝结时间等均符合普通硅酸盐水泥的要求。

  5. Mineralogical, fluid inclusion, and stable isotope constraints on mechanisms of ore deposition at the Samgwang mine (Republic of Korea)—a mesothermal, vein-hosted gold-silver deposit

    Science.gov (United States)

    Yoo, Bong Chul; Lee, Hyun Koo; White, Noel C.

    2010-02-01

    The Samgwang mine is located in the Cheongyang gold district (Cheonan Metallogenic Province) of the Republic of Korea. It consists of eight massive, gold-bearing quartz veins that filled NE- and NW-striking fractures along fault zones in Precambrian granitic gneiss of the Gyeonggi massif. Their mineralogy and paragenesis allow two separate vein-forming episodes to be recognized, temporally separated by a major faulting event. The ore minerals occur in quartz and calcite of stage I, associated with fracturing and healing of veins. Hydrothermal wall-rock alteration minerals of stage I include Fe-rich chlorite (Fe/(Fe+Mg) ratios 0.74-0.81), muscovite, illite, K-feldspar, and minor arsenopyrite, pyrite, and carbonates. Sulfide minerals deposited along with electrum during this stage include arsenopyrite, pyrite, pyrrhotite, sphalerite, marcasite, chalcopyrite, galena, argentite, pyrargyrite, and argentian tetrahedrite. Only calcite was deposited during stage II. Fluid inclusions in quartz contain three main types of C-O-H fluids: CO2-rich, CO2-H2O, and aqueous inclusions. Quartz veins related to early sulfides in stage I were deposited from H2O-NaCl-CO2 fluids (1,500-5,000 bar, average 3,200) with T htotal values of 200°C to 383°C and salinities less than about 7 wt.% NaCl equiv. Late sulfide deposition was related to H2O-NaCl fluids (140-1,300 bar, average 700) with T htotal values of 110°C to 385°C and salinities less than about 11 wt.% NaCl equiv. These fluids either evolved through immiscibility of H2O-NaCl-CO2 fluids as a result of a decrease in fluid pressure, or through mixing with deeply circulated meteoric waters as a result of uplift or unloading during mineralization, or both. Measured and calculated sulfur isotope compositions (δ34SH2S = 1.5 to 4.8‰) of hydrothermal fluids from the stage I quartz veins indicate that ore sulfur was derived mainly from a magmatic source. The calculated and measured oxygen and hydrogen isotope compositions (δ18OH2O

  6. Paediatric pharmacovigilance: use of pharmacovigilance data mining algorithms for signal detection in a safety dataset of a paediatric clinical study conducted in seven African countries

    OpenAIRE

    Kajungu, Dan K.; Annette Erhart; Ambrose Otau Talisuna; Quique Bassat; Corine Karema; Carolyn Nabasumba; Michael Nambozi; Halidou Tinto; Peter Kremsner; Martin Meremikwu; Umberto D'Alessandro; Niko Speybroeck

    2014-01-01

    BACKGROUND: Pharmacovigilance programmes monitor and help ensuring the safe use of medicines which is critical to the success of public health programmes. The commonest method used for discovering previously unknown safety risks is spontaneous notifications. In this study we examine the use of data mining algorithms to identify signals from adverse events reported in a phase IIIb/IV clinical trial evaluating the efficacy and safety of several Artemisinin-based combination therapies (ACTs) for...

  7. Major Brazilian gold deposits - 1982 to 1999

    Science.gov (United States)

    Thorman, Charles H.; DeWitt, Ed; Maron, Marcos A.; Ladeira, Eduardo A.

    2001-07-01

    Brazil has been a major but intermittent producer of gold since its discovery in 1500. Brazil led the world in gold production during the 18th and early 19th centuries. From the late 19th century to the late 20th century, total mining company and garimpeiro production was small and relatively constant at about 5 to 8 t/year. The discovery of alluvial deposits in the Amazon by garimpeiros in the 1970s and the opening of eight mines by mining companies from 1983 to 1990 fueled a major boom in Brazil's gold production, exceeding 100 t/year in 1988 and 1989. However, garimpeiro alluvial production decreased rapidly in the 1990s, to about 10 t/year by 1999. Company production increased about tenfold from about 4 t/year in 1982 to 40 t in 1992. Production from 1992 to the present remained relatively stable, even though several mines were closed or were in the process of closing and no new major mines were put into production during that period. Based on their production history from 1982-1999, 17 gold mines are ranked as major (>20 t) and minor (3-8 t) mines. From 1982-1999, deposits hosted in Archean rocks produced 66% of the gold in Brazil, whereas deposits in Paleoproterozoic and Neoproterozoic rocks accounted for 19% and 15%, respectively. Deposits in metamorphosed sedimentary rocks, especially carbonate-rich rocks and carbonate iron-formation, yielded the great bulk of the gold. Deposits in igneous rocks were of much less importance. The Archean and Paleoproterozoic terranes of Brazil largely lack base-metal-rich volcanogenic massive sulfide deposits, porphyry deposits, and polymetallic veins and sedimentary exhalative deposits. An exception to this is in the Carajás Mineral Province.

  8. Sources and the distribution of heavy metals in the particle size of soil polluted by gold mining upstream of Miyun Reservoir, Beijing: implications for assessing the potential risks.

    Science.gov (United States)

    Li, Qian; Ji, Hongbing; Qin, Fei; Tang, Lei; Guo, Xinyue; Feng, Jinguo

    2014-10-01

    Mining has been carried out upstream of Miyun Reservoir, Beijing, for several decades, and has caused metal emissions to the environment, threatening human health. We conducted a soil survey to assess metal contamination in this area and to determine distribution of heavy metals in the particle size. We attempted to determine the possible sources of the metals and the significance of metals in the fine particle fractions to soil risk assessments. Thirty-four soil samples were collected, and eight samples were partitioned into seven size fractions. Most of the metal concentrations in the soils were higher than the background levels in Beijing, and the metal concentrations and total organic matter (TOC) contents generally increased as the particle size decreased. Each metal except Hg significantly positively correlated with the TOC. The metals in the coarse-grained soils were mainly derived from parent materials, but the metals in the fine fractions were mostly anthropogenic. Statistical analyses showed that there were three metal sources: Cd, Cu, Hg, Pb, and Zn had anthropogenic sources; Co, Cr, Ni, and V had mixed anthropogenic and natural sources; and As and Be had natural sources. The trace metals were primarily in the clay and fine silt fractions, and they might pose health risks through the inhalation of resuspended soil particles (PM10 and PM2.5). The elevated accumulation factors, enrichment factors, and ecological risk indices for the metals in the fine fractions suggest that risk assessments should be based on the fine particle size.

  9. African Literature

    OpenAIRE

    Recek, Denis

    2011-01-01

    The topic of this diploma is the formation and shaping of African literature. The first chapter is about the beginning of African literature. It describes oral literature and its transmission into written literature. Written African literature had great problems in becoming a part of world literature because of its diversity of languages and dialects. Christianity and Islam are mentioned as two religions which had a great impact on African literature. Colonialism is broadly described as an es...

  10. 硐室式削壁充填采矿法在夹皮沟金矿的应用%Application of resue and fill stoping method with excavating chambers to get filling materials in Jiapigou gold mine

    Institute of Scientific and Technical Information of China (English)

    马杰; 陈国山

    2013-01-01

    上向水平分层削壁充填采矿法以水平分层的形式逐层上采并逐层采削围岩进行充填,工作面可以适应矿体的复杂变化,是回采赋存条件复杂的高价值矿体的有效方法之一.但对于上下盘不稳固的采场,采削围岩会造成片帮冒顶.夹皮沟金矿在应用削壁充填采矿法时,针对不同的矿体赋存条件,特别是上下盘围岩稳固情况,对充填方式和采场采准工程布置参数进行了革新,采用硐室取料的方式进行充填,有效地减小了采幅及采场暴露面积和对两帮围岩的破坏.应用实践取得了较好的技术经济效果.%The upward horizontal slicing resuing-filling method proceeds upwards from one horizontal slice to another and in the mean time back fills with materials cut from wall rocks. The method offers highly adaptable working faces,which makes it an effective way to stope orebodies with high value but complex occurrence conditions. However for the stopes with unstable hanging and lying walls, cutting wall rocks may lead to spalling and roof falling. The application of resuing-filling method in Jiapigou gold mine adapts to different orebody occurrence conditions especially the stability of hanging and lying walls. It updated the fill method and the parameters of pre-mining work, adopted the fill method of excavating chambers to get filling materials and effectively reduced the cutting scale, the exposed area of stopes and damage to wall rocks. The application practice achieved satisfactory technical and economical outcome.

  11. TAILINGS-WATER INTERACTION IN XIANGXI GOLD MINE,HUNAN PROVINCE, CHINA: 1. ENVIRONMENTALLY GEOCHEMICAL EFFECTS%湘西金矿尾矿-水相互作用:1.环境地球化学效应

    Institute of Scientific and Technical Information of China (English)

    谭凯旋; 王岳军; 郭锋; 谢焱石

    2001-01-01

    Large amounts of tailings were produced during mining in the Xiangxi Gold Mine, Hunan. The interaction of tailing with water has caused the release and migration of heavy metals in tailings and the contamination to surfacial environments of water bodies,soils and vegetables. The main contaminating elements are Au, Sb, As, Hg and W, and this is consistent with the elemental enrichment features of tailings. The water migration coefficients of heavy metals in tailings tend to decreased in the order: Au>Cd>W>Sb>Pb>As>Zn>Cu, similar to the pollution severity in soils and vegetable, indicating that the pollution is controlled by tailings-water interaction. The biological absorption coefficients of heavy metals vary in a complex manner and are larger with Au, Sb, Cd, and Zn. The metallic element concentrations in plants are mainly controlled by their concentrations in soils and plants, and absorption coefficients.%湘西金矿在生产过程中产生了大量的尾矿。该区尾矿-水相互作用强烈,并引起了尾矿中重金属元素的释放、迁移和对水体、土壤、蔬菜等表生环境的重金属污染。污染程度较大的元素均为Au、Sb、As、Cd、Hg、W等,与尾矿中元素的富集特征相一致。尾矿中重金属元素的水迁移能力由大至小顺序为Au、Cd、W、Sb、Pb、As、Zn、Cu。元素的生物吸收系数由大至小顺序为Cd、Au、Zn、Hg、Sb、Cu、Pb、As、W。植物中金属元素浓度主要受土壤中的浓度、植物种类和吸收能力的影响。

  12. Benefiting Africans

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Along with thriving Sino-African economic and trade ties,Chinese companies have attached greater importance to their social responsibility to Africans.More than 2,000 sweaters woven by Chinese mothers were sent to orphans and disabled children in Kenya and four other African countries in September. This activity was launched by Hengyuanxiang,aleading Chinese wool manufacturer.

  13. Benefiting Africans

    Institute of Scientific and Technical Information of China (English)

    ZHANG ZHIPING

    2011-01-01

    Along with thriving Sino-African economic and trade ties,Chinese companies have attached greater importance to their social responsibility to Africans.More than 2,000 sweaters woven by Chinese mothers were sent to orphans and disabled children in Kenya and four other African countries in September.This activity was launched by Hengyuanxiang,a leading Chinese wool manufacturer.

  14. Discussion on grades of raw ores and raw ores for cyanidation in ore-dressing plant of Longtoushan Gold Mine%龙头山金矿选矿厂原矿品位、氰原品位问题探讨

    Institute of Scientific and Technical Information of China (English)

    姚让彪; 林取乾

    2014-01-01

    针对贵港市金地矿业有限责任公司龙头山金矿选矿厂重选+氰化工艺流程因存在粗粒明金、矿样代表性差、部分金提前浸出,导致原矿品位、氰原品位实际值与理论值存在误差,金属难以平衡的问题。通过改进措施、选取合适的取样点,确定了一种较为合理的计算方法,使其实际值与理论值基本相符。%There are many defects in gravity separation -cyanidation process currently used in ore-dressing plant of Longtoushan Gold Mine,Guigang Jindi mining company,that are the presence of coarse-grained visible gold,poor representativeness of samples and early leached gold ,making the actual value of the grades of raw ores and raw ores for cyanidation deviate from the theoretical one and resulting in the imbalance between metal .To deal with that ,optimiza-tion measures are taken ,proper sampling sites are selected and thus a fairly reasonable calculation method is obtained , making the actual value of the grades consistent with the theoretical one .

  15. Study on the Uptake of Copper, Cadmium and Zinc by Three Plants around the Gold Mining Area%黄金矿区周围三种植物对土壤中铜、镉和锌的吸收

    Institute of Scientific and Technical Information of China (English)

    李庚飞

    2012-01-01

    测定并分析了陕西省潼关县某黄金生产区及附近不同地区生长的三种植物远志(Polygala tenuifolia Willd.)、灰灰菜(Chenopodium album L)、千金子[ Leptochloa chinensis(L)Nees]体内的Cu、Cd和Zn含量,为确定富集植物修复土壤重金属提供依据.结果表明:三种植物中,千金子对Zn和Cu的富集能力均最高,千金子对Zn的富集系数为11.79,转移系数为0.87;对Cu的富集系数和转移系数分别为5.32和0.90.灰灰菜和远志对Zn的富集能力也较强;三种植物对Cd的富集能力均较弱.%The content of heavy metals in three kinds of plants [ Polygala tenuifolia Willd. ,Chenopodium album L. and Leptochloa chinensis ( L. ) Nees ] grown in the heavy metal polluted soil near the gold mine in Tongguan county, Shanxi, China, were investigated to provide the basis for the heavy metal removal of hyperaccumulators. The results were as follows -. Among three kinds of plants in different places, the concentration of zinc and copper in Leptochloa chinensis (L. )Nees. was the strongest. Its concentration factor and transfer factor to zinc was 11. 79 and 0. 87,respectively. And its concentration factor and transfer factor to copper was 5. 32 and 0. 90, respectively. Chenopodium album L. and Polygala tenuifolia Willd. had a strong concentration capacity to zinc. The three kinds of plants had a weak concentration capacity to cadmium.

  16. 黄金矿山大型球磨机综合节能研究及应用%Study on comprehensive energy saving of large-scale ball mills in gold mines and its application

    Institute of Scientific and Technical Information of China (English)

    谢敏雄; 梅治福

    2014-01-01

    球磨机是岩金矿山选矿厂的重要设备,同时也是能耗大户。以三山岛金矿8000 t/d新立选矿厂MQY5.5 m ×8.5 m大型球磨机为工程实例,简要介绍了球磨机磨矿效能的影响因数,着重分析研究了大型球磨机磨矿效能影响因素优化节能、大型球磨机设计及参数优化节能、磨矿自动化及磨矿系统最大临界负荷节能。综合节能研究及生产应用取得了磨矿能耗降低17.24%的显著效果。%Ball mills are important equipment in ore-dressing plant of rock gold mines and they are also quite en-ergy-consuming.The paper,with MQY5.5 m ×8.5 m large-scale ball mills in 8 000 t/d Xinli ore-dressing plant as an example,briefly introduces influence parameters of ball mill efficiency and focuses on energy saving through optimiza-tion of influence parameters,design of large-scale ball mills and energy saving through its parameter optimization,mill-ing automation and energy saving through maximum critical load.A significant reslut of 17.24 %energy saving is a-chieved in the study and production application.

  17. The Role of Cleaner-Production in Ensuring a Cleaner Processing and Mining Environment in a Developing African Country. Case of a Midlands Steel Smelting Plant in Zimbabwe

    Directory of Open Access Journals (Sweden)

    Simon Chinguwa

    2012-08-01

    Full Text Available Mines and Mineral Processing Plants are major contributors to high dust emission. This paper explores Cleaner Production Opportunities, to ensure lower risk of dust explosion, minimum health & safety risks, reduction in environmental issues, operations closer to urban areas, reduction in maintenance and cleaning costs, minimum product shrinkage, load trucks and rail cars faster and to load stockpiles cleanly. The green methods will involve a walk through processing plant and identifying cleaner production opportunities. Characterisation of dust was also done. Dust Control Methods are going to be reviewed with the aim of minimizing dust-raising, containing it, suppressing it or extracting and collecting the dust eventually. The paper will also design and recommend specific methods of dust reduction for specific operations.

  18. CSIR Division of Mining Technology annual review 1993/94

    Energy Technology Data Exchange (ETDEWEB)

    1994-01-01

    The Division of Mining Technology of the CSIR (Council for Scientific and Industrial Research) works in partnership with the mining industry to solve problems threatening the health, safety and well-being of the workforce, and the productivity of mining operations through the development and implementation of knowledge and technology. The annual review describes the Division's research projects in the following field: rock engineering (for gold, platinum and coal mining); mining environment; occupational hygiene; surface environment; and mining equipment and systems (systems and equipment, orebody information, coal mining and causes of accidents). Details are also given of the Division's publications, research and consultancy services and information centre.

  19. Elementary and isotopic geochemistry of vein goethite in laterite-gossanic crusts from the Igarape Bahia gold mine (Carajas, Brazil); Geoquimica elementar e isotopica de Goethita de veios em crostas laterito-gossanicas da mina de ouro do Igarape Bahia (Carajas, Brasil)

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Marcondes Lima da [Para Univ., Belem, PA (Brazil). Centro de Geociencias; Raith, Angelika [Fisons Instrumental Elemental Analysis, Winsford Chesfire (United Kingdom); Schumann, Thomas; Poellmann, Herbert [Halle-Wittenberg Univ., Halle (Germany). Inst. Geologische Wissenschaften

    1996-12-31

    The lateritic crusts of the gold mine from the Igarape Bahia, in Carajas, situated at Para state, Brazil, present themselves frequently sectioned by the goethite sub-vertical veins. The veins have the following measures: until 10 cm of thickness and more than 6 m of length. This work aims to characterize the textural, mineralogical and chemical aspects of these veins, in order to understand its evolution, mainly the relation with the laterites and its geological importance, including the aspects referents to the mineral prospecting. (author) 4 figs., 6 refs.; e-mail: mlc at marajo.ufpa.br

  20. A stochastic exposure assessment model to estimate vanadium intake by beef cattle used as sentinels for the South African vanadium mining industry.

    Science.gov (United States)

    Gummow, B; Kirsten, W F A; Gummow, R J; Heesterbeek, J A P

    2006-10-17

    This paper presents an environmental exposure assessment model for estimating chronic intake of vanadium (a transition metal) by cattle farmed extensively in areas contaminated by vanadium pollutants. The exposure model differs from most other models in several ways: (1) it does not rely heavily on extrapolating information from the point source (e.g. stack height, exit velocity, exit diameter) to the point of exposure. (2) It incorporates the physiological constraints of the species exposed. (3) It takes into account oral as well as inhalation exposure. (4) It addresses terrain, by using measurements at the point of exposure. (5) It accounts for existing background concentrations of pollutants and pollutants from multiple sources. (6) It uses a stochastic process with distribution functions to account for variability in the data over time. Environmental inputs into the model included aerial fall-out sample vanadium (n=566), unwashed grass sample vanadium (n=342) and soluble soil sample vanadium (n=342). Physiological cattle inputs were derived from two cohorts of Brahman-cross sentinel cattle (n=30). The model provided an estimate of the chronic external exposure dose of vanadium for two separate groups of cattle grazing over a 5-year period (1999-2004) immediately adjacent (median dose=2.14mg vanadium/kg body weight/day) and 2km away (median dose=1.07mg/kg/day) from a South African vanadium-processing plant, respectively. The final output of the model is a distribution curve of the probable vanadium intake based on the variability within the inputs over the 5-year period of the study. The model is adaptable enough for application to other transition metals and species (including man), and could be used as an alternative to plume-dispersion modelling.

  1. West African colonial civil servants in the nineteenth century : African participation in British colonial expansion in West Africa

    NARCIS (Netherlands)

    Arhin, K.

    1985-01-01

    From the 1850's to mid 1890's Africans were employed in top positions in the embryonic West African colonial services. This book contains the biographies of three of them: Ferguson on the Gold Coast, Lawson in Sierra Leone and Payne in Nigeria. All three had in common that they believed in British r

  2. Tectonic setting of Late Cenozoic gold mineralization in the gold belt of Costa Rica

    Energy Technology Data Exchange (ETDEWEB)

    Deruyter, V.D.

    1985-01-01

    The Gold Belt of Costa Rica is a northwest-elongated zone 15 km wide by 120 km long containing numerous auriferous quartz veins and pyritic silicified patterns upon which abundant small mines are developed. Gold veins are related principally to northeast-southwest and north-south striking, steeply dipping faults. Higher grade ore and thicker veins invariably occur at intersections of these fracture orientations, indicating simultaneous opening at the time of gold introduction. Restriction of gold veins to the northwest-trending arc of Miocene Aguacate Group andesite volcanic rocks, a product of Cocos Plate subduction, suggested approximately coeval formation, but recognition by the writer of the important role played by 2-5 m.y. old altered, gold mineralized rhyolite dikes intruded along north-south gold vein structures and intimately involved with high grade ores at the Esperanza Mine and Rio Chiquito prospect, for example, suggest a much younger period of fracturing and gold introduction. The rhyolite intrusions are more brittle and stockwork mineralized than andesite host rocks and form bulk tonnage gold targets. Initiation of right-lateral movement along the north-south Panama Fracture Zone at 5 m.y.a. within the pattern of northeastward Cocos Plate subduction may have tapped rhyolites from subvolcanic magma chambers into new faults.

  3. 21st Colloquium on African Geology——CAG21

    Institute of Scientific and Technical Information of China (English)

    Lopo Vasconcelos

    2006-01-01

    @@ Under the auspices of the Geological Society of Africa (GSAf), the Geological Mining Association of Mozambique (AGMM) organized the 21st Colloquium on African Geology under the theme "Geoscience for Poverty Relief.

  4. Water Conservation and Pedogenic Function of Bryophytes in Abandoned Carlin Gold Mine%废弃卡林型金矿区结皮苔藓植物蓄水作用和成土功能研究

    Institute of Scientific and Technical Information of China (English)

    王登富; 王智慧; 张朝晖

    2012-01-01

    The bryophytes found in an abandoned Carlin gold mine of Xingyi City, Guizhou Province were in- vestigated in this study. According to field survey and identification of the bryophyte specimens, seven taxa in six genera of four families were found. Pottiaceae and Bryaceae were the dominant families and no Hepati- cae and Anthocerotae was identified. The life-forms of the bryophyte were mainly short turfs(85.71%) and the others were wefts(14.29%). The dominant bryophytes are Barbula rigidula (Hedw.) Mild., Bryum blindii B. S. G. , Trichostomu brachydontium Bruch. and Brachythecium perminusculum C. Muell. Of these species, the biomass range from 3.00 to 52.40 g/m2, with formed soil varying from 217.50 to 3 695. 80 g/m2, water holding capacity from 35.10 to 684.30 g/m2, and saturated water absorption ratio from 1 170.00% to 3 637.00%. These results indicate that the bryophyte crust found in the mine had great ability to absorb and reserve water and played an important role in soil formation, rock desertification control and ecological environment renovation in karst areas.%通过野外调查和实验室分析,对贵州省兴义市新路废弃卡林型金矿区苔藓植物进行了研究。结果显示,该矿区共计有苔藓植物4科6属7种,未发现苔类和角苔,种类组成较单调,其中丛藓科(Pottiaceae)和真藓科(Bryaceae)为优势科;生活型有2种类型:矮丛集型(85.71%)和交织型(14.29%),矮丛集型占有绝对优势;并对该矿区结皮优势苔藓植物硬叶扭口藓、卵蒴真藓、毛口藓和小青藓的生物量、成土量、饱和吸水率和饱和吸水量进行了测定分析。结果显示,该矿区生物量为3.00~52.40g/m2;成土量为217.50~3 695.80g/m2;饱和吸水量为35.10~684.30g/m2;饱和吸水率为1 170.00%~3 637.00%。研究表明,在喀斯特石漠化严重的废弃金矿区,对于在缺少土壤,水土流失严重和植被破坏大的环境区域,苔藓植物以其特有的

  5. Improvement Measures of Stope Filling Dewatering Process in Sanshandao Gold Mine%三山岛金矿采场充填脱水工艺改进措施

    Institute of Scientific and Technical Information of China (English)

    颜丙乾; 杨鹏; 吕文生

    2015-01-01

    采场充填脱水效果对充填体初凝时间及其短期和长期强度产生较大影响,三山岛金矿采用溢流管溢流脱水和充填挡墙的土工布渗透脱水,脱水效率不能满足现场工作要求。为此,在充填脱水理论研究的基础上,分析了影响充填脱水速度的主要因素,提出了多项充填脱水改进措施。增设竖直或倾斜的脱水管,更有效地排出充填采场中的重力水,同时避免充填料浆中细粒级颗粒堵塞脱水管。改进充填挡墙设计和滤水布的选取,避免细粒级颗粒短时间内聚集在滤水布附近,影响渗透脱水效果。设计充填管道滤水器,在充填料浆进入采空区前,过滤充填料浆中的部分自由水,提高了充填采场中料浆的浓度,减小了采场充填脱水工作量。改变矿山简单脱水方式,进一步提高采场充填脱水效率,避免影响下一步开采工作的顺利开展。%The dewatering of stope filling has a greater impact on the initial setting time of the filling body and its short-term and long-term strength. The overflow dewatering was used in Sanshandao Gold Mine by overflow tube,and penetration de-watering was used by filling retaining geotextile,but the dewatering efficiency can not meet the requirements of field work. The main influence factors of the filling dewatering rate was analyzed on the basis of theoretical research on the filling dewatering, and many improvement measures of filling dewatering are put forward. Additional vertical or inclined dewatering tubes can be used to discharge the filling gravity water more efficiently,meanwhile avoid dewatering tube clogged by the fine-sized particles in filling slurry. The improved design of filling retaining wall and selection of treatment cloth can avoid the fine-sized particles gathered near the water treatment cloth in short time which can affect penetration dewatering. The water filter of filling tube was designed to filter

  6. Longwall mining

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-14

    As part of EIA`s program to provide information on coal, this report, Longwall-Mining, describes longwall mining and compares it with other underground mining methods. Using data from EIA and private sector surveys, the report describes major changes in the geologic, technological, and operating characteristics of longwall mining over the past decade. Most important, the report shows how these changes led to dramatic improvements in longwall mining productivity. For readers interested in the history of longwall mining and greater detail on recent developments affecting longwall mining, the report includes a bibliography.

  7. 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.

  8. Going underground and going after women: trends in sexual risk behaviour among gold miners in South Africa.

    Science.gov (United States)

    Meekers, D

    2000-01-01

    This paper examines trends in risk behaviour among South African gold miners, a population with an estimated HIV prevalence of 10-20%. The study is based on a 1995 and 1997 survey of a random sample gold miners in the town of Welkom, South Africa. The results show that the percentage of miners who perceived they were likely to contract HIV increased from 33% in 1995 to 35% in 1997 (P<0.01). The percentage who had 4 or more partners in the past year decreased from 25% to 13% (P < 0.01), and the percentage whose last sexual partner was their spouse increased from 56% to 70% (P<0.01). Condom use in last intercourse with a spouse increased from 18% to 26% (P < 0.05). Condom use with other partners was considerably higher (67%), but did not increase significantly from 1995. The most likely contributors to this behaviour change were the AIDS awareness programmes implemented by the mining industry and the behaviour change communications of a condom social marketing campaign targeted at miners and commercial sex workers in the mining community.

  9. Gamma-ray pulsars: a gold mine

    CERN Document Server

    Grenier, Isabelle A

    2015-01-01

    The most energetic neutron stars, powered by their rotation, are capable of producing pulsed radiation from the radio up to gamma rays with nearly TeV energies. These pulsars are part of the universe of energetic and powerful particle accelerators, using their uniquely fast rotation and formidable magnetic fields to accelerate particles to ultra-relativistic speed. The extreme properties of these stars provide an excellent testing ground, beyond Earth experience, for nuclear, gravitational, and quantum-electrodynamical physics. A wealth of gamma-ray pulsars has recently been discovered with the Fermi Gamma-Ray Space Telescope. The energetic gamma rays enable us to probe the magnetospheres of neutron stars and particle acceleration in this exotic environment. We review the latest developments in this field, beginning with a brief overview of the properties and mysteries of rotation-powered pulsars, and then discussing gamma-ray observations and magnetospheric models in more detail.

  10. New perspectives on a 140-year legacy of mining and abandoned mine cleanup in the San Juan Mountains, Colorado

    Science.gov (United States)

    Yager, Douglas B.; Fey, David L.; Chapin, Thomas; Johnson, Raymond H.

    2016-01-01

    The Gold King mine water release that occurred on 5 August 2015 near the historical mining community of Silverton, Colorado, highlights the environmental legacy that abandoned mines have on the environment. During reclamation efforts, a breach of collapsed workings at the Gold King mine sent 3 million gallons of acidic and metal-rich mine water into the upper Animas River, a tributary to the Colorado River basin. The Gold King mine is located in the scenic, western San Juan Mountains, a region renowned for its volcano-tectonic and gold-silver-base metal mineralization history. Prior to mining, acidic drainage from hydrothermally altered areas was a major source of metals and acidity to streams, and it continues to be so. In addition to abandoned hard rock metal mines, uranium mine waste poses a long-term storage and immobilization challenge in this area. Uranium resources are mined in the Colorado Plateau, which borders the San Juan Mountains on the west. Uranium processing and repository sites along the Animas River near Durango, Colorado, are a prime example of how the legacy of mining must be managed for the health and well-being of future generations. The San Juan Mountains are part of a geoenvironmental nexus where geology, mining, agriculture, recreation, and community issues converge. This trip will explore the geology, mining, and mine cleanup history in which a community-driven, watershed-based stakeholder process is an integral part. Research tools and historical data useful for understanding complex watersheds impacted by natural sources of metals and acidity overprinted by mining will also be discussed.

  11. 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

    NARCIS (Netherlands)

    van der 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 th

  12. Technical report: Metal concentrations in sediments, and selected biota from mine tailings in Gastineau Channel, Juneau, Alaska [Draft

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Hardrock gold mining occurred in Juneau from 1880 to 1944. Tailings and waste rock from the mines were deposited into Gastineau Channel and formed beaches along...

  13. 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.

  14. ECONOMIC EVALUATION OF GOLD-ORE DUMP REPROCESSING EFFICIENCY

    Directory of Open Access Journals (Sweden)

    N. Y. Samsonov

    2010-06-01

    Full Text Available An economic projection is presented in the paper on the heap leaching technology for extracting a residual gold from the gold-ore dumps accumulated at the exploited or closed gold mines. A brief analysis is performed on the legal status of use this source of raw materials, availability and efficiency of the heap leaching method are reviewed, and the potential users of this method are assessed. An investment plan is created for involving anthropogenic dumps of gold-raw materials at one of the ore deposits in Siberia (heap complex of the North-Western flank of the Sovetskoye minefield, Krasnoyarsk region, North-Yenisey area.

  15. Text Mining.

    Science.gov (United States)

    Trybula, Walter J.

    1999-01-01

    Reviews the state of research in text mining, focusing on newer developments. The intent is to describe the disparate investigations currently included under the term text mining and provide a cohesive structure for these efforts. A summary of research identifies key organizations responsible for pushing the development of text mining. A section…

  16. Índice de exposição à sílica na atividade de mineração de ouro Silica exposure index in gold mining

    Directory of Open Access Journals (Sweden)

    Ana Paula Scalia Carneiro

    2006-02-01

    Full Text Available OBJETIVO: Propor um índice que sintetize a exposição cumulativa à sílica, incluindo intensidade, duração e época da exposição e testá-lo em relação à presença e gravidade de silicose. MÉTODOS: Estudo transversal realizado com 140 ex-mineiros de ouro, residentes em duas localidades do Estado de Minas Gerais, examinados entre 11/1997 e 12/1999. Foram analisadas informações sobre história clínica e ocupacional, radiografia de tórax e espirometria. Casos borderline de silicose pela radiografia foram submetidos à tomografia computadorizada de alta resolução. O índice representa a soma dos escores extraídos da transformação logarítmica das taxas de concentração de sílica respirável nas diversas funções, minas e períodos trabalhados. Foram aplicados testes paramétricos para comparação das médias entre os grupos de interesse. RESULTADOS: O índice proposto apresentou-se discriminativo em relação ao desfecho principal (silicose e aos desfechos secundários (enfisema e tuberculose pulmonar no grupo total, incluindo os diversos estágios da doença, com valores p: 0,008, 0,016 e OBJECTIVE: To develop a cumulative silica exposure index, including time period, duration and intensity of exposure, and to test this index as for occurrence and severity of silicosis. METHODS: A cross-sectional study was carried out comprising 140 former gold miners from two localities in Southeastern Brazil between November 1997 and December 1999. Complete data on occupational and medical histories, chest x-rays and spirometry were analyzed. Borderline cases on the x-rays were also submitted to high-resolution chest computed tomography. The exposure index was the sum of scores obtained by logarithmic transformation of respirable silica concentration related to job tasks, mines and work time. Parametric tests were used for comparing averages between the groups of interest. RESULTS: The silica exposure index was able to discriminate the

  17. Coal: a South African success story

    Energy Technology Data Exchange (ETDEWEB)

    Boers, R.

    1990-01-01

    Describes the South African coal mining industry, including exports domestic use of coal, coal geology and mining methods, employment, labour relations, benefits and social amenities provided for workers, safety and environmental aspects including land reclamation. Also discusses the implications of sanctions on coal and the mining industry, and argues that sanctions have not achieved and cannot achieve the stated objective of the social and political emancipation of black South Africa. Concludes that in order to defeat apartheid, South Africa, needs economic growth and encouragement for those attempting reform.

  18. Geochemical Processes Controlling the Generation and Environmental Impacts of Acid Mine Drainage in Semi Arid Conditions

    OpenAIRE

    Magombedze, Chris

    2006-01-01

    This study evaluates the geochemical processes that control the geochemistry of acid mine drainage in semi arid conditions. The central objective is to characterise and understand the evolution of acid mine drainage and its potential environmental impacts on the Mazowe River sub-catchment, in north east Zimbabwe. The work is based on a case study at three neighbouring metal sulphide mines, namely Trojan Nickel Mine, Mazowe Gold Mine and Iron Duke Pyrites.The methodology used in this research ...

  19. Searching in the Dark: Phenotyping Diabetic Retinopathy in a De-Identified Electronic Medical Record Sample of African Americans.

    Science.gov (United States)

    Restrepo, Nicole A; Farber-Eger, Eric; Crawford, Dana C

    2016-01-01

    A hurdle to EMR-based studies is the characterization and extraction of complex phenotypes not readily defined by single diagnostic/procedural codes. Here we developed an algorithm utilizing data mining techniques to identify a diabetic retinopathy (DR) cohort of type-2 diabetic African Americans from the Vanderbilt University de-identified EMR system. The algorithm incorporates a combination of diagnostic codes, current procedural terminology billing codes, medications, and text matching to identify DR when gold-standard digital photography results were unavailable. DR cases were identified with a positive predictive value of 75.3% and an accuracy of 84.8%. Controls were classified with a negative predictive value of 1.0% as could be assessed. Limited studies of DR have been performed in African Americans who are at an elevated risk of DR. Identification of EMR-based African American cohorts may help stimulate new biomedical studies that could elucidate differences in risk for the development of DR and other complex diseases.

  20. Black gold

    CERN Document Server

    Fletcher, MW

    2016-01-01

    Following the Yom Kippur war of October 1973, OPEC raises the price of oil by 70% along with a 5% reduction in oil production. Len Saunders a highly skilled and knowledgeable British engineer for Jaguar motors, is approached by the UK energy commission in the January of 1974 to create a new propulsion system; using a secret document from a German WW2 scientist, that they have come into possession of. Len Saunders sets to work on creating the holy grail of energy. Seven years later 1981, Haidar Farooq the Kuwait oil minister working at OPEC and head of a secret organisation named Black Gold bec

  1. The Effect of China’s Scramble for Resources and African Resource Nationalism on the Supply of Strategic Southern African Minerals: What Can the United States Do?

    Science.gov (United States)

    2010-01-01

    seek to dominate the South African mining industry and minerals and metals markets. For Southern Africa, resource nationalism and demand from China...that major changes would be taking place in Namibia’s previously tranquil mining industry . In May 2011 the Namibian government acted, contrary to the...the mining industry , a disincentive for investors, and a source of continued decline for South Africa’s mining industry . The 2010/2011 Fraser

  2. The institutional regulation of the sustainability of water resources within mining contexts: accountability and plurality

    NARCIS (Netherlands)

    Sosa Landeo, M.; Zwarteveen, M.Z.

    2014-01-01

    This article reviews recent literature on water and mining and uses illustrations from a large gold mine, Yanacocha, operating in Peru, to assess the effectiveness of institutional mechanisms for safeguarding the sustainability of water resources (and water-based ecosystems) in mining regions. The s

  3. Noble gases, K, U, Th, and Pb in native gold

    Science.gov (United States)

    Engster, O.; Niedermann, S.; Thalmann, C.; Frei, R.; Kramers, J.; KräHenbühl, U.; Liu, Y. Z.; Hofmann, B.; Boer, R. H.; Reimold, W. U.; Bruno, L.

    1995-12-01

    We present determinations of the noble gas and Pb isotopic abundances and of K, Th, and U concentrations of native gold. Our results demonstrate that gold is an excellent carrier for crustal volatiles, but direct dating of gold using the U, Th-4He, 40K-40Ar, and U fission Xe methods was not successful for various reasons. The main significance of this work is the great sensitivity of gold for trapped gases as well as for gases that were produced in situ which gives the prospects of using gold and its fluid and solid inclusions for the study of paleogas composition. Numerous nuclear effects characterize the noble gas inventory of placer gold from Switzerland and Italy, vein gold from Italy, South Africa, and Venezuela, and lode gold from South Africa. The degassing patterns obtained by mass spectrometry show a low-temperature release of volatiles around 500°C from fluid inclusions mainly in vein gold and a high-temperature release from solid inclusions and the gold itself. The low-temperature volatiles represent species that were trapped when the gold crystallized. We investigated the following trapped species: the isotopes of He, Ne, Ar, Kr, Xe, and Pb, and the abundances of K, U, Th, H2O, and CO2. The crustal gases trapped by gold comprise 3He from 6Li(n,α)3H → β- → 3He, 4He and 40Ar from the U, Th, and K decay, and Xe from 238U fission. We observe 4He/40Ar = 3.9 for the radiogenic trapped gases of tertiary gold and a ratio of 1.4 for Archean gold. These ratios are consistent with the production ratios from U and K at the respective times and demonstrate that gold can be used as a sampler of ancient atmospheric gases. The concentrations of U and Th range from a few parts per billion to a few parts per million, and those of K and Pb range up to some tens of parts per million. The antiquity of trapped Pb is indicated by the Pb-Pb model age of about 3000 Ma for the lead extracted from vein gold and quartz of the Lily gold mine (South Africa). Gold also

  4. How CSIR research aids mining industry

    Energy Technology Data Exchange (ETDEWEB)

    Vorster, H.

    1987-04-01

    The paper outlines supporting services to mining by the Council for Scientific and Industrial Research (CSIR) in South Africa. At present three CSIR institutes are actively involved in the programme of the Coal Mining Research Controlling Council (CMRCC). The use of an ultra-modern blasting tunnel to determine the explosive characteristics of South African coal types is considered as well as investigations to determine the influence of strata conditions on the behaviour of different types of roof bolts. The work of the Strength Mechanics Division in checking design and cause of structural failures of mining equipment and the modernization of the coal preparation research plant is described.

  5. Discussion on Geological Features and Mineral-formation Conditions of Jinjibei-gold Mine in Liaoning Province%辽宁省金鸡背金矿地质特征及成矿条件探讨

    Institute of Scientific and Technical Information of China (English)

    吴文奎

    2016-01-01

    Qingyuan is full of different types of gold deposits , gold mineralization points , including Jinjibei-gold deposit located in Tianqiao Village , Xiajiapu Town , Qingyuan Distinct , Fushun Liaoning province , it is affected by the Mesozoic Yanshan period Lazi mountain granite emplacement and the North West to Kaiyuan-Caoshi faulting effects produced in the north -west and north -east structural faults in the crushing altered rock type of gold deposit . The analysis about geological characteristics of gold , which is combined with geophysical and geochemical data . With the summary of Au sources of mineralization and ore- controlling factor conditions and other information , a conclusion that the area has potential and con-ditions for medium large-scale deposits can be draw n .%辽宁抚顺清原县地区分布着不同类型的金矿床、金矿化点,其中金鸡背金矿位于清原县夏家堡镇天桥村,是受中生代燕山期砬子山花岗岩体侵位及北西向开原-草市断裂活动影响,产于北西向和北东向构造断裂中的破碎蚀变岩型金矿。对该区金矿的地质特征并结合物化探资料进行分析,总结金矿成矿物质来源、成矿因素及控矿条件等信息,认为该区具有中-大型矿床的潜力和条件。

  6. African America.

    Science.gov (United States)

    Brodie, Carolyn S.; Brown, Gloria

    1994-01-01

    Presents an annotated bibliography of quality materials by and about African Americans in the areas of poetry, music, folklore, women, picture books, history/collective biography, authors, and professional materials. Activities are suggested in each area for Black History Month. (LRW)

  7. Nevadaite, (Cu2+, Al, V3+)6 [Al8 (PO4)8 F8] (OH 2 (H2O)22, a new phosphate mineral species from the Gold Quarry mine, Carlin, Eureka County, Nevada: description and crystal structure

    Science.gov (United States)

    Cooper, M.A.; Hawthorne, F.C.; Roberts, Andrew C.; Foord, E.E.; Erd, Richard C.; Evans, H.T.; Jensen, M.C.

    2004-01-01

    Nevadaite, (Cu2+, ???, Al, V3+)6 (PO4)8 F8 (OH)2 (H2O)22, is a new supergene mineral species from the Gold Quarry mine, near Carlin, Eureka County, Nevada, U.S.A. Nevadaite forms radiating clusters to 1 mm of prismatic crystals, locally covering surfaces more that 2 cm across; individual crystals are elongate on [001] with a length:width ratio of > 10:1 and a maximum diameter of ???30 ??m. It also occurs as spherules and druses associated with colorless to purple-black fluellite, colorless wavellite, strengitevariscite, acicular maroon-to-red hewettite, and rare anatase, kazakhstanite, tinticite, leucophosphite, torbernite and tyuyamunite. Nevadaite is pale green to turquoise blue with a pale powder-blue streak and a vitreous luster; it does not fluoresce under ultra-violet light. It has no cleavage, a Mohs hardness of ???3, is brittle with a conchoidal fracture, and has measured and calculated densities of 2.54 and 2.55 g/cm3, respectively. Nevadaite is biaxial negative, with ?? 1.540, ?? 1.548, ?? 1.553, 2V(obs.) = 76??, 2V(calc.) = 76??, pleochroic with X pale greenish blue, Y very pale greenish blue, Z blue, and with absorption Z ??? X > Y and orientation X = c, Y = a, Z = b. Nevadaite is orthorhombic, space group P21mn, a 12.123(2), b 18.999(2), c 4.961(1) A?? , V 1142.8(2) A??3, Z = 1, a:b:c = 0.6391:1:0.2611. The strongest seven lines in the X-ray powder-diffraction pattern [d in A??(I)(hkl)] are: 6.077(10)(200), 5.618(9)(130), 9.535(8)(020), 2.983(6)(241), 3.430(4)(041), 2.661(4)(061 , and 1.844(4)(352). A chemical analysis with an electron microprobe gave P2O5 32.54, Al2O3 27.07, V2O3 4.24, Fe2O3 0.07, CuO 9.24, ZnO 0.11, F 9.22, H2O (calc.) 23.48, OH ??? F -3.88, sum 102.09 wt.%; the valence states of V and Fe, and the amount of H2O, were determined by crystal-structure analysis. The resulting empirical formula on the basis of 63.65 anions (including 21.65 H2O pfu) is (CU2+2.00 Zn0.02 V3+0.98 Fe3+0.01 Al1.15)??4.16 Al8 P7.90 O32 [F8.37 (OH 1.63]??10 (H2O

  8. Fraction Distribution and Risk Assessment of Heavy Metals in Iron and Gold Mine Soil of Miyun Reservoir Upstream%密云水库上游金属矿区土壤中重金属形态分布及风险评价

    Institute of Scientific and Technical Information of China (English)

    高彦鑫; 冯金国; 唐磊; 朱先芳; 刘文清; 季宏兵

    2012-01-01

    研究了北京市密云水库上游金属矿区土壤中重金属环境污染和风险评价.从矿区周围采集了土壤和沉积物样品,分析了铁矿开采区和金矿开采区土壤样品中Cd、Mn、Zn、Cu、Pb、Ni、V、Cr的总量及提取态重金属含量,采用Tucker3模型、风险评价编码法(RAC)探讨了矿区土壤中重金属污染程度.研究表明,金属矿区土壤中大多数重金属超出北京市土壤背景值.采用BCR逐级提取法分析土壤中重金属形态,矿区土壤中Mn可交换态含量占总量的20%~30%;Zn、Cd、Pb可交换态和易还原态(Fe-Mn氧化态)含量之和约分别占总量的17%~24%、10%~23%、30%~45%;Cr、Ni、V残渣态含量占总量的80%以上.Tucker3模型分析进一步表明矿区重金属的潜在危害性.密云水库上游铁矿开采区和金矿开采区土壤中Mn的风险指数为0.03%~55.18%和3.94%~67.16%,处于中高潜在生态风险,其它重金属潜在生态风险较低.该结论将为北京市矿山环境污染防治和密云水库的保护提供科学依据.%Environmental pollution and risk assessment of heavy metals in soils of iron and gold mine areas of Miyun Reservoir upstream in Beijing were researched in this article.Soil and sediment samples were collected around the mine areas.The contents and extractable contents of heavy metals(Cd,Mn,Zn,Cu,Pb,Ni,V,Cr) were analyzed.Heavy metal contamination was evaluated by the Tucker3 model and risk assessment code(RAC).The results showed that the concentration of most heavy metals in mine areas were exceeded the soil background of Beijing.The fractions of heavy metals in soils were analyzed by BCR sequential extraction procedure.The results showed that exchangeable fraction content for Mn accounted for 20%-30% of the total concentration;exchangeable and Fe-Mn fractions contents for Zn,Cd,Pb respectively accounted for about 17%-24%,10%-23%,30%-45% of the total concentration;residual fraction contents for

  9. 河北峪耳崖金矿盲竖井主溜井形式与施工设计研究%On Blind Shaft Main Chute Form and Construction Design of Hebei Yuerya Gold Mine

    Institute of Scientific and Technical Information of China (English)

    张景辉; 张大伟

    2014-01-01

    With the gradually development of prospecting and mining work under the wells, large quantity of waste stone and ore increased gradually, and it's important to separate waste stone and ore by main chute and realize the reasonable arrangement of prospecting engineering and mining engineering by separating waste stone and ore by subsection control of main chute. This paper studied how to realize mine releasing subsection control by the arrangement forms of main chute to reduce the loss of mine releasing funnel.%随着矿山井下探矿和采矿工作的逐渐展开,大量的废石和矿石逐渐增加,如何合理利用主溜井实现废石与矿石的分离,利用主溜井的分段控制出矿石和废石来实现探矿工程与采矿工程的合理布置显得越来越重要。本文针对如何利用溜井的布置形式来实现放矿分段控制,减少放矿漏斗损耗进行研究。

  10. 在寒区金矿开采过程中保护环境的土工措施研究%The Elaboration of Geocryotechnological Measures on the Environmental Protection at Gold Mining in Conditions of Cryolitozone

    Institute of Scientific and Technical Information of China (English)

    D.M. Shesternyov; S.B. Tataurov

    2004-01-01

    Causes and consequences of cryolitozone environmental contamination by technogenous mercury have been studied in the paper. Measures have been elaborated and methods for increasing ecological safety of the territories affected by mercury- containing mining wastes have been suggested. It has been proved that comprehensive utilization of mercury-containing heaps allows to solve problems of ecological safety with the least economical expenses.

  11. Assessment of Potential Ecological Risk of Heavy Metals in Soils from Jia-Pi-Gou Gold Mine Area, China%夹皮沟金矿开采区土壤重金属污染潜在生态风险评价

    Institute of Scientific and Technical Information of China (English)

    杨净; 王宁

    2013-01-01

    以松花江上游夹皮沟金矿开采区为研究对象,采用Hakanson潜在生态风险指数法(The Potential Ecological Risk Index)对金矿开采区土壤中Hg、Cu、Zn、Pb、Cd、Cr、Ni等7种重金属元素进行单因子和复合生态风险评价.结果表明,研究区域内的土壤重金属含量明显高于当地土壤背景值,其中28个采样点的Hg平均潜在生态危害系数为464.6,达到极度生态危害程度,Cd平均潜在生态危害系数为140.8,达强度生态危害程度,其余元素均未达到轻度生态危害的上限标准,7种重金属平均潜在生态危害系数依次为Hg>Cd>Pb>Cu>Ni>Cr>Zn.同时,28个采样点平均潜在生态风险指数为637.6,属于很强生态危害,为最高级别,其中,7个采样点的潜在生态风险指数大于600,属于很强生态危害,8个采样点的潜在生态风险指数介于300和600之间,属于强度生态危害,其余为中度和轻度生态危害级别.在7种重金属元素中,Hg元素对区域生态风险的贡献率最高,是构成潜在生态风险的最主要因子.这与金矿开采以及长达190年的混汞提金工艺所带来的环境污染有关.%The ecological risks of seven different soil heavy metals, including Hg, Cu, Zn, Pb, Cd, Cr and Ni, in the Jia-pi-gou gold mine area, which located in the upstream area of Songhua River were discussed using single and compound factor potential ecological risk index. The results showed that the concentration of soils were higher than the local reference values and the soils had serious ecological risks of Hg and Cd with the single ecological risk index of seven elements in sample points of gold mine area, the risk index being 464.6 and 140.8, respectively, and slight risks of Cu, Zn, Pb, Cr and Ni with the index were less than Hg and Cd. The risk order of heavy metals was Hg>Cd>Pb> Cu>Ni>Cr>Zn. Meanwhile, the average ecological risk index of soil heavy metals of the twenty-eight sample points was 637.6. Seven of

  12. African-American Biography.

    Science.gov (United States)

    Martin, Ron

    1995-01-01

    Suggests sources of information for African American History Month for library media specialists who work with students in grades four through eight. Gale Research's "African-American Reference Library," which includes "African-America Biography,""African-American Chronology," and "African-American Almanac,"…

  13. Experiment of Separating Copper Meanwhile Strengthening the Recorery Effect of Associated Gold and Silver in Hongtoushan Copper Mine.%强化红透山铜矿中伴生金银回收效果的选铜试验

    Institute of Scientific and Technical Information of China (English)

    黄红军; 苏建芳; 孙伟

    2011-01-01

    On the precondition of ensuring the high recoveries of copper and zinc minerals. From Hongtoushan the proper grinding fineness,types of collectors and collector dosages for strengthening the recoveries of gold and silver minerals from the complex copper-zinc sulfide containing gold and silver were determined through experimental study. The optimized flotation technology contained one rougher,two scavegings and three cleanings for copper flotation,during which all of the middlings returned to the previous flotation operations accordingly. With the technology utilized in this study,a copper concentrate of 22. 22% Cu with a recovery of 92. 21% were produced. The grades of gold and silver in the copper concentrate were 5. 51 g/t and 295.00 g/t,respectively. The recoveries of the gold and silver in the copper concentrate were 58. 07% and 60. 51% ,respectively.%在确保铜锌高效回收的前提下,通过试验确定了红透山含金银复杂铜锌硫化矿强化金银回收的合适磨矿细度、捕收剂种类及用量.用优化后的工艺技术条件和现场的1粗2扫3精选铜、中矿顺序返回流程处理该矿石,可获得铜品位为22.22%、回收率为92.21%的铜精矿,铜精矿中金、银的品位分别为5.51 g/t和295.00 g/t,回收率分别为58.07%和60.51%.

  14. African Trypanosomiasis

    Science.gov (United States)

    2011-06-01

    Histol. 1977;375:53- 70. 42. Poltera AA, Owor R, Cox JN. Pathological aspects of human African trypanosomiasis (HAT) in Uganda. A post - mortem survey of...nodular lesions , including anthrax or tick bite associated with Rickettsia conorii infection. The chancre is followed by a hemolymphatic stage, dur- ing...electrocardiograph- ic changes and, at times, terminal cardiac insufficiency.41 Pulmonary lesions specifically related to trypanosomiasis are not

  15. Constraints on mineralisation and hydrothermal alteration in the Nalunaq gold deposit, South Greenland

    DEFF Research Database (Denmark)

    Bell, Robin-Marie Fairbairn

    and hydrolysis reactions are important in locally precipitating gold, which may suggest an Au(HS)2- transport complex for gold. A c. 20 cm wide biotite-arsenopyrite alteration zone surrounds the gold-quartz veins locally, and denotes areas of high-gold grades. Implicit 3-Dimentional modelling has revealed......Summary: Nalunaq is located in South Greenland and is a small high gold-grade deposit, which for the majority of its operational life was Greenland's only metalliferous mine. Gold is hosted in narrow quartz veins which are cross-cut by late-stage faults. Gold-quartz veins are hosted by fine......-and - medium grained amphibolite of the Nanortalik Nappe. Detailed petrographic and geochronological studies have revealed a multi-stage hydrothermal alteration system, with alteration pre-and post-dating gold mineralisation. The hydrothermal alteration records a transition from upper-amphibolite facies...

  16. Obesity and African Americans

    Science.gov (United States)

    ... Data > Minority Population Profiles > Black/African American > Obesity Obesity and African Americans African American women have the ... ss6304.pdf [PDF | 3.38MB] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  17. Successes, challenges and lessons from a novel deployment of Xpert(®) MTB/RIF at a major South African public event [Short Communication].

    Science.gov (United States)

    Page-Shipp, L; Stevens, W; Clark, D; Scott, L; Olsen, F; Kisbey-Green, H; Mametja, D; Churchyard, G

    2014-04-01

    In a mobile deployment of Xpert(®) MTB/RIF (Xpert) at the public event for 2012 South African World TB Day, Xpert testing was offered to tuberculosis (TB) symptomatic clients from gold mining and surrounding communities. Considerations before implementation included effective TB symptom screening; safe, effective sputum collection; uninterrupted electricity supply; stringent instrument verification and provision of on-site results. Public event Xpert testing is feasible; however, the case-finding rate was very low (0.7%). We recommend exploring enhanced symptom screening algorithms to improve pre-test probability, cost-effectiveness analysis, exploring alternate electrical fail-safes and on-site data connectivity and improving management of client expectations.

  18. Social big data mining

    CERN Document Server

    Ishikawa, Hiroshi

    2015-01-01

    Social Media. Big Data and Social Data. Hypotheses in the Era of Big Data. Social Big Data Applications. Basic Concepts in Data Mining. Association Rule Mining. Clustering. Classification. Prediction. Web Structure Mining. Web Content Mining. Web Access Log Mining, Information Extraction and Deep Web Mining. Media Mining. Scalability and Outlier Detection.

  19. Isotope Geochemistry of Gold Ore Deposits in the Gezhen Shear Zone, Qiongxi, Hainan Island

    Institute of Scientific and Technical Information of China (English)

    夏勇

    2004-01-01

    Gold deposits hosted in the Gezhen shear zone at Qingxi, Hainan Island occur in the Precambrian metamorphic rock series and are regionally developed in the N-E direction along the tectonic zone. From northeast to southwest are distributed the Tuwaishan-Baoban gold mining district, the Erjia gold mining district and the Bumo gold mining district, making up the most industrially important gold metallogenesis zone on the Hainan Island. Isotope geochemical studies of the typical gold deposits in this metallogenesis zone indicate that their ore-forming materials stemmed largely from the Baoban Group migmatite series, though the involvement of some plutonic materials could not be ruled out. The ore fluids are the mixture of migmatitized hydrothermal solutions and meteoric waters in addition to the involvement of local magmatic hydrothermal solutions. The superimposition of plutonic materials and magmatic hydrothermal solutions is controlled by the deformation environment of the shear zone and later magmatic activities. Obvious variations are noticed in isotopic composition in the region studied, probably related to tectonic deformation, metamorphism and other evolutionary characteristics. This study is of great significance in understanding the relationship between the shear zone and gold metallogenesis, the rules of gold metallogenesis and gold ore prognosis.

  20. The market for large rigid haul trucks in surface mining

    Energy Technology Data Exchange (ETDEWEB)

    Gilewicz, P.

    2002-04-15

    Originally published in 2001 this updated report provides a definition of the market for large rigid haulers in surface mining. The analysis covers changes to the mining market segments buying these machines including the gains made by coal producers, retrenchment in copper mining, the consolidation taking place among gold mining companies, and the expansion of iron ore producers in Australia and Brazil. It includes a detailed accounting of 2001 truck shipments, and an analysis of trends in the Ultra-truck segment. It concludes with a revised forecast for shipments through 2006. 12 charts, 56 tabs., 2 apps.

  1. Gold, coal and oil.

    Science.gov (United States)

    Dani, Sergio U

    2010-03-01

    Jared Diamond has hypothesized that guns, germs and steel account for the fate of human societies. Here I propose an extension of Diamond's hypothesis and put it in other terms and dimensions: gold, coal and oil account not only for the fate of human societies but also for the fate of mankind through the bodily accumulation of anthropogenic arsenic, an invisible weapon of mass extinction and evolutionary change. The background is clear; arsenic species fulfill seven criteria for a weapon of mass extinction and evolutionary change: (i) bioavailability to all living organisms; (ii) imperceptibility; (iii) acute toxicity; (iv) bioaccumulation and chronic toxicity; (v) adverse impact on reproductive fitness and reproductive outcomes and early-age development and growth in a wide range of microbial, plant and animal species including man; (vi) widespread geographical distribution, mobility and ecological persistence on a centennial to millennial basis and (vii) availability in necessary and sufficient amounts to exert evolutionarily meaningful effects. The proof is becoming increasingly feasible as human exploitation of gold, coal and oil deposits cause sustainable rises of arsenic concentrations in the biosphere. Paradoxically, humans are among the least arsenic-resistant organisms because humans are long-lived, encephalized and complex social metazoans. An arsenic accumulation model is presented here to describe how arsenic accumulates in the human body with increasing age and at different provisionally safe exposure levels. Arsenic accumulates in the human body even at daily exposure levels which are within the lowest possible WHO provisional tolerance limits, yielding bodily arsenic concentrations which are above WHO provisional limits. Ongoing consequences of global scale arsenic poisoning of mankind include age-specific rises in morbidity and mortality followed by adaptive changes. The potential rise of successful forms of inborn resistance to arsenic in humans

  2. Spatial Distribution, Fractionation and Pollution Assessment of Heavy Metals in Wanzhuang Gold Mining Field in Upstream Part of Water Conservation Area of Beijing, China%北京市水源涵养区上游万庄金矿田土壤重金属空间分布、形态特征及污染评价

    Institute of Scientific and Technical Information of China (English)

    张爱星; 聂义宁; 季宏兵; 冯金国; 秦飞

    2014-01-01

    The objective of this study was to investigate the spatial distribution, fractionation and contamination degree of heavy metals in soils of gold mine and tailings of Pinggu in Beijing. The spatial distributions of As, Cd, Cu, Pb, and Zn were basically the same. Their pollu-tion was more serious in the gold mining and surrounding area, which was obviously affected by human activities. However, the spatial dis-tribution of Cr and Ni showed that the most polluted area was the tailings. Exchange and reducible fractions of Cd accounted for about 20%~30%of the total Cd, respectively. Zinc and Pb were dominated by reducible fraction, which is potential pollution source. Pb, As, Hg, Zn, and Cd came mainly from mine mining, metal smelting and other human activities. The geo-accumulation index showed that the studied areas were seriously polluted by Pb, As and Cd, but slightly by Ni and Cr. The soils had not been contaminated by Hg. Some sample points showed mild and moderate Cu pollution.%对北京市水源涵养地平谷金矿及尾矿库土壤重金属(As、Cd、Cu、Pb、Cr、Ni、Zn和Hg)的空间分布特征、形态特征及污染现状进行研究与评价。空间分布图显示,As、Cd、Cu、Pb和Zn显示出基本相同的分布情况,污染相对较严重的区域大部分分布在金矿区及周边,受到人为活动的显著影响;Cr和Ni的空间分布特征表明污染严重的区域为尾矿库矿区周边。采用改进的BCR法提取土壤中重金属形态,采用ICP-OES测定。结果表明,Cd可交换态及易还原态占总量的20%~30%,Zn、Pb的易还原态含量较高,为潜在污染源。利用统计学分析,Pb、As、Hg、Zn、Cd可能来源于矿山的开采、金属冶炼等人为活动。地累积指数评价结果表明,研究区域土壤中8种重金属的含量,除Hg外基本均处于污染状态,其中:Ni、Cr、Hg都处于轻度污染或未污染程度;Cu个别采样点处于偏中

  3. The 1849 gold rush was in California, not the Klondike

    Science.gov (United States)

    Stern, David P.

    In the book review of The Barren Lands: An Epic Search for Diamonds in the North American Arctic (Eos, May 13, 2003), one sentence caught my eye: ``the man who triggered a mining stampede not seen since the Klondike Gold Rush of 1849.''

  4. The black Dutchmen : African soldiers in the Netherlands East Indies

    NARCIS (Netherlands)

    Kessel, van W.M.J.; Kessel, van W.M.J.

    2002-01-01

    Between 1831 and 1872 some 3000 African recruits sailed from Elmina (Gold Coast, now Ghana) to Batavia, the capital of the Netherlands East Indies. They had been recruited to serve in the Dutch colonial army, which throughout most of the 19th century experienced a chronic shortage of European manpow

  5. Coal Mines, Active - Longwall Mining Panels

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Coal mining has occurred in Pennsylvania for over a century. A method of coal mining known as Longwall Mining has become more prevalent in recent decades. Longwall...

  6. Preparation and characterization of magnetic nanoparticles for the on-line determination of gold, palladium, and platinum in mine samples based on flow injection micro-column preconcentration coupled with graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Ye, Juanjuan; Liu, Shuxia; Tian, Miaomiao; Li, Wanjun; Hu, Bin; Zhou, Weihong; Jia, Qiong

    2014-01-01

    A simple and highly selective procedure for on-line determination of trace levels of Au, Pd, and Pt in mine samples has been developed using flow injection-column adsorption preconcentration coupled with graphite furnace atomic absorption spectrophotometry (FI-column-GFAAS). The precious metals were adsorbed on the as-synthesized magnetic nanoparticles functionalized with 4'-aminobenzo-15-crown-5-ether packed into a micro-column and then eluted with 2% thiourea + 0.1 mol L(-1) HCl solution prior to the determination by GFAAS. The properties of the magnetic adsorbents were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). Various experimental parameters affecting the preconcentration of Au, Pd, and Pt were investigated and optimized. Under the optimal experimental conditions, the detection limits of the developed technique were 0.16 ng mL(-1) for Au, 0.28 ng mL(-1) for Pd, and 1.01 ng mL(-1) for Pt, with enrichment factors of 24.3, 13.9, and 17.8, respectively. Precisions, evaluated as repeatability of results, were 1.1%, 3.9%, and 4.4% respectively for Au, Pd, and Pt. The developed method was validated by the analysis of Au, Pd, and Pt in certified reference materials and mine samples with satisfactory results.

  7. Process mining

    DEFF Research Database (Denmark)

    van der Aalst, W.M.P.; Rubin, V.; Verbeek, H.M.W.

    2010-01-01

    Process mining includes the automated discovery of processes from event logs. Based on observed events (e.g., activities being executed or messages being exchanged) a process model is constructed. One of the essential problems in process mining is that one cannot assume to have seen all possible...... behavior. At best, one has seen a representative subset. Therefore, classical synthesis techniques are not suitable as they aim at finding a model that is able to exactly reproduce the log. Existing process mining techniques try to avoid such “overfitting” by generalizing the model to allow for more...... behavior. This generalization is often driven by the representation language and very crude assumptions about completeness. As a result, parts of the model are “overfitting” (allow only for what has actually been observed) while other parts may be “underfitting” (allowfor much more behavior without strong...

  8. Asteroid mining

    Science.gov (United States)

    Gertsch, Richard E.

    1992-01-01

    The earliest studies of asteroid mining proposed retrieving a main belt asteroid. Because of the very long travel times to the main asteroid belt, attention has shifted to the asteroids whose orbits bring them fairly close to the Earth. In these schemes, the asteroids would be bagged and then processed during the return trip, with the asteroid itself providing the reaction mass to propel the mission homeward. A mission to one of these near-Earth asteroids would be shorter, involve less weight, and require a somewhat lower change in velocity. Since these asteroids apparently contain a wide range of potentially useful materials, our study group considered only them. The topics covered include asteroid materials and properties, asteroid mission selection, manned versus automated missions, mining in zero gravity, and a conceptual mining method.

  9. Time series analysis of gold production in Malaysia

    Science.gov (United States)

    Muda, Nora; Hoon, Lee Yuen

    2012-05-01

    Gold is a soft, malleable, bright yellow metallic element and unaffected by air or most reagents. It is highly valued as an asset or investment commodity and is extensively used in jewellery, industrial application, dentistry and medical applications. In Malaysia, gold mining is limited in several areas such as Pahang, Kelantan, Terengganu, Johor and Sarawak. The main purpose of this case study is to obtain a suitable model for the production of gold in Malaysia. The model can also be used to predict the data of Malaysia's gold production in the future. Box-Jenkins time series method was used to perform time series analysis with the following steps: identification, estimation, diagnostic checking and forecasting. In addition, the accuracy of prediction is tested using mean absolute percentage error (MAPE). From the analysis, the ARIMA (3,1,1) model was found to be the best fitted model with MAPE equals to 3.704%, indicating the prediction is very accurate. Hence, this model can be used for forecasting. This study is expected to help the private and public sectors to understand the gold production scenario and later plan the gold mining activities in Malaysia.

  10. Africans and the myth of rural retirement in South Africa, ca 1900-1950.

    Science.gov (United States)

    MacKinnon, Aran S

    2008-06-01

    The South African mining industry relied upon a massive African migrant workforce from the rural areas. Rural transformations in this migrant labor system form an important part of the story of developing capitalism in industrializing South Africa. Yet, recent historical studies on southern African migrant and rural wage labor have paid little attention to life adjustments made by the elderly and those 'burned out' by the mines and forced to leave formal wage employment in the urban areas. The South African segregationist state's rhetoric implied that 'retired' Africans could find economic security in their designated rural reserves. Indeed, legislation sought to prohibit Africans who were not employed from remaining in the 'white' urban areas. By the 1930s, however, the reserves were rapidly deteriorating. Many elderly Africans could not retire and were forced to seek wage labor. This raises significant questions about how retirement came to be defined and experienced by Africans in South Africa during a critical period of dramatic economic decline in the 1930s and 40s, and what the underlying material circumstances of African South Africans were with regard to adaptations to employment and ageing-related life changes. In many cases, elderly Africans were forced to forgo retirement, and find wage labor, usually in the most poorly paid, least sought-after or dangerous fields of employment. This article thus seeks to illuminate critical generational dimensions of the impact of segregation and racism in South Africa prior to the formal articulation of Apartheid.

  11. Data mining

    CERN Document Server

    Gorunescu, Florin

    2011-01-01

    The knowledge discovery process is as old as Homo sapiens. Until some time ago, this process was solely based on the 'natural personal' computer provided by Mother Nature. Fortunately, in recent decades the problem has begun to be solved based on the development of the Data mining technology, aided by the huge computational power of the 'artificial' computers. Digging intelligently in different large databases, data mining aims to extract implicit, previously unknown and potentially useful information from data, since 'knowledge is power'. The goal of this book is to provide, in a friendly way

  12. 新城金矿盲竖井矿石溜井塌方段快速修复施工技术与实践%Construction Technology and Practice in Quick Restoration of the Collapsed Section of the Ore Chute of the Blind Shaft in Xincheng Gold Mine

    Institute of Scientific and Technical Information of China (English)

    付常鹏; 黄永庆; 戚克辉; 周新勍

    2015-01-01

    新城金矿盲竖井矿石溜井在生产过程中-830 m 水平至-930 m 水平井壁多次塌方,大块毛石堵塞下部振动放矿机,造成盲竖井矿石提升系统瘫痪。矿石溜井修复期间,结合现场施工条件,采取简单实用的施工设备,严格按设计要求施工,圆满地完成了该工程,并介绍了该段矿石溜井快速修复的成功经验。%For the ore chute in Xincheng Gold Mine,the ore lifting system broke down in the blind shaft as a result of several collapses of the horizontal well walls ranging from -830m to -930m in production process and subsequent blocking of large bubbles in the lower vibrating ore - drawing machine. In order to repair the failing ore chute,simple and practical construction equipment are used and construction as set out in the design by taking into account field construction conditions are carried out. At the end,the project achieves complete success at a high rate of speed. The article mainly provides successful ways of quick repairing the section of the ore chute.

  13. Gold phytomining. A review of the relevance of this technology to mineral extraction in the 21st century.

    Science.gov (United States)

    Wilson-Corral, Victor; Anderson, Christopher W N; Rodriguez-Lopez, Mayra

    2012-11-30

    The precious metal gold can be found at high concentration in tailings dumps and waste rock piles at many mining locations around the world. Conventional technology is generally unable to economically recover this residual gold, and, as a result, the potential resource is wasted, presenting environmental risk to the wider ecosystem through particulate and dissolved metal leaching and erosion. For the past 14 years, the idea of gold phytomining to recover this gold resource has been researched by various scientific groups worldwide. A number of plant species have been tested under laboratory, greenhouse, and field conditions to determine their potential for use in the phytoextraction of gold. This paper presents a review of reported gold phytomining trials developed in the laboratory, the greenhouse under soil and hydroponic conditions, as well as in the field, between 1998 and 2011. A summary economic assessment for gold phytomining in Mexico is also presented. Mexico is an example of a developing country with a long history of gold mining that has a large resource of sites that might be suitable to gold phytomining. The technology remains limited by certain environmental and plant physiology factors. However, the increase in the market price for gold during the first decade of the 21st century and into 2011, and advances recorded for the gold concentration and biomass yield of a range of plant species, suggest that gold phytomining might be an economically viable technology.

  14. Potencialidades do Pinus pinaster e Cytisus multiflorus na fitoestabilização de escombreiras na mina de ouro de Santo António (Penedono Potencialities of Pinus pinaster and Cytisus multiflorus on the phytostabilization of the Santo António (Penedono gold mine dumps

    Directory of Open Access Journals (Sweden)

    M.M. Abreu

    2007-07-01

    Full Text Available A mina de Santo António, localizada a cerca de 10 km ao norte de Penedono (Viseu, foi um importante centro mineiro, tendo-se aí principalmente explorado o ouro e outros elementos químicos, como o arsénio. Actualmente, todo o complexo mineiro está abandonado e bastante degradado. As escombreiras, cortadas por dois barrancos de grande dimensão, estão sujeitas a intensa erosão eólica e hídrica. Estas apresentam teores totais elevados para vários elementos, dos quais se destacam As, Pb, Cd e Au que atingem, respectivamente, 40 000, 653, 14 e 9,8 mg kg-1 . Estudou-se na área mineira, e em particular na envolvente das escombreiras, os solos e as plantas aí desenvolvidas (Pinus pinaster, Quercus pyrenaica, Castanea sativa, Cytisus multiflorus e uma gramínea do género Agrostis. As águas de drenagem da escombreira não vegetalizada apresentavam valores de pH de 2,58 e teores de As e Cd respectivamente de 160 e 0,05 mg/L. As águas recolhidas a jusante de escombreiras vegetalizadas com pinheiros e giestas, mostraram um decréscimo drástico de todos os elementos, em especial do As que ocorria com valores ambientalmente aceitáveis (The Santo António mine is located 10 km north of Penedono (Viseu, Portugal. This mine was in the first half of the twenty’s century an important gold and arsenic mining centre. Nowadays the mining complex is abandoned and presents high level of physical degradation. The waste dumps crossed by two large gullies are under strong water and wind erosion. The total concentrations of As, Pb, Cd e Au, in the dump material reached values as high as 40 000, 653, 14 and 9,8 mg kg-1, respectively. Soils and native plants as Pinus pinaster, Quercus pyrenaica, Castanea sativa, Cytisus multiflorus and gramineous plants (gen. Agrostis from the mining area and the waste dumps surroundings were collect and analysed. The draining waters from a no vegetated dump presented a pH value of 2.58, and As and Cd concentrations of 160

  15. The South African nuclear industry

    Energy Technology Data Exchange (ETDEWEB)

    Walmsley, John

    1997-07-01

    The history of the South African nuclear industry is outlined and its present status described. Eskom, the state electric utility, generates 5% of its output from two 921MWe PWRs sited at Koeberg near Capetown. A pebble bed variant of the HTGR is being considered as an option for future nuclear power generation. The Atomic Energy Corporation (AEC) in the past developed a complete front-end fuel cycle capability, conversion of the mining output of ammonium diuranate to UF{sub 6}, enrichment and fuel fabrication facilities, post-irradiation facilities for Koeberg fuel and one of the best low level waste repositories in the world. It also designed a nuclear weapon, six of which were built and later dismantled. Recently, government policy has dictated drastic staff reductions at AEC. The enrichment plant has been dismantled and the PWR fuel fabrication is under threat of closure. Considerable effort is being put into Molecular Laser Isotope Separation, in cooperation with the French organisation COGEMA, as a project with good commercial prospects in the medium term. The Council for Nuclear Safety is the licensing authority for Koeberg, AEC activities and mining and minerals processing. Uranium production in the mines has dropped dramatically with South Africa now being eighth in the world ranking whereas at its peak in 1980 it ranked third. (UK).

  16. Introduction of Mercury-free Gold Extraction Methods to Medium-Scale Miners and Education of Health Care Providers to Reduce the use of Mercury in Sorata, Bolivia

    Directory of Open Access Journals (Sweden)

    Peter W. U. Appel

    2015-01-01

    Conclusions. The gold ores tested during the project proved amenable to mercury-free gold extraction using borax smelting. The miners also realized that gold recovery increased when performing mercury-free gold extraction. The miners decided to stop using mercury and a follow-up project cleaned their mining equipment for mercury and modified the processing lines. The health care providers were also successfully trained.

  17. Mercury content in electrum from artisanal mining site of Mongolia

    Energy Technology Data Exchange (ETDEWEB)

    Murao, Satoshi [Geological Survey of Japan, AIST, Higashi 1-1-1, No. 7, Tsukuba 305-8567 (Japan)]. E-mail: s.murao@aist.go.jp; Naito, Kazuki [Geological Survey of Japan, AIST, Higashi 1-1-1, No. 7, Tsukuba 305-8567 (Japan); Dejidmaa, Gunchin [Geological Information Center, Mineral and Petroleum Resources Authority of Mongolia, State Building No. 5, Ulaanbaatar (Mongolia); Sie, Soey H. [CSIRO, P.O. Box 136, North Ryde, NSW 1670 (Australia)

    2006-08-15

    In Mongolia, artisanal gold mining, modern gold rush, in which people use mercury to extract gold, is being proliferated rapidly and the mercury contamination of mining site is becoming a serious social issue. For the risk assessment of mercury, it is necessary to understand how much mercury is introduced to the environment from what kind of materials during mining activity. It is already known that major contribution of the contamination comes from mercury that was bought at shops and brought to mining sites by miners. However, no information is available on how much mercury is removed from electrum (natural gold grain) to the environment. Since gold deposit is always accompanied by mercury anomaly, it is anticipated that electrum grains contain some amount of mercury of natural origin, and this mercury (primary mercury) contributes to some extent to the contamination. In order to clarify how much mercury is incorporated in electrum grains, micro-PIXE at CSIRO was used for grain-by-grain analysis. The result showed that electrum from study area contains mercury up to 8260 ppm. It is concluded that for the risk management of mercury contamination, release of natural mercury from electrum grains during smelting must not be ignored.

  18. Distribution Characteristics and Risk Assessment of Mercury Pollution in the River Water and Sediment of the Songhua River Upstream Gold Mining Area%松花江上游金矿开采区河流水体和沉积物中汞的污染特征及风险评估

    Institute of Scientific and Technical Information of China (English)

    李雅芬; 王景; 王宁

    2013-01-01

    The distribution characteristic of mercury pollution caused by gold mining and transformation rules of mercury and methylmercury were studied through collecting water and sediment samples of the river near the Jiapigou goldfield located in the upper reaches of the Songhua River. The results show that total mercury content of the upstream river water is higher than the downstream river water, in particular, the mercury content reduces with increasing distance from the mining area when the river is near gold mine. However, in the sediment, the higher total mercury content is found in the lower reaches of the river and upper stream samples show lower total mercury content. Both of the highest total mercury content and methylmercury content of water samples are detected in the jiapigou river section, which is 0.86 μg·L-1 and 4.14 ng·L-1 respectively. The highest total mercury content of sediment samples is detected in the laojinchang river section, and the highest methylmercury content of sediment samples is detected in the erdaogou river section, which is 9.00 mg·kg-1 and 4.02 μg·kg-1 respectively. The results of mercury and methylmercury assessment show that severe mercury pollution is found in 22.22% of the river water and moderate mercury pollution is found in the else river section, and methylmercury pollution is severe in whole river water based on single factor index method. It can be found that the mercury pollution in the river sediment is very serious based on the geo-accumulation pollution index method and the potential ecological risk assessment method. The pollution situation is high environmental risk and ecological risk, it should be paid high attention by people.%通过采集松花江上游夹皮沟金矿开采区附近河流的水和沉积物样品,研究了因金矿开采带来的汞和甲基汞污染的分布特征和规律.结果表明:该区域河流水中总汞含量的分布规律表现为河流上游高于下游,尤其是有金矿的河

  19. Controls on gold deposits in Hoggar, Tuareg Shield (Southern Algeria)

    Science.gov (United States)

    Aissa, Djamal-Eddine; Marignac, Christian

    2017-03-01

    The Hoggar shield belongs to the 3000 km-long Pan-African Trans-Saharan belt that was formed in the Neoproterozoic, between 750 and 500 Ma by continental collision between the converging West African craton, Congo craton and Saharan Metacraton. More than 600 gold occurrences have been identified by ORGM, which are confined along North-South Pan-African megashear zones stretching some hundreds of kilometres long. Until now, no global classification and mineral paragenesis characterisation have been proposed for the Hoggar's gold mineralization. In this paper, we briefly review the main gold mineralization, in order to classify them and to highlight their characteristics and controls. According to field work, spectral, microscopic and microthermometric studies, these mineralization can be globally classified asorogenic type shear zone, which can subdivided into three main sub-types according to the degree of their relationships with the major Pan-African shear zones: (i) Ultramylonite-mylonite hosted including Tirek and Amesmessa, world class deposits; (ii) Granite hosted, including Tekouyat occurrence (iii) Volcano-sediment hosted including Tiririne and In Abbegui deposits. All the deposits are coeval and were formed at the end of the post-collisional stage (530-520 Ma). InHoggar, gold mineralization depend on a double control, first order giant sub-meridian shear zone control and the gold districts disposed in N40°-50°E corridors that may be interpreted as extensional. Indeed, the Hoggar gold province appears to have been controlled at all scales by the late transtensive reactivation of the Pan-African mega-shear zones, and by the correlative heat flux associated with the linear lithospheric delamination processes accompanying this reactivation; which are also responsible for the very lateHoggar magmatic events. At Amesmessa, gold deposition was promoted by the mixing of metamorphic fluids issued from the In Ouzzal Archean-Proterozoic basement with magmatic

  20. Mining Method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Shik; Lee, Kyung Woon; Kim, Oak Hwan; Kim, Dae Kyung [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

    1996-12-01

    The reducing coal market has been enforcing the coal industry to make exceptional rationalization and restructuring efforts since the end of the eighties. To the competition from crude oil and natural gas has been added the growing pressure from rising wages and rising production cost as the workings get deeper. To improve the competitive position of the coal mines against oil and gas through cost reduction, studies to improve mining system have been carried out. To find fields requiring improvements most, the technologies using in Tae Bak Colliery which was selected one of long running mines were investigated and analyzed. The mining method appeared the field needing improvements most to reduce the production cost. The present method, so-called inseam roadway caving method presently is using to extract the steep and thick seam. However, this method has several drawbacks. To solve the problems, two mining methods are suggested for a long term and short term method respectively. Inseam roadway caving method with long-hole blasting method is a variety of the present inseam roadway caving method modified by replacing timber sets with steel arch sets and the shovel loaders with chain conveyors. And long hole blasting is introduced to promote caving. And pillar caving method with chock supports method uses chock supports setting in the cross-cut from the hanging wall to the footwall. Two single chain conveyors are needed. One is installed in front of chock supports to clear coal from the cutting face. The other is installed behind the supports to transport caved coal from behind. This method is superior to the previous one in terms of safety from water-inrushes, production rate and productivity. The only drawback is that it needs more investment. (author). 14 tabs., 34 figs.

  1. Planning the Mine and Mining the Plan

    Science.gov (United States)

    Boucher, D. S.; Chen, N.

    2016-11-01

    Overview of best practices used in the terrestrial mining industry when developing a mine site towards production. The intent is to guide planners towards an effective and well constructed roadmap for the development of ISRU mining activities. A strawman scenario is presented as an illustration for lunar mining of water ice.

  2. Application of the superfine fraction analysis method in ore gold geochemical prospecting in the Shamanikha-Stolbovsky Area (Magadan Region)

    Science.gov (United States)

    Makarova, Yuliya; Sokolov, Sergey; Glukhov, Anton

    2014-05-01

    The Shamanikha-Stolbovsky gold cluster is located in the North-East of Russia, in the basin of the Kolyma River. In 1933, gold placers were discovered there, but the search for significant gold targets for more than 50 years did not give positive results. In 2009-2011, geochemical and geophysical studies, mining and drilling were conducted within this cluster. Geochemical exploration was carried out in a modification based on superimposed secondary sorption-salt haloes (sampling density of 250x250 m, 250x50 m, 250x20 m) using the superfine fraction analysis method (SFAM) because of complicated landscape conditions (thick Quaternary sediments, widespread permafrost). The method consists in the extraction of superfine fraction (quartz formation are identified within the anomalous geochemical field core zone. 3. In all these prospects, mining and drilling penetrated gold ore bodies within the identified potentially gold zones. The Nadezhda target now has the status of gold deposit.

  3. Heart Disease and African Americans

    Science.gov (United States)

    ... Minority Population Profiles > Black/African American > Heart Disease Heart Disease and African Americans Although African American adults are ... were 30 percent more likely to die from heart disease than non-Hispanic whites. African American women are ...

  4. Exploring the techno-economic feasibility of mine rock waste utilisation in road works: The case of a mining deposit in Ghana.

    Science.gov (United States)

    Agyeman, Stephen; Ampadu, Samuel I K

    2016-02-01

    Mine rock waste, which is the rock material removed in order to access and mine ore, is free from gold processing chemical contaminants but presents a significant environmental challenge owing to the large volumes involved. One way of mitigating the environmental and safety challenges posed by the large volume of mine rock waste stockpiled in mining communities is to find uses of this material as a substitute for rock aggregates in construction. This article reports on a study conducted to evaluate the engineering properties of such a mine deposit to determine its suitability for use as road pavement material. Samples of mine rock waste, derived from the granitic and granodioritic intrusive units overlying the gold-bearing metavolcanic rock and volcano-clastic sediments of a gold mining area in Ghana, were obtained from three mine rock waste disposal facilities and subjected to a battery of laboratory tests to determine their physical, mechanical, geotechnical, geometrical and durability properties. The overall conclusion was that the mine rock waste met all the requirements of the Ghana Ministry of Transportation specification for use as aggregates for crushed rock subbase, base and surface dressing chippings for road pavements. The recommendation is to process it into the required sizes for the various applications.

  5. Gold resource modeling using pod indicator kriging

    Science.gov (United States)

    Bargawa, Waterman Sulistyana; Rauf, Abdul; Amri, Nur Ali

    2016-02-01

    This paper describes an implementation of the pod indicator kriging method used to gold resource modeling. Method such as ordinary kriging estimate the mean grade of a block that is fairly large. The usual outcome is that large blocks rarely turn out to be all ore or all waste, thus making reserve estimates an incorrect estimate of what will be mined. Pod indicator kriging offers a solution to this problem by estimating the distribution of grade values within a large block, rather than just estimating the mean grade of the block. Knowing the distribution of grade value within the block, it is then easy to calculate the proportion of the block that is above cutoff grade and the grade of the ore above cutoff grade. This research shows that the pod indicator kriging model is quite applicable and reliable in gold resourcemodeling.

  6. Inner Mongolia Wunugetu Copper & Molybdenum Mine Launched into Full-load Trial Run

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>Recently,the Inner Mongolia Wunugetu Moun-tain Copper and Molybdenum Mine officially entered full load trial operation stage.This Pro-ject is constructed by Inner Mongolia MiningCo Ltd under the China National Gold GroupCorporation with an initial investment of

  7. Metal contamination in environmental media in residential areas around Romanian mining sites

    Science.gov (United States)

    Hard-rock mining for metals, such as gold, silver, copper, zinc, iron and others, is recognized to have a significant impact on the environmental media, soil and water, in particular. Toxic contaminants released from mine waste to surface water and groundwater is the primary co...

  8. Depression and African Americans

    Science.gov (United States)

    ... You are here Home » Depression And African Americans Depression And African Americans Not “Just the Blues” Clinical ... or spiritual communities. Commonly Asked Questions about Clinical Depression How do I get help for clinical depression? ...

  9. The relative valuation of gold

    OpenAIRE

    Baur, Dirk G.; Beckmann, Joscha; Czudaj, Robert

    2016-01-01

    Gold is a globally traded asset and held in large quantities by investors and central banks. Since there is no established model to assess if the price of gold is overvalued or undervalued, we propose a relative valuation framework based on gold price ratios. We analyze gold prices relative to commodity prices, consumer prices, stock prices, dividend and bond yields and find that the relative value of gold varies significantly over time indicating pronounced periods of mispricing of gold rela...

  10. Controle da transmissão da malária em área de garimpo no Estado do Amapá com participação da iniciativa privada Control of malaria transmission in a gold-mining area in Amapá State, Brazil, with participation by private enterprise

    Directory of Open Access Journals (Sweden)

    Álvaro Augusto Couto

    2001-08-01

    Full Text Available Reportamos no presente trabalho a caracterização epidemiológica da malária, seguida da implantação de um programa de controle da endemia em uma área de garimpo, localizada ao norte do estado do Amapá. Considera-se a influência desta região no número total de casos do estado e o impacto da doença na população representada pelos funcionários e empreiteiros da Mineração Novo Astro S/A, bem como pela comunidade da Vila de Lourenço, Município de Calçoene, Amapá e garimpos adjacentes. O impacto das ações de controle adotadas no âmbito do programa, caracterizam-se pela significativa redução da incidência da malária na área e a redução da morbi-mortalidade. Ressalta-se a importância da participação da iniciativa privada, principalmente aquelas que desenvolvem projetos de grande porte na região Amazônica brasileira, no controle das endemias prevalentes na região, particularmente a malária.This paper reports on the epidemiological characterization of malaria following implementation of a program to control the endemic in a gold-mining area in northern Amapá State. The study focuses on total malaria cases in Amapá and the impact of the disease on the population, as represented by the Mineração Novo Astro S/A company and its employees as well as the community of Vila de Lourenço in the municipality of Calçoene, and adjacent gold miners. The effect of control measures in the program area is indicated by a significant reduction in malaria incidence and malaria-related morbidity and mortality. The importance of participation by private enterprise is emphasized, particularly in large projects for the control of endemic diseases (notably malaria in the Amazon Region.

  11. Development of opencast mines

    Energy Technology Data Exchange (ETDEWEB)

    Szebenyi, F.

    1987-01-01

    The role and works of the Central Institute for Mining Development and its legal predecessors, the Mining Research Institute and Mines Design Institute, in relation with opencast lignite mining in Hungary, are summarized. Investigations aimed at the determination of the heating technical properties of lignites are reviewed. Different lignite mines, their geological features, production possibilities and development conditions are outlined.

  12. Characteristics of Gold(Molybdenum) Mineralization in Shimengou Mine of Song County and Ore-finding Prospect%嵩县大石门沟矿区钼矿化特征及找矿前景分析

    Institute of Scientific and Technical Information of China (English)

    郭学志; 莫鸿飞

    2014-01-01

    Based on the great progress in mine-finding in No.25 gold (molybdenum) vein and No. 201 molybdenum vein in Dashimengou Mine in Song County. Regional geology, formation and lithology, geologic tectonic structure, parent-rock alteration, physical and chemical characteristics and mineralization features are analyzed. It is found that the geological condition is favorable to mineralization of gold and polymetallic ore in the Dashimengou mine area. It is concluded that study of the characteristics of polymetallic mineralization in the area is of great significance to guiding ore-finding in the area.%嵩县大石门沟矿区 25 号脉钼矿和 201号钼矿脉找矿取得重大突破,对区内成矿的区域地质特征、地层岩性、地质构造、围岩蚀边变、物化探特征、矿产特征等特征进行了分析研究,认为矿区成矿区域有利, 成矿地质条件优越,是钼和多金属成矿的有利地区。因此,研究区内钼等多金属矿化特征,对指导该区找矿具有十分重要的意义。

  13. Causes and consequences of a tropical forest gold rush in the Guiana Shield, South America.

    Science.gov (United States)

    Hammond, David S; Gond, Valéry; de Thoisy, Benoit; Forget, Pierre-Michel; DeDijn, Bart P E

    2007-12-01

    Statistical and spatial analyses of both historical time series and remotely sensed data show a link between the spatial distribution and growth of gold production across the Guiana Shield in northeast Amazonia. Results indicate that an exponential rise in production across an expanding area is primarily a delayed response to the 1971-1978 market flotation of international gold prices. The subsequent 10-fold (2-fold) average nominal (real) price increase has provided a compelling economic incentive to mass exploitation of lower-grade gold deposits. The ground-based and remotely sensed distributions of mining activity are strongly attached to these deposits that dominate the region's gold geology. The presence of these gold-bearing formations in conservation and sustainable timber zones has sparked social conflict and environmental degradation across the region. Left unmanaged, more than a quarter-million square-kilometer area of tropical forest zoned for protection and sustainable management could ultimately be compromised by the price-driven boom in gold mining through poorly integrated resource use planning, lack of reclamation effort, and control of illegal operations. Serious public health issues propagated through the unregulated mining environment further erode the financial benefits achieved through gold extraction. This study demonstrates in part how international economic policies successfully stabilizing more conspicuous centers of the global economy can have unintended but profound environmental and social impacts on remote commodity frontiers.

  14. Gold in the Books

    Institute of Scientific and Technical Information of China (English)

    江河

    2002-01-01

    In the present Chinese market, more and more businessmen turn to the profit-making trade. Even some counters in the bookstores are selling gold rings, necklaces, bracelets, etc. One day a school teacher asked a store assistant,“Why are you selling gold in your bookstore?”

  15. 渭河下游某金矿排水渠附近土壤中Ag、Ni、Cd和Mo的污染分析%Analysis of soil contamination by Ag, Ni, Cd and Mo along a gold mine drainage canal down Weihe River

    Institute of Scientific and Technical Information of China (English)

    李庚飞

    2012-01-01

    The soil around a gold mine near Weihe River was chosen as the research object, and the contents of heavy metals were analyzed including silver, nickel, cadmium and molybdenum, so as to provide the theoretical basis for treating soil contamination and establishing the artificial ecological restoration system. The results show that the Nemerow comprehensive pollution indexes of the soil are all more than 3 in all sampling area and they are in gross pollution. The contents of silver, nickel, cadmium and molybdenum are all very high in all sample regions with the average contents in the descending order nickel > cadmium > silver > molybdenum. The descending order according to the single factor pollution index is cadmium > silver > molybdenum > nickel. The variation coefficients of all heavy metals are the highest in the fourth sample region, and the contents distribution of all heavy metals is inhomogeneous. It may be caused by other pollution sources. The main pollution sources may be caused by the irrigation and diffusion of waste water,the mineral waste residue dust and vehicle and so on in the mine area.%以渭河附近某金矿排水沟周边土壤为研究对象,对土壤中Ag、Ni、Cd和Mo 4种重金属含量进行分析,为渭河周围土壤污染治理及人工生态修复提供依据.实验结果表明,5个样区内梅罗综合污染指数均大于3,处于严重污染状态;Ag、Ni、Cd和Mo在5个样区中含量均很高,其平均值总体存在Ni> Cd> Ag>Mo;各重金属单项污染指数值总体存在Cd>Ag> Mo>Ni;第4样区重金属变异系数较大,各样点重金属含量分布不均一,外源污染严重.各样区污染主要来源于矿区废水排放与灌溉,以及废渣粉尘和车辆扬尘等.

  16. Linguistic Imperialism: African Perspectives.

    Science.gov (United States)

    Phillipson, Robert

    1996-01-01

    Responds to an article on aspects of African language policy and discusses the following issues: multilingualism and monolingualism, proposed changes in language policy from the Organization for African Unity and South African initiatives, the language of literature, bilingual education, and whose interests English-language teaching is serving.…

  17. Resource and Geological Characteristics of Gold Deposits in India%印度共和国金矿资源及其地质特征

    Institute of Scientific and Technical Information of China (English)

    成功; 邱献引; 孙卫宾; 李尚林; 罗彦军

    2015-01-01

    India’s gold mine has four basic types:greenstone belt type,conglomerate-type,alluvial gold mine and associated gold mine.India’s gold mine has a feature of wide distribution,relative concentration,less large and rich mineral deposits,and the great depth and so on.Greenstone type gold mine which is the most important gold type in India,concentrates Precambrian greenstone belt in South India craton and central India craton.Kolar gold mine and Hutii gold mine in the East of Darwar craton in south India are typical greenstone type gold mines. Kolar gold mine is a super-giant gold deposit with an average gold grade of 16 g/t,and gold reserves > 1 000 t;Hutti gold mine is a large gold deposit with an average grade of 4.85 g/t,and gold reserves >150 t.The proved reserves of India’s gold mine is very limited,but a lot of smaller gold deposits are widely distributed in India craton greenstone belts,which indicates there is a very good potential of gold resource.Increasing the investment in the exploration and development of India’s gold mine will make more gold resources with great value be discovered and may also completely change the status quo of India gold.%印度金矿类型主要有4种:绿岩型、砾岩型、砂金及伴生金矿,具有分布广、相对集中、规模小、品位低及埋深较大等特点。绿岩型金矿是印度最重要的金矿类型,集中分布在南印度克拉通和印度中央克拉通的前寒武系绿岩带中。南部东塔尔瓦尔克拉通的科拉尔金矿和胡蒂金矿是典型的绿岩型金矿,其中,科拉尔金矿金平均品位为16 g/t,黄金储量>1000 t,属于超大型金矿床;胡蒂金矿金平均品位为4.85 g/t,黄金储量>150 t,属于大型金矿床。印度金矿探明储量十分有限,但大量较小规模金矿广泛分布在印度克拉通绿岩带,预示印度金矿具有很好的资源潜力。增加印度金矿勘探和开发投入,将发现更多具有重要价值的金

  18. Exploration and Mining Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2002-09-01

    This Exploration and Mining Technology Roadmap represents the third roadmap for the Mining Industry of the Future. It is based upon the results of the Exploration and Mining Roadmap Workshop held May 10 ñ 11, 2001.

  19. Coal Mine Permit Boundaries

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — ESRI ArcView shapefile depicting New Mexico coal mines permitted under the Surface Mining Control and Reclamation Act of 1977 (SMCRA), by either the NM Mining these...

  20. Artisanal and small scale mining in India: selected studies and an overview of the issues

    Energy Technology Data Exchange (ETDEWEB)

    Mihir Deb; Garima Tiwari; Kuntala Lahiri-Dutt [University of Delhi, Delhi (India). School of Environmental Studies

    2008-09-15

    In India, mining is one of the main economic activities since time immemorial, giving rise to a long historical tradition of artisanal mining. As modern mining rose during the colonial occupation, artisanal mining activities began to be overlooked and this great tradition became obscure. This invisibility, added with confusion with regard to legally accepted definitions has enhanced the negligence of the artisanal mining sector in India. This study draws attention to the contemporary artisanal mining practices in India - both traditional and non-traditional ones - with regard to four commodities, gold, tin, coal and lignite, and gemstones. It briefly discusses the occurrences of such mining, their salient features and concludes with four specific recommendations. Recommendations primarily deal with the need for creation of a broader information base, delineating a responsible body to deal with this kind of mining, legal reforms leading to definitional changes and finally, the recognition of the poverty alleviation potential of this sector in view of the Millennium Development Goals.

  1. Characterization of the potential mercury contamination in the Apolobamba gold mining area, Bolivia Caracterización de la contaminación potencial por mercurio en el área minera de Apolobamba, Bolivia Caracterizaçao da potencial contaminaçao por mercúrio na área mineira de Apolobamba, Bolívia

    Directory of Open Access Journals (Sweden)

    José A. Acosta

    2011-11-01

    Full Text Available

    A large amount of Hg is used for gold extraction through the amalgamation process in the Apolobamba gold mining area located in the northwest part of La Paz, Bolivia. This mining operation may produce a very serious impact on the ecosystems, as well as on the health of miners and inhabitants, mainly due to the primitive methods used in the gold recovery. The objective of this work was to characterize the potential contamination of total Hg in soils, sediments, water, and plants in a mining area of Bolivia. Results showed that there was atmospheric deposition of Hg in the study area. Accumulation of this metal in the studied soils and sediments was one of the highest in the world, but Hg in aquatic solution was below the detection limit of the analytical method of the studied lakes and rivers. The highest concentration of Hg was found in the river sediments of the Sunchullí- Viscachani (102 mg kg-1, and in the sediments of Sunchullí and Viscachani lakes (12.3 and 11.7 mg kg-1, respectively. These concentrations may pose a serious problem for aquatic life, related ecosystems and human health. Therefore, there is a need to study Hg availability and speciation in soils and sediments to better understand the cycling of Hg in the area.

    Una gran cantidad de Hg se utiliza para la extracción de oro mediante el proceso de amalgamación en la zona minera de Apolobamba, localizada al noroeste de La Paz, Bolivia. Este tipo de actividad puede estar generando un impacto muy grave tanto para los ecosistemas, como para la salud de los mineros y habitantes de la zona, principalmente debido a los métodos poco tecnificados utilizados en la recuperación del oro. El objetivo de este estudio fue caracterizar la contaminación potencial que supone la presencia de Hg total en suelos, sedimentos, agua y plantas. Los resultados mostraron que existía una deposición atmosf

  2. 16 CFR Appendix to Part 23 - Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled...

    Science.gov (United States)

    2010-01-01

    ... Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate, Silver, and Platinum Industry...—Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate... be considered in any assay for quality of a gold filled, gold overlay and rolled gold plate...

  3. Flooding of S. Dakota mine stalls plans for laboratory

    CERN Multimedia

    Chang, K

    2003-01-01

    The owner of a former gold mine in South Dakota turned off the pumps allowing water to begin accumulating in the tunnels below ground. The site had previously been proposed as the location for a new underground particle physics and astronomy laboratory (1 page).

  4. Mining review

    Science.gov (United States)

    McCartan, L.; Morse, D.E.; Plunkert, P.A.; Sibley, S.F.

    2004-01-01

    The average annual growth rate of real gross domestic product (GDP) from the third quarter of 2001 through the second quarter of 2003 in the United States was about 2.6 percent. GDP growth rates in the third and fourth quarters of 2003 were about 8 percent and 4 percent, respectively. The upward trends in many sectors of the U.S. economy in 2003, however, were shared by few of the mineral materials industries. Annual output declined in most nonfuel mining and mineral processing industries, although there was an upward turn toward yearend as prices began to increase.

  5. Coal Mines, Abandoned - Digitized Mined Areas

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Coal mining has occurred in Pennsylvania for over a century. The maps to these coal mines are stored at many various public and private locations (if they still...

  6. Wikipedia Mining

    Science.gov (United States)

    Nakayama, Kotaro; Ito, Masahiro; Erdmann, Maike; Shirakawa, Masumi; Michishita, Tomoyuki; Hara, Takahiro; Nishio, Shojiro

    Wikipedia, a collaborative Wiki-based encyclopedia, has become a huge phenomenon among Internet users. It covers a huge number of concepts of various fields such as arts, geography, history, science, sports and games. As a corpus for knowledge extraction, Wikipedia's impressive characteristics are not limited to the scale, but also include the dense link structure, URL based word sense disambiguation, and brief anchor texts. Because of these characteristics, Wikipedia has become a promising corpus and a new frontier for research. In the past few years, a considerable number of researches have been conducted in various areas such as semantic relatedness measurement, bilingual dictionary construction, and ontology construction. Extracting machine understandable knowledge from Wikipedia to enhance the intelligence on computational systems is the main goal of "Wikipedia Mining," a project on CREP (Challenge for Realizing Early Profits) in JSAI. In this paper, we take a comprehensive, panoramic view of Wikipedia Mining research and the current status of our challenge. After that, we will discuss about the future vision of this challenge.

  7. Mineralization Types of Gold in Central Inner Mongolia, China

    Institute of Scientific and Technical Information of China (English)

    Liang Yihong; Zhang Hongying

    2000-01-01

    There are four mineralization types of gold in Central Inner Mongolia: mylonite type, quartz vein type, quartzpotash- feldspar vein type and alteration type.Ore bodies of mylonite type were controlled by ductile shear zone. Both of ore and gangue minerals were undergone ductile deformation. Mineralization age is about 2040Ma and represents the metallogenetic process in deep tectonic level.There are three types of quartz veins differed from genesis mechanism. Small scaled, lens- shaped quartz veins formed during ductile shearing are found in mylonite ore bodies. Decation quartz veins are in the ore bodies of alteration type. Infiltration quartz veins are main gold- bearing bodies for some gold deposits such as Bainaimiao and Saiwusu gold mines. It also occurred in many other deposits from the middle Proterozoic to the Mesozoic.Quartz potash- feldspar veins are observed in the Palaeozoic and occurred in middle tectonic level.Gold deposits of alteration type such as Donghuofang and Saihudong occurred in shallow tectonic level of the Mesozoic.In short, from the Proterozoic to the Mesozoic, mineralization types varied from mylonite type to quartz potash- feldspar vein type and to alteration type. Gold - bearing quartz veins changed from syn - ductile - shearing quartz vein to infiltration vein and to decation quartz vein. Mineralization developed from deep to middle and to shallow level.

  8. Prelude to Gold

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    FEMALE Chinese athletes Fu Mingxia and Wang Junxia recorded outstanding performances at 1996 Atlanta Olympic Games. Fu Mingxia won gold medals in both platform and springboard diving, and in so doing became the first double medal winner in Olympic diving since 1960. Wang Junxia, the holder of several world records in women’s long distance events, struggled against the odds and captured gold in the 5,000-meter event,

  9. Discussion on Precautions against the Law Risk of African Investment of Chinese Mining Companies -In the Perspective of Chinese Mining Companies in Zambia%论中资矿业企业非洲投资法律风险的防范--以赞比亚中资矿业企业为视角

    Institute of Scientific and Technical Information of China (English)

    乔慧娟

    2014-01-01

    This paper first introduces the main legal risks that Chinese mining companies faced: war and internal violence, nationalization, changes in the law, employment, environmental protection, and safety in production. On account of this, this paper proposes that before the investment, Chinese mining companies should fully understand the legal environment of the host country, and accede to stabilization clause in the investment agreement. At the same time, the political risk that we are likely to encounter should be arranged insurance. The law of host country must be abided by strictly. In addition, overseas investment legal risk prevention mechanism should be established inside the enterprises.%中资矿业企业非洲矿业投资面临的主要法律风险(含政治风险)有战争和内乱、国有化、法律变动、劳工雇佣、环境保护及安全生产等风险。建议中资矿业企业在非投资前要充分了解东道国法律环境,在投资协议中加入“稳定条款”,对可能遇到的政治风险进行投保,并且要严格遵守东道国法律,在企业内部建立海外投资法律风险防范机构。

  10. National Underground Mines Inventory

    Science.gov (United States)

    1983-10-01

    08 019 726 LONG PARK 15 0502379 08 095 2904 GEO a1 MINE 0502383 08 085 2904 BESSIE 0 MINE 0502387 08 667 2904 PAYSTREAK 0502397 08 113 2904 BUENO MILL...35 061QUESTA MINE 2901267 35 055 43560 ’ RUDY NO, I S 2 2901364 35 031 MT, TAYLOR 2901375 35 061 0 MARQUEZ SHAFT 2901597 35 031 6534 MARIANO LAKE MINE

  11. Mining lore : Bankhead, mining for coal

    Energy Technology Data Exchange (ETDEWEB)

    Nichiporuk, A.

    2007-09-15

    Bankhead, Alberta was one of the first communities to be established because of mining. It was founded in 1903 by the Canadian Pacific Railway (CPR) on Cascade Mountain in the Bow River Valley of Banff National Park. In 1904, Mine No. 80 was opened by the Pacific Coal Company to fuel CPR's steam engines. In order to avoid flooding the mine, the decision was made to mine up the steep seams instead of down. The mine entered full production in 1905. This article described the working conditions and pay scale for the mine workers, noting that there was not much in terms of safety equipment. There were many accidents and 15 men lost their lives at the mine. During the mine's 20-year operation, miners went on strike 6 times. The last strike marked the closure of the mine in June 1922 and the end of industry in national parks. CPR was ordered to clear out and move the mining equipment as well as the houses, buildings and essentially the entire town. During its peak production, Mine No. 80 produced about a half million tons of coal. 1 ref., 1 fig.

  12. Seeking a Valid Gold Standard for an Innovative, Dialect-Neutral Language Test

    Science.gov (United States)

    Pearson, Barbara Zurer; Jackson, Janice E.; Wu, Haotian

    2014-01-01

    Purpose: In this study, the authors explored alternative gold standards to validate an innovative, dialect-neutral language assessment. Method: Participants were 78 African American children, ages 5;0 (years;months) to 6;11. Twenty participants had previously been identified as having language impairment. The Diagnostic Evaluation of Language…

  13. Reading the African context

    Directory of Open Access Journals (Sweden)

    Musonda Bwalya

    2012-12-01

    Full Text Available There is so much alienation, pain and suffering in our today�s world. In this vein, African Christianity, a voice amongst many voices, should seek to be a transformational religion for the whole of life, affecting all facets of human life towards a fuller life of all in Africa. This article sought to highlight and point to some of the major societal challenges in the African context which African Christianity, as a life-affirming religion, should continue to embrace, re-embrace and engage with, if it has to be relevant to the African context. In this vein, the article argued that a correct reading of the African context would lead to a more relevant theory and praxis of African Christianity for the benefit of all African peoples and their global neighbours. The contention of this article was that