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Sample records for lakes ore carriers

  1. Aluminum substitution in goethite in lake ore

    Directory of Open Access Journals (Sweden)

    Carlson, L.

    1995-06-01

    Full Text Available The extent of substitution of Fe by Al in goethite in 32 lake ore samples collected from 11 lakes in Finland varied between 0 and 23 mol-%. The data indicated a negative relationship between Al-substitution and the particle size of lake ore. Differences in the Al-substitution were apparent between sampling sites, suggesting that kinetic and environmental variation in lake ore formation influences the substitution. Non-substituted goethite is formed in coarse-grained sediments with locally high concentrations of Fe due to iron-rich springs. Unit cell edge lengths and volumes of goethite varied as function of Al-subsitution but deviated from the Vegard relationship towards higher values.

  2. Estimation of springing response for 550 000 DWT ore carrier

    Science.gov (United States)

    Adenya, Christiaan Adika; Ren, Huilong; Li, Hui; Wang, Di

    2016-09-01

    The desire to benefit from economy of scale is one of the major driving forces behind the continuous growth in ship sizes. However, models of new large ships need to be thoroughly investigated to determine the carrier's response in waves. In this work, experimental and numerical assessments of the motion and load response of a 550,000 DWT ore carrier are performed using prototype ships with softer stiffness, and towing tank tests are conducted using a segmented model with two schemes of softer stiffness. Numerical analyses are performed employing both rigid body and linear hydroelasticity theories using an in-house program and a comparison is then made between experimental and numerical results to establish the influence of stiffness on the ore carrier's springing response. Results show that softer stiffness models can be used when studying the springing response of ships in waves.

  3. Natural Ores as Oxygen Carriers in Chemical Looping Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Hanjing; Siriwardane, Ranjani; Simonyi, Thomas; Poston, James

    2013-08-01

    Chemical looping combustion (CLC) is a combustion technology that utilizes oxygen from oxygen carriers (OC), such as metal oxides, instead of air to combust fuels. The use of natural minerals as oxygen carriers has advantages, such as lower cost and availability. Eight materials, based on copper or iron oxides, were selected for screening tests of CLC processes using coal and methane as fuels. Thermogravimetric experiments and bench-scale fixed-bed reactor tests were conducted to investigate the oxygen transfer capacity, reaction kinetics, and stability during cyclic reduction/oxidation reaction. Most natural minerals showed lower combustion capacity than pure CuO/Fe{sub 2}O{sub 3} due to low-concentrations of active oxide species in minerals. In coal CLC, chryscolla (Cu-based), magnetite, and limonite (Fe-based) demonstrated better reaction performances than other materials. The addition of steam improved the coal CLC performance when using natural ores because of the steam gasification of coal and the subsequent reaction of gaseous fuels with active oxide species in the natural ores. In methane CLC, chryscolla, hematite, and limonite demonstrated excellent reactivity and stability in 50-cycle thermogravimetric analysis tests. Fe{sub 2}O{sub 3}-based ores possess greater oxygen utilization but require an activation period before achieving full performance in methane CLC. Particle agglomeration issues associated with the application of natural ores in CLC processes were also studied by scanning electron microscopy (SEM).

  4. Estimation of Springing Response for 550 000 DWT Ore Carrier

    Institute of Scientific and Technical Information of China (English)

    Christiaan Adika Adenya; Huilong Ren; Hui Li; Di Wang

    2016-01-01

    The desire to benefit from economy of scale is one of the major driving forces behind the continuous growth in ship sizes. However, models of new large ships need to be thoroughly investigated to determine the carrier’s response in waves. In this work, experimental and numerical assessments of the motion and load response of a 550,000 DWT ore carrier are performed using prototype ships with softer stiffness, and towing tank tests are conducted using a segmented model with two schemes of softer stiffness. Numerical analyses are performed employing both rigid body and linear hydroelasticity theories using an in-house program and a comparison is then made between experimental and numerical results to establish the influence of stiffness on the ore carrier’s springing response. Results show that softer stiffness models can be used when studying the springing response of ships in waves.

  5. Morphological Comparison of U3O8 Ore Concentrates from Canada Key Lake and Namibia Sources

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Daniel S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tandon, Lav [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Patrick Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-11

    Uranium ore concentrates from two different sources were examined using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The ore powders are referred to as Namibia (id. no. 90036, LIMS id. no. 18775) and Canada Key Lake (id. no. 90019, LIMS id. no. 18774). Earlier work identified the ores as the U₃O₈ phase of uranium oxide using x-ray diffraction. Both sets of powders were in the form of dark brown to black powder fines. However, the Canada Key Lake concentrates contained larger chunks of material on the millimeter scale that were easily visible to the unaided eye. The powders were mounted for SEM examination by hand dispersing a small amount onto conductive sticky tape. Two types of applicators were used and compared: a fine-tipped spatula and a foam-tipped applicator. The sticky tape was on a standard SEM “tee” mount, which was tapped to remove loose contamination before being inserted into the SEM.

  6. MERCURY IN METAL ORE DEPOSITS: AN UNRECOGNIZED, WIDESPREAD SOURCE TO LAKE SUPERIOR SEDIMENTS, CONTRIBUTION #1072

    Science.gov (United States)

    Mining operations have worked the rich mineral resources of the Lake Superior Basin for over 150 years, leaving industrially impacted regions with tailing piles and smelters. In Lake Superior sediments, mercury and copper inventories increase towards shorelines and are highly cor...

  7. MERCURY IN METAL ORE DEPOSITS: AN UNRECOGNIZED, WIDESPREAD SOURCE TO LAKE SUPERIOR SEDIMENTS, CONTRIBUTION #1072

    Science.gov (United States)

    Mining operations have worked the rich mineral resources of the Lake Superior Basin for over 150 years, leaving industrially impacted regions with tailing piles and smelters. In Lake Superior sediments, mercury and copper inventories increase towards shorelines and are highly cor...

  8. Oxygen Carrier Aided Combustion (OCAC of Wood Chips in a Semi-Commercial Circulating Fluidized Bed Boiler Using Manganese Ore as Bed Material

    Directory of Open Access Journals (Sweden)

    Magnus Rydén

    2016-11-01

    Full Text Available Oxygen Carrier Aided Combustion (OCAC is realized by using an active oxygen-carrying bed material in fluidized bed boilers. The active material is reduced in fuel rich parts of the boiler and oxidized in air rich parts. Advantages could be achieved such as new mechanisms for oxygen transport in space and time. Here calcined manganese ore has been used as active bed material in a 12 MWth circulating fluidized bed boiler. The fuel was wood chips and the campaign lasted more than two weeks. From an operational point of view, manganese ore worked excellently. From the temperature profile of the boiler it can be concluded that fuel conversion was facilitated, especially in the dense bottom bed. The effect did not always translate to reduced emissions, which suggests that final combustion in the cyclone outlet was also influenced. Substituting 10% of the sand bed with manganese ore made it possible to reduce the air to fuel ratio without generating large amounts of CO. The use of 100% manganese ore resulted in higher emissions of CO than the sand reference, but, when combined sulphur feeding, dramatic reductions in CO emissions, up to 90% compared to sand reference, was achieved.

  9. The Life Cycle of Mercury Within the Clear Lake Aquatic Ecosystem: From Ore to Organism

    Science.gov (United States)

    Suchanek, T. H.; Suchanek, T. H.; Nelson, D. C.; Nelson, D. C.; Zierenberg, R. A.; King, P.; King, P.; McElroy, K.; McElroy, K.

    2001-12-01

    Clear Lake (Lake County) is located in the geologically active Clear Lake volcanics mercury (Hg) bearing Franciscan formation within the Coast Range of California, which includes over 300 abandoned Hg mines and prospects. Intermittent mining at the Sulphur Bank Mercury Mine (from 1872-1957), now a USEPA SuperFund site, has resulted in approximately 100 metric tonnes of Hg being deposited into the aquatic ecosystem of Clear Lake, with sediment concentrations of total-Hg as high as 650 mg/kg (parts per million = ppm) near the mine, making Clear Lake one of the most Hg contaminated lakes in the world. As a result, largemouth bass and other top predatory fish species often exceed both the Federal USFDA recommended maximum recommended concentrations of 1.0 ppm and the State of California level of 0.5 ppm. Acid rock drainage leaches Hg and high concentrations of sulfate from the mine site through wasterock and subsurface conduits through subsediment advection and eventually upward diffusion into lake sediments and water. When mineral-laden pH 3 fluids from the mine mix with Clear Lake water (pH 8), an alumino-silicate precipitate (floc) is produced that promotes the localized production of toxic methyl Hg. Floc "hot spots" in sediments near the mine exhibit low pH, high sulfate, anoxia and high organic loading which create conditions that promote Hg methylation by microbial activity, especially in late summer and fall. Wind-driven currents transport methyl-Hg laden floc particles throughout Clear Lake, where they are consumed by plankton and benthic invertebrates and bioaccumulated throughout the food web. While Clear Lake biota have elevated concentrations of methyl-Hg, they are not as elevated as might be expected based on the total Hg loading into the lake. A science-based management approach, utilizing over 10 years of data collected on Hg cycling within the physical and biological compartments of Clear Lake, is necessary to affect a sensible remediation plan.

  10. SHRIMP U-Pb ages of xenotime and monazite from the Spar Lake red bed-associated Cu-Ag deposit, western Montana: Implications for ore genesis

    Science.gov (United States)

    Aleinikoff, John N.; Hayes, Timothy S.; Evans, Karl V.; Mazdab, Frank K.; Pillers, Renee M.; Fanning, C. Mark

    2012-01-01

    Xenotime occurs as epitaxial overgrowths on detrital zircons in the Mesoproterozoic Revett Formation (Belt Supergroup) at the Spar Lake red bed-associated Cu-Ag deposit, western Montana. The deposit formed during diagenesis of Revett strata, where oxidizing metal-bearing hydrothermal fluids encountered a reducing zone. Samples for geochronology were collected from several mineral zones. Xenotime overgrowths (1–30 μm wide) were found in polished thin sections from five ore and near-ore zones (chalcocite-chlorite, bornite-calcite, galena-calcite, chalcopyrite-ankerite, and pyrite-calcite), but not in more distant zones across the region. Thirty-two in situ SHRIMP U-Pb analyses on xenotime overgrowths yield a weighted average of 207Pb/206Pb ages of 1409 ± 8 Ma, interpreted as the time of mineralization. This age is about 40 to 60 m.y. after deposition of the Revett Formation. Six other xenotime overgrowths formed during a younger event at 1304 ± 19 Ma. Several isolated grains of xenotime have 207Pb/206Pb ages in the range of 1.67 to 1.51 Ga, and thus are considered detrital in origin. Trace element data can distinguish Spar Lake xenotimes of different origins. Based on in situ SHRIMP analysis, detrital xenotime has heavy rare earth elements-enriched patterns similar to those of igneous xenotime, whereas xenotime overgrowths of inferred hydrothermal origin have hump-shaped (i.e., middle rare earth elements-enriched) patterns. The two ages of hydrothermal xenotime can be distinguished by slightly different rare earth elements patterns. In addition, 1409 Ma xenotime overgrowths have higher Eu and Gd contents than the 1304 Ma overgrowths. Most xenotime overgrowths from the Spar Lake deposit have elevated As concentrations, further suggesting a genetic relationship between the xenotime formation and Cu-Ag mineralization.

  11. Magnetization of exsolution intergrowths of hematite and ilmenite: Mineral chemistry, phase relations, and magnetic properties of hemo-ilmenite ores with micron- to nanometer-scale lamellae from Allard Lake, Quebec

    DEFF Research Database (Denmark)

    McEnroe, S.A.; Robinson, P.; Langenhorst, F.

    2007-01-01

    Hemo-ilmenite ores from Allard Lake, Quebec, were first studied over 50 years ago. Interest was renewed in these coarsely exsolved oxides, based on the theory of lamellar magnetism as an explanation for the high and stable natural remanent magnetizations (NRMs), 32 to 120 A/ m, reported here...

  12. 40万吨矿砂船全船和局部振动研究%Global and Local Vibration Research on 400,000DWT Ore Carrier

    Institute of Scientific and Technical Information of China (English)

    张新伟; 吴小康; 陆利平

    2011-01-01

    Based on Finite-element method, a study of global and local vibration of 400,000dwt ore carrier is performed in this paper. The research performs the added mass by using fluid-solid coupled method; adopts static condensed method to process component mode analysis; and caries on Holden method to load propeller induced pressure. The calculation results conclude that multiple spots of hull appear heavy vibration character due to the condition without main engine top bracing installation. Based on this conclusion, a scheme of adding top bracing is proposed. The whole ship performance satisfies and meets the requirement of ISO 6954 well after the proposal has been performed.%通过有限元法对一艘40万吨矿砂船进行了全船和局部的振动性能预报.在预报过程中通过流固耦合方法添加附连水,用界面位移综合法进行局部模态分析,并用Holden法加载螺旋桨激励.计算中发现:因为主机未加横撑而引起的船体多处剧烈振动.最终提出了添加横撑的方案.该方案能使40万吨矿砂船振动性能改良,满足ISO6954标准.

  13. 水泥改性铁矿石载氧体的煤化学链燃烧实验研究%Experiments on Chemical-looping Combustion of Coal With Cement-Decorated Iron Ore as Oxygen Carrier

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      对天然铁矿石混合水泥进行改性,在流化床上进行了煤化学链燃烧试验研究,考察改性后载氧体的氧化−还原反应性能。结果表明,水泥能够有效地促进水气变换反应的进行,使得煤气化产物中 CO 份额减小、H2份额增大。改性后载氧体比表面积和孔容积显著增大,反应活性得到提高,燃料反应器出口气体中仅存在微量CO、H2,其浓度远低于纯铁矿石为载氧体的实验结果。在20次循环试验中,水泥改性铁矿石能大幅提高 CO2体积份额;对不同循环后载氧体的扫描电镜表征显示,水泥能够有效阻止载氧体颗粒表面的晶粒在高温下的液相接触,降低载氧体颗粒氧化再生过程中单位体积的热量释放强度,缓解烧结现象的发生,维持载氧体颗粒多孔的结构特性。%Experiments on chemical looping combustion of coal were conducted in a fluidized bed using cement-decorated iron ore as oxygen carrier. The reactivity of the oxygen carrier during redox experiments was investigated. The results indicate that the addition of cement effectively promotes the water-gas shift reaction, leading to the decrease of CO fraction and the increase of H2 fraction in coal gasification products. After decorated the oxygen carrier gets its specific surface area and pore volume increased significantly, and reactivity improved as a result. Further, the concentrations of CO and H2 in the flue gas of the fuel reactor are far lower than that of the experiments for pure iron ore. The volume fractions of CO2 for cement-decorated iron ore increase greatly during 20 cycles. Characterization of reduced oxygen carrier with scanning electron microscope (SEM) indicates that cement can prevent the surface grains of the oxygen carrier from gathering in the liquid phase under high temperature, and reduce the heat density released in a unit volume of the oxygen carrier particle in the oxidization process

  14. Kellad orelis

    Index Scriptorium Estoniae

    2000-01-01

    18. VI Tallinna toomkirikus organist Ines Maidre (kaastegev Kristjan Mäeots) kontsert "Kellad orelis". Kontserdiga esitleb I. Maidre ka oma samanimelist CD-d (kujundaja Margus Haavamägi), mis on osaliselt sisse mängitud Tallinna toomkiriku Ladegasti-Saueri orelil. Tänavu tähistatakse toomkiriku Maarja kella ja Lunastaja kella 315. aastapäeva.

  15. The sources of our iron ores. II

    Science.gov (United States)

    Burchard, E.F.

    1933-01-01

    In this instalment** the iron ore deposits of the Lake Superior States, which normally furnish about 80 per cent, of the annual output of the United States, are described together with historical notes on discovery and transportation of ore. Deposits in the Mississippi Valley and Western States are likewise outlined and the sources of imported ore are given. Reviewing the whole field, it is indicated that the great producing deposits of the Lake Superior and southern Appalachian regions are of hematite in basin areas of sedimentary rocks, that hydrated iron oxides and iron carbonates are generally found in undisturbed comparatively recent sediments, and that magnetite occurs in metamorphic and igneous rocks; also that numerical abundance of deposits is not a criterion as to their real importance as a source of supply. Statistics of production of iron ore and estimates of reserves of present grade conclude the paper.

  16. The Shilu Iron Ore Deposit in Hainan Province, South China: A Structurally and Hydrothermally Reworked and Re-Enriched Lake-Superior-Type BIF Iron Deposit%The Shilu Iron Ore Deposit in Hainan Province,South China: A Structurally and Hydrothermally Reworked and Re-Enriched Lake-Superior-Type BIF Iron Deposit

    Institute of Scientific and Technical Information of China (English)

    XU De-ru; WANG Zhi-lin; XIAO Yong; Bakun-Czubarow Nonna; LIU Zhao-lu; WANG Li; FU Qi-ji; WU Jun; Kusiak Monika Agnieszka

    2009-01-01

    @@ The Shilu iron ore deposit, located in the western Hainan Province, South China, is one of the most important iron-ore mining districts in China not only for its huge reserves of hematite- rich ores, but also for its potentially economic significance of associated metals of copper, cobalt, nickel, silver, lead and zinc, and of non-metals of dolomite, quartzite,barite,gypsum and sulfur.

  17. Lake

    Science.gov (United States)

    Wien, Carol Anne

    2008-01-01

    The lake is blue black and deep. It is a glaciated finger lake, clawed out of rock when ice retracted across Nova Scotia in a northerly direction during the last ice age. The lake is narrow, a little over a mile long, and deep, 90 to 190 feet in places according to local lore, off the charts in others. The author loves to swim there, with a sense…

  18. Indium-Carrier Minerals in Polymetallic Sulphide Ore Deposits: A Crystal Chemical Insight into an Indium Binding State Supported by X-ray Absorption Spectroscopy Data

    Directory of Open Access Journals (Sweden)

    Diogo Rosa

    2012-11-01

    Full Text Available Indium is a typical chalcophile element of the Earth’s crust, with a very low average content that seldom forms specific minerals, occurring mainly as dispersed in polymetallic sulphides. Indium recovery is based primarily on zinc extraction from sphalerite, the prototype of so-called tetrahedral sulphides, wherein metal ions fill half of the available tetrahedral sites within the cubic closest packing of sulphur anions, leaving interstices accessible for further in-filling. Ascertaining the tendency towards the establishment of In-In interactions through an x-ray absorption spectroscopy approach would efficiently contribute to understanding the behavior of indium in the carrier mineral. The successful results of applying such a near-edge absorption (XANES study at In L3-edge to samples collected at the Lagoa Salgada polymetallic orebody in the Iberian Pyrite Belt (IPB are described and the crystal chemistry of indium is re-evaluated, disclosing a potential clue for the metal binding state in polymetallic sulphides.

  19. Controls on the distribution of arsenic in lake sediments impacted by 65 years of gold ore processing in subarctic Canada: the role of organic matter

    Science.gov (United States)

    Galloway, Jennifer; Palmer, Michael; Swindles, Graeme T.; Sanei, Hamed; Jamieson, Heather E.; Parsons, Michael; Macumber, Andrew L.; Patterson, Tim; Falck, Hendrik

    2017-04-01

    Gold mines in the Yellowknife region of the Northwest Territories, Canada, operated from 1938 to 2003 and released approximately 20,000 tonnes of arsenic trioxide to the environment through stack emissions. This release resulted in highly elevated arsenic concentrations in lake surface waters and sediments relative to Canadian drinking water standards and guidelines for the protection of aquatic life. High northern latitudes are experiencing substantial impacts, including changes in bio-physico-chemical processes, due to climate change. Determining the affect of warming climate on contamination is complicated by the fact that little is known of climate change controls on As mobility and bioavailability. Further, while the role of dissolved organic matter in As cycling is relatively well characterized in soils and wetland sediments, few studies have investigated the role of solid organic matter in lacustrine systems. We use a meta-analytical approach to better understand controls on sedimentary arsenic distribution in lakes within a 50 km2 area of historic mineral processing activities. Arsenic concentrations in near surface sediments of the 100 lakes studied range from 5 mg/kg to over 10,000 mg/kg (median 81 mg/kg). Distance from the historical Giant Mine roaster stack and the amount of labile organic matter (S1 carbon as determined by Rock Eval pyrolysis) in lake sediments are the variables most strongly correlated with sedimentary As concentrations (Spearman's rank correlation As:distance from historic roaster rs=-0.57, phydrocarbons derived from readily degradable geolipids and pigments predominantly originating from authochthonous organic matter, represents a small portion of the overall total organic carbon in the sedimentary material analyzed (median 2.33 wt.%). However, this fraction of organic matter has large potential to influence element concentrations in lake sediments through coating of pre-existing solid-phase As-mineral complexes, direct As

  20. Lake height variation measurement utilizing GNSS reflected signal carrier phase%利用GNSS反射信号载波测量湖面高度变化

    Institute of Scientific and Technical Information of China (English)

    姚彦鑫; 杨东凯; 张其善

    2009-01-01

    A lake height variation measurement method utilizing global navigation satellite system ( GNSS ) reflected signal carrier phase was given. Carrier phase observation equations were built firstly. Then the single-differences between the carrier phase observation measurements for direct and reflected signal and the double-differences between epochs were calculated. A large amount of errors was eliminated by the differencing process. Also, the geometry path differences of direct and reflected signal were derived. The lake height variation was calculated using observation measurement and elevation information from separate satellite. The weighted average of the lake height variations from various satellites was derived to improve the precision and reliability of the measuring system. Simulation confirms that the precision of millimeter order is achieved with the method under - 15 dB signal to noise ratio( SNR).%给出一种利用导航卫星反射信号的载波相位测量光滑湖面高度变化的方法.首先建立载波相位观测方程,通过在直射与反射信号的观测量之间求单差,再在历元间求双差的方法,消除了大量误差并得到了直射与反射信号的几何路径差;然后根据各颗卫星的观测值和高度角等信息计算出湖面高度变化,并把各卫星得到的湖面高度度变化值进行加权平均以提高测量系统的精度和可靠性.仿真验证了方法在-15 dB信噪比下达到了毫米级的测量精度.

  1. Processing of lateritic ores

    Energy Technology Data Exchange (ETDEWEB)

    Collier, D.E.; Ring, R.J. [Environment Division, Australian Nuclear Science and Technology Organisation, Menai, New South Wales (Australia); McGill, J.; Russell, H. [Energy Resources of Australia Ltd., Ranger Mine, Jabiru, Northern Territory (Australia)

    2000-07-01

    Highly weathered or lateritic ores that contain high proportions of fine clay minerals present specific problems when they are processed to extract uranium. Of perhaps the greatest significance is the potential of the fine minerals to adsorb dissolved uranium (preg-robbing) from leach liquors produced by processing laterites or blends of laterite and primary ores. These losses can amount to 25% of the readily soluble uranium. The clay components can also restrict practical slurry densities to relatively low values in order to avoid rheology problems in pumping and agitation. The fine fractions also contribute to relatively poor solid-liquid separation characteristics in settling and/or filtration. Studies at ANSTO have characterised the minerals believed to be responsible for these problems and quantified the effects of the fines in these types of ores. Processing strategies were also examined, including roasting, resin-in-leach and separate leaching of the laterite fines to overcome potential problems. The incorporation of the preferred treatment option into an existing mill circuit is discussed. (author)

  2. Complexing and hydrothermal ore deposition

    CERN Document Server

    Helgeson, Harold C

    1964-01-01

    Complexing and Hydrothermal Ore Deposition provides a synthesis of fact, theory, and interpretative speculation on hydrothermal ore-forming solutions. This book summarizes information and theory of the internal chemistry of aqueous electrolyte solutions accumulated in previous years. The scope of the discussion is limited to those aspects of particular interest to the geologist working on the problem of hydrothermal ore genesis. Wherever feasible, fundamental principles are reviewed. Portions of this text are devoted to calculations of specific hydrothermal equilibriums in multicompone

  3. Hunting for Iron Ore Bargains

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    One of China’s leading steel mills has turned to smaller mines for long-term, lowcost iron ore supplies china’s oldest steel producer is looking to South America to fulfill its iron ore needs in the face of rising prices from

  4. Rock-magnetism and ore microscopy of the magnetite-apatite ore deposit from Cerro de Mercado, Mexico

    Science.gov (United States)

    Alva-Valdivia, L. M.; Goguitchaichvili, A.; Urrutia-Fucugauchi, J.; Caballero-Miranda, C.; Vivallo, W.

    2001-03-01

    Rock-magnetic and microscopic studies of the iron ores and associated igneous rocks in the Cerro de Mercado, Mexico, were carried out to determine the magnetic mineralogy and origin of natural remanent magnetization (NRM), related to the thermo-chemical processes due to hydrothermalism. Chemical remanent magnetization (CRM) seems to be present in most of investigated ore and wall rock samples, replacing completely or partially an original thermoremanent magnetization (TRM). Magnetite (or Ti-poor titanomagnetite) and hematite are commonly found in the ores. Although hematite may carry a stable CRM, no secondary components are detected above 580°, which probably attests that oxidation occurred soon enough after the extrusion and cooling of the ore-bearing magma. NRM polarities for most of the studied units are reverse. There is some scatter in the cleaned remanence directions of the ores, which may result from physical movement of the ores during faulting or mining, or from perturbation of the ambient field during remanence acquisition by inhomogeneous internal fields within these strongly magnetic ore deposits. The microscopy study under reflected light shows that the magnetic carriers are mainly titanomagnetite, with significant amounts of ilmenite-hematite minerals, and goethite-limonite resulting from alteration processes. Magmatic titanomagnetites, which are found in igneous rocks, show trellis, sandwich, and composite textures, which are compatible with high temperature (deuteric) oxy-exsolution processes. Hydrothermal alteration in ore deposits is mainly indicated by martitization in oxide minerals. Grain sizes range from a few microns to >100 mm, and possible magnetic state from single to multidomain, in agreement with hysteresis measurements. Thermal spectra, continuous susceptibility measurements, and IRM (isothermal remanent magnetization) acquisition suggest a predominance of spinels as magnetic carriers, most probably titanomagnetites with low

  5. Microbial reduction of iron ore

    Science.gov (United States)

    Hoffmann, Michael R.; Arnold, Robert G.; Stephanopoulos, Gregory

    1989-01-01

    A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry.

  6. NV - Assessment of wildlife hazards associated with mine pit lakes

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Several open pit mines in Nevada lower groundwater to mine ore below the water table. After mining, the pits partially fill with groundwater to form pit lakes. Water...

  7. Uranium mill ore dust characterization

    Energy Technology Data Exchange (ETDEWEB)

    Knuth, R.H.; George, A.C.

    1980-11-01

    Cascade impactor and general air ore dust measurements were taken in a uranium processing mill in order to characterize the airborne activity, the degree of equilibrium, the particle size distribution and the respirable fraction for the /sup 238/U chain nuclides. The sampling locations were selected to limit the possibility of cross contamination by airborne dusts originating in different process areas of the mill. The reliability of the modified impactor and measurement techniques was ascertained by duplicate sampling. The results reveal no significant deviation from secular equilibrium in both airborne and bulk ore samples for the /sup 234/U and /sup 230/Th nuclides. In total airborne dust measurements, the /sup 226/Ra and /sup 210/Pb nuclides were found to be depleted by 20 and 25%, respectively. Bulk ore samples showed depletions of 10% for the /sup 226/Ra and /sup 210/Pb nuclides. Impactor samples show disequilibrium of /sup 226/Ra as high as +-50% for different size fractions. In these samples the /sup 226/Ra ratio was generally found to increase as particle size decreased. Activity median aerodynamic diameters of the airborne dusts ranged from 5 to 30 ..mu..m with a median diameter of 11 ..mu..m. The maximum respirable fraction for the ore dusts, based on the proposed International Commission on Radiological Protection's (ICRP) definition of pulmonary deposition, was < 15% of the total airborne concentration. Ore dust parameters calculated for impactor duplicate samples were found to be in excellent agreement.

  8. A Study of Occurrences of Ag in Pb-Zn-Cu Ore Deposits in China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A systematic study of occurrences of silver in 156 Pb-Zn-Cu ore deposits indicates that silver mainly occurs in nonferrous metal ore deposits in forms of association and paragenesis. It occurs mainly as independent minerals in nature and occasionally as ion adsorption, isomorphous or amorphous silver minerals. Nearly 190 silver minerals have been discovered in China. Their shapes, constituents, textures, grain sizes, embedded types, distribution patterns, mineral assemblages and metallogenic series suggest that these characteristics are closely related to geneses of deposits and dependent of ore-forming conditions. Pb, Zn and Cu sulphides are the main carrier minerals of silver. The partition of silver in ore is constrained by the mineralization intensity, grain size and embedded form of silver minerals and mineral assemblages.

  9. Limno-chemical and microbiology aspects in Uranium Pit Mine Lake (Osamu Utsumi), in Antas and Bortolan reservoirs under the influence of effluent Ore Treatment Unit, Caldas - Minas Gerais State, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ronqui, Leilane B.; Nasciment, Marcos R.L. do; Roque, Claudio V.; Bruschi, Armando; Borba Junior, Palvo J.; Nascimento, Heliana A. F. do, E-mail: leilanebio@yahoo.com.br, E-mail: pmarcos@cnen.gov.br, E-mail: cvroque@cnen.gov.br, E-mail: abruschi@cnen.gov.br, E-mail: jouber_borba@hotmail.com, E-mail: hazevedo@cnen.gov.br [Comissao Nacional de Energia Nuclear (LAPOC/CNEN), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas; Almeida, Tito C.M. de, E-mail: titoalmeida2008@gmail.com [Universidade do Vale do Itajai (CTT-Mar/UNIVALI), SC (Brazil). Centro de Ciencias Tecnologicas da Terra e do Mar

    2013-07-01

    Due to high natural radioactivity there in Pocos de Caldas Plateau (Minas Gerais State, Brazil) and the existence of the first uranium mine in Brazil (Pit Mine Osamu Utsumi - Mineral Treatment Unit/Brazilian Nuclear Industries, MTU/BNI), which is characterized by an open-pit mine presents as increased environmental liability the formation of acid mine drainage, this study was conducted to evaluate the limno-chemicals and microbiology aspects (protozooplankton and bacterioplankton) belonging to uranium pit mine lake (PM) and evaluate the possible effects of acid effluents treated and discharged by MTU/BNI in Antas reservoir-AR and downstream of this, the Bortolan reservoir-BR. Besides the realization of abiotic and microbiology analysis of protozooplankton and bacterioplankton; was held standardization and deployment of the Fluorescence 'In Situ' Hybridization (FISH) technical using oligonucleotide probes for extremophile Archaea and Bacteria. According to the results, the PM showed the highest values for the chemical variables, lower pH values, lower protozooplankton density, however, protozooplanktonic high biomass showing the presence of tolerant species in this extreme environment. Antas and Bortolan reservoirs showed differences in the abiotic and biotic variables, AR showed suffer greater interference of acid effluents released at P41point and downstream of this at P14 point, lower protozooplankton biomass, lower bacterial density and pollution characteristics of inorganic sources. Using the FISH technique standard in this study to water bodies evaluated, it was possible to detect the presence of the extremophile bacteria of the Archaea domain in the three water bodies. The results of this study contribute to the knowledge of the pit mine lakes limnology which have become a major concern due to increased mining in the open. (author)

  10. Aircraft Carriers

    DEFF Research Database (Denmark)

    Nødskov, Kim; Kværnø, Ole

    There are many indications that China is actively researching the design of an aircraft carrier. It is unknown whether China will initiate the actual acquisition of a carrier, but the indications that are available of their research into aircraft carriers and carrier-capable aircraft, as well...... as their purchases of aircraft carrier systems, makes it more than likely that the country is preparing such an acquisition. China has territorial disputes in the South China Sea over the Spratly Islands and is also worried about the security of its sea lines of communications, by which China transports the majority...... of its foreign trade, as well as its oil imports, upon which the country is totally dependent. China therefore has good reasons for acquiring an aircraft carrier to enable it to protect its national interests. An aircraft carrier would also be a prominent symbol of China’s future status as a great power...

  11. Research on Magnesite Ore Purification

    Directory of Open Access Journals (Sweden)

    Berisha, K.

    2009-12-01

    Full Text Available Magnesite ore, consisting mainly of magnesite, MgCO3 is a chief mineral source for production of high quality refractory materials based on highly pure MgO. However, the presence of calcium and silicium mineral impurities in the ore adversely affect refractoriness. The removal of silicate minerals is now a routine process but it is not so for calcium minerals impurities. In this work, the new method for the removal of calcium mineral impurities from magnesite ore has been investigated. It is based on extraction of calcium hydroxide from the calcined hydrated ore with the solution of magnesium nitrate. The results show that it is possible to remove up to 65–83 % of calcium oxide (CaO within five minutes, and up to 88–95 % within an hour. The process itself is complex, but mainly under mass transfer control. It is possible to use waste materials produced as fertilizer in agriculture thus helping in environmental protection.

  12. Virtual phosphorus ore requirement of Japanese economy.

    Science.gov (United States)

    Matsubae, Kazuyo; Kajiyama, Jun; Hiraki, Takehito; Nagasaka, Tetsuya

    2011-08-01

    Phosphorus is indispensable for agricultural production. Hence, the consumption of imported food indirectly implies the import of phosphorus resources. The global consumption of agricultural products depends on a small number of ore-producing countries. For sustainable management of phosphorus resources, the global supply and demand network should be clarified. In this study, we propose the virtual phosphorus ore requirement as a new indicator of the direct and indirect phosphorus requirements for our society. The virtual phosphorus ore requirement indicates the direct and indirect demands for phosphorus ore transformed into agricultural products and fertilizer. In this study, the virtual phosphorus ore requirement was evaluated for the Japanese economy in 2005. Importantly, the results show that our society requires twice as much phosphorus ore as the domestic demand for fertilizer production. The phosphorus contained in "eaten" agricultural products was only 12% of virtual phosphorus ore requirement.

  13. Measurement of moisture in mill feed ore

    Energy Technology Data Exchange (ETDEWEB)

    Timm, A.R.; Moench, P.; Moisel, E. (Council for Mineral Technology, Randburg (South Africa))

    1985-04-01

    The control of the moisture in the feed to a mill is very important for efficient mill operation. Water is added continuously to the ore fed to a mill to maintain a suitable mix of ore and moisture in the mill. However, problems arise because of the large variation in the moisture content of the ore, which affects the efficiency of the grind. If too little moisture is present, the mill is unable to grind the ore finely enough, creating instead a thick 'porridge' that causes the mill to choke up. On the other hand, too much moisture results in inefficient grinding because the ore is flushed through the mill too quickly. Several techniques are available for measuring moisture and Mintek undertook an investigation in an attempt to develop a reliable robust moisture meter suitable for monitoring the moisture content of ore, which include the following: neutron backscattering, infrared absorption, microwaves, capacitance and moisture as a function of conductivity.

  14. Evolution of ore deposits on terrestrial planets

    Science.gov (United States)

    Burns, R. G.

    1991-01-01

    Ore deposits on terrestrial planets materialized after core formation, mantle evolution, crustal development, interactions of surface rocks with the hydrosphere and atmosphere, and, where life exists on a planet, the involvement of biological activity. Core formation removed most of the siderophilic and chalcophilic elements, leaving mantles depleted in many of the strategic and noble metals relative to their chondritic abundances. Basaltic magma derived from partial melting of the mantle transported to the surface several metals contained in immiscible silicate and sulfide melts. Magmatic ore deposits were formed during cooling, fractional crystallization and density stratification from the basaltic melts. Such ore deposits found in earth's Archean rocks were probably generated during early histories of all terrestrial planets and may be the only types of igneous ores on Mars. Where plate tectonic activity was prevalent on a terrestrial planet, temporal evolution of ore deposits took place. Repetitive episodes of subduction modified the chemical compositions of the crust and upper mantles, leading to porphyry copper and molybdenum ores in calc-alkaline igneous rocks and granite-hosted tin and tungsten deposits. Such plate tectonic-induced mineralization in relatively young igneous rocks on earth may also have produced hydrothermal ore deposits on Venus in addition to the massive sulfide and cumulate chromite ores associated with Venusian mafic igneous rock. Sedimentary ore deposits resulting from mechanical and chemical weathering in reducing atmospheres in Archean earth included placer deposits (e.g., uraninite, gold, pyrite ores). Chromite, ilmenite, and other dense unreactive minerals could also be present on channel floors and in valley networks on Mars, while banded iron formations might underlie the Martian northern plains regions. As oxygen evolved in earth's atmosphere, so too did oxide ores. By analogy, gossans above sulfide ores probably occur on Mars

  15. Evolution of ore deposits on terrestrial planets

    Science.gov (United States)

    Burns, R. G.

    1991-01-01

    Ore deposits on terrestrial planets materialized after core formation, mantle evolution, crustal development, interactions of surface rocks with the hydrosphere and atmosphere, and, where life exists on a planet, the involvement of biological activity. Core formation removed most of the siderophilic and chalcophilic elements, leaving mantles depleted in many of the strategic and noble metals relative to their chondritic abundances. Basaltic magma derived from partial melting of the mantle transported to the surface several metals contained in immiscible silicate and sulfide melts. Magmatic ore deposits were formed during cooling, fractional crystallization and density stratification from the basaltic melts. Such ore deposits found in earth's Archean rocks were probably generated during early histories of all terrestrial planets and may be the only types of igneous ores on Mars. Where plate tectonic activity was prevalent on a terrestrial planet, temporal evolution of ore deposits took place. Repetitive episodes of subduction modified the chemical compositions of the crust and upper mantles, leading to porphyry copper and molybdenum ores in calc-alkaline igneous rocks and granite-hosted tin and tungsten deposits. Such plate tectonic-induced mineralization in relatively young igneous rocks on earth may also have produced hydrothermal ore deposits on Venus in addition to the massive sulfide and cumulate chromite ores associated with Venusian mafic igneous rock. Sedimentary ore deposits resulting from mechanical and chemical weathering in reducing atmospheres in Archean earth included placer deposits (e.g., uraninite, gold, pyrite ores). Chromite, ilmenite, and other dense unreactive minerals could also be present on channel floors and in valley networks on Mars, while banded iron formations might underlie the Martian northern plains regions. As oxygen evolved in earth's atmosphere, so too did oxide ores. By analogy, gossans above sulfide ores probably occur on Mars

  16. Up-dated ore composition data (Central ore-field, Kuznetsk Alatau

    Directory of Open Access Journals (Sweden)

    Bushmanov A.

    2016-01-01

    Full Text Available Applying scanning electron microscope (SEM, energy-dispersive microanalyzer and X-ray ray fluorescence microscope the ore mineral composition in Central gold-ore field ore field (Kuznetsk Alatau was investigated. Eleven new minerals were detected in this ore field. The differentiated behavior of mineral formation stages in veinsand near-veined beresites was determined. The composition of native gold was studied, as well as the distribution of trace elements in pyrite.

  17. Hageri alustas oreli taastamisega / Inge Põlma

    Index Scriptorium Estoniae

    Põlma, Inge

    2009-01-01

    1851. aastal eesti orelimeistri Carl Tantoni valmistatud ja 1892. aastal Gustav Terkmanni poolt kohendatud Hageri Lambertuse kiriku oreli restaureerimisest, ekspertiisi tegi rootsi organist Göran Grahn

  18. Iron from Zealandic bog iron ore -

    DEFF Research Database (Denmark)

    Lyngstrøm, Henriette Syrach

    2011-01-01

    og geologiske materiale, metallurgiske analyser og eksperimentel arkæologiske forsøg - konturerne af en jernproduktion med udgangspunkt i den sjællandske myremalm. The frequent application by archaeologists of Werner Christensen’s distribution map for the occurrence of bog iron ore in Denmark (1966...... are sketched of iron production based on bog iron ore from Zealand....

  19. The Luster of Iron Ore Prices

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    China battles its way out of an iron ore stalemate by finding alternative supplier After months of seesawing, China’s iron ore negotiators appear to be breaking through the tight encirclement of suppliers. On August 17, the China Iron and Steel Association (CISA) announced that Fortescue

  20. Fuzzy Comprehensive Appraisal of Concealed Ore Deposits

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper, the transformation from the fuzzy to the accurate process is exemplified by the Jiaodong gold ore deposits concentrated region where the mathematical analysis is used to appraise and forecast regional concealed gold ore deposits. In this sense, this paper presents a new way to the appraisal of the non-traditional mineral resources.

  1. Biomass for iron ore sintering

    Energy Technology Data Exchange (ETDEWEB)

    Zandi, M.; Martinez-Pacheco, M.; Fray, T.A.T. [Corus Research Development & Technology, Rotherham (United Kingdom)

    2010-11-15

    Within an integrated steelworks, iron ore sinter making is an energy intensive process. In recent years, biomass is becoming an attractive alternative source of energy to traditional fossil fuels such as coal. In this study, commercially available biomass materials suited to sinter making have been identified as an alternative source of fuel to coke breeze. Olive residues, sunflower husk pellets, almond shells, hazelnut shells and Bagasse pellets have been characterised and prepared for sintering. A laboratory sinter pot has been employed for studying sintering behaviour of biomass material. On average, the calorific values of selected biomass materials, on a dry basis, are about 65% of dry coke breeze. It was found that less of this energy would be available in sinter making due to the evaporation of some of the volatile matter ahead of the flame front. At a replacement rate of 25%, the crushed sunflower husk pellets showed the closest thermal profile to that of coke breeze alone in the size range of -0.8 to +0.6 mm. A specification of less than 1 mm has been recommended for the studied biomass materials when co-firing biomass with coke breeze for iron ore sintering.

  2. Advances in research of sulphide ore textures and their implications for ore genesis

    Institute of Scientific and Technical Information of China (English)

    GU Lianxing; ZHENG Yuanchuan; TANG Xiaoqian; WU Changzhi; HU Wenxuan

    2006-01-01

    Important advances in research of sulphide ore textures in recent years have deepened our understanding of ore genesis of related mineral deposits. Pressure solution of sulphide minerals has been suggested as a mechanism for remobilization of ore materials,whereas pressure solution of the gangues is believed to raise the grade of the primary ores. We have known that precipitation of base metal sulphides from fluids prefers crystal and crack surfaces of pyrite to form overgrowth. Therefore, pyrite-bearing embryo beds in a sedimentary sequence can be acted as effective crystal seed beds and are favorable for fluid overprinting to form huge statabound deposits. Texture studies of various sulphides can be used to interpret the entire history of sedimentation, diagenesis, deformation and metamorphism of the ores. The study of chalcopyrite disease in sphalerite has brought about the idea of zone refining, and given a new explanation to metal zonation in massive sulphide deposits. Ductile shearing of sulphide ores may form ore mylonites, which will become oreshoots enriched in Cu, Au and Ag during late-stage fluid overprinting. Despite that various modern analytical techniques are being rapidly developed, ore microscopy remains to be an unreplaceable tool for ore geologists. Combined with these modern techniques, this tool will help accelerate the development of theories on ore genesis.

  3. Nitrile O-ring Cracking: A Case of Vacuum Flange O-ring Failures

    Energy Technology Data Exchange (ETDEWEB)

    Dees, Craig

    2016-07-01

    A review of recent nitrile O-ring failures in ISO-KF vacuum flange connections in glovebox applications is presented. An investigation of a single “isolated” o-ring failure leads to the discovery of cracked nitrile o-rings in a glovebox atmospheric control unit. The initial cause of the o-ring failure is attributed to ozone degradation. However, additional investigation reveals nitrile o-ring cracking on multiple gloveboxes and general purpose piping, roughly 85% of the nitrile o-rings removed for inspection show evidence of visible cracking after being in service for 18 months or less. The results of material testing and ambient air testing is presented, elevated ozone levels are not found. The contributing factors of o-ring failure, including nitrile air sensitivity, inadequate storage practices, and poor installation techniques, are discussed. A discussion of nitrile o-ring material properties, the benefits and limitations, and alternate materials are discussed. Considerations for o-ring material selection, purchasing, storage, and installation are presented in the context of lessons learned from the nitrile o-ring cracking investigation. This paper can be presented in 20 minutes and does not require special accommodations or special audio visual devices.

  4. Oolitic ores in the Bakchar iron-ore cluster (Tomsk Oblast)

    Science.gov (United States)

    Rudmin, M. A.; Mazurov, A. K.

    2016-12-01

    Oolitic iron ores are typified, and their morphology and composition are studied. Special attention is focused on the character of distribution of valuable and harmful admixtures and determination of the principal minerals concentrating these elements. As a result of this study, three types of ores are identified, such as "loose" ores, cemented ores with glauconite-chlorite-clay cement, and well-cemented ores with siderite cement. The morphology and composition of the ore oolites are characterized. The forms of occurrence of calcium phosphates (anapaite) and phosphates of rare-earth elements (monazite, cularite) that are related to the harmful phosphorus admixture are described. According to the analysis of the elemental composition, the fractions of (-1…+0.2) and (-1…+0.1) mm in the western and eastern segments, respectively, may be promising for processing.

  5. Endogenic Au-Ag polymetallic ore deposits and ore-bearing potentiality of strata

    Institute of Scientific and Technical Information of China (English)

    WANG Baode; NIU Shuyin; SUN Aiqun; XIE Yan; LUO Yi; LIU Hailong; WANG Yanhua

    2010-01-01

    The problem of ore-bearing potentiality of the strata involves metallogenic theory and ore-search orientation. Studies of the spatial distribution of endogenic Au-Ag polymetallic ore deposits in North Hebei indicated that the strata in which ore deposits occurred range in age from Paleozoic, Proterozoic to Mesozoic. In addition the ore deposits are characterized as being strata-bound in nature. The arise and establishment of "extracting" viewpoint may be attributed to the following three reasons: 1) influence by the idea of "ore-source bed"; 2) limitation of analytical techniques in the 1980s' (especially gold element); and 3) a small number of samples (sampling locations were mostly disturbed by mineralization). Studies have shown that ore-forming materials would most probably come from the deep interior of the Earth. Deep-seated ore-bearing materials including Au-Ag polymetals were brought to the shallow levels by way of mantle plume-mantle sub-plume-mantle branch structure multi-stage evolution, finally leading to the formation of ore deposits.

  6. Geological Characteristics of Epithermal Ore Concentrated Areas and Epithermal Ore Deposits in China

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The epithermal ore concentrated area is located in Southwestern China. We systematically study the regional geological characteristics such as the basement of Proterozoic, the capping bed, Moho, geothermal feature and tectonics, and discuss the relationship between distributed characteristics of the epithermal ore deposits and ore-control factors in this paper. It is concluded that the conditions, under which the epithermal ore deposits form, are huge thick basement of Proterozoic, long-time and wide-scope developed capping bed and weak magmatic activity. The basement of Proterozoic that enriches volcanic matters and carbon and the carbonaceous-bearing and paleo-pool-bearing capping bed provides main ore source. The large and deep faults and paleopool accordance with gravity anomaly gradient control the distribution of epithermal ore deposits. The lithologic assembles of microclastic rocks and carbonate rocks in the capping bed provide spaces of ore precipitation and create conditions of ore precipitation. The coincidence of many geological factors above forms the epithermal ore concentrated area.

  7. Understanding Lateritic Ore Agglomeration Behaviour as a ...

    African Journals Online (AJOL)

    user

    istics, low grade lateritic ores require more aggressive but costly chemical and hydrometallurgical techniques (e.g., leaching in ... Isothermal, batch agglomeration tests involving 30 and 44 % w/w sulphuric acid ... *Loss of ignition. Table 2: ...

  8. Research of Geochemical Associations of Nephelin Ores

    Science.gov (United States)

    Vulf, M.; Simonov, K.; Sazonov, A.

    The instant paper concerns research of distribution petrogenic chemical members in urtit ore body of Kia-Shaltyrsk deposit. Rocks of the deposit are ore for producing alum earth. Actuality of the subject based on outlooks of detection noble metal ore-bearing (Au, Pt, Pd, Rh, Ru) in alkaline rocks of Siberia, including rocks of Kia-Shaltyrsk deposit (Kuznetsk Alatau). The main purpose of analysis of distribution of members is directed to detection of a non-uniformity of distribution of substance and segments enriched with alum earth and noble members. The basic solved problems are following: o Creation regression models of ore body; o Definition of cumulative distribution functions of members in a contour of ore body; o The analysis of the obtained outcomes in geologic terms. For construction regression models the full-scale data was used, which was presented by the results of the spectral and silicate analyses of gold and petrogenic members containing 130 assays arranged in ore body. A non-linear multiparameter model of the ore body based on components of nephelin ore using neural net approach was constructed. For each member the corresponding distribution function is produced. The model is constructed on the following members: Au, Al2O3, SiO2, Fe2O3, CaO, MgO, SO3, R2O ((Na2O+K2O) -1) and losses of burning. The error of model forecasting membersS concentrations was from 0.02 up to 20%. Large errors basically connected with assays located near contact of ore body and ad- jacent strata or with very high concentrations of members; also they can be connected with different genesis of rocks or superposition of other processes. The analysis of concentrations of members and normalised absolute errors of the fore- cast has shown, that all members can be sectioned into two groups: first: Al2O3, SiO2, R2O, Fe2O3 and second: Au, losses of burning, CaO, MgO, SO3. The distribution of 1 gold is tightly connected with calcium and losses of burning and spatially linked with zones

  9. Biomining: metal recovery from ores with microorganisms.

    Science.gov (United States)

    Schippers, Axel; Hedrich, Sabrina; Vasters, Jürgen; Drobe, Malte; Sand, Wolfgang; Willscher, Sabine

    2014-01-01

    Biomining is an increasingly applied biotechnological procedure for processing of ores in the mining industry (biohydrometallurgy). Nowadays the production of copper from low-grade ores is the most important industrial application and a significant part of world copper production already originates from heap or dump/stockpile bioleaching. Conceptual differences exist between the industrial processes of bioleaching and biooxidation. Bioleaching is a conversion of an insoluble valuable metal into a soluble form by means of microorganisms. In biooxidation, on the other hand, gold is predominantly unlocked from refractory ores in large-scale stirred-tank biooxidation arrangements for further processing steps. In addition to copper and gold production, biomining is also used to produce cobalt, nickel, zinc, and uranium. Up to now, biomining has merely been used as a procedure in the processing of sulfide ores and uranium ore, but laboratory and pilot procedures already exist for the processing of silicate and oxide ores (e.g., laterites), for leaching of processing residues or mine waste dumps (mine tailings), as well as for the extraction of metals from industrial residues and waste (recycling). This chapter estimates the world production of copper, gold, and other metals by means of biomining and chemical leaching (bio-/hydrometallurgy) compared with metal production by pyrometallurgical procedures, and describes new developments in biomining. In addition, an overview is given about metal sulfide oxidizing microorganisms, fundamentals of biomining including bioleaching mechanisms and interface processes, as well as anaerobic bioleaching and bioleaching with heterotrophic microorganisms.

  10. Mechanism of mechanical activation for sulfide ores

    Institute of Scientific and Technical Information of China (English)

    HU Hui-ping; CHEN Qi-yuan; YIN Zhou-lan; HE Yue-hui; HUANG Bai-yun

    2007-01-01

    Structural changes for mechanically activated pyrite, sphalerite, galena and molybdenite with or without the exposure to ambient air, were systematically investigated using X-ray diffraction analysis(XRD), particle size analysis, gravimetrical method, X-ray photo-electron spectroscopy(XPS) and scanning electron microscopy(SEM), respectively. Based on the above structural changes for mechanically activated sulfide ores and related reports by other researchers, several qualitative rules of the mechanisms and the effects of mechanical activation for sulfide ores are obtained. For brittle sulfide ores with thermal instability, and incomplete cleavage plane or extremely incomplete cleavage plane, the mechanism of mechanical activation is that a great amount of surface reactive sites are formed during their mechanical activation. The effects of mechanical activation are apparent. For brittle sulfide ores with thermal instability, and complete cleavage plane, the mechanism of mechanical activation is that a great amount of surface reactive sites are formed, and lattice deformation happens during their mechanical activation. The effects of mechanical activation are apparent. For brittle sulfide ores with excellent thermal stability, and complete cleavage plane, the mechanism of mechanical activation is that lattice deformation happens during their mechanical activation. The effects of mechanical activation are apparent. For sulfide ores with high toughness, good thermal stability and very excellent complete cleavage plane, the mechanism of mechanical activation is that lattice deformation happens during their mechanical activation, but the lattice deformation ratio is very small. The effects of mechanical activation are worst.

  11. How Many Ore-Bearing Asteroids?

    CERN Document Server

    Elvis, Martin

    2013-01-01

    A simple formalism is presented to assess how many asteroids contain ore, i.e. commercially profitable material, and not merely a high concentration of a resource. I apply this formalism to two resource cases: platinum group metals (PGMs) and water. Assuming for now that only Ni-Fe asteroids are of interest for PGMs, then 1% of NEOs are rich in PGMs. The dearth of ultra-low delta-v (= US$1 B and the population of near-Earth objects (NEOs) larger than 100 m diameter is ~20,000 (Mainzer et al. 2011) the total population of PGM ore-bearing NEOs is roughly 10. I stress that this is a conservative and highly uncertain value. For example, an order of magnitude increase in PGM ore-bearing NEOs occurs if delta-v can as large as 5.7 km s-1. Water ore for utilization in space is likely to be found in ~1/1100 NEOs. NEOs as small as 18 m diameter can be water-ore-bodies because of the high richness of water (~20%) expected in ~25% of carbonaceous asteroids, bringing the number of water-ore-bearing NEOs to ~9000 out of th...

  12. Ores and Climate Change - Primary Shareholders

    Science.gov (United States)

    Stein, Holly J.; Hannah, Judith L.

    2015-04-01

    Many in the economic geology community concern themselves with details of ore formation at the deposit scale, whether tallying fluid inclusion data to get at changes in ore-forming fluids or defining structures that aid and abet mineralization. These compilations are generally aimed at interpretation of events at the site of ore formation, with the goal being assignment of the deposit to a sanctioned ore deposit model. While providing useful data, this approach is incomplete and does not, by itself, serve present-day requirements for true interdisciplinary science. The ore-forming environment is one of chaos and disequilibrium at nearly all scales (Stein, 2014). Chaos and complexity are documented by variably altered rocks, veins or disseminated mineralization with multi-generational fluid histories, erratic and unusual textures in host rocks, and the bitumen or other hydrocarbon products entwined within many ore deposits. This should give pause to our drive for more data as a means to find "the answer". The answer lies in the kind of data collected and more importantly, in the way we interpret those data. Rather than constructing an ever-increasing catalog of descriptive mutations on sanctioned ore deposit models (e.g., IOGC or Iron-Oxide Copper Gold deposits), the way forward is to link source and transport of metals, sulfur, and organic material with regional and ultimately whole Earth chemical evolution. Important experimental work provides chemical constraints in controlled and behaved environments. To these data, we add imagination and interpretation, always tying back to field observations. In this paper, several key points are made by way of ore deposit examples: (1) many IOCG deposits are outcomes of profound changes in the chemistry of the Earth's surface, in the interplay of the atmosphere, hydrosphere, biosphere, and lithosphere; (2) the redox history of Fe in deep earth may be ultimately expressed in the ore-forming sequence; and (3) the formation of

  13. PREDICTION OF LOCATION OF HIDDEN ORE DEPOSITS IN THE AGED ORE FIELDS:AN EXAMPLE FROM FENGHUANGSHAN ORE FIELD,TONGLING,CHINA

    Institute of Scientific and Technical Information of China (English)

    LIU; Liang-ming; PENG; Sheng-lin; YIANG; Qun-zhou; SHAO; Yong-jun; WANG; Zhi-qiang

    2001-01-01

    This paper discusses the strategy for successfully predicting the location of potential hidden ore bodies in aged ore field,and presents the result of location prediction of hidden ore bodies in Fenghuangshan ore field,Tongling.Innovative conceptual targeting procedures based on a genetic understanding of mineralization systems,carefully geological investigation and correct deduction,together with new geochemical and geophysical technology and integrating of comprehensive information are all very important for the successful prediction.In the aged Fenghuangshan ore field,through researching by application of the metallogenic theory of polygenetic compound ore deposits and triple-frequency induced polarization method and exploration tectono-geochemical method,we predicted location and quality of hidden ore bodies.According to the prediction,hidden high quality Cu-Au ore bodies of skarn type and porphyry type have been discovered.

  14. Mobility factors of cracked ore in vibrating-ore draw shafts

    Institute of Scientific and Technical Information of China (English)

    WU Ai-xiang; JIANG Li-chun; CHEN Jia-sheng

    2005-01-01

    The mobile factors of cracked ore in vibrating-ore draw shafts were analyzed. The results show that the mobile coefficient of cracked ores will be mainly influenced by the combination of ore physical factors if the structure dimension and parameters of vibrating ore-draw shafts are sure. It decreases with increasing the cohesion, lump content, lump size and powder content and increases with increasing the porosity. The coefficient decreases with increasing the moisture content, but increases after the moisture content reaches a certain value. Uniform grain leads to better mobility, non-uniform grain leads to worse mobility. The value of the mobile coefficient should be in a range of 0.31.1 when designing the vibrating ore-draw shafts. According to correlation degree of grey system theory, the effects of factors on the mobility of cracked ore are given in the weight decreasing consequence as follows: moisture content, lump content, distribution of grain size, lump size, porosity, cohesion and powder ore content. It is unreasonable to neglect any one because the values of their weights are not obvious.

  15. Contrasting REE Signatures on Manganese Ores of Iron Ore Group in North Orissa, India

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The distribution pattern of Rare Earth Elements (REE) in three categories of manganese ores viz.stratiform, stratabound-replacement, and detrital of Precambrian Iron Ore Group from north Orissa, India was reported.These categories of Mn-ore differed in their major and trace chemistry and exhibited contrasting REE signature.The stratiform ores were relatively enriched in REE content (697 μg·g-1) and their normalized pattern showed both positive Ce and Eu anomalies, whereas the stratabound-replacement types were comparatively depleted in REE content (211 μg·g-1) and showed negative Ce and flat Eu signatures.The detrital categories showed mixed REE pattern.The data plotted in different discrimination diagrams revealed a mixed volcaniclastic and chemogenic source of material for stratiform categories, and LREE (Light Rare Earth Elements) and HREE (Heavy Rare Earth Elements) are contributed by such sources, respectively.In contrast, the stratabound ore bodies were developed during the remobilization of stratiform ores, and associated Mn-containing rocks under supergene condition followed by the redeposition of circulating mineralized colloidal solutions in structurally favorable zones.During this process, some of the constituents were found only in very low concentration within stratabound ores, and this is attributed to their poor leachability/mobility.The detrital ores did not exhibit any significant characteristic in respect of REE as their development was via a complex combination of processes involving weathering, fragmentation, recementation, and burial under soil cover.

  16. Geology and ore deposits of the Pioche district, Nevada

    Science.gov (United States)

    Westgate, L.G.; Knopf, Adolph

    1932-01-01

    LOCATION AND SURFACE FEATURES The Bristol Range, Highland, and Ely Range quadrangles make up the larger part of a. rectangular area 35 miles north and south by 24 miles east and west, which lies 19 miles west of the Nevada-Utah line and about 250 miles southwest of Salt Lake City. The district lies within the Great Basin, a semiarid region of alternating mountain ranges and intermontane plains floored largely by outwash from the mountains. The plain, which slopes away from the ranges, stands between 4,700 and 6,000 feet above the sea. The Bristol and Highland Ranges, which are separated only by a low gap, form an almost continuous north-south range that rises about 2,500 feet above the highest part of the surrounding plain, to general altitudes of 8,000 to 9,000 feet, though the highest point, Highland Peak, reaches 9,395 feet. A lower range, the Ely Range, with a northwesterly trend, lies farther east and nearly in touch with the Bristol-Highland Range. The town of Pioche lies midway on the. eastern foot of the Ely Range. ROOKS OF THE PIOOHB REGION The rocks of the ranges are Paleozoic sediments, Tertiary (?) lavas and intrusive rocks, and Pliocene (?) tuffs. The Paleozoic sediments have a total thickness of nearly 18,000 feet. Over 8,000 feet of the Cambrian has been measured without reaching its base. The lowest Cambrian formation is a quartzite, of which only the upper 1,500 feet is exposed, and this is followed by 1,200 feet of shale, 400 feet of limestone, aoid 150 feet of shale. Above this second shale the upper three-fourths of the Cambrian consists of limestone and dolomitic limestone. It is in the quartzite and in the limestone interbedded in and bounding the shales that the main ore bodies of the district have been found. Above the Cambrian comes 1,795 feet of Ordovician limestone, with some interbedded dolomite and with a 50-foot quartzite a, third of the way down from the top; 75 feet of Silurian dolomite; 3,000 feet of Middle Devonian dolomite with

  17. Hydrogen carriers

    Science.gov (United States)

    He, Teng; Pachfule, Pradip; Wu, Hui; Xu, Qiang; Chen, Ping

    2016-12-01

    Hydrogen has the potential to be a major energy vector in a renewable and sustainable future energy mix. The efficient production, storage and delivery of hydrogen are key technical issues that require improvement before its potential can be realized. In this Review, we focus on recent advances in materials development for on-board hydrogen storage. We highlight the strategic design and optimization of hydrides of light-weight elements (for example, boron, nitrogen and carbon) and physisorbents (for example, metal-organic and covalent organic frameworks). Furthermore, hydrogen carriers (for example, NH3, CH3OH-H2O and cycloalkanes) for large-scale distribution and for on-site hydrogen generation are discussed with an emphasis on dehydrogenation catalysts.

  18. Selective Flocculation of Dilband Iron Ore, Pakistan

    Directory of Open Access Journals (Sweden)

    Muhammad Ishaque Abro

    2011-04-01

    Full Text Available Selective flocculation for long is known as one of the beneficiation techniques applicable to the concentration of finely disseminated ores. The success of this technique is based on the selective adsorption of an organic polymer on the mineral particles to be flocculated. In present study beneficiation of finely disseminated Dilband iron ore using selective flocculation has been attempted. The effect of pH, sodium silicate (Na2SiO3, sodium hexametaphosphate (Na2OP2O5, sodium trypolyphosphate (Na5P3O10, ethylediaminetretracetae (NaCH2-CH2N, flocculant doses, and flocculant mixing method on the selective adsorption of corn starch on hematite, the chief iron mineral, was studied comprehensively. Improvement in grade was assessed by XRF analysis of the flocculation products. The selective flocculation upgraded the ore from 52% hematite (i.e. 39% Fe to 60% hematite (i.e. 45% Fe with an average hematite recovery of 15%. Appreciable increase in ore grade with sufficiently poor recovery suggested that selective flocculation process is not adequate beneficiating technique to upgrade the Dilband iron ore due to heavily intergrowth of impurities.

  19. The physical hydrogeology of ore deposits

    Science.gov (United States)

    Ingebritsen, Steven E.; Appold, M.S.

    2012-01-01

    Hydrothermal ore deposits represent a convergence of fluid flow, thermal energy, and solute flux that is hydrogeologically unusual. From the hydrogeologic perspective, hydrothermal ore deposition represents a complex coupled-flow problem—sufficiently complex that physically rigorous description of the coupled thermal (T), hydraulic (H), mechanical (M), and chemical (C) processes (THMC modeling) continues to challenge our computational ability. Though research into these coupled behaviors has found only a limited subset to be quantitatively tractable, it has yielded valuable insights into the workings of hydrothermal systems in a wide range of geologic environments including sedimentary, metamorphic, and magmatic. Examples of these insights include the quantification of likely driving mechanisms, rates and paths of fluid flow, ore-mineral precipitation mechanisms, longevity of hydrothermal systems, mechanisms by which hydrothermal fluids acquire their temperature and composition, and the controlling influence of permeability and other rock properties on hydrothermal fluid behavior. In this communication we review some of the fundamental theory needed to characterize the physical hydrogeology of hydrothermal systems and discuss how this theory has been applied in studies of Mississippi Valley-type, tabular uranium, porphyry, epithermal, and mid-ocean ridge ore-forming systems. A key limitation in the computational state-of-the-art is the inability to describe fluid flow and transport fully in the many ore systems that show evidence of repeated shear or tensional failure with associated dynamic variations in permeability. However, we discuss global-scale compilations that suggest some numerical constraints on both mean and dynamically enhanced crustal permeability. Principles of physical hydrogeology can be powerful tools for investigating hydrothermal ore formation and are becoming increasingly accessible with ongoing advances in modeling software.

  20. A new radiation shielding material: Amethyst ore

    Energy Technology Data Exchange (ETDEWEB)

    Korkut, Turgay, E-mail: turgaykorkut@hotmail.co [Faculty of Science and Art, Department of Physics, Ibrahim Cecen University, Agri (Turkey); Korkut, Hatun [Faculty of Science and Art, Department of Physics, Ibrahim Cecen University, Agri (Turkey); Karabulut, Abdulhalik; Budak, Goekhan [Faculty of Science, Department of Physics, Atatuerk University, Erzurum (Turkey)

    2011-01-15

    This paper describes a new radiation shielding material, amethyst ore. We have determined the elemental composition of amethyst using WDXRF spectroscopy technique. To see the shielding capability of amethyst for several photon energies, these results have been used in simulation process by FLUKA Monte Carlo radiation transport code. Linear attenuation coefficients have been calculated according to the simulation results. Then, these values have been compared to a fine shielding concrete material. The results show that amethyst shields more gamma beams than concrete. This investigation is the first study about the radiation shielding properties of amethyst ore.

  1. METALLOGENIC SYSTEM OF DACHANG TINPOLYMETALLIC ORE FIELD

    Institute of Scientific and Technical Information of China (English)

    WU Xiang-bin; DAI Ta-gen; WANG Zhi-bin; FANG Sheng-kui

    2001-01-01

    The Dachang tin-polymetallic ore field in northern Guangxi,China,lies in a mid-late Paleozoic rift that borders up the southern boundary of the Jiangnan-Xuefeng Massif.As a giant ore deposit,it deposited in middle of the Nandang-Hechi metallogenic zone.The orehosting strata are of the Devonion,which shows the evident characteristics of polymetallic elements,i.e: ,Sn,Zn,Pb,Sb,As,Cu,Ag,In,Ge,Cd,et al.,and over 1 000 000 t tin reserves.

  2. Partitioning properties of rare earth ores in China

    Institute of Scientific and Technical Information of China (English)

    CHI Ru'an; LI Zhongjun; PENG Cui; ZHU Guocai; XU Shengming

    2005-01-01

    The properties of rare earth partitioning in Chinese industrial rare earth ores were analyzed. Rare earth ores can be divided into the single-mineral type ore with bastnaesite, the multi-mineral type ore with bastnaesite and monazite, and the weathering crust type. Both the Bayan Obo rare earth ore and the Zhushan rare earth ore are a kind of mixed ore, consisting of bastnaesite and monazite. Their rare earth partitionings are strongly enriched in light rare earths, where CeO2 is 50% and the light rare earth partitioning is totally over 95%. The Mianning rare earth ore as well as the Weishan rare earth is a kind of rare earth ore only having bastnaesite. Their rare earth partitionings are also strongly enriched in light rare earths,in which CeO2 is 47% and the light rare earth partitioning is totally over 94%. For the weathering crust type rare earth ore,there are the Longnan rare earth ore, the Xunwu rare earth ore, and the middle yttrium and rich europium ore. In the Longnan rare earth ore, which is strongly enriched in heavy rare earths, Y2O3 is 64.83%, and the heavy and light rare earth partitionings are 89.40% and 10.53%, respectively. In the Xunwu rare earth ore, which is strongly enriched in light rare earths, CeO2 is 47.16%, and the light rare earth partitioning is totally 93.25%. Y and Eu are enriched in the middle yttrium and rich europium ore. Its middle rare earth partitioning is totally over 10%, and Eu2O3 and Y2O3 are over 0.5% and 20%,respectively, which are mainly industrial resources of the middle and the heavy rare earths.

  3. Sintering Properties and Optimal Blending Schemes of Iron Ores

    Institute of Scientific and Technical Information of China (English)

    Dauter0liveira; WUSheng—li; DAIYu—ming; XUJian; CHEN Hong

    2012-01-01

    In order to obtain good sintering performance, it is important to understand sintering properties of iron ores. Sintering properties including chemical composition, granulation and high-temperature behaviors of ores from China, Brazil and Australia. Furthermore, several indices were defined to evaluate sintering properties of iron ores. The results show that: for chemical composition, Brazilian ores present high TFe, low SiOz, and low Alz03 con- tent. For granulation, particle diameter ratio of Brazilian ores are high; particle intermediate fraction of Chinese con- centrates are low; and average particle size and clay type index of Australian ores are high. For high-temperature properties, ores from China, Brazil and Australia present different characteristics. Ores from different origins should be mixed together to obtain good high-temperature properties. According to the analysis of each ore's sintering prop- erties, an ore blending scheme (Chinese concentrates 20 ~-1- Brazilian ores 400//oo -k Australian ores 40 ~) was sugges- ted. Moreover, sinter pot test using blending mix was performed, and the results indicated that the ore blending scheme led to good sintering performance and sinter quality.

  4. HANDLING, STORAGE AND IRON ORE QUALITY

    Directory of Open Access Journals (Sweden)

    Fabiana Fonseca Fortes

    2012-06-01

    Full Text Available This paper aims to identify handling and storage impact in iron ore quality, in their physical and chemical characteristics most important for a mining. It is tried to show the interferences in iron ore quality caused by the handling equipment and stockpiling. The research is restricted to Complexo Vargem Grande (Vale. The timeline was demarcated based on the formation of stockpiling. The fieldwork enables data collection and distinction of the routine procedures of casual operations handling. The quantitative analysis is conducted by the statistical method. As a conclusion, handling and storage identified are able to insert changes in physical and chemical characteristics of iron ore. Storage contributes to reduce variability of silica and alumina concentrations, but contributes too particle size deterioration. The handling induces degradation and segregation. However, there is the possibility to decrease handling of the ore and to establish the ideal size of stocks on the system in study, improving the efficiency of the system and consequent in global costs.

  5. Sources of ores of the ferroalloy metals

    Science.gov (United States)

    Burchard, E.F.

    1933-01-01

    Since all steel is made with the addition of alloying elements, the record of the metallic raw materials contributory to the steel industry would be far from complete without reference to the ferroalloy metals. This paper, therefore, supplements two preceding arvicles on the sources of our iron ores. The photographs, with the exception of those relating to molybdenum and vanadium, are by the author.

  6. Lake Cadagno

    DEFF Research Database (Denmark)

    Tonolla, Mauro; Storelli, Nicola; Danza, Francesco

    2017-01-01

    Lake Cadagno (26 ha) is a crenogenic meromictic lake located in the Swiss Alps at 1921 m asl with a maximum depth of 21 m. The presence of crystalline rocks and a dolomite vein rich in gypsum in the catchment area makes the lake a typical “sulphuretum ” dominated by coupled carbon and sulphur cyc...

  7. Mining and processing of uranium ores at the Streltsovsky ore field

    Energy Technology Data Exchange (ETDEWEB)

    Ovseytchuk, V.A.; Litvinenko, V.G.; Kultishev, V.I. [Joint Stock Company, Priargunsky Industrial Mining and Chemical Union, Krasnokamensk, Chita Region (Russian Federation)

    2000-07-01

    The uranium deposits of Streltsovsky ore fields provide raw materials for Russian nuclear industry. For this region, it is important to achieve continued and increased activities in the recovery of mineral resources of uranium. Similarly, maintaining the mining and processing of uranium ores ensures the supply of raw materials for the nuclear industry. With the current operations, increasing the mining and processing activities would increase the cost of production of uranium oxides due to decreasing grades of ore body. After a review of the existing economic, technological and natural factors, a solution was proposed based on the joint application of underground mining and ore enrichment and processing with the help of hydrometallurgical process, in-situ leaching. Reduction of operation coasts and creation of radiation-safe working conditions could be achieved with the application of these systems involving concrete hardening in the mines and in-situ leaching of ore. With the help of economic-mathematical modeling, methods for rational application of various technologies could be determined and their processing parameters were specified. A reduction of coasts could be obtained and favorable conditions could be established for improvement in the treatment of lower grade ores by heap leaching. Application of purification of mine waters and tailing pond reduces the influence of the radiation and the impact on the natural environment. (author)

  8. Hydrogen Reduction of Hematite Ore Fines to Magnetite Ore Fines at Low Temperatures

    Directory of Open Access Journals (Sweden)

    Wenguang Du

    2017-01-01

    Full Text Available Surplus coke oven gases (COGs and low grade hematite ores are abundant in Shanxi, China. Our group proposes a new process that could simultaneously enrich CH4 from COG and produce separated magnetite from low grade hematite. In this work, low-temperature hydrogen reduction of hematite ore fines was performed in a fixed-bed reactor with a stirring apparatus, and a laboratory Davis magnetic tube was used for the magnetic separation of the resulting magnetite ore fines. The properties of the raw hematite ore, reduced products, and magnetic concentrate were analyzed and characterized by a chemical analysis method, X-ray diffraction, optical microscopy, and scanning electron microscopy. The experimental results indicated that, at temperatures lower than 400°C, the rate of reduction of the hematite ore fines was controlled by the interfacial reaction on the core surface. However, at temperatures higher than 450°C, the reaction was controlled by product layer diffusion. With increasing reduction temperature, the average utilization of hydrogen initially increased and tended to a constant value thereafter. The conversion of Fe2O3 in the hematite ore played an important role in the total iron recovery and grade of the concentrate. The grade of the concentrate decreased, whereas the total iron recovery increased with the increasing Fe2O3 conversion.

  9. Hydrogen Plasma Processing of Iron Ore

    Science.gov (United States)

    Sabat, Kali Charan; Murphy, Anthony B.

    2017-06-01

    Iron is currently produced by carbothermic reduction of oxide ores. This is a multiple-stage process that requires large-scale equipment and high capital investment, and produces large amounts of CO2. An alternative to carbothermic reduction is reduction using a hydrogen plasma, which comprises vibrationally excited molecular, atomic, and ionic states of hydrogen, all of which can reduce iron oxides, even at low temperatures. Besides the thermodynamic and kinetic advantages of a hydrogen plasma, the byproduct of the reaction is water, which does not pose any environmental problems. A review of the theory and practice of iron ore reduction using a hydrogen plasma is presented. The thermodynamic and kinetic aspects are considered, with molecular, atomic and ionic hydrogen considered separately. The importance of vibrationally excited hydrogen molecules in overcoming the activation energy barriers, and in transferring energy to the iron oxide, is emphasized. Both thermal and nonthermal plasmas are considered. The thermophysical properties of hydrogen and argon-hydrogen plasmas are discussed, and their influence on the constriction and flow in the of arc plasmas is considered. The published R&D on hydrogen plasma reduction of iron oxide is reviewed, with both the reduction of molten iron ore and in-flight reduction of iron ore particles being considered. Finally, the technical and economic feasibility of the process are discussed. It is shown that hydrogen plasma processing requires less energy than carbothermic reduction, mainly because pelletization, sintering, and cokemaking are not required. Moreover, the formation of the greenhouse gas CO2 as a byproduct is avoided. In-flight reduction has the potential for a throughput at least equivalent to the blast furnace process. It is concluded that hydrogen plasma reduction of iron ore is a potentially attractive alternative to standard methods.

  10. Hydrogen Plasma Processing of Iron Ore

    Science.gov (United States)

    Sabat, Kali Charan; Murphy, Anthony B.

    2017-03-01

    Iron is currently produced by carbothermic reduction of oxide ores. This is a multiple-stage process that requires large-scale equipment and high capital investment, and produces large amounts of CO2. An alternative to carbothermic reduction is reduction using a hydrogen plasma, which comprises vibrationally excited molecular, atomic, and ionic states of hydrogen, all of which can reduce iron oxides, even at low temperatures. Besides the thermodynamic and kinetic advantages of a hydrogen plasma, the byproduct of the reaction is water, which does not pose any environmental problems. A review of the theory and practice of iron ore reduction using a hydrogen plasma is presented. The thermodynamic and kinetic aspects are considered, with molecular, atomic and ionic hydrogen considered separately. The importance of vibrationally excited hydrogen molecules in overcoming the activation energy barriers, and in transferring energy to the iron oxide, is emphasized. Both thermal and nonthermal plasmas are considered. The thermophysical properties of hydrogen and argon-hydrogen plasmas are discussed, and their influence on the constriction and flow in the of arc plasmas is considered. The published R&D on hydrogen plasma reduction of iron oxide is reviewed, with both the reduction of molten iron ore and in-flight reduction of iron ore particles being considered. Finally, the technical and economic feasibility of the process are discussed. It is shown that hydrogen plasma processing requires less energy than carbothermic reduction, mainly because pelletization, sintering, and cokemaking are not required. Moreover, the formation of the greenhouse gas CO2 as a byproduct is avoided. In-flight reduction has the potential for a throughput at least equivalent to the blast furnace process. It is concluded that hydrogen plasma reduction of iron ore is a potentially attractive alternative to standard methods.

  11. LIMNOLOGY, LAKE BASINS, LAKE WATERS

    Directory of Open Access Journals (Sweden)

    Petre GÂŞTESCU

    2009-06-01

    Full Text Available Limnology is a border discipline between geography, hydrology and biology, and is also closely connected with other sciences, from it borrows research methods. Physical limnology (the geography of lakes, studies lake biotopes, and biological limnology (the biology of lakes, studies lake biocoenoses. The father of limnology is the Swiss scientist F.A. Forel, the author of a three-volume entitled Le Leman: monographie limnologique (1892-1904, which focuses on the geology physics, chemistry and biology of lakes. He was also author of the first textbook of limnology, Handbuch der Seenkunde: allgemeine Limnologie,(1901. Since both the lake biotope and its biohydrocoenosis make up a single whole, the lake and lakes, respectively, represent the most typical systems in nature. They could be called limnosystems (lacustrine ecosystems, a microcosm in itself, as the American biologist St.A. Forbes put it (1887.

  12. Pre-colombian mercury pollution associated with the smelting of argentiferous ores in the Bolivian Andes.

    Science.gov (United States)

    Cooke, Colin A; Balcom, Prentiss H; Kerfoot, Charles; Abbott, Mark B; Wolfe, Alexander P

    2011-02-01

    The development of the mercury (Hg) amalgamation process in the mid-sixteenth century triggered the onset of large-scale Hg mining in both the Old and New Worlds. However, ancient Hg emissions associated with amalgamation and earlier mining efforts remain poorly constrained. Using a geochemical time-series generated from lake sediments near Cerro Rico de Potosí, once the world's largest silver deposit, we demonstrate that pre-Colonial smelting of Andean silver ores generated substantial Hg emissions as early as the twelfth century. Peak sediment Hg concentrations and fluxes are associated with smelting and exceed background values by approximately 20-fold and 22-fold, respectively. The sediment inventory of this early Hg pollution more than doubles that associated with extensive amalgamation following Spanish control of the mine (1574-1900 AD). Global measurements of [Hg] from economic ores sampled world-wide indicate that the phenomenon of Hg enrichment in non-ferrous ores is widespread. The results presented here imply that indigenous smelting constitutes a previously unrecognized source of early Hg pollution, given naturally elevated [Hg] in economic silver deposits.

  13. High-rate behaviour of iron ore pellet

    Directory of Open Access Journals (Sweden)

    Gustafsson Gustaf

    2015-01-01

    Full Text Available Iron ore pellets are sintered, centimetre-sized spheres of ore with high iron content. Together with carbonized coal, iron ore pellets are used in the production of steel. In the transportation from the pelletizing plants to the customers, the iron ore pellets are exposed to different loading situations, resulting in degradation of strength and in some cases fragmentation. For future reliable numerical simulations of the handling and transportation of iron ore pellets, knowledge about their mechanical properties is needed. This paper describes the experimental work to investigate the dynamic mechanical properties of blast furnace iron ore pellets. To study the dynamic fracture of iron ore pellets a number of split Hopkinson pressure bar tests are carried out and analysed.

  14. Ore fluid geochemistry of the Jinlongshan Carlin type gold ore belt in Shaanxi Province, China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The Jinlongshan gold ore belt in southern Shaanxi Province contains a number of Carlin-type gold deposits in the Qinling collisional orogenic belt. Their fluid inclusions are of the Na+ - Cl- type. From the main metallogenic stage to later stages, the total quantity of anions and cations, temperature and deoxidation parameter (R) for fluid inclusions all gradu ally decreased, suggesting the gradual intensification of fluid oxidation, the reduction of met allogenic depth and the input of meteoric water and organic components. The deposits were formed during crustal uplifting and hence had similar tectonic settings to orogenic gold depos its. The CO2 contents and CO2/H2O values of the ore fluid increased from early to late sta ges, and the wall-rock alteration is represented by decarbonation, which is inconsistent with the characteristics of orogenic gold deposits. It is also discovered that Na + , K + ,SO42-, Cl-and the total amounts of anions and cations in the inclusions in quartz are higher than those in the coexisting calcite. The H, O and C isotope ratios indicate that the ore fluid was sourced from meteoric water and metamorphic devolatilisation of the sedimentary rocks that host the ores. The high background δ18O and δ13C values of wall rocks resulted in high δ18O and δ13 C values of ore fluid and also high δ 18 O and δ 13 C values of hydrothermal minerals such as quartz and carbonate. The carbon in ore fluid stemmed largely from the hosting strata. The δ 18O and δ13C values of Fe-calcite and the δD values of fluid inclusions are lower than those of calcite and quartz. In terms of the theory of coordination chemistry, all these differences can be ascribed to water-rock interaction in the same fluid system, instead, to the multi source of ore fluid.

  15. Dose calculations for intakes of ore dust

    Energy Technology Data Exchange (ETDEWEB)

    O`Brien, R.S

    1998-08-01

    This report describes a methodology for calculating the committed effective dose for mixtures of radionuclides, such as those which occur in natural radioactive ores and dusts. The formulae are derived from first principles, with the use of reasonable assumptions concerning the nature and behaviour of the radionuclide mixtures. The calculations are complicated because these `ores` contain a range of particle sizes, have different degrees of solubility in blood and other body fluids, and also have different biokinetic clearance characteristics from the organs and tissues in the body. The naturally occurring radionuclides also tend to occur in series, i.e. one is produced by the radioactive decay of another `parent` radionuclide. The formulae derived here can be used, in conjunction with a model such as LUDEP, for calculating total dose resulting from inhalation and/or ingestion of a mixture of radionuclides, and also for deriving annual limits on intake and derived air concentrations for these mixtures. 15 refs., 14 tabs., 3 figs.

  16. Iron ore weathering potentials of ectomycorrhizal plants.

    Science.gov (United States)

    Adeleke, R A; Cloete, T E; Bertrand, A; Khasa, D P

    2012-10-01

    Plants in association with soil microorganisms play an important role in mineral weathering. Studies have shown that plants in symbiosis with ectomycorrhizal (ECM) fungi have the potential to increase the uptake of mineral-derived nutrients. However, it is usually difficult to study many of the different factors that influence ectomycorrhizal weathering in a single experiment. In the present study, we carried out a pot experiment where Pinus patula seedlings were grown with or without ECM fungi in the presence of iron ore minerals. The ECM fungi used included Pisolithus tinctorius, Paxillus involutus, Laccaria bicolor and Suillus tomentosus. After 24 weeks, harvesting of the plants was carried out. The concentration of organic acids released into the soil, as well as potassium and phosphorus released from the iron ore were measured. The results suggest that different roles of ectomycorrhizal fungi in mineral weathering such as nutrient absorption and transfer, improving the health of plants and ensuring nutrient circulation in the ecosystem, are species specific, and both mycorrhizal roots and non-mycorrhizal roots can participate in the weathering process of iron ore minerals.

  17. Vertical mill simulation applied to iron ores

    Directory of Open Access Journals (Sweden)

    Douglas Batista Mazzinghy

    2015-04-01

    Full Text Available The application of vertical mills in regrind circuits is consolidated. This type of mill is now attracting interest in primary grinding applications, due to its higher efficiency when compared to ball mills, which are usually used at this stage. In this study, a coarse sample of iron ore was tested in a pilot scale grinding circuit with a vertical mill. Other three samples of pellet feed had already been tested with the methodology used in this study. The sample of coarse iron ore was characterized in laboratory tests carried out in a small batch ball mill. Selection and breakage function parameters were determined from the laboratory tests. The parameters were then used for simulating the pilot scale tests using Modsim™ software. The model previously implemented in Modsim™ has been successfully applied to represent the vertical mill operated with different ores. The simulations produced particle size distributions that were very close to the actual size distributions, and the predictions were accomplished only by imputing the calibrated parameters from the batch tests, the power draw and the feed size distribution of the pilot tests. The methodology is therefore useful for scale-up and simulation of vertical mills, only requiring laboratory tests that can be carried out in standard laboratory batch ball mills with small amounts of samples.

  18. Isotopic Characteristics of Mesozoic Au-Ag Polymetallic Ore Deposits in Northern Hebei and Their Ore-Forming Materials Source

    Institute of Scientific and Technical Information of China (English)

    王宝德; 牛树银; 孙爱群; 李红阳

    2003-01-01

    It has long been a controversy about the source of ore-forming materials of Au-Agpolymetallic deposits both in metallogenic theory and in ore-searching practice. In terms of alarge wealth of the isotopic statistics data from Indosinian-Yanshanian endogenic ore deposits innorthern Hebei (generally referring to the areas along the northern part of Taihang Mountainsand northern Hebei, the same below) , it is considered that the ore-forming materials came fromthe deep interior of the Earth, which had migrated through plumes to the Earth surface while ex-perienced multi-stage evolution and then emplaced progressively in favorable structural loci toform ores. Their isotope data show that 559 sulfur isotopic data from 40 ore deposits are, for themost part, within the range of - 5‰ - 5‰, with a high degree of homogenization, indicatingthat the sulfur is derived mainly from magma; 200 lead isotope data from 37 ore deposits indi-cate that the ore-forming materials are principally of mantle source though some crust-source ma-terial was involved; 96 oxygen, hydrogen and carbon isotope data from 34 ore deposits illustratethat the ore-forming fluids are dominated by magmatic water while other sources of water wouldbe involved. It may therefore be seen that the formation of endogenic deposits has nothing to dowith the strata.

  19. Physical-chemical conditions of ore deposition

    Science.gov (United States)

    Barton, P.B.

    1981-01-01

    Ore deposits form under a wide range of physical and chemical conditions, but those precipitating from hot, aqueous fluids-i.e. the hydrothermal deposits-form generally below 700??C and at pressures of only 1 or 2 kbar or less. Natural aqueous fluids in rocks may extract metal and sulfur from a variety of rock types or may acquire them as a residual heritage from a crystallizing silicate magma. Ore-forming hydrothermal fluids never appear as hot springs (except in deep, submarine situations) because they boil, mix with surface waters, and cool, thereby losing their ore-bearing ability before reaching the surface. Mineral systems function as chemical buffers and indicators just as buffers and indicators function in a chemical laboratory. By reading the record written in the buffer/indicator assemblages of minerals one can reconstruct many aspects of the former chemical environment. By studying the record of changing conditions one may deduce information regarding the processes functioning to create the succession of chemical environments and the ore deposits they represent. The example of the OH vein at Creede, Colorado, shows a pH buffered by the K-feldspar + muscovite + quartz assemblage and the covariation of S2 and O2 buffered by the assemblage chlorite + pyrite + quartz. Boiling of the ore fluid led to its oxidation to hematite-bearing assemblages and simultaneously produced an intensely altered, sericitic capping over the vein in response to the condensation of vapors bearing acidic components. The solubility of metals as calculated from experimental and theoretical studies of mineral solubility appears too low by at least one or two powers of ten to explain the mineralization at Creede. In contrast to Creede where the mineral stabilities all point to a relatively consistent chemistry, the Mississippi Valley type deposits present a puzzle of conflicting chemical clues that are impossible to reconcile with any single equilibrium situation. Thus we must

  20. Physical-chemical conditions of ore deposition

    Science.gov (United States)

    Barton, Paul B.

    Ore deposits form under a wide range of physical and chemical conditions, but those precipitating from hot, aqueous fluids-i.e. the hydrothermal deposits-form generally below 700°C and at pressures of only 1 or 2 kbar or less. Natural aqueous fluids in rocks may extract metal and sulfur from a variety of rock types or may acquire them as a residual heritage from a crystallizing silicate magma. Ore-forming hydrothermal fluids never appear as hot springs (except in deep, submarine situations) because they boil, mix with surface waters, and cool, thereby losing their ore-bearing ability before reaching the surface. Mineral systems function as chemical buffers and indicators just as buffers and indicators function in a chemical laboratory. By reading the record written in the buffer/indicator assemblages of minerals one can reconstruct many aspects of the former chemical environment. By studying the record of changing conditions one may deduce information regarding the processes functioning to create the succession of chemical environments and the ore deposits they represent. The example of the OH vein at Creede, Colorado, shows a pH buffered by the K-feldspar + muscovite + quartz assemblage and the covariation of S 2 and O 2 buffered by the assemblage chlorite + pyrite + quartz. Boiling of the ore fluid led to its oxidation to hematite-bearing assemblages and simultaneously produced an intensely altered, sericitic capping over the vein in response to the condensation of vapors bearing acidic components. The solubility of metals as calculated from experimental and theoretical studies of mineral solubility appears too low by at least one or two powers of ten to explain the mineralization at Creede. In contrast to Creede where the mineral stabilities all point to a relatively consistent chemistry, the Mississippi Valley type deposits present a puzzle of conflicting chemical clues that are impossible to reconcile with any single equilibrium situation. Thus we must

  1. 40 CFR 440.10 - Applicability; description of the iron ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Iron Ore Subcategory § 440.10 Applicability; description of the iron ore subcategory. The provisions of this subpart A are applicable to discharges from (a) mines operated to obtain iron ore, regardless of the type of ore...

  2. EXPLANATORY MODEL OF SPOT PRICE OF IRON ORE

    Directory of Open Access Journals (Sweden)

    Juan Enrique Villalva A.

    2015-11-01

    Full Text Available The objective of this study was to construct an explanatory model of the spot price of iron ore in the international market. For this, the method of multiple linear regressions was used. As a dependent variable, the spot price of iron ore (62% Fe China Tianjin port was taken, between 2010 and 2013. As independents variables were taken seven variables of international iron ore market. The resulting model includes variables: Iron ore inventory in Chinese ports, Baltic Dry Index (BDI, Iron ore exports from Brazil & Australia and Chinese Rebar Steel Price, as explanatory variables of the behavior of the spot price of iron ore in the international market. The model has an adjusted coefficient of determination R2 of 0.90, and was validated by comparing its predictions vs. known values of 2014.

  3. Genesis of Gold- Silver Deposits in Qingchengzi Ore Field

    Institute of Scientific and Technical Information of China (English)

    Wei Min

    2001-01-01

    The gold - silver complex ore field of Qingchengzi is located in Liaohe group of Liaodong rift. The gold - silver ore bodies mainly lie in Dashiqiao group and Gaixian group, which provides ore - forming materials for the mineralization. For taking place multi - period and multi - stage magmatic activities, the ore - forming materials in the formation had had dynamothermal metamorphism for a long time and enriched and formed ore bodies after magmatism in Indo- Chinese and Yanshan epoch. The ore bodies are controlled by stratigraphic formation and stored in the interformational faults and schistosity belts. Silicalite is the most important indicator for searching them. Although the Pb - Zn and the gold - silver deposits are the same series of mineralized products, their positions are different, resulting from the differences of elements nature and mineralized conditions. The gold silver deposits belong to strata - bound and hysterogenetic mesothermal - epithermal deposit.

  4. Chemical Looping Combustion of Hematite Ore with Methane and Steam in a Fluidized Bed Reactor

    Directory of Open Access Journals (Sweden)

    Samuel Bayham

    2017-08-01

    Full Text Available Chemical looping combustion is considered an indirect method of oxidizing a carbonaceous fuel, utilizing a metal oxide oxygen carrier to provide oxygen to the fuel. The advantage is the significantly reduced energy penalty for separating out the CO2 for reuse or sequestration in a carbon-constrained world. One of the major issues with chemical looping combustion is the cost of the oxygen carrier. Hematite ore is a proposed oxygen carrier due to its high strength and resistance to mechanical attrition, but its reactivity is rather poor compared to tailored oxygen carriers. This problem is further exacerbated by methane cracking, the subsequent deposition of carbon and the inability to transfer oxygen at a sufficient rate from the core of the particle to the surface for fuel conversion to CO2. Oxygen needs to be readily available at the surface to prevent methane cracking. The purpose of this work was to demonstrate the use of steam to overcome this issue and improve the conversion of the natural gas to CO2, as well as to provide data for computational fluid dynamics (CFD validation. The steam will gasify the deposited carbon to promote the methane conversion. This work studies the performance of hematite ore with methane and steam mixtures in a 5 cm fluidized bed up to approximately 140 kPa. Results show an increased conversion of methane in the presence of steam (from 20–45% without steam to 60–95% up to a certain point, where performance decreases. Adding steam allows the methane conversion to carbon dioxide to be similar to the overall methane conversion; it also helped to prevent carbon accumulation from occurring on the particle. In general, the addition of steam to the feed gas increased the methane conversion. Furthermore, the addition of steam caused the steam methane reforming reaction to form more hydrogen and carbon monoxide at higher steam and methane concentrations, which was not completely converted at higher concentrations and

  5. Rock Magnetic and Oxide Microscopy Studies of two South American Iron-Ore Deposits

    Science.gov (United States)

    Alva-Valdivia, L. M.

    2005-05-01

    Microscopy and rock-magnetic studies of the iron oxide-ore and host rocks in the Cristales-Pleito Melon (Chile) and Jacupiranga (Brazil) deposits were carried out to characterize and compare the magnetic mineralogy and the processes that affected the natural remanent magnetization (NRM) during emplacement and evolution of the iron-ore deposits. The microscopy study under reflected light shows that magnetic carriers are mainly magnetites, with minor amounts of ilmenite-hematite minerals. Titanomagnetite, shows trellis texture, which is compatible with high temperature oxy-exsolution processes. Grain sizes range from a few microns to >100 µm, and dominant magnetic state pseudo-single-domain, in agreement with hysteresis measurements. Thermal spectra, continuous susceptibility measurements, and isothermal remanent magnetization (IRM) acquisition suggest a predominance of some spinels (titanomagnetite or titanomaghemite) with low-Ti content as magnetic carriers. These data help to investigate the magnetic domain states and the remanence acquisition processes, and to assess their significance as a source of magnetic anomalies.

  6. Paleomagnetic dating of non-sulfide Zn-Pb ores in SW Sardinia (Italy: a first attempt

    Directory of Open Access Journals (Sweden)

    L. Sagnotti

    2005-06-01

    Full Text Available A first paleomagnetic investigation aimed at constraining the age of the non-sulfide Zn-Pb ore deposits in the Iglesiente district (SW Sardinia, Italy was carried out. In these ores, the oxidation of primary sulfides, hosted in Cambrian carbonate rocks, was related to several paleoweathering episodes spanning from the Mesozoic onward. Paleomagnetic analyses were performed on 43 cores from 4 different localities, containing: a non-oxidized primary sulfides and host rock, b oxidized Fe-rich hydrothermal dolomites and (c supergene oxidation ore («Calamine». Reliable data were obtained from 18 samples; the others show uninterpretable results due to low magnetic intensity or to scattered demagnetization trajectories. Three of them show a scattered Characteristic Remanent Magnetization (ChRM, likely carried by the original (i.e. Paleozoic magnetic iron sulfides. The remaining 15 samples show a well defined and coherent ChRM, carried by high-coercivity minerals, acquired after the last phase of counterclockwise rotation of Sardinia (that is after 16 Myr, in a time interval long enough to span at least one reversal of the geomagnetic field. Hematite is the main magnetic carrier in the limestone, whereas weathered hydrothermal dolomite contains goethite or a mixture of both. The results suggest that paleomagnetism can be used to constrain the timing of oxidation in supergene-enriched ores.

  7. Source of ore-forming material for the Huangtuliang gold deposit, Hebei Province and ore prospecting in the deep periphery

    Institute of Scientific and Technical Information of China (English)

    NIU Shuyin; SUN Aiqun; WANG Baode; HAN Yuchou; WEI Minghui; ZHANG Hai; ZHANG Ge; SHI Ping; WANG Wenxing

    2008-01-01

    The Huangtuliang gold deposit is characterized by its wide and large ore belt, stable extension and closely spaced orebodies. Unfortunately, no orebody was found by deep drilling. As a result, ore prospecting in this region was once put into dilemma. Detailed analysis of ore-forming and ore-controlling structures in the mining district by the authors has revealed that the ore-forming and ore-controlling structure in this mining district is a steeply dipping (85°-110°/∠70°-85° N-NNE), spade-shaped ductile shear zone, and the ore-controlling structures are a series of nearly erected second-ordered faults which are developed in the upper part of the ductile shear zone, intersecting with the ductile shear zone. Deep cutting of the ductile shear zone made it possible the ascending of ore fluids from the mantle plume at depth and these ore fluids would migrate upwards along the ductile shear zone under certain temperature and pressure conditions. Along their ascending path, the ore fluids would extract ore-forming elements from the country rocks and the extracted ore-forming elements would be deposited as ores in the hanging-wall second-ordered faults. The reason why no orebody was found in early prospecting at depth is that northward-dipping drilling in the southern part of the shear zone extended so deeply as to be beneath the shear zone. Only shallow-level orebodies could be found by southward-dipping drilling practice in the northern part of the shear zone.The location where deep-seated orebodies occurred shifted northwards and the orebodies occurred at greater depth.Therefore, it is natural that no orebody could be found when drill core passed through the shear zone. After the ore-forming and ore-controlling structures were well understood, the focus of ore prospecting was placed on the deep-level, northward-penetrating veins. In this way a number of new blind orebodies of great thickness have been found. On the basis of research development in the mining

  8. Sulfuric acid leaching of mechanically activated manganese carbonate ore

    Directory of Open Access Journals (Sweden)

    Kenan Yıldız

    2010-06-01

    Full Text Available Acidic leaching of mechanically activated manganese ore from Denizli – Tavas was investigated. The ore was activated mechanically in a planetary mill and the amorphisation in manganese structure was analyzed with X-ray diffraction. The parameters in acidic leaching of the ore were milling time, acid concentration and time. All experiments were performed at 25°C with solid to liquid ratio: 1/10. The activation procedure led to amorphization and structural disordering in manganese ore and accelerated the dissolution of manganese in acidic media.

  9. Tectonomagmatic Metallogenic System of Dexing Ore Field, Jiangxi, China

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    13 ore deposits and a large number of ore occurrences cluster in Dexing ore field which is 20 km long and 12 km wide. The tectonic evolution, magmatism, as well as the metallogeny are controlled by the Northeast Jiangxi deep-seated fracture belt (NJDFB). The source is believed to have been derived from the Meso-Neoproterozoic marine volcanism. The magmatic activity of Mesozoic I-type granite could have provided the metal elements, thermal fluid, heat, and the space for ore-forming processes. A unified geological model is proposed, which combines the tectonism, magmatism and metallogeny as the basic control of the giant metal mineralizations.

  10. Pros and Cons,Iron Ore Price Hikes

    Institute of Scientific and Technical Information of China (English)

    Tang Jingtao

    2008-01-01

    @@ Backaround Baostecl and CVRD reached an agreement on the price hikes of 65 percent and 71 percent in February.And in June Baosteel and Rio Tinto which is the largest iron ore company in Australia reached an agreement on the price hikes of 79.88 percent on the iron ore fines and 96.5 percent on the iron ore lumps.This is the first time that two kinds of the iron ore price grew at the same time in Asian market.

  11. Radon emanation from low-grade uranium ore.

    Science.gov (United States)

    Sahu, Patitapaban; Mishra, Devi Prasad; Panigrahi, Durga Charan; Jha, Vivekanand; Patnaik, R Lokeswara

    2013-12-01

    Estimation of radon emanation in uranium mines is given top priority to minimize the risk of inhalation exposure due to short-lived radon progeny. This paper describes the radon emanation studies conducted in the laboratory as well as inside an operating underground uranium mine at Jaduguda, India. Some of the important parameters, such as grade/(226)Ra activity, moisture content, bulk density, porosity and emanation fraction of ore, governing the migration of radon through the ore were determined. Emanation from the ore samples in terms of emanation rate and emanation fraction was measured in the laboratory under airtight condition in glass jar. The in situ radon emanation rate inside the mine was measured from drill holes made in the ore body. The in situ(222)Rn emanation rate from the mine walls varied in the range of 0.22-51.84 × 10(-3) Bq m(-2) s(-1) with the geometric mean of 8.68 × 10(-3) Bq m(-2) s(-1). A significant positive linear correlation (r = 0.99, p 222)Rn emanation rate and the ore grade was observed. The emanation fraction of the ore samples, which varied in the range of 0.004-0.089 with mean value of 0.025 ± 0.02, showed poor correlation with ore grade and porosity. Empirical relationships between radon emanation rate and the ore grade/(226)Ra were also established for quick prediction of radon emanation rate from the ore body.

  12. Remobilisation features and structural control on ore grade distribution at the Konkola stratiform Cu-Co ore deposit, Zambia

    OpenAIRE

    Torremans, K.; Gauquie, J.; Boyce, A. J.; Barrie, C.D.; Sikazwe, O.; Muchez, P.H.

    2013-01-01

    The Konkola deposit is a high grade stratiform Cu–Co ore deposit in the Central African Copperbelt in Zambia. Economic mineralisation is confined to the Ore Shale formation, part of the Neoproterozoic metasedimentary rocks of the Katanga Supergroup. Petrographic study reveals that the copper–cobalt ore minerals are disseminated within the host rock, sometimes concentrated along bedding planes, often associated with dolomitic bands or clustered in cemented lenses and in layer-parallel and irre...

  13. Role of ore mineralogy in optimizing conditions for bioleaching low-grade complex sulphide ores

    Institute of Scientific and Technical Information of China (English)

    P. A. OLUBAMBI; S. NDLOVU; J. H. POTGIETER; J. O. BORODE

    2008-01-01

    The role that ore mineralogy plays in understanding and optimizing the conditions favouring the bioleaching of complex sulphide ore containing high amounts of siderite was studied using mixed cultures of mesophilic bacteria, with emphasis on zinc,lead and copper recoveries. The influencing parameters investigated include particle size, stirring speed, volume of inoculum, pulp density, and pH. The results show that the mixed mesophilic cultures can extract about two and a half times the amount of zinc than copper over an equivalent period of time. The highest zinc and copper recoveries of 89.2% and 36.4% respectively are obtained at particle size of 75 μm, stirring speed of 150 r/min, pulp density of 10% (w/v), 12% (v/v) inoculum concentration, and a pH of 1.6. Variations in elemental composition within different particle sizes resulting from the mineralogy of the ore account for the bioleaching behaviour at varying particle sizes. The dissolution at varying pulp density, volume of inoculum, solution pH and the low solution potential observed are also influenced by ore mineralogy.

  14. Bioprocessing of ores: Application to space resources

    Science.gov (United States)

    Johansson, Karl R.

    The role of microorganisms in the oxidation and leaching of various ores (especially those of copper, iron, and uranium) is well known. This role is increasingly being applied by the mining, metallurgy, and sewage industries in the bioconcentration of metal ions from natural receiving waters and from waste waters. It is concluded that bioprocessing using bacteria in closed reactors may be a variable option for the recovery of metals from the lunar regolith. Obviously, considerable research must be done to define the process, specify the appropriate bacteria, determine the necessary conditions and limitations, and evaluate the overall feasibility.

  15. Project StORe: Social Science report

    OpenAIRE

    Burton, Guy

    2006-01-01

    There was widespread support across the social science research community regarding the aims of the StORe Project Nearly half of social science respondents claimed that both source-to-output and out-put-to source repositories would offer a ‘significant advantage to my work’; a third in both cases claimed it would be ‘useful but not of major significance’ Postgraduate students were generally more enthusiastic about source-to-output and output-to-source repositories than acade...

  16. Sedimentary exhalative nickel-molybdenum ores in south China

    Science.gov (United States)

    Lott, D.A.; Coveney, R.M.; Murowchick, J.B.; Grauch, R.I.

    1999-01-01

    Unique bedded Ni-Mo ores hosted by black shales were discovered in localized paleobasins along the Yangzte platform of southern China in 1971. Textural evidence and radiometric dates imply ore formation during sedimentation of black shales that grade into readily combustible beds, termed stone coals, which contain 10 to 15 percent organic carbon. Studies of 427 fluid inclusions indicate extreme variation in hydrothermal brine salinities that were contained by Proterozoic dolostones underlying the ore zone in Hunan and Guizhou. Variations of fluid inclusion salinities, which range from 0.1 to 21.6 wt percent NaCl equiv, are attributed to differences in the compositions of brines in strata underlying the ore bed, complicated by the presence of seawater and dilute fluids that represent condensates of vapors generated by boiling of mineralizing fluids or Cambrian meteoric water. The complex processes of ore deposition led to scattered homogenization temperatures ranging from 100??to 187??C within the Hunan ore zone and from 65??to 183??C within the Guizhou ore zone. While living organisms probably did not directly accumulate metals in situ in sufficient amounts to explain the unusually high grades of the deposits, sulfur isotope ratios indicate that bacteria, now preserved as abundant microfossils, provided sufficient sulfide for the ores by reduction of seawater sulfate. Such microbiota may have depended on vent fluids and transported organic matter for key nutrients and are consistent with a sedex origin for the ores. Vent fluids interacted with organic remains, including rounded fragments of microbial mats that were likely transported to the site of ore deposition by the action of waves and bottom currents prior to replacement by ore minerals.

  17. Mixed State and High Effective Utilization of Pilbara Blending Iron Ore Powder%Mixed State and High Effective Utilization of Pilbara Blending Iron Ore Powder

    Institute of Scientific and Technical Information of China (English)

    CAO Yong-guo; WU Sheng-li; HAN Hong-liang; WANG Hong-wei; XUE Fang; LIU Xiao-qin

    2011-01-01

    Pilbara blending iron ore powder (PB powder) is blending ores with good and poor quality iron ores, so how to use PB power effectively is a problem. The self-characteristics of PB powder and its single-components were studied respectively such as the macroscopic properties, microscopic properties, and high-temperature properties the behavior and effect in the sintering were mastered. Then based on the new ore-proportioning idea of iron ores sintering characteristics complementary, the principles on the effective use of PB powder were discussed, and was fur ther validated through the sintering pot test and industrial production. The results show that PB powder is composed of three kinds of iron ore, and the sintering characteristics of different iron ores are obviously discrepant. With the ore-proportioning optimization based on the iron ores sintering characteristics complementary, the proportion of PB iron ore powder can be increased to more than 45 %.

  18. Estimate of the trophic status of subarctic Imandra Lake

    Directory of Open Access Journals (Sweden)

    Terent'eva I. A.

    2017-03-01

    Full Text Available The object of study is Imandra Lake – the largest reservoir of the Murmansk region. The lake is being influenced by the long-term and multi-factorial activities of mining and ore processing industries, air pollution and energetics. Moreover, the drain of municipal sewage from the large settlements situated on the lake's watershed makes a serious contribution to water pollution. As a result the lake has accumulated a significant amount of pollutants and nutrients that resulted currently in an increase of the toxic load on the lake system. One of the main ecological problems also is the intensification of the anthropogenic eutrophication processes. The aim of this study is to evaluate the current trophic status of Imandra Lake using the trophic index (TSI with the average annual values of the parameters: chlorophyll, total nitrogen, total phosphorus, and total organic carbon and to find the dynamics of these parameters' changes during more than 20-year period. The study of the trophic status of Imandra Lake has been performed for the period 1991–2013 yrs. using the trophic state index developed by Carlson, Kratzer and Bresonik, Dunalska. According to the calculated values of the indexes Bolshaja Imandra Lake corresponds to eutrophic-mesotrophic trophic status, Yokostrovskaya Imandra Lake could be described as mesotrophic. Babinskaja Imandra Lake that subjected to essential nutrient loading is close to the oligotrophic trophic status. However, some parts of Babinskaja Imandra Lake refer to the mesotrophic state due to influence of industrial, household and heated water of the Kola atomic power station. Thus, this part of Imadra Lake could be considered as a meso-oligotrophic status. It has been established that currently nitrogen is a limiting factor for development of algae in Imandra Lake. Based on the mathematical Vollenweider model the critical phosphorus loading values to control such an important nutrient element as phosphorus have been

  19. PRACTICAL AND PREDICTIVE MODELLING OF ORE DEPOSITS IN HYDROTHERMAL SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    ZHAO Chong-bin; B.E.Hobbs; H.B.Muhlhaus; A.Ord

    2001-01-01

    @@ Over the past five years,we have been making efforts to develop a practical and predictive tool to explore for giant ore deposits in hydrothermal systems.Towards this goal,a significant progress has been made towards a better understanding of the basic physical and chemical processes behind ore body formation and mineralization in hydrothermal systems.

  20. PRACTICAL AND PREDICTIVE MODELLING OF ORE DEPOSITS IN HYDROTHERMAL SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    ZHAO; Chong-bin; B.E.Hobbs; H.B.Muhlhaus; A.Ord

    2001-01-01

    Over the past five years,we have been making efforts to develop a practical and predictive tool to explore for giant ore deposits in hydrothermal systems.Towards this goal,a significant progress has been made towards a better understanding of the basic physical and chemical processes behind ore body formation and mineralization in hydrothermal systems.……

  1. Experimental study of ore gabbro liquid immiscibility

    Institute of Scientific and Technical Information of China (English)

    SANG; Zunan; XIA; Bin; ZHOU; Yongsheng; JIN; Zhenmin

    2005-01-01

    In this paper, the authors present the results of a preliminary experimental study on partial melting of fine-grained gabbro, Panzhihua, Sichuan Province, China. Experiments were conducted under (confining) pressure ranging from 450 to 500 MPa and temperature of 900-1200℃. The results show that the initial melt is distributed along grain boundaries and triple junctions. Liquid immiscibility phenomena are noted in the melt with two compositional different melt phases, i.e. matrix and sphere phases. The matrix phase is relatively rich in Si, Al and K, and is depleted in Mg, Fe, Ca, Na and Ti, whereas the sphere phase shows opposite trends. The calculation of the melt free energy indicates that the liquid immiscibility is governed by the rule of thermodynamics, as the liquid immiscibility would result in the decrease in free energy of the melt system. The field relationships suggest that the liquid immiscibility may have played an important role in the generation of ore magma of Panzhihua V-Ti magnetite ore deposit. This study thus provides experimental constraints on the mechanism of the formation of V-Ti magnetite deposite.

  2. Excited response of granular ores in vibrating field

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The dynamical theory was utilized to probe into the law of the excited response of granular ores generated by the exciting action of exciter and the influence of wave propagation in vibrating field. The exciter with double axes was presented as an example, and the principle of exciter and its mathematical expression of the excitation force were given. The granular ores have viscidity and damping speciality, on the basis of which the motion equation of excited response of ores was established and the approximate expression of mode-displacement by harmonic excitation and the steady effect solution of coordinate response were deduced. Utilizing the step-by-step integration method, the recursion relation matrix of displacement, velocity and acceleration of the excited response of ores were obtained, and the computational flow chart and a computational example were given. The results show that the excited response can change the dynamical character and the flowing characteristic of granular ores.

  3. Playa Lakes

    Data.gov (United States)

    Kansas Data Access and Support Center — This digital dataset provides information about the spatial distribution of soil units associated with playa lakes. Specific soil types have been designated by the...

  4. Manganese redox cycling in Lake Imandra: impact on nitrogen and the trace metal sediment record

    Directory of Open Access Journals (Sweden)

    J. Ingri

    2011-01-01

    Full Text Available Sediment and water samples from the mine-polluted Yokostrovskaya basin in Lake Imandra have been analysed. Three major processes have influenced the accumulation and distribution of metals in the sediment: (1 Development of the apatite-nepheline and the sulfide ore mining industries. (2 Secondary formation of sulphides in the upper sediment column. (3 Redox cycling of Mn in the surface sediment and in the bottom water.

    This study demonstrate the dominant role of the Mn redox cycling in controlling distribution of several major and trace elements, especially during the winter stratification period. Mn oxides act as a major scavenger and carrier for the non-detrital fraction of Al, Ca, K, Mg, P, Ba, Co, Cu, Ni, Mo and Zn in the bottom water. Aluminium, Ca, K, Mg, P, Cu, Ni and Zn are mainly sorbed at the surface of the particulate Mn phase, while Ba and Mo form a phase (or inner sphere complex with Mn. Co is associated with the Mn-rich phase, probably by oxidation of Co(II to a trivalent state by the particulate Mn surface. Formation and dissolution of Mn particles most likely also control anoxic ammonium oxidation to nitrate and reduction of nitrate to N2. It is shown that secondary sulphides in Lake Imandra sediments are fed with trace metals primarily scavenged from the dissolved phase in the water column. This enrichment process, driven by the Mn-redox cycle, therefore changes the sediment record by the transfer of a dissolved pollution signal to the particulate sediment record, thus making it more complicated to trace direct influence of particles from different pollution sources.

  5. High-temperature performance prediction of iron ore fines and the ore-blending programming problem in sintering

    Institute of Scientific and Technical Information of China (English)

    Bing-ji Yan; Jian-liang Zhang; Hong-wei Guo; Ling-kun Chen; Wei Li

    2014-01-01

    The high-temperature performance of iron ore fines is an important factor in optimizing ore blending in sintering. However, the application of linear regression analysis and the linear combination method in most other studies always leads to a large deviation from the desired results. In this study, the fuzzy membership functions of the assimilation ability temperature and the liquid fluidity were proposed based on the fuzzy mathematics theory to construct a model for predicting the high-temperature performance of mixed iron ore. Comparisons of the prediction model and experimental results were presented. The results illustrate that the prediction model is more accurate and effec-tive than previously developed models. In addition, fuzzy constraints for the high-temperature performance of iron ore in this research make the results of ore blending more comparable. A solution for the quantitative calculation as well as the programming of fuzzy constraints is also introduced.

  6. Summary of the mineralogy of the Colorado Plateau uranium ores

    Science.gov (United States)

    Weeks, Alice D.; Coleman, Robert Griffin; Thompson, Mary E.

    1956-01-01

    In the Colorado Plateau uranium has been produced chiefly from very shallow mines in carnotite ores (oxidized vanadiferous uranium ores) until recent deeper mining penetrated black unoxidized ores in water-saturated rocks and extensive exploration has discovered many deposits of low to nonvanadiferous ores. The uranium ores include a wide range from highly vanadiferous and from as much as one percent to a trace of copper, and contain a small amount of iron and traces of lead, zinc, molybdenum, cobalt, nickel, silver, manganese, and other metals. Recent investigation indicates that the carnotite ores have been derived by progressive oxidation of primary (unoxidized) black ores that contain low-valent uranium and vanadium oxides and silicates. The uranium minerals, uraninite and coffinite, are associated with coalified wood or other carbonaceous material. The vanadium minerals, chiefly montroseite, roscoelite, and other vanadium silicates, occur in the interstices of the sandstone and in siltstone and clay pellets as well as associated with fossil wood. Calcite, dolomite, barite and minor amounts of sulfides, arsenides, and selenides occur in the unoxidized ore. Partially oxidized vanadiferous ore is blue black, purplish brown, or greenish black in contrast to the black or dark gray unoxidized ore. Vanadium combines with uranium to form rauvite. The excess vanadium is present in corvusite, fernandinite, melanovanadite and many other quadrivalent and quinquevalent vanadium minerals as well as in vanadium silicates. Pyrite and part or all of the calcite are replaced by iron oxides and gypsum. In oxidized vanadiferous uranium ores the uranium is fixed in the relatively insoluble minerals carnotite and tyuyamunite, and the excess vanadium commonly combines with one or more of the following: calcium, sodium, potassium, magnesium, aluminum, iron, copper, manganese, or barium, or rarely it forms the hydrated pentoxide. The relatively stable vanadium silicates are little

  7. Cohesive strength of iron ore granules

    Directory of Open Access Journals (Sweden)

    Contreras Rafael Jaimes

    2017-01-01

    Full Text Available We present an experimental and numerical investigation of the mechanical strength of crude iron ore (Hematite granules in which capillary bonds between primary particles are the source of internal cohesion. The strength is measured by subjecting the granules to vertical compression between two plates. We show that the behavior of the granules is ductile with a well-defined plastic threshold which increases with the amount of water. It is found that the compressive strength scales with capillary cohesion with a pre-factor that is nearly independent of size polydispersity for the investigated range of parameters but increases with friction coefficient between primary particles. This weak dependence may be attributed to the class of fine particles which, due to their large number, behaves as a cohesive matrix that controls the strength of the granule.

  8. Cohesive strength of iron ore granules

    Science.gov (United States)

    Contreras, Rafael Jaimes; Berger, Nicolas; Izard, Edouard; Douce, Jean-François; Koltsov, Alexey; Delenne, Jean-Yves; Azema, Emilien; Nezamabadi, Saeid; van Loo, Frédéric; Pellenq, Roland; Radjai, Farhang

    2017-06-01

    We present an experimental and numerical investigation of the mechanical strength of crude iron ore (Hematite) granules in which capillary bonds between primary particles are the source of internal cohesion. The strength is measured by subjecting the granules to vertical compression between two plates. We show that the behavior of the granules is ductile with a well-defined plastic threshold which increases with the amount of water. It is found that the compressive strength scales with capillary cohesion with a pre-factor that is nearly independent of size polydispersity for the investigated range of parameters but increases with friction coefficient between primary particles. This weak dependence may be attributed to the class of fine particles which, due to their large number, behaves as a cohesive matrix that controls the strength of the granule.

  9. Exact linear modeling using Ore algebras

    CERN Document Server

    Schindelar, Kristina; Zerz, Eva

    2010-01-01

    Linear exact modeling is a problem coming from system identification: Given a set of observed trajectories, the goal is find a model (usually, a system of partial differential and/or difference equations) that explains the data as precisely as possible. The case of operators with constant coefficients is well studied and known in the systems theoretic literature, whereas the operators with varying coefficients were addressed only recently. This question can be tackled either using Gr\\"obner bases for modules over Ore algebras or by following the ideas from differential algebra and computing in commutative rings. In this paper, we present algorithmic methods to compute "most powerful unfalsified models" (MPUM) and their counterparts with variable coefficients (VMPUM) for polynomial and polynomial-exponential signals. We also study the structural properties of the resulting models, discuss computer algebraic techniques behind algorithms and provide several examples.

  10. Improved polynomial remainder sequences for Ore polynomials.

    Science.gov (United States)

    Jaroschek, Maximilian

    2013-11-01

    Polynomial remainder sequences contain the intermediate results of the Euclidean algorithm when applied to (non-)commutative polynomials. The running time of the algorithm is dependent on the size of the coefficients of the remainders. Different ways have been studied to make these as small as possible. The subresultant sequence of two polynomials is a polynomial remainder sequence in which the size of the coefficients is optimal in the generic case, but when taking the input from applications, the coefficients are often larger than necessary. We generalize two improvements of the subresultant sequence to Ore polynomials and derive a new bound for the minimal coefficient size. Our approach also yields a new proof for the results in the commutative case, providing a new point of view on the origin of the extraneous factors of the coefficients.

  11. Rigid Ideals and Radicals of Ore Extensions

    Institute of Scientific and Technical Information of China (English)

    Chan Yong Hong; Tai Keun Kwak; S. Tariq Rizvi

    2005-01-01

    For an endomorphism σ of a ring R, Krempa called σ a rigid endomorphism if aσ(a) = 0 implies a= 0 for a ∈ R. A ring R is called rigid if there exists a rigid endomorphism of R. In this paper, we extend the σ-rigid property of a ring R to an ideal of R. For a σ-ideal Ⅰ of a ring R, we call Ⅰ a σ-rigid ideal if aσ(a) ∈Ⅰ implies a ∈Ⅰ for a ∈ R. We characterize σ-rigid ideals and study related properties. The connections of the prime radical and the upper nil radical of R with the prime radical and the upper nil radical of the Ore extension R[x; σ, δ], respectively, are also investigated.

  12. Super-Enrichment of Dispersed Elements and Associated Ore Deposits

    Institute of Scientific and Technical Information of China (English)

    高振敏; 姚林波

    2004-01-01

    Dispersed elements do not always occur as associated elements in the ore deposits of other elements. Instead, they can constitute independent ore deposits. The focus of this paper is placed on the mechanism of super-enrichment of the four dispersed elements TI, Ge, Se, and Te under favorable geological conditions, where their enrichment coefficients are so high that their abundances can reach n×103-n×104, sometimes even up to n×106 times (e. g. Te) those of the crust. As a result, they can form their independent ore deposits. Studies have shown that such independent ore deposits are mostly distributed in the southwestern part of China, most of which belong to low-temperature ore deposits, ranging in age from Yanshanian to Himalayan(Cretaceous to Cenozoic), with a significant time gap with the host strata. Moreover, this paper also deals with the existing forms (as independent minerals, occurring isomorphously and being adsorbed) of the dispersed elements in those independent ore deposits. The discovery of independent ore deposits of dispersed elements is a great breakthrough in the study of dispersed element metallogenesis.

  13. Leaching hydrodynamics of weathered elution-deposited rare earth ore

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Both porosity (φ) and permeability (k) of the weathered elution-deposited rare earth ores are basic hydrodynamic parameters for RE leaching. The relationship between k and φ of two typical rare earth ores of South China in the packed bed was investigated by measuring the flow (Q) under various leaching pressure difference (Δp). The experimental results show that the relationship between k and φ is unique, moreover the relationship between Q and Δp is in accord with the Darcy's law. The effects of the type of ores, the leaching reagents and its concentration, the granule ore size on the leaching permeability have also been investigated. It is demonstrated that kH (for heavy RE ore, kH=35.98 mm2)>kM-H (for middle-heavy RE ore,kM-H=28.50 mm2), whereas k(NH4NO3)>k(NH4Cl)>k[(NH4)2SO4], and the k value increases with increasing leaching reagents concentration and granule ore size(k0.60~0.75 mm=99.96 mm2,k0.125~0.60 mm=11.83 mm2, k0.074~0.125 mm=0.84 mm2).

  14. Direct Biohydrometallurgical Extraction of Iron from Ore

    Energy Technology Data Exchange (ETDEWEB)

    T.C. Eisele

    2005-10-01

    A completely novel approach to iron extraction was investigated, based on reductive leaching of iron by anaerobic bacteria. Microorganisms were collected from an anaerobic bog where natural seepage of dissolved iron was observed. This mixed culture was used to reduce insoluble iron in a magnetite ore to the soluble ferrous (Fe{sup +2}) state. While dissolution rates were slow, concentrations of dissolved iron as high as 3487 mg/l could be reached if sufficient time was allowed. A factorial study of the effects of trace nutrients and different forms of organic matter indicated that the best dissolution rates and highest dissolved iron concentrations were achieved using soluble carbohydrate (sucrose) as the bacterial food source, and that nutrients other than nitrogen, phosphorus, potassium, sodium, and acetate were not necessary. A key factor in reaching high levels of dissolved iron was maintaining a high level of carbon dioxide in solution, since the solubility of iron carbonates increases markedly as the quantity of dissolved carbon dioxide increases. Once the iron is dissolved, it has been demonstrated that the ferrous iron can then be electroplated from solution, provided that the concentration of iron is sufficiently high and the hydrogen ion concentration is sufficiently low. However, if the leaching solution is electrolyzed directly, organic matter precipitates at the cathode along with the metallic iron. To prevent this problem, the ferrous iron should be separated from the bulk solution in a more concentrated, purified form. One route to accomplishing this is to take advantage of the change in solubility of ferrous iron as a function of carbon dioxide concentration. By cycling the concentration of carbon dioxide in solution, it is possible to produce an iron-rich concentrate that should be suitable for electrolysis. This represents the first viable hydrometallurgical method for leaching iron directly from ore and producing metallic iron.

  15. Sulfur isotope geochemistry of ore and gangue minerals from the Silesian-Cracow Mississippi Valley-type ore district, Poland

    Science.gov (United States)

    Leach, D.L.; Vets, J.G.; Gent, C.A.

    1996-01-01

    Studies of the sulfur isotopic composition of ore and gangue minerals from the Silesian-Cracow Zn-Pb district were conducted to gain insights into processes that controlled the location and distribution of the ore deposits. Results of this study show that minerals from the Silesian-Cracow ore district have the largest range of sulfur isotope compositions in sulfides observed from any Mississippi Valley-type ore district in the world. The ??34S values for sulfide minerals range from +38 to -32 per mil for the entire paragenetic sequence but individual stages exhibit smaller ranges. There is a well developed correlation between the sulfur isotope composition and paragenetic stage of ore deposition. The first important ore stage contains mostly positive ??34S values, around 5 per mil. The second stage of ore formation are lower, with a median value of around -5 to -15 per mil, and with some values as low as -32 per mil. Late stage barite contains isotopically heavy sulfur around +32 per mil. The range in sulfur isotope compositions can be explained by contributions of sulfur from a variety of source rocks together with sulfur isotope fractionations produced by the reaction paths for sulfate reduction. Much of the variation in sulfur isotope compositions can be explained by bacterial reduction of sedimentary sulfate and disequilibrium reactions by intermediate-valency sulfur species, especially in the late-stage pyrite and sphalerite. Organic reduction of sulfate and thermal release of sulfur from coals in the Upper Silesian Coal Basin may have been important contributors to sulfur in the ore minerals. The sulfur isotopic data, ore mineral textures, and fluid inclusion data, are consistent with the hypothesis that fluid mixing was the dominant ore forming mechanism. The rather distinct lowering of ?? 34S values in sulfides from stage 2 to stage 3 is believed to reflect some fundamental change in the source of reduced sulfur and/or hydrology of the ore

  16. In the early morning of 23 June 2000, the bulk ore carrier MV ...

    African Journals Online (AJOL)

    spamer

    carrying about 1 344 tons of heavy fuel oil (viscosity. 180 centistokes, pour ... INITIAL IMPACT OF THE TREASURE OIL SPILL ON SEABIRDS OFF WESTERN. SOUTH AFRICA ... South African Journal of Marine Science 22. 2000. 34°. 33°. V.

  17. Peptide-Carrier Conjugation

    DEFF Research Database (Denmark)

    Hansen, Paul Robert

    2015-01-01

    To produce antibodies against synthetic peptides it is necessary to couple them to a protein carrier. This chapter provides a nonspecialist overview of peptide-carrier conjugation. Furthermore, a protocol for coupling cysteine-containing peptides to bovine serum albumin is outlined....

  18. Water leaching of titanium from ore flotation residue.

    Science.gov (United States)

    Jaworska, Malgorzata M; Guibal, Eric

    2003-01-01

    Copper ore tailings were tested for the stability of titanium submitted to water leaching in three different reactor systems (agitated vessel, bioreactor and percolated fixed-bed column). For each of these systems, titanium extraction did not exceed 1% of the available metal. Biomass removed from ore residue adsorbed a small part of the titanium with sorption capacities below 20-30 mg g(-1), but most of this biomass was sequestered in the ore residue. Oxygen and carbon dioxide concentrations were monitored and changes in concentration correlated with bacteria development at the initial stage of the process and to fungal development in the latter stages.

  19. Microstructure of Bentonite in Iron Ore Green Pellets

    OpenAIRE

    Bhuiyan, Iftekhar U.; Mouzon, Johanne; Schröppel, Birgit; Kaech, Andres; Dobryden, Illia; Forsmo, Seija P.E.; Hedlund, Jonas

    2017-01-01

    Sodium-activated calcium bentonite is used as a binder in iron ore pellets and is known to increase strength of both wet and dry iron ore green pellets. In this article, the microstructure of bentonite in magnetite pellets is revealed for the first time using scanning electron microscopy. The microstructure of bentonite in wet and dry iron ore pellets, as well as in distilled water, was imaged by various imaging techniques (e.g., imaging at low voltage with monochromatic and decelerated beam ...

  20. Biological-Chemical Oxidation of Ore Minerals at Pezinok Deposit

    Directory of Open Access Journals (Sweden)

    Martin Chovan

    2004-12-01

    Full Text Available The article presents results of leaching experiments of the comparison between chemical and biological-chemical leaching, at the same conditions in solution, of ores from the Sb-(Au- base metal deposit Pezinok (Malé Karpaty Mts., Western Carpathians, Slovakia. The research study shows the oxidation order and the progression of present ore minerals (löllingite, arsenopyrite, stibnite, native Sb, gudmundite, berthierite, pyrite, sphalerite and chalcopyrite. There are discussed differences between chemical and biological-chemical leaching activity of various ore minerals at the surface of polished sections. The extent of the leaching of sulphide minerals is significantly higher than that without bacteria.

  1. Tourmaline as a recorder of ore-forming processes

    Science.gov (United States)

    Slack, J.F.; Trumbull, R.B.

    2011-01-01

    Tourmaline occurs in diverse types of hydrothermal mineral deposits and can be used to constrain the nature and evolution of ore-forming fl uids. Because of its broad range in composition and retention of chemical and isotopic signatures, tourmaline may be the only robust recorder of original mineralizing processes in some deposits. Microtextures and in situ analysis of compositional and isotopic variations in ore-related tourmaline provide valuable insights into hydrothermal systems in seafl oor, sedimentary, magmatic, and metamorphic environments. Deciphering the hydrothermal record in tourmaline also holds promise for aiding exploration programs in the search for new ore deposits.

  2. Start of exploration and mining of uranium ores in Hungary

    Energy Technology Data Exchange (ETDEWEB)

    Mikolay, I.; Szomolanyi, G. (Mecseki Ercbanyaszati Vallalat, Pecs II (Hungary))

    1983-09-01

    The mining of uranium ores is the youngest branch in the history of the Hungarian ore mining. The exploration for uranium ores started in Hungary in the decade from 1947, using simple methods at the beginning to apply more developed technologies later on. From the year 1952 Soviet geologists and geophysicists joined the explorations using the most advanced instruments, in co-operation with the Hungarian experts. From 1953 explorations and developments have been concentrated on the SW area of Mountain Mecsek so that by 1957 the preliminary conditions of a successful Hungarian uranium mining were established.

  3. 40 CFR 440.90 - Applicability; description of the antimony ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... antimony ore subcategory. 440.90 Section 440.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Antimony Ore Subcategory § 440.90 Applicability; description of the antimony ore subcategory. The provisions of...

  4. 40 CFR 440.20 - Applicability; description of the aluminum ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... aluminum ore subcategory. 440.20 Section 440.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Aluminum Ore Subcategory § 440.20 Applicability; description of the aluminum ore subcategory. The provisions of...

  5. 40 CFR 440.50 - Applicability; description of the titanium ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... titanium ore subcategory. 440.50 Section 440.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Titanium Ore Subcategory § 440.50 Applicability; description of the titanium ore subcategory. The provisions of...

  6. 40 CFR 440.70 - Applicability; description of the nickel ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... nickel ore subcategory. 440.70 Section 440.70 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Nickel Ore Subcategory § 440.70 Applicability; description of the nickel ore subcategory. The provisions of this...

  7. 40 CFR 440.40 - Applicability; description of the mercury ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... mercury ore subcategory. 440.40 Section 440.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Mercury Ore Subcategory § 440.40 Applicability; description of the mercury ore subcategory. The provisions of subpart...

  8. 40 CFR 440.110 - Applicability; description of the platinum ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... platinum ore subcategory. 440.110 Section 440.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Platinum Ores Subcategory § 440.110 Applicability; description of the platinum ore subcategory. The provisions of...

  9. 40 CFR 440.60 - Applicability; description of the tungsten ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... tungsten ore subcategory. 440.60 Section 440.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Tungsten Ore Subcategory § 440.60 Applicability; description of the tungsten ore subcategory. The provisions of...

  10. Geochemistry of Rare Earth Elements in Xikeng Ag-Pb-Zn Ore Deposit, South Anhui, China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper, a comparative study is done on the geochemical charateristics of REE in ore, ore-hosted rocks of Lantian group, granite related to ore deposit, and altered rocks for tracing origin of ore-forming materials. The result indicates that the ore-forming fluid and ore-forming materials for Xikeng silver-polymetallic ore deposit were derived from Yixian granite's magmatic activity. Water-rock reaction of the hydrothermal fluid with the carbonate-rich stratum led the altered rock to relatively enrich in HREE.

  11. Studies on Sulfating Roasting Process for Mianning Bastnasite and Baotou Mixed RE Concentrate Ore

    Institute of Scientific and Technical Information of China (English)

    Miao Guangli

    2004-01-01

    Some processes of sulfating roasting and water leaching of crude Mianning RE concentrate ore, of fine Mianning RE concentrate ore, of Baotou RE concentrate ore and of their mixture were investigated.The result shows that the mixture of Mianning and Baotou RE concentrate ore has the optimum leaching rate and rate of recovery when the mixture ratio is 1:4.The recovery rate of the mixture is higher by 14.76% than that of crude Mianning RE concentrate ore, by 5.0 % than that of Mianning fine RE concentrate ore and by 2.4 % than that of Baotou RE concentrate ore.

  12. Experimental study on preferential solution flow during dump leaching of low-grade ores

    Institute of Scientific and Technical Information of China (English)

    YIN Sheng-hua; WU Ai-xiang; SU Yong-ding; ZHANG Jie

    2007-01-01

    The phenomenon of preferential solution flow during dump leaching of low-grade ores was studied. The formative mechanism of preferential solution flow was investigated through analyzing the relationship between permeability and ore diameter,and the relationship between surface tension and ore diameter. The preferential solution flow happened within the fine ore area when the dump was unsaturated. And it could happen within the coarse ore area when the dump became saturated. The results of experiment show that the outflow of coarse ore area increases sharply with higher applied rate. The outflow of fine ore area is greater than that of coarse ore area when the applied rate is below 3.2 L/min, and the preferential solution flow happens in fine ore area. But the preferential solution flow happens in coarse ore area when the applied rate is higher than 3.2 L/min. The result of the experiment is consistent with the mechanism analyzing.

  13. Geochemical Studies on Dachang Antimony Ore Deposit in Qinglong,Guizhou Province

    Institute of Scientific and Technical Information of China (English)

    张启厚

    1999-01-01

    The Dachang antimony deposit in Qinglong,Guizhou Province,is strictly controlled by the “Dachang Layer” which is a complex altered rock occurring at unconformity between the Permian Emeishan basalt and the Maokou limestone.Based on the studies of the hanging-and foot-wall rocks,the trace elements and REE contents of the rocks and ores and heavy placer minerals in the basalt,this paper is focused on the relations between these data and the “Dachang Layer”and its hanging- and oot-wall rocks.The author pointed out that the “Dachang Layer” and basalt are the source-beds of antimony;ilmenite and magnetite are the major mineral carriers of antimony.In the processes of halmyrosis and burial metamorphism of the “Dachang Layer” an basalt,antimony was mobilized along with the mobilization of iron and was preliminarily concentrated in the“ Dachang Layer”.

  14. Arsenic bioleaching in medical realgar ore and arsenic- bearing ...

    African Journals Online (AJOL)

    medical realgar ore that allowed much higher leaching rates ... bioleaching behavior between mixed unadapted ... Acid drainage from copper mine, Zhongtiao Mountain, Shanxi,. China ..... during high temperature bioleaching of gold-bearing.

  15. ITABIRITE IRON ORE CONCENTRATION BY PNEUMATIC FLOTATION CELL

    Directory of Open Access Journals (Sweden)

    Angelo Quintiliano Nunes da Silva

    2015-06-01

    Full Text Available The main iron ore processing plants in Brazil operate through reverse cationic flotation. Many studies have been conducted in order to improve flotation efficiency by optimization process variables. The pneumatic flotation cell stands out due to the simplicity to and to the intense contact particle/bubble promoted by the pulp feeding system. In this study, laboratory scale and pilot were conducted using a sample of itabirite iron ore. The objectives are evaluating the performance of this device using low grade iron ore, and drawing a comparison with laboratory scale tests on conventional flotation cell. The results indicate the potential application of pneumatic flotation cell to the ore tested. Adjustments in the feed particle size and process optimizations can be performed on the concentrate, reaching Fe and SiO2 grades used by the industry

  16. Microstructure of bentonite in iron ore green pellets.

    Science.gov (United States)

    Bhuiyan, Iftekhar U; Mouzon, Johanne; Schröppel, Birgit; Kaech, Andres; Dobryden, Illia; Forsmo, Seija P E; Hedlund, Jonas

    2014-02-01

    Sodium-activated calcium bentonite is used as a binder in iron ore pellets and is known to increase strength of both wet and dry iron ore green pellets. In this article, the microstructure of bentonite in magnetite pellets is revealed for the first time using scanning electron microscopy. The microstructure of bentonite in wet and dry iron ore pellets, as well as in distilled water, was imaged by various imaging techniques (e.g., imaging at low voltage with monochromatic and decelerated beam or low loss backscattered electrons) and cryogenic methods (i.e., high pressure freezing and plunge freezing in liquid ethane). In wet iron ore green pellets, clay tactoids (stacks of parallel primary clay platelets) were very well dispersed and formed a voluminous network occupying the space available between mineral particles. When the pellet was dried, bentonite was drawn to the contact points between the particles and formed solid bridges, which impart strength to the solid compact.

  17. Carbothermal Upgrading of the Awaso Bauxite Ore using Waste ...

    African Journals Online (AJOL)

    Michael

    2015-06-01

    Jun 1, 2015 ... Ore using Waste Pure Water Sachets as Reductant”, Ghana Mining Journal, Vol. ... content) and the emergence of low grade bauxite with high iron oxide content calls for ... effects on the alumina extraction process (Lu et al.,.

  18. ENVIRONMENTAL ISSUE IN COPPER ORE FLOTATION BY XANTHATES

    National Research Council Canada - National Science Library

    Zoran Markovic

    2015-01-01

      This paper presents some investigation results about potassium ethyl xanthate (PEX) stability in water solution at higher pH and in presence of mineral chalcopyrite, related to flotation of copper minerals from copper ore...

  19. Measurement and Modelling of Blast Movement to Reduce Ore ...

    African Journals Online (AJOL)

    user

    growth both from new discoveries and the develop- ment of Subika ... search have developed innovative tools and tech- niques to .... 7 Histogram of Horizontal Blast Displace ment from All Five .... Better QA/QC along the ore/waste boundaries.

  20. Radioanalysis of RE enrichment of ion adsorption type RE ores

    CERN Document Server

    Zhao Shu Quan; Hu He Ping; Li Fu Sheng; Chen Ying Min; LiuShiMing

    2002-01-01

    Objective: To analyze the radioactivity in Rare Earth (RE) enrichment of ion adsorption type RE ores. Methods: Using HPGe-gamma spectrometer to analyze the activity ratio of gamma radionuclides in kind of samples, using FJ-2603 low background alpha, beta measurement apparatus to measure their total alpha and total beta activities, and using X-ray fluorescence spectrometer to analyze contents of La sub 2 O sub 3 and Y sub 2 O sub 3 , respectively. Results: HPGe gamma spectroscopy and X-ray fluorescence spectroscopy are simple, convenient and non-destructive methods of analyzing radionuclides and La sub 2 O sub 3 , Y sub 2 O sub 3 in RE enrichment of ion adsorption type RE ores, respectively. Conclusion: The basic data were provided for radiation protection and treatment of gas, liquid and solid waste in RE production of ion adsorption type RE ores; method and experience were provided for studying ion adsorption type RE ores

  1. By lithology Zbruch deposits (Lower Sarmatian Nikopol manganese ore Basin

    Directory of Open Access Journals (Sweden)

    Bogdanovich V.V.

    2010-06-01

    Full Text Available Based on lithologic-paleogeographic study Zbruch layers of Nikopol manganese ore Basin sediments described lithological and genetic types of rocks and facies conditions of formation of deposits.

  2. Great Lakes

    Science.gov (United States)

    Edsall, Thomas A.; Mac, Michael J.; Opler, Paul A.; Puckett Haecker, Catherine E.; Doran, Peter D.

    1998-01-01

    The Great Lakes region, as defined here, includes the Great Lakes and their drainage basins in Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, and New York. The region also includes the portions of Minnesota, Wisconsin, and the 21 northernmost counties of Illinois that lie in the Mississippi River drainage basin, outside the floodplain of the river. The region spans about 9º of latitude and 20º of longitude and lies roughly halfway between the equator and the North Pole in a lowland corridor that extends from the Gulf of Mexico to the Arctic Ocean.The Great Lakes are the most prominent natural feature of the region (Fig. 1). They have a combined surface area of about 245,000 square kilometers and are among the largest, deepest lakes in the world. They are the largest single aggregation of fresh water on the planet (excluding the polar ice caps) and are the only glacial feature on Earth visible from the surface of the moon (The Nature Conservancy 1994a).The Great Lakes moderate the region’s climate, which presently ranges from subarctic in the north to humid continental warm in the south (Fig. 2), reflecting the movement of major weather masses from the north and south (U.S. Department of the Interior 1970; Eichenlaub 1979). The lakes act as heat sinks in summer and heat sources in winter and are major reservoirs that help humidify much of the region. They also create local precipitation belts in areas where air masses are pushed across the lakes by prevailing winds, pick up moisture from the lake surface, and then drop that moisture over land on the other side of the lake. The mean annual frost-free period—a general measure of the growing-season length for plants and some cold-blooded animals—varies from 60 days at higher elevations in the north to 160 days in lakeshore areas in the south. The climate influences the general distribution of wild plants and animals in the region and also influences the activities and distribution of the human

  3. A geochemical assessment of possible lunar ore formation

    Science.gov (United States)

    Haskin, Larry A.; Colson, Russell O.; Vaniman, David

    The Moon apparently formed without appreciable water or other relatively volatile materials. Interior concentrations of water or other volatile substances appear to be extremely low. On Earth, water is important to the genesis of nearly all types of ores. Thus, some have reasoned that only abundant elements would occur in ore concentrations. The definition and recognition of ores on the Moon challenge the imaginations and the terrestrial perceptions of ore bodies. Lunar ores included solar-wind soaked soils, which contain abundant but dilute H, C, N, and noble gases (including He-3). Oxygen must be mined; soils contain approximately 45 percent (wt). Mainstream processes of rock formation concentrated Si, Mg, Al, Fe, and Ca, and possibly Ti and Cr. The highland surface contains approximately 70 percent (wt) feldspar (mainly CaAl2Si2O8), which can be separated from some highland soils. Small fragments of dunite were collected; dunite may occur in walls and central peaks of some craters. Theoretical extensions of observations of lunar samples suggest that the Moon may have produced ores of trace elements. Some small fragments have trace-element concentrations 104 times higher than the lunar average, indicating that effective geochemical separations occurred; processes included fractional crystallization, silicate immiscibility, vaporization and condensation, and sulfide metamorphism. Operations of these processes acting on indigenous materials and on meteoritic material in the regolith could have produced ores. Infalling carbonaceous meteorites and comets have added water and hydrocarbons that may have been cold-trapped. Vesicles in basalts, pyroclastic beads, and reported transient events suggest gag emission from the lunar interior; such gas might concentrate and transport rare elements. Large impacts may disperse ores or produce them through deposition of heat at depth and by vaporization and subsequent condensation. The main problem in assessing lunar resources is

  4. Composite cam carrier

    Energy Technology Data Exchange (ETDEWEB)

    Wicks, Christopher Donald; Madin, Mark Michael

    2017-03-14

    A cam carrier assembly includes a cylinder head having valves and a camshaft having lobes. A cam carrier has a first side coupled with the cylinder head engaging around the valves and a second side with bearing surfaces supporting the camshaft. A series of apertures extend between the first and second sides for the lobes to interface with the valves. The cam carrier is made of carbon fiber composite insulating the camshaft from the cylinder head and providing substantial weight reduction to an upper section of an associated engine.

  5. Asymmetric Carrier Random PWM

    DEFF Research Database (Denmark)

    Mathe, Laszlo; Lungeanu, Florin; Rasmussen, Peter Omand;

    2010-01-01

    This paper presents a new fixed carrier frequency random PWM method, where a new type of carrier wave is proposed for modulation. Based on the measurements, it is shown that the spread effect of the discrete components from the motor current spectra is very effective independent of the modulation...... index. The flat motor current spectrum generates an acoustical noise close to the white noise, which may improve the acoustical performance of the drive. The new carrier wave is easy to implement digitally, without employing any external circuits. The modulation method can be used in open, as well...

  6. Uranium and thorium recovery in thorianite ore-preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Gaiotte, Joao V.M. [Universidade Federal de Alfenas, Pocos de Caldas, MG (Brazil); Villegas, Raul A.S.; Fukuma, Henrique T., E-mail: rvillegas@cnen.gov.br, E-mail: htfukuma@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Pocos de Caldas, MG (Brazil). Lab. de Pocos de Caldas

    2011-07-01

    This work presents the preliminary results of the studies aiming to develop a hydrometallurgical process to produce uranium and thorium concentrates from thorianite ore from Amapa State, Brazil. This process comprises two major parts: acid leaching and Th/U recovery using solvent extraction strategies. Thorianite ore has a typical composition of 60 - 70% of thorium, 8 - 10% lead and 7 - 10% uranium. Sulfuric acid leaching operational conditions were defined as follows: acid/ore ratio 7.5 t/t, ore size below 65 mesh (Tyler), 2 hours leaching time and temperature of 100 deg C. Leaching tests results showed that uranium and thorium recovery exceeded 95%, whereas 97% of lead ore content remained in the solid form. Uranium and thorium simultaneous solvent extraction is necessary due to high sulfate concentration in the liquor obtained from leaching, so the Primene JM-T primary anime was used for this extraction step. Aqueous raffinate from extraction containing sulfuric acid was recycled to the leaching step, reducing acid uptake around 60%, to achieve a net sulfuric acid consumption of 3 t/t of ore. Uranium and thorium simultaneous stripping was performed using sodium carbonate solution. In the aqueous stripped it was added sulfuric acid at pH 1.5, followed by a second solvent extraction step using the tertiary amine Alamine 336. The following stripping step was done with a solution of sodium chloride, resulting in a final solution of 23 g L-1 uranium. (author)

  7. Study on the multi-sources of ore-forming materials and ore-forming fluids in the Huize lead-zinc ore deposit

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhenliang; HUANG Zhilong; GUAN Tao; YAN Zaifei; GAO Derong

    2005-01-01

    The Huize large-sized Pb-Zn deposit in Yunnan Province, China, is characterized by favorable metallogenic background and particular geological settings. This suggested that the ore-forming mechanism is relatively unique. On the basis of geological features such as the contents of mineralization elements, the REE concentrations of gangue calcites, the REE concentrations of calcite veins in the NE-trending tectonic zone and the Pb, Sr, C, H and O isotopic compositions of different minerals, this paper presents that the ore-forming materials and ore-forming fluids of the deposit were derived from various types of strata or rocks. This is a very significant conclusion for us to further discuss the mineralization mechanism of the deposit at depth and establish an available genetic model.

  8. KEY ROLE OF METALLOGENIC THEORY OF POLYGENETIC COMPOUND ORE DEPOSITS IN LOCATION PREDICTION OF HIDDEN ORE DEPOSITS IN DIWA REGIONS

    Institute of Scientific and Technical Information of China (English)

    PENG; Sheng-lin; LIU; Liang-ming; LAI; Jian-qing

    2001-01-01

    The metallogenic theory of polygenetic compound ore deposit is the Important basis for location prediction of hidden ore deposits in diwa regions.It can play an important role in each step of prediction research,targeting procedure,acquiring information and integrating information.In this paper,the authors discusses how to construct geological concept by using of the metallogenic theory of polygenetic ore deposits for predicting targeting area,to arrange investigation and detection for getting enough useful information,and to analyze and integrate information for reaching a trustful prediction conclusion.According to these strategies,we conduct a successful prediction of location of hidden ore bodies in the outer of the Fenghuangshan copper mine,a principal producing mine in Tongling Cu-Au district.

  9. Great Lakes/St. Lawrence Seaway Regional Transportation Study; Great Lakes Area Industries.

    Science.gov (United States)

    1981-11-01

    in either vertical or horizontal rotary kilns . Most states have limestone deposits, but much of that used by the steel industry comes from Michigan...Others Amoco 3 National Gypsum 6 Cement Transit Company 7 Erie Sand 3 Subtotal 19 TOTAL 140 * I Source: Lake Carriers Association. I I III-21 I

  10. Transport network and flow mechanism of shallow ore-bearing magma in Tongling ore cluster area

    Institute of Scientific and Technical Information of China (English)

    DENG; Jun; WANG; Qingfei; HUANG; Dinghua

    2006-01-01

    Abundant studies revealed that shallow intrusions of the Yanshanian epoch resulted in the mass mineralization of the Tongling region. Various evidences showed there existed a concealed magma chamber at -10 km depth in the middle part of this region during Yanshanian epoch, from which the ore-forming magma was generated and then transported to the superficial layer. Yet the transport network and flow mechanism of the shallow ore-bearing magma, the key problem associ- ated with ore-forming process, was relatively little focused on. Integrate analysis of structural me- chanics, statistical fractal and geological facts suggested that NE trending high-angle fold-related thrust faults and the tessellated basement ones served as the main pathways for the shallow magma's transporting, moreover, the saddle void spaces among adjacent strata in the folds upon this fault system provided the place for magma's emplacement. So the folds in the upper part and faults in the lower part of the upper crust constituted the fluid's transport and emplacement network. During the deformation of geologic body with multi-layer structure, the layers in the upper part tended to fold when received the jacking stress from the lower part, while the lower one inclined to fault undergoing loads of the upper part. And the producing probability of this structure assemblage was highly increased in the condition, such as in the Tongling area, that the mechanic rigidity of the lower layers was stronger than that of the upper ones. For the pre-existence of fluid-conducting network, the top magma with high volatile in the magma chamber transported rapidly to the superficial layer in dyking pattern, located in the void spaces of folds, filled and reconstructed them. The sudden drop of pressure caused the fluid unmixing from the magma and mass ore-forming elements concentration. Pulse activity of the dyking may be the principal reason why magmatic bodies in the Tongling area were spatially

  11. Ceramic colorant from untreated iron ore residue.

    Science.gov (United States)

    Pereira, Oscar Costa; Bernardin, Adriano Michael

    2012-09-30

    This work deals with the development of a ceramic colorant for glazes from an untreated iron ore residue. 6 mass% of the residue was added in suspensions (1.80 g/cm(3) density and 30s viscosity) of white, transparent and matte glazes, which were applied as thin layers (0.5mm) on engobeb and not fired ceramic tiles. The tiles were fired in laboratory roller kiln in a cycle of 35 min and maximum temperatures between 1050 and 1180°C. The residue and glazes were characterized by chemical (XRF) and thermal (DTA and optical dilatometry) analyses, and the glazed tiles by colorimetric and XRD analyses. The results showed that the colorant embedded in the transparent glaze results in a reddish glaze (like pine nut) suitable for the ceramic roof tile industry. For the matte and white glazes, the residue has changed the color of the tiles with temperature. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Ferrite grade iron oxides from ore rejects

    Indian Academy of Sciences (India)

    K S Rane; V M S Verenkar; P Y Sawant

    2001-06-01

    Iron oxyhydroxides and hydroxides were synthesized from chemically beneficiated high SiO2/Al2O3 low-grade iron ore (57.49% Fe2O3) rejects and heated to get iron oxides of 96–99.73% purity. The infrared band positions, isothermal weight loss and thermogravimetric and chemical analysis established the chemical formulas of iron-oxyhydroxides as -FeOOH.0.3H2O; -FeOOH.0.2H2O and amorphous FeOOH. The thermal products of all these were -Fe2O3 excepting that of -FeOOH.0.3H2O which gave mainly -Fe2O3 and some admixture of -Fe2O3. The hydrazinated iron hydroxides and oxyhydroxides, on the other hand, decomposed autocatalytically to mainly -Fe2O3. Hydrazine method modifies the thermal decomposition path of the hydroxides. The saturation magnetization, s, values were found to be in the range 60–71 emu g–1 which are close to the reported values for -Fe2O3. Mechanism of the -Fe2O3 formation by hydrazine method is discussed.

  13. Ore mineralogy of the Serra Pelada Au-Pd-Pt deposit, Carajás, Brazil and implications for ore-forming processes

    Science.gov (United States)

    Berni, Gabriel V.; Heinrich, Christoph A.; Lobato, Lydia M.; Wall, Vic

    2016-08-01

    Serra Pelada is a world-class hydrothermal Au-Pd-Pt deposit located at the eastern border of the Amazon craton, northern Brazil. The rocks at Serra Pelada have experienced intense tropical weathering for about 70 Ma, but drill core samples preserve the primary mineralogy and hydrothermal alteration features, with extreme grades of Au, Pd and Pt individually reaching hundreds of parts per million (ppm) by weight. Mineralization at Serra Pelada occurs in hydrothermally altered metasiltstones and dolomitic metasandstones at the hinge zone of a recumbent syncline, comprising zones of hematite, chlorite-carbon, argillic, and siliceous alteration. The main hydrothermal gangue minerals are quartz, kaolinite, sericite, amesite, hematite, monazite, florencite and variable amounts of highly reflective carbonaceous matter. Hydrothermal carbon input is evident from precipitated carbon occurring along crenulation planes and veinlets associated with the precious metals. Ore and accessory minerals include a variety of sulphide, selenide, arsenide, sulphate and oxide minerals, including gold with variable metal contents, palladian gold, fischesserite, sudovikovite, sperrylite, selenian braggite, isomertieite, mertieite-II and secondary Au-Pt-Pd alloys. The composition of fischesserite varies from the ideal formula (Ag3AuSe2) towards a more Ag-rich composition, indicating a disordered solid solution form that is stable only above 260 °C, consistent with the high thermal maturity of associated carbonaceous matter approaching graphite. Primary ore and gangue minerals at Serra Pelada comprise a suite of elements that are best transported in oxidising conditions and precipitated upon reduction. This suggests that fluid mixing between a highly oxidised (metal carrier) and a reduced fluid was a key process for high-grade noble metal precipitation at Serra Pelada.

  14. Characteristics and origin of ore-forming fluids of Jinchangqing gold (copper) ore deposit (s) in Xiangyun, Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    HE Mingqin; SONG Huanbin; LIU Jiajun; LI Chaoyang

    2005-01-01

    On the basis of results of the studies of primary fluid inclusions, and the hydrogen and oxygen isotope data, the authors concluded that the early-stage ore-forming fluid from the Jinchangqing gold (copper) ore deposit is a kind of sulfate type hot brine characterized by medium temperature and salinity, genetically related to the late-stage ore-forming fluid derived from an acidic and more reductive environment. However, the late-stage ore-forming fluid is a sort of low temperature and low salinity chloride-type hot brine which originated from a lower pressure, acidic and more oxidative environment. In general, the ore fluids were derived from the late-stage, or largely from the early-stage groundwater-derived meteoric water, which has a 12‰-17‰ heavier oxygen isotopic composition than the original rain water (δ 18 O= -15.3‰ ), and were formed during gold mineralization as a product of oxygen isotope exchange during the reaction between ore-forming fluid and wall rocks under a lower water/rock ratio condition.

  15. Photoinduced Transformation between Charge Carrier and Spin Carrier in Polymers

    Institute of Scientific and Technical Information of China (English)

    MEI Yuan; ZHAO Chang; SUN Xin

    2006-01-01

    By dynamical simulations, we show a transforming process between neutral soliton (spin carrier) and charged soliton (charge carrier) in polymers via photo-excitation, taking a polaron as the transitional bridge. It is photoinduced transformation between spin carrier and charge carrier. In this way, we demonstrate an access for polymers to be applied to spintronics.

  16. Effects of barium chlorine treatment of uranium ore on /sup 222/Rn emanation and /sup 226/Ra leachability from mill tailings

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, S.A.; Church, S.L.; Whicker, F.W.

    1985-01-01

    The purpose of this laboratory study was to investigate the effectiveness of barium chloride treatment of uranium ore on /sup 222/Rn emanation from mill tailings, /sup 226/Ra level in waste-water, and the leachability of radium from tailings. It has been shown that barium sulfate is an excellent carrier for radium and that barium sulfate crystals have high retention capacity for radon gas produced by radium trapped within the lattice. Ground uranium ore from a mine in Wyoming was mixed with water to form a 1:1 ratio before barium and potassium chlorides were added at concentrations of 0, 10, 25, 50, and 100 mg per liter of slurry. The ore was then subjected to a simulated mill process using sulfuric acid leaching. The liquid representing tailings pond water was separated and analyzed for /sup 226/Ra and the solid fraction, representing mill tailings, was tested for radon emanation and the leachability of radium by deionized water. This study suggests that barium treatment of uranium ore prior to sulfuric acid leaching could be effective in reducing radon emanation from tailings and also in reducing the /sup 226/Ra concentration of waste-water. Leachability of radium from treated tailings was markedly reduced.

  17. Fluorosilicone and silicone o-ring aging study.

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, Robert; Gillen, Kenneth T.

    2007-10-01

    Fluorosilicone o-ring aging studies were performed. These studies examined the compressive force loss of fluorosilicone o-rings at accelerated (elevated) temperatures and were then used to make predictions about force loss at room temperature. The results were non-Arrhenius with evidence for a lowering in Arrhenius activation energies as the aging temperature was reduced. The compression set of these fluorosilicone o-rings was found to have a reasonably linear correlation with the force loss. The aging predictions based on using the observed curvature of the Arrhenius aging plots were validated by field aged o-rings that yielded degradation values reasonably close to the predictions. Compression set studies of silicone o-rings from a previous study resulted in good correlation to the force loss predictions for the fluorosilicone o-rings from this study. This resulted in a preliminary conclusion that an approximately linear correlation exists between compression set and force decay values for typical fluorosilicone and silicone materials, and that the two materials age at similar rates at low temperatures. Interestingly, because of the observed curvature of the Arrhenius plots available from longer-term, lower temperature accelerated exposures, both materials had faster force decay curves (and correspondingly faster buildup of compression set) at room temperature than anticipated from typical high-temperature exposures. A brief study on heavily filled conducting silicone o-rings resulted in data that deviated from the linear relationship, implying that a degree of caution must be exercised about any general statement relating force decay and compression set.

  18. Bathymetry of Lake Michigan

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Michigan has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  19. Bathymetry of Lake Ontario

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Ontario has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  20. Designated Wildlife Lakes - points

    Data.gov (United States)

    Minnesota Department of Natural Resources — This is a point shapefile of Designated Wildlife Lakes in Minnesota. This shapefile was created by converting lake polygons from the Designated Wildlife Lakes...

  1. Great Lakes Bathymetry

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lakes Michigan, Erie, Saint Clair, Ontario and Huron has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and...

  2. Bathymetry of Lake Superior

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Superior has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  3. Hydrography - Lakes Assessments - Attaining

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This layer shows only attaining lakes of the Integrated List. The Lakes Integrated List represents lake assessments in an integrated format for the Clean Water Act...

  4. Bathymetry of Lake Huron

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Huron has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  5. Hydrothermal REE and Zr Ore Forming Processes in Peralkaline Granitic Systems

    Science.gov (United States)

    Gysi, A. P.

    2015-12-01

    Anorogenic peralkaline igneous systems display extreme enrichment of REE and Zr with a hydrothermal overprint leading to post-magmatic metal mobilization. Strange Lake in Canada, for example, is a mid-Proterozoic peralkaline granitic intrusion and host to a world-class REE-Zr deposit with >50 Mt ore (>1.5 wt.% REE and >3 wt.% Zr). In contrast to porphyry systems, peralkaline systems are poorly understood and hydrothermal metal mobilization models are only in the early stage of their development. This is partly due to the paucity of thermodynamic data for REE-bearing minerals and aqueous species, and the complexity of the hydrothermal fluids (enrichment of F, P and Cl), which make it difficult to develop thermodynamic models of metal partitioning. This study aims to show the link between alteration stages and metal mobilization using Strange Lake as a natural laboratory and combine these observations with numerical modeling. Four types of alteration were recognized at Strange Lake: i) alkali (i.e. K and Na) metasomatism related to interaction with NaCl-bearing orthomagmatic fluids, ii) acidic alteration by HCl-HF-bearing fluids originating from the pegmatites followed by iii) aegirinization of the border of the pegmatites and surrounding granites and by iv) pervasive Ca-F-metasomatism. The acidic alteration accounts for most of the hydrothermal metal mobilization in and outward from the pegmatites, whereas the Ca-F-metasomatism led to metal deposition and resulted from interaction of an acidic F-rich fluid with a Ca-bearing fluid. Numerical simulations of fluid-rock reactions with saline HCl-HF-bearing fluids at 400 °C to 250 °C indicate that temperature, availability of F/Cl and pH limit the mobility of Zr and REE. Fluids with pH hydrothermal metal mobilization in peralkaline granitic systems is the formation of a fluid-buffered subsystem providing the acids and ligands required for REE and Zr mobilization.

  6. The value of energy carriers

    NARCIS (Netherlands)

    Gool, W. van

    1987-01-01

    The value of energy carriers can be described thermodynamically by the amount of heat (enthalpy method) or work (exergy or availability method) that can be obtained from the carriers. Prices for energy carriers are used in economics to express their values. The prices for energy carriers are often r

  7. Gamma Spectrometric Analysis of Iron Ore Samples of Arak, Iran

    Directory of Open Access Journals (Sweden)

    Reza Pourimani

    2016-09-01

    Full Text Available Introduction Iron ore is one of the most important natural raw materials that is widely used for manufacturing iron and steel. This type of ore contains various amounts of radionuclides; thus, exposing workers handling their extraction, transportation, and processing to radiation. Materials and Methods In this study, 12 ore samples (each mass weighing about 2 kg were collected from the iron ore mining areas of Arak region, Iran. The specific activities of 226Ra, 232Th, and 40K were determined usinggamma-ray spectrometry method employing high-purity germanium (HPGe detector. Results The specific activities of 226Ra, 232Th, and 40K in samples were 9.39-271.70 Bq/kg, -3 Sv/y suggested in International Commission of Radiological Protection (ICRP Publication 82. Conclusion The gamma ray spectrometric analysis showed that the specific activities of natural radionuclides in samples, except for limonite ore, were within the worldwide range. The effective dose received by workers was much lower than the maximum acceptable value (1000 μSv/y; therefore, the level of radiations in this mine had no adverse consequences for public health.

  8. Existing State and Partitioning of Rare Earth on Weathered Ores

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The existing state and partitioning of rare earth (RE) on weathered ores in Longnan County (LN), Xingfeng County(XF) and Ninghua County(NH) were characterized systematically by standard geological analytical methods. It is found that RE in the weathered rare earth ores exist as four phases: (a) water soluble, (b) ion-exchangeable, (c) colloidal sediment (oxides), (d) minerals, in which mainly as ion exchangeable phase, accounting for nearly 80% of total RE,with about 20% in the form of colloid sediment phase and mineral phase, but very little as aqueous soluble phase. These rare earth partitioning were mainly chosen mid-heavy RE elements, occupying above 60%, but not equal in the four phases. The mid-heavy RE elements were primarily enriched in the ion exchangeable phase up to 40%, while the containment of cerium dioxide is below 2%. The cerium deficiency occurs in the ion exchangeable phase in weathered ore. It results from that the Ce3+ is oxidized into Ce4+ and changes into CeO2. For LN ore, the containment of Y is high in weathered ore because Y-minerals are abundant in original rock.

  9. Microbial Beneficiation of Salem Iron Ore Using Penicillium purpurogenum

    Science.gov (United States)

    Mishra, M.; Pradhan, M.; Sukla, L. B.; Mishra, B. K.

    2011-02-01

    High alumina and silica content in the iron ore affects coke rate, reducibility, and productivity in a blast furnace. Iron ore is being beneficiated all around the world to meet the quality requirement of iron and steel industries. Choosing a beneficiation treatment depends on the nature of the gangue present and its association with the ore structure. The advanced physicochemical methods used for the beneficiation of iron ore are generally unfriendly to the environment. Biobeneficiation is considered to be ecofriendly, promising, and revolutionary solutions to these problems. A characterization study of Salem iron ore indicates that the major iron-bearing minerals are hematite, magnetite, and goethite. Samples on average contains (pct) Fe2O3-84.40, Fe (total)-59.02, Al2O3-7.18, and SiO2-7.53. Penicillium purpurogenum (MTCC 7356) was used for the experiment . It removed 35.22 pct alumina and 39.41 pct silica in 30 days in a shake flask at 10 pct pulp density, 308 K (35 °C), and 150 rpm. In a bioreactor experiment at 2 kg scale using the same organism, it removed 23.33 pct alumina and 30.54 pct silica in 30 days at 300 rpm agitation and 2 to 3 l/min aeration. Alumina and silica dissolution follow the shrinking core model for both shake flask and bioreactor experiments.

  10. On the use of bastnasite ore as a phosphor material

    Energy Technology Data Exchange (ETDEWEB)

    Mohapatra, M., E-mail: manojm@barc.gov.in; Natarajan, V.; Rajeswari, B.; Dhobale, A.R.; Godbole, S.V.

    2014-01-15

    Bastnasite ore obtained from Indian Rare Earth (IRE) was investigated for its possible use as a phosphor material. The material was characterized by X-ray diffraction (XRD), energy dispersive X-ray fluorescence (EDXRF), photoacoustic spectroscopy (PAS), photoluminescence (PL) and electron paramagnetic resonance spectroscopy (EPR) techniques. XRD studies revealed the semi processed ore to be consisting of single phase CeO{sub 2} with no other impurities. EDXRF studies revealed the presence of ‘Th’ and traces of ‘Sm’ along with ‘Ce’ in the sample. PAS studies revealed the presence of strong charge transfer from oxygen to cerium in the system. PL studies confirmed the presence of at least four trivalent rare earths, viz. Sm, Eu, Dy and Tb in the system in trace quantities. The emission spectrum and decay time data were evaluated. It was observed that the rare earth ions are situated at distorted sites in the system surrounded by defect centers. EPR studies confirmed the presence of Ce{sup 3+}in the system along with electron trapped in oxygen ion vacancies. CIE indices for the ore sample were evaluated and it was seen that the overall emission from the system was in the ‘magenta’ region of the visible spectrum. The emission intensities were also compared with that of commercial samples. -- Highlights: • Characterization of bastnasite ore as a phosphor material. • Role of RE impurities in the luminescence • CIE index of the bastnasite ore.

  11. Flotation technology of refractory low-grade molybdenum ore

    Institute of Scientific and Technical Information of China (English)

    Du Shuhua; Luo Zhenfu

    2013-01-01

    Because of the low grade,high oxidation rate and the accumulation of little associated metal sulfide ore in the molybdenum concentrate during flotation,the Qingyang molybdenum ore is difficult to beneflciate.The experimental studies of grinding fineness,the amount of roughing modifier,depressant and collector were completed.In the cleaning process,the contrast experiments of one regrinding.the regrinding and scrubbing,two-stage regrinding was carried.The result shows that the grade of molybdenum ore concentrate is 45.31%,the recovery is 65.98% and the rich ore ratio reaches 20.59% by the regrinding and scrubbing seven cleaning,the regrinding of concentrations from middling of molybdenum-sulfur separation.The regularly-concentrated material from the apparatus was as the middling products.Hence,ideal beneficiation index can be obtained with a rational mineral processing,which offers new beneficiating technology for the refractory low-grade molybdenum ore in China.

  12. NOVEL BINDERS AND METHODS FOR AGGLOMERATION OF ORE

    Energy Technology Data Exchange (ETDEWEB)

    S.K. Kawatra; T.C. Eisele; J.A. Gurtler; C.A. Hardison; K. Lewandowski

    2004-04-01

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking.

  13. Great Lakes Science Center

    Data.gov (United States)

    Federal Laboratory Consortium — Since 1927, Great Lakes Science Center (GLSC) research has provided critical information for the sound management of Great Lakes fish populations and other important...

  14. Carrier transport uphill. I. General

    DEFF Research Database (Denmark)

    Rosenberg, T; Wilbrandt, W

    1963-01-01

    A quantitative treatment of a carrier pump operating with two carrier forms C and Z is presented. Asymmetric metabolic reactions are assumed to transform Z into C on one and C into Z on the other side of the membrane, establishing a carrier cycle. The kinetical consequences of this mechanism...... concords with equilibrating carrier systems in all characteristic kinetical features is taken to indicate that the carrier mechanism contributes more to the characteristic transport features than the connection with metabolism....

  15. The production and use of citric acid for the removal of potassium from the iron ore concentrate of the Sishen Iron Ore Mine, South Africa

    Directory of Open Access Journals (Sweden)

    Peter J. Williams

    2010-04-01

    Full Text Available The depletion of the richer iron ore worldwide has made it necessary to process lower quality iron ore. Certain substances, such as potassium, contained within the lower quality iron ore, have a detrimental effect on the smelting process during steel manufacturing. Therefore, international steel-making companies charge penalties when purchasing iron ore concentrates containing high concentrations of potassium. To date, lower quality iron ore has been blended with high quality iron ore in an attempt to alleviate the potassium concentrations in the export iron ore; however, the ratio of low quality iron ore to high quality iron ore is increasing, thereby becoming an escalating problem within the economic functioning of the Sishen Iron Ore Mine. It has, therefore, become necessary to develop an economically viable and environmentally friendly process to reduce the high potassium concentrations contained in the iron ore concentrate of the Sishen Iron Ore Mine. In this study, we compared solid substrate and submerged fermentation using Aspergillus niger for the production of citric acid, which is used for the chemical leaching of potassium from the iron ore concentrate. It was found that submerged fermentation proved to be more economical and efficient, producing a maximum citric acid concentration of 102.3 g/L in 96 h of fermentation. ‘Heap leaching’ simulation experiments were found to be uneconomical, due to the required addition of fungal growth medium every 5 days as a result of growth factor depletion within this time; however, this process removed 17.65% of the potassium from the iron ore concentrate. By contrast, chemical leaching of potassium from the iron ore concentrate proved to be most efficient when using a 1 mol citric acid leaching solution at 60 ºC, removing 23.53% of the potassium contained within the iron ore concentrate. Therefore, the most economical and efficient process for the removal of potassium from the iron

  16. Chemical state mapping of heterogeneous reduction of iron ore sinter

    Science.gov (United States)

    Kimura, M.; Takeichi, Y.; Murao, R.; Obayashi, I.; Hiraoka, Y.; Liu, Y.

    2017-06-01

    Iron ore sinter constitutes the major component of the iron-bearing burden in blast furnaces, and its reduction mechanism is one of the keys to improving the productivity of ironmaking. Iron ore sinter is composed of multiple iron oxide phases and calcium ferrites (CFs), and their heterogeneous reduction was investigated in terms of changes in iron chemical state: FeIII, FeII, and Fe0 were examined macroscopically by 2D X-ray absorption and microscopically by 3D transmission X-ray microscopy (TXM). It was shown that the reduction starts at iron oxide grains rather than at calcium ferrite (CF) grains, especially those located near micropores. The heterogeneous reduction causes crack formation and deteriorates the mechanical strength of the sinter. These results help us to understand the fundamental aspects of heterogeneous reduction schemes in iron ore sinter.

  17. Complex sulphide-barite ore leaching in ferric chloride solution

    Directory of Open Access Journals (Sweden)

    Miroslav Sokić

    2016-06-01

    Full Text Available The results of research on the leaching process of complex sulphide-barite ore were presented in this paper. The leaching process was carried out in a laboratory autoclave by ferric chloride solution. Considering that those minerals are represented in complex structural-textural relationships, it is not possible to extract lead, zinc and copper minerals from ore by flotation methods. The obtained results confirmed possibility of the ore processing directly, by chemical methods. The effect of temperature, time and oxygen partial pressure on the lead, zinc and copper dissolution was studied. The maximal leaching degree was achieved at 100 °C and amount of 91.5 % for Pb, 96.1 % for Zn and 60.7 % for Cu. Leaching at temperatures above 100 °C is impractical.

  18. A hybrid decision support system for iron ore supply

    Directory of Open Access Journals (Sweden)

    A. Samolejová

    2012-01-01

    Full Text Available Many European metallurgical companies are forced to import iron ore from remote destinations. For these companies it is necessary to determine the amount of iron ore that will have to be ordered and to create such a delivery schedule so that the continuous operation of blast-furnace plant is not disrupted and there is no exceedingly large stock of this raw material. The objective of this article is to design the decision support system for iron ore supply which would effi ciently reduce uncertainty and risk of that decision-making. The article proposes a hybrid intelligent system which represents a combination of diff erent artifi cial intelligence methods with dynamic simulation technique for that purpose.

  19. Treatment of coking wastewater by using manganese and magnesium ores.

    Science.gov (United States)

    Chen, Tianhu; Huang, Xiaoming; Pan, Min; Jin, Song; Peng, Suchuan; Fallgren, Paul H

    2009-09-15

    This study investigated a wastewater treatment technique based on natural minerals. A two-step process using manganese (Mn) and magnesium (Mg) containing ores were tested to remove typical contaminants from coking wastewater. Under acidic conditions, a reactor packed with Mn ore demonstrated strong oxidizing capability and destroyed volatile phenols, chemical oxygen demand (COD)(,) and sulfide from the coking wastewater. The effluent was further treated by using Mg ore to remove ammonium-nitrogen and phosphate in the form of magnesium ammonium phosphate (struvite) precipitates. When pH of the wastewater was adjusted to 1.2, the removal efficiencies for COD, volatile phenol and sulfide reached 70%, 99% and 100%, respectively. During the second step of precipitation, up to 94% of ammonium was removed from the aqueous phase, and precipitated in the form of struvite with phosphorus. The struvite crystals showed a needle-like structure. X-ray diffraction and transmission electron microscopy were used to characterize the crystallized products.

  20. Investigation of chemical suppressants for inactivation of sulfide ores

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to investigate the effective control method of spontaneous combustion in the mining of sulfide ore deposits, This paper presents the testing results of several selected chemicals (water glass, calcium chloride, calcium oxide, magnesium oxide and their composites) as oxidation suppressants for sulfide ores. A weight increment scaling method was used to measure suppressant performance, and this method proved to be accurate, simple and convenient. Based on a large number of experiments, the test results show that four types of chemical mixtures demonstrate a good performance in reducing the oxidation rate of seven active sulfide ore samples by up to 27% to 100% during an initial 76 d period. The mixtures of water glass mixed with calcium chloride and magnesium oxide mixed with calcium chloride can also act as fire suppressants when used with fire sprinkling systems.

  1. Beneficiation of the gold bearing ore by gravity and flotation

    Science.gov (United States)

    Gül, Alim; Kangal, Olgaç; Sirkeci, Ayhan A.; Önal, Güven

    2012-02-01

    Gold concentration usually consists of gravity separation, flotation, cyanidation, or the combination of these processes. The choice among these processes depends on the mineralogical characterization and gold content of the ore. Recently, the recovery of gold using gravity methods has gained attention because of low cost and environmentally friendly operations. In this study, gold pre-concentrates were produced by the stepwise gravity separation and flotation techniques. The Knelson concentrator and conventional flotation were employed for the recovery of gold. Gold bearing ore samples were taken from Gümüşhane Region, northern east part of Turkey. As a result of stepwise Knelson concentration experiments, a gold concentrate assaying around 620 g/t is produced with 41.4wt% recovery. On the other hand, a gold concentrate about 82 g/t is obtained with 89.9wt% recovery from a gold ore assaying 6 g/t Au by direct flotation.

  2. Calcination-Digestion-Desliming of Phosphorus Ore Bearing Rare Earth

    Institute of Scientific and Technical Information of China (English)

    Zhang Qin; Zhang Jie; Wang Jing; Qiu Yue qin

    2004-01-01

    The recoveries of phosphorus and RE of ore from Zhijin in Guizhou were studied.The influences of the calcination temperature, resident time, the digested time and water volume of the calcinating on concentrate yield by desliming were also investigated by orthogonal design.Appropriate calcination temperature is initial condition that makes carbonate mineral decomposition.The recovery of phosphorus is 83.02% and rare earth is 90.56% in phosphorus concentrate when calcined temperature is 900 ℃, other conditions include: calcined time is 30 min, digestion water volume is 300 ml, digestion time is 20 min.The results show that the pre-treatment of the ore is favorable for the separation and enrichment of rare earth from phosphorus ore, and a process of calcination-digestion-desliming was promised.

  3. Fossil bacteria in Xuanlong iron ore deposits of Hebei Province

    Institute of Scientific and Technical Information of China (English)

    DAI Yongding; SONG Haiming; SHEN Jiying

    2004-01-01

    Discovered in Early Proterozoic Xuanlong iron ore deposits are six genera of fossil iron bacteria, i. e. sphere (coenobium of) rod-shaped (monomer) Naumanniella, ellipsoid elliptical Ochrobium, sphere spherical Siderocapsa and chain spherical Siderococcus, chain rod-shaped Leptothrix and Lieskeella, and six genera of fossil blue bacteria, namely sphere spherical Gloeocapsa, Synechocystis and Globobacter, chain spherical Anabaena and Nostoc, and constrictive septate tubular Nodularia. The biomineralized monomers and coenobia of the two categories of bacteria, together with hematite plates made up the bacteria pelletal, bacteria silky,bacteria fibrous and clasty bacteria pelletal textural lamina. The bacteria pelletal laminae combined with other bacteria laminae to make up oncolite, stromatolite and laminate. The precipitation of iron oxide was accelerated due to iron and blue bacteria cohabiting on microbial film or mat. The Xuanlong iron ore deposits are microbial binding ore deposits of ocean source.

  4. Novel Binders and Methods for Agglomeration of Ore

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler

    2006-12-31

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking. This project has identified several acid-resistant binders and agglomeration procedures that can be used for improving the energy efficiency of heap leaching, by preventing the ''ponding'' and ''channeling'' effects that currently cause reduced recovery and extended leaching cycle times. Methods have also been developed for iron ore

  5. Control of Rock Mechanics in Underground Ore Mining

    Science.gov (United States)

    Golik, V. I.; Efremenkov, A. B.

    2017-07-01

    Performance indicators in underground mining of thick iron fields can be insufficient since geo-mechanic specifics of ore-hosting fields might be considered inadequately, as a consequence, critical deformations and even earth’s surface destruction are possible, lowering the indicators of full subsurface use, this way. The reason for it is the available approach to estimating the performance of mining according to ore excavation costs, without assessing losses of valuable components and damage to the environment. The experimental approach to the problem is based on a combination of methods to justify technical capability and performance of mining technology improvement with regard to geomechanical factors. The main idea of decisions to be taken is turning geo-materials into the condition of triaxial compression via developing the support constructions of blocked up structural rock block. The study was carried out according to an integrated approach based on the analysis of concepts, field observations, and simulation with the photo-elastic materials in conditions of North Caucasus deposits. A database containing information on the deposit can be developed with the help of industrial experiments and performance indicators of the field can be also improved using the ability of ore-hosting fields to develop support constructions, keeping the geo-mechanical stability of the system at lower cost, avoiding ore contamination at the processing stage. The proposed model is a specific one because an adjustment coefficient of natural and anthropogenic stresses is used and can be adopted for local conditions. The relation of natural to anthropogenic factors can make more precise the standards of developed, prepared and ready to excavation ore reserves relying on computational methods. It is possible to minimize critical stresses and corresponding deformations due to dividing the ore field into sectors safe from the standpoint of geo-mechanics, and using less cost

  6. Isolation and identification of iron ore-solubilising fungus

    Directory of Open Access Journals (Sweden)

    Damase Khasa

    2010-09-01

    Full Text Available Potential mineral-solubilising fungi were successfully isolated from the surfaces of iron ore minerals. Four isolates were obtained and identified by molecular and phylogenetic methods as close relatives of three different genera, namely Penicillium (for isolate FO, Alternaria (for isolates SFC2 and KFC1 and Epicoccum (for isolate SFC2B. The use of tricalcium phosphate (Ca3(PO42in phosphate-solubilising experiments confirmed isolate FO as the only phosphate solubiliser among the isolated fungi. The bioleaching capabilities of both the fungus and its spent liquid medium were tested and compared using two types of iron ore materials, conglomerate and shale, from the Sishen Iron Ore Mine as sources of potassium (K and phosphorus (P. The spent liquid medium removed more K (a maximum of 32.94% removal, from conglomerate, than the fungus (a maximum of 21.36% removal, from shale. However, the fungus removed more P (a maximum of 58.33% removal, from conglomerate than the spent liquid medium (a maximum of 29.25% removal, from conglomerate. The results also indicated a potential relationship between the removal of K or P and the production of organic acids by the fungus. A high production of gluconic acid could be related to the ability of the fungus to reduce K and P. Acetic, citric and maleic acids were also produced by the fungus, but in lower quantities. In addition, particle size and iron ore type were also shown to have significant effects on the removal of potassium and phosphorus from the iron ore minerals. We therefore conclude that the spent liquid medium from the fungal isolate FO can potentially be used for biobeneficiation of iron ore minerals.

  7. Novel Binders and Methods for Agglomeration of Ore

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler

    2006-12-31

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking. This project has identified several acid-resistant binders and agglomeration procedures that can be used for improving the energy efficiency of heap leaching, by preventing the ''ponding'' and ''channeling'' effects that currently cause reduced recovery and extended leaching cycle times. Methods have also been developed for iron ore

  8. [Assessment of Soil Fluorine Pollution in Jinhua Fluorite Ore Areas].

    Science.gov (United States)

    Ye, Qun-feng; Zhou, Xiao-ling

    2015-07-01

    The contents of. soil total fluorine (TF) and water-soluble fluorine (WF) were measured in fluorite ore areas located in Jinhua City. The single factor index, geoaccumulation index and health risk assessment were used to evaluate fluorine pollution in soil in four fluorite ore areas and one non-ore area, respectively. The results showed that the TF contents in soils were 28. 36-56 052. 39 mg.kg-1 with an arithmetic mean value of 8 325.90 mg.kg-1, a geometric mean of 1 555. 94 mg.kg-1, and a median of 812. 98 mg.kg-1. The variation coefficient of TF was 172. 07% . The soil WF contents ranged from 0. 83 to 74. 63 mg.kg-1 with an arithmetic mean value of 16. 94 mg.kg-1, a geometric mean of 10. 59 mg.kg-1, and a median of 10. 17 mg.kg-1. The variation coefficient of WF was 100. 10%. The soil TF and WF contents were far higher than the national average level of the local fluorine epidemic occurrence area. The fluoride pollution in soil was significantly affected by human factors. Soil fluorine pollution in Yangjia, Lengshuikeng and Huajie fluorite ore areas was the most serious, followed by Daren fluorite ore area, and in non-ore area there was almost no fluorine pollution. Oral ingestion of soils was the main exposure route. Sensitivity analysis of model parameters showed that children's weight exerted the largest influence over hazard quotient. Furthermore, a significant positive correlation was found among the three kinds of evaluation methods.

  9. Challenges facing the North American iron ore industry

    Science.gov (United States)

    Jorgenson, J.D.

    2005-01-01

    During the 20th century, the iron ore mining industries of Canada and the United States passed through several periods of transformation. The beginning of the 21st century has seen yet another period of transformation, with the economic failure of a number of steel companies, the acquisition of their facilities by more viable steelmakers, and the consolidation of control within the North American iron ore industry. Changes in Canadian and United States iron ore production and the market control structure involved are analysed. The consolidation of ownership, formation of foreign joint ventures within Nordi America, planned divestitures of upstream activities by steelmakers, and industry changes made to ensure availability of feedstocks will be reviewed. The ttaditional isolation of the Canadian and United States iron ore operations and their strong linkage to downstream steel production will be discussed in the context of a changing global economy. Management-labour conflicts that have taken place and agreements made during 2000 through 2004 will be discussed in the context of the economic environment leading up to these agreements. Cooperative agreements between competing Canadian and United States companies to resolve client needs in processing and blending will be examined. A joint industry-government project designed to use new technology to produce direct reduced iron nuggets of 96 - 98 per cent iron content using non-coking coals will also be assessed. Changes in iron ore transportation methods, ownership and infrastructure will be reviewed for both rail and inland waterway transport between Canadian and United States companies. A brief analysis of social and environmental issues relating to sustainable development of the Canadian-United States iron ore industry will be included.

  10. Intestinal solute carriers

    DEFF Research Database (Denmark)

    Steffansen, Bente; Nielsen, Carsten Uhd; Brodin, Birger

    2004-01-01

    A large amount of absorptive intestinal membrane transporters play an important part in absorption and distribution of several nutrients, drugs and prodrugs. The present paper gives a general overview on intestinal solute carriers as well as on trends and strategies for targeting drugs and/or pro...

  11. Autonomous component carrier selection

    DEFF Research Database (Denmark)

    Garcia, Luis Guilherme Uzeda; Pedersen, Klaus; Mogensen, Preben

    2009-01-01

    in local areas, basing our study case on LTE-Advanced. We present extensive network simulation results to demonstrate that a simple and robust interference management scheme, called autonomous component carrier selection allows each cell to select the most attractive frequency configuration; improving...

  12. Ore-forming Conditions and Prospecting in the West Kunlun Area, Xinjiang, China

    Institute of Scientific and Technical Information of China (English)

    DONG Yongguan; GUO Kunyi; XIAO Huiliang; ZHANG Chuanlin; ZHAO Yu

    2004-01-01

    The West Kunlun ore-forming belt is located between the northwestern Qinghai-Tibet Plateau and southwestern Tarim Basin. It situated between the Paleo-Asian Tectonic Domain and Tethyan Tectonic Domain. It is an important component of the giant tectonic belt in central China (the Kunlun-Qilian-Qinling Tectonic Belt or the Central Orogenic Belt). Many known ore-forming belts such as the Kunlun-Qilian Qinling ore-forming zone, Sanjiang (or Threeriver) ore-forming zone, Central Asian ore-forming zone, etc. pass through the West Kunlun area. Three ore-forming zones and seven ore-forming subzones were classified, and eighteen mineralization areas were marked. It is indicated that the West Kunlun area is one of the most favorable region for finding out large and superlarge ore deposits.

  13. A study of the distribution of rare-metals in kuroko-type ore

    Energy Technology Data Exchange (ETDEWEB)

    Murao, S. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience]|[Geological Survey of Japan, Tsukuba, Ibaraki (Japan); Sie, S.H.; Suter, G.F. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

    1996-12-31

    We have performed PIXE analysis of kuroko-type ore from the JADE hydrothermal site of the Okinawa Trough, Japan using the proton microprobe (PIXEPROBE). We analysed five kinds of ores dredged from the sea floor: (I) barite ore with small sulfide dissemination; (2) sphalerite-pyrite chimney; (3) pyrite ore; (4) sulfide veinlets in strongly altered rock; and (5) pyrite megacrystals in strongly altered rock. The analyses revealed that the trace element distribution is regulated by the occurrence mode of the ore, and within each ore, by the crystal structure. The distribution suggests that the hydrothermal system for kuroko ore formation is quite heterogeneous and its chemistry is controlled by local factors such as difference in temperature, and that in-situ PIXE analyses are essential for effective beneficiation strategy for the rare-metals from kuroko-type ore. (authors). 10 refs., 1 tab.

  14. Mining remittances corresponding to metalliferous ores: regulation and budget impact

    Directory of Open Access Journals (Sweden)

    N. Asaloș

    2016-04-01

    Full Text Available Economic statistics and forecasting show that Romania has a very favourable potential as far as the metalliferous ores are concerned. As these are owned by the state, once they are allowed to be exploited, they generate considerable amounts for the consolidated public budget. The present paper is meant to conduct a synthetic analysis on the topic of mining remittances from an economic perspective, by considering the juridical framework of capitalizing deposits of ferrous and non-ferrous ores, correlated with the general regulations concerning property and the specific existing regulations of the EU and of the countries that have experience and potential in the mining sector.

  15. Bioleaching of copper oxide ore by Pseudomonas aeruginosa

    Science.gov (United States)

    Shabani, M. A.; Irannajad, M.; Azadmehr, A. R.; Meshkini, M.

    2013-12-01

    Bioleaching is an environmentally friendly method for extraction of metal from ores. In this study, bioleaching of copper oxide ore by Pseudomonas aeruginosa was investigated. Pseudomonas aeruginosa is a heterotrophic bacterium that can produce various organic acids in an appropriate culture medium, and these acids can operate as leaching agents. The parameters, such as particle size, glucose percentage in the culture medium, bioleaching time, and solid/liquid ratio were optimized. Optimum bioleaching conditions were found as follows: particle size of 150-177 μm, glucose percentage of 6%, bioleaching time of 8 d, and solid/liquid ratio of 1:80. Under these conditions, 53% of copper was extracted.

  16. A novel optical granulometry algorithm for ore particles

    Directory of Open Access Journals (Sweden)

    Junhao Y.

    2010-01-01

    Full Text Available This paper proposes a novel algorithm to detect the particle size distribution of ores with irregular shapes and dim edges. This optical granulometry algorithm is particularly suitable for blast furnace process control, so its result can be used directly as a reliable basis for control system dynamics optimization. The paper explains the algorithm and its concept, as well as its method, which consists of five steps to detect ore granularity and distribution. A series of comparative experiments under industrial environments proved that this novel algorithm, compared with conventional ones, improves the accuracy of granulometry.

  17. 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.

  18. Bioleaching of copper oxide ore by P seudomonas aeruginosa

    Institute of Scientific and Technical Information of China (English)

    MA Shabani; M Irannajad; AR Azadmehr; M Meshkini

    2013-01-01

    Bioleaching is an environmentally friendly method for extraction of metal from ores. In this study, bioleaching of copper oxide ore by Pseudomonas aeruginosa was investigated. Pseudomonas aeruginosa is a heterotrophic bacterium that can produce various organic acids in an appropriate culture medium, and these acids can operate as leaching agents. The parameters, such as particle size, glucose percentage in the culture medium, bioleaching time, and solid/liquid ratio were optimized. Optimum bioleaching conditions were found as follows: particle size of 150-177 μm, glucose percentage of 6%, bioleaching time of 8 d, and solid/liquid ratio of 1:80. Under these conditions, 53%of copper was extracted.

  19. Environmental nuclear-geophysical ore monitoring in mines of Corporation Kazakhmys PLC.

    Science.gov (United States)

    Yefimenko, Sergei; Yefimenko, Olga; Makarov, Dmitriy

    2014-01-01

    An environmental monitoring of ore composition in complex deposits of Kazakhstan (the Zhezkazgan, Kusmuryn, Artemjevsk, Kounrad, Taskura and Zhaman-Aibat deposits) is carried out using EDXRF spectrometers RPP-12, RLP-21 and RLP-21T. The monitoring of ore concentrates in Satpaev, Balkhashsk and Zhezkazgan processing plants and in Zhezkazgan copper smelter continues at present time. The monitoring suggests data on new promising elements and environmental pollutants in ores and new trends in distribution of bound elements in ores.

  20. 26 CFR 1.272-1 - Expenditures relating to disposal of coal or domestic iron ore.

    Science.gov (United States)

    2010-04-01

    ... domestic iron ore. 1.272-1 Section 1.272-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... relating to disposal of coal or domestic iron ore. (a) Introduction. Section 272 provides special treatment... sometimes referred to as a “coal royalty contract” or “iron ore royalty contract”) for the disposal of coal...

  1. 75 FR 68788 - Ore Knob Mine Superfund Site; Jefferson, Ashe County, North Carolina; Notice of Settlement

    Science.gov (United States)

    2010-11-09

    ... Doc No: 2010-28260] ENVIRONMENTAL PROTECTION AGENCY [Docket EPA-RO4-SFUND-2010-0893, FRL-9223-8] Ore... Protection Agency has entered into a settlement for reimbursement of past response costs concerning the Ore..., identified by Docket ID No. EPA-RO4- SFUND-2010-0893 or Site name Ore Knob Mine Superfund Site by one of...

  2. IMPACT: How ORE Findings Have Affected Decisions in Austin and Beyond.

    Science.gov (United States)

    Wilkinson, David, Ed.; Ligon, Glynn, Ed.

    Over the years, findings of the Office of Research and Evaluation (ORE) of the Austin (Texas) Independent School District (AISD) have had a significant impact on decisions made in the district and sometimes beyond it. The ORE's impact in the AISD is reviewed in 16 areas. Some of the major findings are summarized: (1) ORE studies of retention in…

  3. 40 CFR 440.80 - Applicability; description of the vanadium ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... vanadium ore subcategory. 440.80 Section 440.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Vanadium Ore Subcategory (Mined Alone and Not as a Byproduct) § 440.80 Applicability; description of the vanadium...

  4. 28 CFR 79.62 - Criteria for eligibility for claims by ore transporters.

    Science.gov (United States)

    2010-07-01

    ... ore transporters. 79.62 Section 79.62 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) CLAIMS UNDER THE RADIATION EXPOSURE COMPENSATION ACT Eligibility Criteria for Claims by Ore Transporters § 79.62 Criteria for eligibility for claims by ore transporters. To establish eligibility for...

  5. 28 CFR 79.63 - Proof of employment as an ore transporter.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Proof of employment as an ore transporter... RADIATION EXPOSURE COMPENSATION ACT Eligibility Criteria for Claims by Ore Transporters § 79.63 Proof of employment as an ore transporter. (a) The Department will accept, as proof of employment for the time...

  6. Nonlinear Effects of Laser Surface Modification of Ore Minerals

    Directory of Open Access Journals (Sweden)

    N.A. Leonenko

    2015-12-01

    Full Text Available The effect of continuous laser radiation on complex ore minerals objects containing gold, not extracted by monerd methods was investigated. It was established the formation of different structural surfaces of gold, revealed general patterns of sintering and concentration of sub-micron gold.

  7. Challenges facing the North American iron ore industry

    Science.gov (United States)

    Jorgenson, J.D.

    2006-01-01

    Summary: This report is derived from a presentation the author presented in late September at the Iron Ore 2005 Conference sponsored by The Australasian Institute of Mining and Metallurgy and held in Fremantle, Western Australia. Some slight revisions have been made for the new audience.

  8. Reduction Mechanism of Chromite Ore in Blast Furnace

    Institute of Scientific and Technical Information of China (English)

    LI Yi-wei; DING Wei-zhong; LU Xiong-gang; XU Kuang-di

    2004-01-01

    The structural changes and reduction degree of chromite ore in blast furnace were studied by optical micrograph analysis, scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDXA). The smelting reduction mechanism of chromite in blast furnace was primarily discussed.

  9. Technogenic hydrogeochemical anomalies of tungsten deposits in Kykylbey ore region

    Institute of Scientific and Technical Information of China (English)

    Leonid V.Zamana; Larisa P.Chechel

    2004-01-01

    Peculiarities of the tungsten deposits drainage flow chemical composition formation, the development of which was ceased almost 40 years ago, have been considered. Migration peculiarities of ore components have been covered, and forms of their migration have been calculated. Inertial characteristics of the surface flow contamination are shown.

  10. When People Talk, AISD Listens! ORE Districtwide Surveys, 1983.

    Science.gov (United States)

    Austin Independent School District, TX. Office of Research and Evaluation.

    The Austin Independent School District (AISD) Office of Research and Evaluation (ORE) conducts three surveys to contribute to more informed and better decision-making. The Questions for Teachers and Questions for Administrators surveys are both sent out annually to determine the attitudes of District staff on issues of importance districtwide. The…

  11. ORE's GENeric Evaluation SYStem: GENESYS 1988-89.

    Science.gov (United States)

    Baenen, Nancy; And Others

    GENESYS--GENeric Evaluation SYStem--is a method of streamlining data collection and evaluation through the use of computer technology. GENESYS has allowed the Office of Research and Evaluation (ORE) of the Austin (Texas) Independent School District to evaluate a multitude of contrasting programs with limited resources. By standardizing methods and…

  12. Rock Smelting of Copper Ores with Waste Heat Recovery

    Science.gov (United States)

    Norgate, Terry; Jahanshahi, Sharif; Haque, Nawshad

    It is generally recognised that the grades of metallic ores are falling globally. This trend can be expected to increase the life cycle-based energy requirement for primary metal production due to the additional amount of material that must be handled and treated in the mining and mineral processing stages of the metal production life cycle. Rock (or whole ore) smelting has been suggested as a possible alternative processing route for low grade ores with a potentially lower energy intensity and environmental impact than traditional processing routes. In this processing route, the beneficiation stage is eliminated along with its associated energy consumption and greenhouse gas emissions, but this is partially offset by the need for more solid material to be handled and heated up to smelting temperatures. A life cycle assessment study was carried out to assess the potential energy and greenhouse gas benefits of a conceptual flowsheet of the rock smelting process, using copper ore as an example. Recovery and utilisation of waste heat in the slag (via dry slag granulation) and offgas streams from the smelting step was also included in the study, with the waste heat being utilised either for thermal applications or electricity generation.

  13. Method and set-up for uranium ore sorting

    Energy Technology Data Exchange (ETDEWEB)

    Dragulescu, E.; Ivascu, M.; Popescu, D.; Semenescu, G. (Institutul de Fizica si Inginerie Nucleara, Bucharest (Romania)); Gherea, Gh. (Intreprinderea metalelor rare, Bucuresti (Romania)); Draga, Z.; Funaru, Gh. (Exploatarea miniera Oravita, Oravita (Romania))

    1981-01-01

    A method was studied for uranium ore sorting. After the discussion of the principle, some particular conditions of the sorting are pointed out. A radiometric assembly is described and some results obtained on the simulator and in industrial conditions are reported.

  14. Phases transformation of nickel lateritic ore during dehydration

    Directory of Open Access Journals (Sweden)

    Huang Q.

    2011-01-01

    Full Text Available The high magnesium nickel laterite ore need first be dehydrated if it is treated by the pirometallurgical means. The nickel laterite ore was dehydrated in a laboratory scale sintering pot in this study. The dehydration mechanism was studied by using the thermo-gravimetric (TG tests, differential thermal analysis (DTA, and X-ray diffraction (XRD experiments. The measurements indicated that chlorite (Fe,Mg,Al6(Si,Al4O10(OH8 and serpentine Mg21Si12O28(OH34H2O are the primary phases, while FeO(OH and (Fe,Mg,3Si4O10(OH2 are the minor phases in the ore. The water in the ore can be divided as free water, crystal water, and hydroxyl group. During the heating process, the temperature range for the removal of the free water is 25~140˚C, for the crystal water it is 200~480 ˚C, and for the hydroxyl group it is 500~800˚C. The experiments with various coal dosages show that the temperatures of off-gas and burden increase with an increase in coal dosage. The sinter samples were analyzed using XRD. The results demonstrated that olivine (Mg,Fe2SiO4 and spinel MgFe2O4 are the main bonding phases.

  15. Hemimorphite Ores: A Review of Processing Technologies for Zinc Extraction

    Science.gov (United States)

    Chen, Ailiang; Li, Mengchun; Qian, Zhen; Ma, Yutian; Che, Jianyong; Ma, Yalin

    2016-10-01

    With the gradual depletion of zinc sulfide ores, exploration of zinc oxide ores is becoming more and more important. Hemimorphite is a major zinc oxide ore, attracting much attention in the field of zinc metallurgy although it is not the major zinc mineral. This paper presents a critical review of the treatment for extraction of zinc with emphasis on flotation, pyrometallurgical and hydrometallurgical methods based on the properties of hemimorphite. The three-dimensional framework structure of hemimorphite with complex linkage of its structural units lead to difficult desilicification before extracting zinc in the many metallurgical technologies. It is found that the flotation method is generally effective in enriching zinc minerals from hemimorphite ores into a high-grade concentrate for recovery of zinc. Pure zinc can be produced from hemimorphite or/and willemite with a reducing reagent, like methane or carbon. Leaching reagents, such as acid and alkali, can break the complex structure of hemimorphite to release zinc in the leached solution without generation of silica gel in the hydrometallurgical process. For optimal zinc extraction, combing flotation with pyrometallurgical or hydrometallurgical methods may be required.

  16. Detection of diamond in ore using pulsed laser Raman spectroscopy

    CSIR Research Space (South Africa)

    Lamprecht, GH

    2007-10-01

    Full Text Available The viability of using pulsed laser excited Raman spectroscopy as a method for diamond detection from ore, has been investigated. In this method the spontaneous Stokes Raman signal is used as indicator of diamond, and a dual channel system...

  17. Development of Passenger Air Carriers

    Directory of Open Access Journals (Sweden)

    Igor Diminik

    2006-09-01

    Full Text Available The work presents the development of carriers in passengerair traffic, and the focus is on the development and operationsof carriers in chartered passenger transport. After the SecondWorld War, there were only scheduled air carriers. The need formass transport of tourists resulted in the development of chartercarriers or usage of scheduled carriers under different commercialconditions acceptable for tourism. Eventually also low-costcarriers appeared and they realize an increasing share in thepassenger transport especially in the aviation developed countries.

  18. Novel Binders and Methods for Agglomeration of Ore

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler

    2006-09-30

    Heap leaching is one of the methods being used to recover metal from low grade ore deposits. The main problem faced during heap leaching is the migration of fine grained particles through the heap, forming impermeable beds which result in poor solution flow. The poor solution flow leads to less contact between the leach solution and the ore, resulting in low recovery rates. Agglomeration of ore into coarse, porous masses prevents fine particles from migrating and clogging the spaces and channels between the larger ore particles. Currently, there is one facility in the United States which uses agglomeration. This operation agglomerates their ore using leach solution (raffinate), but is still experiencing undesirable metal recovery from the heaps due to agglomerate breakdown. The use of a binder, in addition to the leach solution, during agglomeration would help to produce stronger agglomerates that did not break down during processing. However, there are no known binders that will work satisfactorily in the acidic environment of a heap, at a reasonable cost. As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. Increasing copper recovery in heap leaching by the use of binders and agglomeration would result in a significant decrease in the amount of energy consumed. Assuming that 70% of all the leaching heaps would convert to using agglomeration technology, as much as 1.64*10{sup 12} BTU per year would be able to be saved if a 25% increase in copper recovery was experienced, which is equivalent to saving approximately 18% of the energy currently being used in leaching heaps. For every week a leach cycle was decreased, a savings of as much as 1.23*10{sup 11} BTU per week would result. This project has identified several acid-resistant binders and agglomeration procedures. These binders and experimental procedures will be able to be used for use in improving the energy efficiency of

  19. Bathymetry of Lake Erie and Lake Saint Clair

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Erie and Lake Saint Clair has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and...

  20. Effects of Mineral Composition and Microstructure on Crack Resistance of Sintered Ore

    Institute of Scientific and Technical Information of China (English)

    YING Zi-wei; JIANG Mao-fa; XU Li-xian

    2006-01-01

    Vickers indentation test was used to study the effects of mineral composition and microstructure on crack resistance of sintered ore, and the initiation and propagation of cracks in different minerals contained in sintered ore were examined. The results indicate that the microstructure of calcium ferrites is a major factor influencing crack resistance of sintered ore. Finer grain size of calcium ferrite will lead to higher cracking threshold and better crack resistance of sintered ore. The formation of calcium ferrite with fine grain size during sintering process is favorable for crack resistance of sintered ore.

  1. Fundamentals of fast reduction of ultrafine iron ore at low temperature

    Institute of Scientific and Technical Information of China (English)

    Pei Zhao; Peimin Guo

    2008-01-01

    Fundamentals on the fast reduction of ultrafine iron ore at low temperature, including characterization of ultrafine ore, de- oxidation thermodynamics of stored-energy ultrafine ore, kinetics of iron ore deoxidation, and deoxidation mechanism, etc., and a new ironmaking process are presented in this article. Ultrafine ore concentrate with a high amount of stored energy can be produced by mechanical milling, and can be dcoxidated fast below 700℃ by either the coal-based or gas-based process. This novel process has some advantages over others: high productivity, low energy consumption, and environmental friendliness.

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

    Science.gov (United States)

    Trubachev, AI; Zykov, NV

    2017-02-01

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

  3. The Effect of Polystyrene on the Carrier Flotation of Fine Smithsonite

    Directory of Open Access Journals (Sweden)

    Xiangfeng Zhang

    2017-03-01

    Full Text Available Carrier flotation is a common technique used to improve flotation recovery of ultrafine ores. In this study, we used coarse polystyrene as the carrier material to enhance flotation recovery of fine smithsonite (ZnCO3 particles. Sodium oleate was used as the collector and played a role in the adhesion of fine smithsonite to polystyrene due to its amphipathic properties. The carrier feature of polystyrene was demonstrated using particle size analysis, total organic carbon, and scanning electron microscopy. The fine smithsonite particles coated the polystyrene particles through a reaction between the active zinc sites and the carboxyl head groups of the oleate adsorbed on smithsonite and through a hydrophobic interaction between polystyrene and the hydrocarbon chains of the oleate. Newly enlarged particle aggregates with smithsonite shells enhanced collision and attachment of the hydrophobized aggregates with bubbles, which accelerated smithsonite flotation recovery.

  4. Maintainable substrate carrier for electroplating

    Science.gov (United States)

    Chen, Chen-An [Milpitas, CA; Abas, Emmanuel Chua [Laguna, PH; Divino, Edmundo Anida [Cavite, PH; Ermita, Jake Randal G [Laguna, PH; Capulong, Jose Francisco S [Laguna, PH; Castillo, Arnold Villamor [Batangas, PH; Ma,; Xiaobing, Diana [Saratoga, CA

    2012-07-17

    One embodiment relates to a substrate carrier for use in electroplating a plurality of substrates. The carrier includes a non-conductive carrier body on which the substrates are placed and conductive lines embedded within the carrier body. A plurality of conductive clip attachment parts are attached in a permanent manner to the conductive lines embedded within the carrier body. A plurality of contact clips are attached in a removable manner to the clip attachment parts. The contact clips hold the substrates in place and conductively connecting the substrates with the conductive lines. Other embodiments, aspects and features are also disclosed.

  5. Maintainable substrate carrier for electroplating

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chen-An; Abas, Emmanuel Chua; Divino, Edmundo Anida; Ermita, Jake Randal G.; Capulong, Jose Francisco S.; Castillo, Arnold Villamor; Ma, Diana Xiaobing

    2016-08-02

    One embodiment relates to a substrate carrier for use in electroplating a plurality of substrates. The carrier includes a non-conductive carrier body on which the substrates are placed and conductive lines embedded within the carrier body. A plurality of conductive clip attachment parts are attached in a permanent manner to the conductive lines embedded within the carrier body. A plurality of contact clips are attached in a removable manner to the clip attachment parts. The contact clips hold the substrates in place and conductively connecting the substrates with the conductive lines. Other embodiments, aspects and features are also disclosed.

  6. Lake metabolism scales with lake morphometry and catchment conditions

    DEFF Research Database (Denmark)

    Stæhr, Peter A.; Baastrup-Spohr, Lars; Jensen, Kaj Sand

    2012-01-01

    We used a comparative data set for 25 lakes in Denmark sampled during summer to explore the influence of lake morphometry, catchment conditions, light availability and nutrient input on lake metabolism. We found that (1) gross primary production (GPP) and community respiration (R) decline with lake...... in lake morphometry and catchment conditions when comparing metabolic responses of lakes to human impacts....

  7. Development of Technology for Enrichment of Silver Containing Ores

    Science.gov (United States)

    Shekiladze, Asmati; Kavtelashvili, Otari; Bagnashvili, Mamuka

    2016-10-01

    The progress of Georgian economics is substantially associated with a development of new deposits of mineral resources. Among them is the David-Gareji deposit where at present the intensive searching geological works are performed. The work goal involves the elaboration of the technology for processing of silver-containing quartz-barite ores. Without its development the mining of more valuable gold-polymetallic ores is impossible. Because of ore complexity silver and barite are considered in a common technological aspect. The investigations were carried out on the representative samples of quartz-barite ores containing 78-88 g/ton of silver and 27-29 % of silver is a nugget in the form of the simple sulphides and chlorides. The ore is characterized by fine coalescence of barite and ore-generating minerals. Non-ferrous metals haven't any industrial value because of their very low content. Therefore, for the processing of the ores under study the direct selective scheme of flotation enrichment was chosen and the formula of optimal reagent regime was elaborated. Potassium xanthogenate is used as a collector for flotation of silver minerals and pine oil- as a foaming agent. The effect of the pulp - pH and medium temperature on silver flotation was studied. It was established that the silver is actively floats in neutral medium. For barite flotation the various collectors were tested: sulfidezid cotton oil-soap stock, soaps of fatty acids and alkyl sulphates of C12 - C16 row, among the “Baritol” is the most efficient one. Depression of the barren rock was carried out by liquid glass in alkaline medium. The effect of pulp pH on barite flotation has been investigated. The best results were obtained at pH=8.5. The increase of the pulp alkalinity has no essential effect on the indexes of the barite enrichment. Conditional concentrate of the barite is obtained by two fold purification of the main flotation concentrate by the addition of the liquid glass to the re

  8. China's emergence as the world's leading iron-ore-consuming country

    Science.gov (United States)

    Kirk, W.S.

    2004-01-01

    China has become the leading iron ore consuming nation, and, based on recent steel production capacity increases and plans for more, its consumption will almost certainly to continue to grow. China's iron ore industry, however, faces a number of problems. China's iron ore is low-grade, expensive to process, and its mines are being depleted. For many Chinese steelmakers, particularly in the coastal regions, the delivered cost of domestic iron ore, is more than the delivered cost of foreign ore. Thus China's iron ore imports are expected to increase. As China's growth continues, it will almost certainly surpass Japan to become the leading iron ore importing country as well. Without China's increasing appetite for iron ore, the world iron ore market would be flat or declining. China's recent imports largely offset the slump in demand in North America and Europe. China is regarded by the iron ore industry as the growth sector for the next decade. Although Chinese imports are expected to continue their rapid increase and imports in other Asian countries are expected to continue growing, there appears to be enough greenfield and expansion projects to meet future demand for iron ore worldwide. Present suppliers of iron ore, Australia, Brazil, India, and South Africa, will probably be the chief beneficiaries of China's increasing consumption of iron ore. How long China can continue its extraordinary growth is the primary issue for the future of the iron ore industry. Based on the number and size of planned blast furnaces it appears that China's growth could continue for several more years. ?? 2004 Taylor and Francis.

  9. Glycosylation of solute carriers

    DEFF Research Database (Denmark)

    Pedersen, Nis Borbye; Carlsson, Michael C; Pedersen, Stine Helene Falsig

    2016-01-01

    as their posttranslational regulation, but only relatively little is known about the role of SLC glycosylation. Glycosylation is one of the most abundant posttranslational modifications of animal proteins and through recent advances in our understanding of protein-glycan interactions, the functional roles of SLC......Solute carriers (SLCs) are one of the largest groups of multi-spanning membrane proteins in mammals and include ubiquitously expressed proteins as well as proteins with highly restricted tissue expression. A vast number of studies have addressed the function and organization of SLCs as well...

  10. DNR 24K Lakes

    Data.gov (United States)

    Minnesota Department of Natural Resources — Medium scale lake polygons derived from the National Wetlands Inventory (NWI) polygons and MnDOT Basemap lake delineations. Integrated with the DNR 24K Streams...

  11. Lake trout rehabilitation in Lake Ontario

    Science.gov (United States)

    Elrod, Joseph H.; O'Gorman, Robert; Schneider, Clifford P.; Eckert, Thomas H.; Schaner, Ted; Bowlby, James N.; Schleen, Larry P.

    1995-01-01

    Attempts to maintain the native lake trout (Salvelinus namaycush) population in Lake Ontario by stocking fry failed and the species was extirpated by the 1950s. Hatchery fish stocked in the 1960s did not live to maturity because of sea lamprey (Petromyzon marinus) predation and incidental commercial harvest. Suppression of sea lampreys began with larvicide treatments of Lake Ontario tributaries in 1971 and was enhanced when the tributaries of Oneida Lake and Lake Erie were treated in the 1980s. Annual stocking of hatchery fish was resumed with the 1972 year class and peaked at about 1.8 million yearlings and 0.3 million fingerlings from the 1985–1990 year classes. Survival of stocked yearlings declined over 50% in the 1980 s and was negatively correlated with the abundance of lake trout > 550 mm long (r = −0.91, P < 0.01, n = 12). A slot length limit imposed by the State of New York for the 1988 fishing season reduced angler harvest. Angler harvest in Canadian waters was 3 times higher in eastern Lake Ontario than in western Lake Ontario. For the 1977–1984 year classes, mean annual survival rate of lake trout age 6 and older was 0.45 (range: 0.35–0.56). In U.S. waters during 1985–1992, the total number of lake trout harvested by anglers was about 2.4 times greater than that killed by sea lampreys. The number of unmarked lake trout < 250 mm long in trawl catches in 1978–1992 was not different from that expected due to loss of marks and failure to apply marks at the hatchery, and suggested that recruitment of naturally-produced fish was nil. However, many of the obstacles which may have impeded lake trout rehabilitation in Lake Ontario during the 1980s are slowly being removed, and there are signs of a general ecosystem recovery. Significant recruitment of naturally produced lake trout by the year 2000, one interim objective of the rehabilitation plan for the Lake, may be achieved.

  12. The genesis of the base metal ore deposit from Herja

    Directory of Open Access Journals (Sweden)

    Gheorghe Damian

    2003-04-01

    Full Text Available The Herja ore deposit is one of the most known of the Baia Mare Neogene metallogenetic district and is associated with a complex stock of Pannonian age. The hydrothermal alterations associated with the mineralizations are represented by: the propylitization, the argillization, the phyllic and potassic alteration. The monoascenedant character of the mineralizations is predominant. The magmatic intrusions have been sequential placed and have represented the heat, metals and hydrothermal solutions source. In the first stages of mineralization the hydrothermal solutions contain predominantly magmatic water and in the final stages the water is of connate and meteoric origin. According to the structural magmatic control, to the mineralogical composition and to the hydrothermal alterations, the Herja ore deposits are of a low sulphidation epithermal systems type.

  13. Creep in model pillars. [Salt, trona, and potash ore

    Energy Technology Data Exchange (ETDEWEB)

    Obert, L.

    1965-03-01

    A study was made of the deformational behavior (creep) of pillars made from three quasi-plastic rock--salt, trona, and potash ore. The first phase of this study considers the design of a model pillar suitable for creep tests; in the second phase, six model pillars were prepared from salt from two sources, from trona, and from potash ore. The pillars in each group were subjected to a different but constant axial stress, and the axial strain was measured for 1,000 hours. An analysis of the data shows that in general the creep rate for these model pillars can be expressed by the relationship .epsilon = K/sub 1/ sigma/sub 0//sup n/, where .epsilon is the strain rate, sigma/sub 0/ is the applied stress, and K/sub 1/ and n are constants. For the rocks included in this test, n ranged from 2.4 to 3.3.

  14. Genesis of ion-adsorption type REE ores in Thailand

    Science.gov (United States)

    Sanematsu, K.; Yoshiaki, K.; Watanabe, Y.

    2012-04-01

    Ion-adsorption type REE deposits, which have been economically mined only in southern China, are predominant supply sources for HREE in the world. The ore bodies consist of weathered granites called ion-adsorption ores. The majority of REE (>50 %) are electrostatically adsorbed onto weathering products in the ores and they can be extracted by ion exchange using an electrolyte solution (e.g., ammonium sulfate solution). Recently the occurrences of ion-adsorption ores have been reported in Indochina, SE Asia. In this study, we discuss geochemical and mineralogical characteristics of parent granites and weathered granites in Thailand in order to reveal the genesis of ion-adsorption ores. Permo-Triassic and Cretaceous-Paleogene granite plutons are distributed from northern Thailand to western Indonesia through eastern Myanmar and Peninsular Malaysia. They are mostly ilmenite-series calcalkaline biotite or hornblende-biotite granites. REE contents of the granites range from 60 to 600 ppm and they are relatively high in Peninsula Thailand. REE-bearing minerals consist mainly of apatite, zircon, allanite, titanite, monazite and xenotime. Some I-type granites contain REE fluorocarbonate (probably synchysite-(Ce)) in cavities and cracks in feldspars and it is the dominant source of REE for ion-adsorption ores because the fluorocarbonate is easily soluble during weathering. In contrast, insoluble monazite and xenotime are not preferable for ion-adsorption ores although they are common ore minerals of placer REE deposits. Weathered granites show REE contents ranging from 60 to 1100 ppm in Thailand because REE are relatively immobile compared with mobile elements (e.g., Na, K, Ca). In the weathered granites, REE are contained in residual minerals and secondary minerals and are adsorbed onto the surface of weathering products. A weathering profile of granite with ion-adsorption type mineralization can be divided into upper and lower parts based on REE enrichment and Ce

  15. Speciation and recovery of chromium from chromite ore processing residues.

    Science.gov (United States)

    Sreeram, K J; Ramasami, T

    2001-10-01

    The processing of chromite ore is associated with the generation of large quantities of solid wastes containing chromium, which have been disposed of as landfill for many years. The mobilization and operational speciation of chromium contained in soils contaminated with metal salts are important in terms of the environment. Several methods have been employed for the extraction and recovery of solid wastes. Chromium contained in contaminated soils and solid wastes can be categorized as exchangeable, oxidizable, carbonate-bound, reducible and residual. The results from this study indicate a need for efficient leaching methodologies in chromite ore processing plants to decrease the non-detrital fractions of chromium in the residue. Aggressive methodologies are required to recover chromium from the detrital fractions. The potential benefits of employing sodium peroxide for the complete recovery of chromium from chromite residue have been demonstrated, and the need to ensure the safety of the process has been emphasized.

  16. Phase transformations of siderite ore by the thermomagnetic analysis data

    Science.gov (United States)

    Ponomar, V. P.; Dudchenko, N. O.; Brik, A. B.

    2017-02-01

    Thermal decomposition of Bakal siderite ore (that consists of magnesium siderite and ankerite traces) was investigated by thermomagnetic analysis. Thermomagnetic analysis was carried-out using laboratory-built facility that allows automatic registration of sample magnetization with the temperature (heating/cooling rate was 65°/min, maximum temperature 650 °C) at low- and high-oxygen content. Curie temperature gradually decreases with each next cycles of heating/cooling at low-oxygen content. Curie temperature decrease after 2nd cycle of heating/cooling at high-oxygen content and do not change with next cycles. Final Curie temperature for both modes was 320 °C. Saturation magnetization of obtained samples increases up to 20 Am2/kg. The final product of phase transformation at both modes was magnesioferrite. It was shown that intermediate phase of thermal decomposition of Bakal siderite ore was magnesiowustite.

  17. Method of winning aluminum metal from aluminous ore

    Science.gov (United States)

    Loutfy, Raouf O.; Keller, Rudolf; Yao, Neng-Ping

    1981-01-01

    Aluminous ore such as bauxite containing alumina is blended with coke or other suitable form of carbon and reacted with sulfur gas at an elevated temperature. For handling, the ore and coke can be extruded into conveniently sized pellets. The reaction with sulfur gas produces molten aluminum sulfide which is separated from residual solid reactants and impurities. The aluminum sulfide is further increased in temperature to cause its decomposition or sublimation, yielding aluminum subsulfide liquid (AlS) and sulfur gas that is recycled. The aluminum monosulfide is then cooled to below its disproportionation temperature to again form molten aluminum sulfide and aluminum metal. A liquid-liquid or liquid-solid separation, depending on the separation temperature, provides product aluminum and aluminum sulfide for recycle to the disproportionation step.

  18. Direct reduction of iron ore by biomass char

    Science.gov (United States)

    Zuo, Hai-bin; Hu, Zheng-wen; Zhang, Jian-liang; Li, Jing; Liu, Zheng-jian

    2013-06-01

    By using thermogravimetric analysis the process and mechanism of iron ore reduced by biomass char were investigated and compared with those reduced by coal and coke. It is found that biomass char has a higher reactivity. The increase of carbon-to-oxygen mole ratio (C/O) can lead to the enhancement of reaction rate and reduction fraction, but cannot change the temperature and trend of each reaction. The reaction temperature of hematite reduced by biomass char is at least 100 K lower than that reduced by coal and coke, the maximum reaction rate is 1.57 times as high as that of coal, and the final reaction fraction is much higher. Model calculation indicates that the use of burden composed of biomass char and iron ore for blast furnaces can probably decrease the temperature of the thermal reserve zone and reduce the CO equilibrium concentration.

  19. Cadmium extraction from phosphate ore. Effect of microwave

    Directory of Open Access Journals (Sweden)

    Zahia Benredjem

    2016-09-01

    Full Text Available This study discusses the operating variables for removal of cadmium from phosphate ore using Na2EDTA. These variables include the reaction time, Na2EDTA concentration, liquid/phosphate ore ratio, number of extractions and microwave extraction. Na2EDTA induced a two-step extraction process including a rapid extraction within the first hour, and a subsequent gradual release that occurred over the following hours. The cadmium extraction efficiency increased progressively with the increasing of Na2EDTA concentration. The extraction efficiency of cadmium increased with increasing liquid/phosphate ratio in the 5–200 range. Consecutive extractions using low concentrations were more effective than a single soil extraction with concentrated Na2EDTA. Microwave was beneficial to improve the removal in soil washing, and using microwave could partly substitute for agitation.

  20. Bacterial leaching of discarded copper ores from Yongping, China

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The elementary and phase analysis of discarded copper ores from Yongping of China has been performed. The experiments of extracting copper from the discarded copper ores were done with the mixed bacteria obtained through a series of enrichment,separation, domestication and combination tests. The results show that in the process of bioleaching, the pH value rises at first and drops gradually. The Eh value keeps rising along with the time and the appropriate Eh value varying between 750 and 800 mV will benefit the bioleaching copper. The high concentration of ferric ions is detrimental to the bioleaching copper. The results of bioleaching copper are good. That is, the copper recovery is 31.8% after 27 days.

  1. Flotation studies on low grade graphite ore from eastern India

    Institute of Scientific and Technical Information of China (English)

    Vasumathi N.; Vijaya Kumar T.V.; Ratchambigai S.; Subba Rao S.; Bhaskar Raju G

    2015-01-01

    A low grade graphite ore from eastern India was beneficiated by flotation to improve its quality. The ore was composed of 87.80%ash and 8.59%fixed carbon. Primary coarse wet grinding (d80:186 lm) followed by rougher flotation in Denver flotation cell using diesel as collector and pine oil as frother yielded a rougher concentrate. Regrinding (d80:144 lm) of this rougher concentrate was opted for further libera-tion of graphite. It was followed by cleaning in laboratory flotation column. This combined process of relatively coarse primary grinding followed by regrinding and cleaning in flotation column resulted in final concentrate of 7.44% yield with 89.65% fixed carbon and 6.00% ash. This approach of two-stage grinding to recover the flake graphite at the coarsest possible grind can help to minimize grinding energy costs. A conceptual flow sheet which is cost effective was developed based on this methodology.

  2. Natural radionuclide concentrations in two phosphate ores of east Algeria

    Energy Technology Data Exchange (ETDEWEB)

    Lakehal, Ch. [Department of Physics, Mentouri Constantine University, 25000 Constantine (Algeria); Ramdhane, M., E-mail: ramdhane@hotmail.co [Department of Physics, Mentouri Constantine University, 25000 Constantine (Algeria); Boucenna, A. [Department of Physics, Ferhat-Abbas University, 19000 Setif (Algeria)

    2010-05-15

    Ore is considered as an important source of many elements such as the iron, phosphorus, and uranium. Concerning the natural radionuclides, their concentrations vary from an ore to other depending on the chemical composition of each site. In this work, two phosphate ores found in East of Algeria have been chosen to assess the activity concentration of natural radionuclides represented mainly by three natural radioactive series {sup 238}U, {sup 235}U and {sup 232}Th, and the primordial radionuclide {sup 40}K where they were determined using ultra-low background, high-resolution gamma-ray spectroscopy. The measured activity concentrations of radioactive series ranged from 6.2 +- 0.4 to 733 +- 33 Bq.kg{sup -1} for the {sup 232}Th series, from 249 +- 16 to 547 +- 39 Bq.kg{sup -1} for the {sup 238}U series, around 24.2 +- 2.5 Bq.kg{sup -1} for the {sup 235}U series, and from 1.4 +- 0.2 to 6.7 +- 0.7 Bq.kg{sup -1} for {sup 40}K. To assess exposure to gamma radiation in the two ores, from specific activities of {sup 232}Th, {sup 40}K and {sup 226}Ra, three indexes were determined: Radium equivalent (Ra{sub eq}), external and internal hazard indexes (H{sub ex} and H{sub in}), their values ranged from 831 +- 8 to 1298 +- 14 Bq.kg{sup -1} for Ra{sub eq}, from 2.2 +- 0.4 to 3.5 +- 0.7 Bq.kg{sup -1} for H{sub ex}, and from 4.2 +- 0.7 to 4.5 +- 0.7 Bq.kg{sup -1} for H{sub in}.

  3. The extractive metallurgy of south africa's platinum ores

    Science.gov (United States)

    Cramer, Larry A.

    2001-10-01

    The extraction technology for platinum-group metals (PGMs) has changed dramatically in the last 80 years, and the changes are likely to continue for years to come. This article will review advances in PGM extraction, including developments in semi-autogenous and fully autogenous milling; flotation equipment applications for treating high-chrome ores; increases in power densities for future smelting furnaces, and new methods for meeting rising environmental standards.

  4. Uranium recovery from Uro area phosphate ore, Nuba Mountains, Sudan

    Directory of Open Access Journals (Sweden)

    Abdelmajid A. Adam

    2014-11-01

    Full Text Available This study was carried out in a laboratory scale to recover uranium from Uro area phosphate ore in the eastern part of Nuba Mountains in Sudan. Phosphate ore samples were collected, and analyzed for uranium abundance. The results showed that the samples contain a significant concentration of uranium with an average of 310.3 μg/g, which is 2.6 times higher than the world average of phosphate. The green phosphoric acid obtained from the samples was found to contain uranium in the range of 186–2049 μg/g, with an average of 603.3 μg/g, and about 98% of uranium content of the phosphate ore was rendered soluble in the phosphoric acid. An extraction process using 25% tributylphosphate, followed by stripping process using 0.5 M sodium carbonate reported that more than 98% of uranium in the green phosphoric acid exists as uranyl tricarbonate complex, moreover, sodic decomposition using 50% sodium hydroxide showed that about 98% of the uranium was precipitated as sodium diuranate concentrate that is known as the yellow cake (Na2U2O7. Further purification and calcinations of the yellow cake led to the formation of the orange powder of uranium trioxide (UO3. The chemical analysis of the obtained uranium concentrates; yellow cake and uranium trioxide proved their nuclear purity and that they meet the standard commercial specification. The obtained results proved that uranium from Uro phosphate ore was successfully recovered as uranium trioxide with an overall recovery percentage of 93%.

  5. PROCESS FOR THE RECOVERY OF URANIUM FROM PHOSPHATIC ORE

    Science.gov (United States)

    Long, R.L.

    1959-04-14

    A proccss is described for the recovery of uranium from phosphatic products derived from phosphatic ores. It has been discovered that certain alkyl phosphatic, derivatives can be employed in a direct solvent extraction operation to recover uranium from solid products, such as superphosphates, without first dissolving such solids. The organic extractants found suitable include alkyl derivatives of phosphoric, pyrophosphoric, phosof the derivative contains from 4 to 7 carbon atoms. A diluent such as kerosene is also used.

  6. Bioprocessing low grade copper ores - a promising alternative

    OpenAIRE

    Guezennec, Anne-Gwenaëlle; d'Hugues, Patrick

    2015-01-01

    International audience; This paper presents an overview of the work performed by the BRGM team in the last 10 years on the development of bio-hydrometallurgy dedicated to the processing of low-grade copper ores from the Kupferschiefer deposits. It covers selection and adaptation of microbial consortia, optimization of process operating parameters such as solid contents, the relationship between bioleaching performance and mineralogy, testing operating parameters to overcome chalcopyrite recal...

  7. THE SOLUBILITY OF MILAS BAUXITE ORE IN SULPHURIC ACI

    Directory of Open Access Journals (Sweden)

    Mustafa GULFEN

    2001-06-01

    Full Text Available The effects of calcination conditions,sulphuric acid concentrations and dissolvingtemperature and period as parameters to thesolubility of the bauxite ore from Gobekdagı reservesin Mugla-Milas region were investigated. The bauxitesamples were calcined in different periods at differenttemperatures. Then the solubility of the calcinedbauxite samples in sulphuric acid solution wasexamined. Dissolving activation energy (Ea wascalculated using the optimum kinetics equation andthe results obtained from the solubility studiesexamined dissolving temperatures and periods

  8. LAKE VICTORIA BASIN

    African Journals Online (AJOL)

    selected satellite lakes and Mara River in Lake Victoria basin, during wet and dry seasons in. 2002. Samples ... The wet season recorded higher biomass in all satellite lakes than during the dry season (t = 2.476, DF ..... communication. Urbana ...

  9. Atmospheric emission of polychlorinated naphthalenes from iron ore sintering processes.

    Science.gov (United States)

    Liu, Guorui; Zheng, Minghui; Du, Bing; Nie, Zhiqiang; Zhang, Bing; Liu, Wenbin; Li, Cheng; Hu, Jicheng

    2012-10-01

    Iron ore sintering processes constitute significant sources of dioxins, and studies have confirmed a close correlation between polychlorinated naphthalenes (PCNs) and dioxin formation. Thus, iron ore sintering processes are thought to be a potential source of PCNs, although intensive investigations on PCN emissions from sintering processes have not been carried out. Therefore, the aim of the present study was to qualify and quantify PCN emissions from nine sintering plants operating on different industrial scales. PCN concentrations ranged from 3 to 983 ng m(-3) (0.4-23.3 pg TEQ(PCN) m(-3)) and emission factors ranged from 14 to 1749 μg t(-1) (0.5-41.5 ng TEQ(PCN) t(-1)), with a geometric mean of 84 μg t(-1) (2.1 ng TEQ(PCN) t(-1)). The estimated annual emission of PCNs from sintering processes in China was 1390 mg TEQ(PCN). These figures will assist in the development of a PCN emissions inventory. Regarding emission characteristics, PCNs mainly comprised low-chlorinated homologs. The ratios of several characteristic PCN congeners were also measured and compared with those from other sources. Taken together, these results may provide useful information for identifying the sources of PCNs produced by iron ore sintering processes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. On the problems of the Litija ore field

    Directory of Open Access Journals (Sweden)

    Ivan Mlakar

    1994-12-01

    Full Text Available All available information on the now inaccessible Pb-Zb-Ba deposits Litija, Zavrstnik, Zagorica, Maljek, Hrastarija and Štriglovec was critically evaluated. Data were completed and numerous earlier unsolved questions were answered.In the studied area the existence of a Middle Triassic tectonic-erosional phase was proved, the Old Tertiary overthrust structure analyzed and the relative ages of various neotectonic fault systems established.Special attention was attributed to the Litija, or Sitarjevec, deposit. On the ground of data on position of thick shale intercalations within Carboniferous sandstone the geological structure of the deposit was reconstructed, proofs on the conforming or unconforming position of orebodies collected, and certain relati¬onships between the pre-ore and post-ore tectonics clarified. With geochemical investigations the presence of an extensive dispersion halo was proved, in which the anomalies produced by Pb, Hg and Ba are the best expressed.Also the position of other deposits in space and in stratigraphic column was defined. At the end also the author's views on genesis and age of mineralization are presented. Orebodies are hydrothermal. subvertical, epignetic and predominantly discordant, with poorly expressed vertical zoning.The work is a synthesis of understanding of geological structure and mineralization in the Litija ore field.

  11. Extracting phosphoric iron under laboratorial conditions smelting bog iron ores

    Science.gov (United States)

    Török, B.; Thiele, A.

    2013-12-01

    In recent years it has been indicated by archaeometric investigations that phosphoric-iron (P-iron, low carbon steel with 0,5-1,5wt% P), which is an unknown and unused kind of steel in the modern industry, was widely used in different parts of the world in medieval times. In this study we try to explore the role of phosphorus in the arhaeometallurgy of iron and answer some questions regarding the smelting bog iron ores with high P-content. XRF analyses were performed on bog iron ores collected in Somogy county. Smelting experiments were carried out on bog iron ores using a laboratory model built on the basis of previously conducted reconstructed smelting experiments in copies of excavated furnaces. The effect of technological parameters on P-content of the resulted iron bloom was studied. OM and SEM-EDS analyses were carried out on the extracted iron and slag samples. On the basis of the material analyses it can be stated that P-iron is usually extracted but the P-content is highly affected by technological parameters. Typical microstructures of P-iron and of slag could also be identified. It could also be established that arsenic usually solved in high content in iron as well.

  12. Contact mechanical analysis of O-ring stresses

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Kyu

    2007-02-15

    The purpose of this project is to develop the approximate solutions of contact traction and internal stress of an O-ring by using a two dimensional elasticity for enhancing the design and failure prediction technology. Investigated were the applicability of Lindley's formulae of contact force prediction and the Hertz theory. Three cases of O-ring installation were considered. The approximate solution of contact tractions and internal stresses of each case were derived. The key results are summarized as follows: 1. It is verified that Lindley's formulae predicts the relationship between the fractional compression and contact force. 2. In the case of Case I, II and III without internal pressure, it is found that a function form of the contact traction is the Hertzian. So it is possible to express the traction with a Hertzian form and correction factors. 3. The internal stresses are derived in the case of the Hertzian traction profile. The stresses at the center of O-ring show a satisfactory result when compared with the finite element result.

  13. Treatment of coking wastewater by using manganese and magnesium ores

    Energy Technology Data Exchange (ETDEWEB)

    Chen Tianhu; Huang Xiaoming; Pan Min [School of Resources and Environmental Engineering, Hefei University of Technology, Hefei City 230009 (China); Jin Song, E-mail: sjin@uwyo.edu [MWH Americas, 3665 JFK Parkway, Suite 206, Fort Collins, CO 80525 (United States); Department Civil and Architectural Engineering, University of Wyoming, Laramie, WY 82071 (United States); Peng Suchuan [School of Resources and Environmental Engineering, Hefei University of Technology, Hefei City 230009 (China); Fallgren, Paul H. [Western Research Institute, 365 North 9th Street, Laramie, WY 82072 (United States)

    2009-09-15

    This study investigated a wastewater treatment technique based on natural minerals. A two-step process using manganese (Mn) and magnesium (Mg) containing ores were tested to remove typical contaminants from coking wastewater. Under acidic conditions, a reactor packed with Mn ore demonstrated strong oxidizing capability and destroyed volatile phenols, chemical oxygen demand (COD){sub ,} and sulfide from the coking wastewater. The effluent was further treated by using Mg ore to remove ammonium-nitrogen and phosphate in the form of magnesium ammonium phosphate (struvite) precipitates. When pH of the wastewater was adjusted to 1.2, the removal efficiencies for COD, volatile phenol and sulfide reached 70%, 99% and 100%, respectively. During the second step of precipitation, up to 94% of ammonium was removed from the aqueous phase, and precipitated in the form of struvite with phosphorus. The struvite crystals showed a needle-like structure. X-ray diffraction and transmission electron microscopy were used to characterize the crystallized products.

  14. Source of ore-forming substances and theoretical problems of metallogeny relevant to the Bayan Obo Fe-REE ore deposits in Inner Mongolia,China

    Institute of Scientific and Technical Information of China (English)

    曹荣龙; 朱寿华; 王俊文

    1995-01-01

    The source of rare earth elements (REE) ore-forming substances is identified to be extremelydistinct from that of iron ores.The Bayan Obo Fe-REE ore deposits were generated by a composite processof both crustal and mantle source mineralization.The original iron bodies are of a sedimentary deposit fromsupergenesis,while the REE ores have been formed by mantle fluid metasomatism superimposed upon thepre-existing iron bodies.It is believed that the REE ore deposit would be controlled by intracontinental hotspot.The H8 dolomite in mine regions belongs to normal sedimentary carbonate rock,its C and O isotopiccomposition rules out the possibility comparable with magrnatic carbonatite.The Sm-Nd isochrons of separatedREE minerals have shown two REE peak mineralization periods:early-middle Proterozoic (1 700 Ma±480 Ma) andCaledonia (424-402 Ma).

  15. 76 FR 75601 - Lake State Railway Company-Intra-Corporate Family Merger Exemption-Saginaw Bay Southern Railway...

    Science.gov (United States)

    2011-12-02

    ... Surface Transportation Board Lake State Railway Company--Intra-Corporate Family Merger Exemption--Saginaw Bay Southern Railway Company Lake State Railway Company (LSRC) and Saginaw Bay Southern Railway... railway accounting purposes, LSRC functions today as an Interline Settlement System (ISS) carrier, while...

  16. Ore petrography of low-grade siliceous manganese ores from the Bonai-Keonjhar belt, Orissa, India: The influence of mineral-fabric on their beneficiation

    Institute of Scientific and Technical Information of China (English)

    Mishra Subrat; Mohapatra Birendra Kumar; Dash Nilima; Rao Danda Srinivas

    2011-01-01

    Low grade siliceous manganese ores from the iron ore group of the Bonai-Keonjhar belt,Orissa,India are found mostly in shear zones.The ore characteristics of siliceous manganese ore samples from three different mines,viz.the Shankar (Barbil OMC lease hold area),the Sone-Patuli (Patmunda,OMM lease hold area),and the Musaghar (Roida,OMDC lease hold area),were studied.These siliceous manganese ores are of three types,respectively:(i) spongy-granular; (ii) massive-mosaic; and (iii) hard-mylonitized.The spongy-granular type contains granular,saccharoidal quartz and the major manganese mineral present is pyrolusite.The second type contains well crystallized quartz and cryptomelane,while the third has cherty,fine grained quartz (mylonite) along with romanechite.All three ores were subjected to physical beneflciation under similar conditions.Both gravity and magnetic separation techniques were employed.The mineral-fabric of the ores has been correlated to the extent of their beneflciation using these physical techniques.Of these three ores only the spongy-granular type responded well to upgrading.The feed with 22% Mn content could be upgraded to 44% with a 28% yield and a 49% recovery.The good response to beneficiation of the spongygranular sample could be due to the large euhedral crystals of pyrolusite and the friable nature of the saccharoidal quartz.This study reveals the influence of mineral-fabric on beneficiation of low grade ore,siliceous Mn ore in particular.

  17. LIQUIFIED NATURAL GAS (LNG CARRIERS

    Directory of Open Access Journals (Sweden)

    Daniel Posavec

    2010-12-01

    Full Text Available Modern liquefied natural gas carriers are double-bottom ships classified according to the type of LNG tank. The tanks are specially designed to store natural gas cooled to -161°C, the boiling point of methane. Since LNG is highly flammable, special care must be taken when designing and operating the ship. The development of LNG carriers has begun in the middle of the twentieth century. LNG carrier storage space has gradually grown to the current maximum of 260000 m3. There are more than 300 LNG carriers currently in operation (the paper is published in Croatian.

  18. From BIF to Iron Ore - A journey from nanocrystals to huge iron ore deposits of the Hamersley Province, Australia

    OpenAIRE

    Egglseder, Mathias

    2017-01-01

    Banded iron formations (BIFs) are extraordinary rocks because they provide important information about the Precambrian atmosphere and hydrosphere, the global rise of oxygen, and they host the world’s major iron ore deposits. The unique texture and petrology of BIF, which mainly comprise alternating layers of iron oxides and chert remain poorly understood. Although the mineral assemblage is of diagenetic or metamorphic origin, BIF textures are interpreted as sedimentary st...

  19. Leaching of Silver from Boorchi Ag-Pb Ore in Mongolia with Acidic Thiourea Solution

    Institute of Scientific and Technical Information of China (English)

    Nyamdelger Shirchinnamjil; 杨超; 方兆珩

    2008-01-01

    A hydrometalhirgical process to extract silver from the silver-lead ore in Boorchi, Mongolia by using thiourealeaching solution is studied in this work. Through the observation of optical and scanning electron microscopes, and energyspectral analysis, it is determined that 5 kinds of silver minerals exist in the ore, including argentite, Ag-tetrahedrite,Ag-Zn-Sb-tetrahedrite, freibergite and acanthite. The experimental results of direct thiourea leaching of the ore show that56%~60% of silver is leached. The main reason for the low leaching rate is due to silver minerals enveloped in galena andother minerals, even though the ore is ground to the particle size of 75 μm. When the ore is pretreated with ammoniumcarbonate solution under oxidation, the experimental results of thiourea leaching show that the leaching rate of silver increasesto near 75% with the pretreatment. Based on the leaching experiments, a principle hydrometallurgical technological route toextract silver from the Ag-Pb ore is proposed.

  20. A spatial evaluation of historic iron mining impacts on current impaired waters in Lake Superior's Mesabi Range.

    Science.gov (United States)

    Baeten, John; Langston, Nancy; Lafreniere, Don

    2017-10-05

    This paper examines the water quality legacies of historic and current iron mining in the Mesabi Range, the most productive iron range in the history of North America, producing more than 42% of the world's iron ore in the 1950s. Between 1893 and 2016, 3.5 × 10(9) t of iron ore were shipped from the Mesabi Range to steel plants throughout the world. We map historic sites and quantities of iron mining, ore processing, water use, and tailings deposition within subwatershed boundaries. We then map the locations of impaired lakes within HUC-12 subwatershed boundaries within the Mesabi Range, using government datasets created for US federal Clean Water Act reporting. Comparing watersheds with and without historic mining activity, watersheds with historic mining activity currently contain a greater percentage of impaired lakes than control watersheds within the same range. These results suggest that historic iron ore mining and processing in the Mesabi Range affected water quality on a landscape scale, and these legacies persist long after the mines have closed. This paper outlines a novel spatial approach that land managers and policy makers can apply to other landscapes to assess the effects of past mining activity on watershed health.

  1. Effects of iron oxidizing bacteria in thiourea leaching of gold ores

    OpenAIRE

    甲斐, 敬美; 山崎, 研市; 高橋, 武重; カイ, タカミ; ヤマサキ, ケンイチ; タカハシ, タケシゲ; KAI, Takami; YAMASAKI, Kenichi; Takahashi, Takeshige

    1991-01-01

    Bacterial leaching was combined with thiourea method for the gold leaching from ores. For gold bearing pyrites, biological pre-oxidation has been generally perfomed. In the present study, we carried out the biological treatment to the high silicate bearing ores by using the iron oxidizing bacteria, Thiobacillus ferrooxidans. The recovery of gold and silver was enhanced by the biological pretreatment, while the effects of the treatment was influenced by the types of gold ores. Since the biolog...

  2. Analysis of Characteristics of Ore about Iron Deposit of Da Hong Mountain in Yun Nan Province

    Directory of Open Access Journals (Sweden)

    Zhang Yuefeng

    2016-01-01

    Full Text Available This thesis aims to analyse the deposit characteristics about Da Hong Mountains Iron ore in Yunnan province. The texture and structure, especially the chemical composition, is different in every section of deposit after comparing. Moreover, the content of SiO2 is much higher than general iron ore. However, the content of other noble metals cannot reach the lowest industrial grade. Da Hong Mountains Iron ore has unique features because of metallogenic periods.

  3. Chemical composition analysis of raw materials used in iron ore sinter plants in Poland

    Directory of Open Access Journals (Sweden)

    D. Burchart-Korol

    2014-07-01

    Full Text Available The main goal of the study was the analysis of the chemical compositions of raw materials used in iron ore sinter plants in Poland. The iron ore sintering process is the largest source of emissions of dust and gas pollution in the iron and steel industry. Hematite ores, magnetite concentrates, admixtures (dolomite, limestone and burnt lime, fuels (coke breeze, anthracite and by-products are used in Poland to produce the sinter mixture.

  4. The Revovery of Copper and Cobalt from Oxidized Copper Ore and Converter Slag

    OpenAIRE

    ZİYADANOĞULLARI, Berrin; ZİYADANOĞULLARI, Recep

    1999-01-01

    The aim of this study was to develop a method for obtaining copper and cobalt from oxidized copper ore and converter slag. In order to convert the copper and cobalt into sulfate compounds the main step was to roast the samples obtained by sulfurization and transfer the samples into solution. First the oxidized copper ore was roasted, followed by the mixture of converter slag and oxidized copper ore. Since the levels of copper and cobalt were low, the sulfurization process was carri...

  5. Geological and Mineralogical-technological features chromite ore from nickel-weathering crusts Average Bug

    Directory of Open Access Journals (Sweden)

    Perkov E.S.

    2013-09-01

    Full Text Available Conditions of occurrence and distribution features of chromites ore bodies in the ultra-basic nickel bearing weathering crusts of Middle Bug Area are considered. Main types of exogenous chromites ores in weathering crusts and beyond of them are identified as well as mineralogical, chemical and grain features of mineralization are given. Obtained data are substantiated in order to apply them while developing the efficient schemes of mining and processing of exogenous chromites ores.

  6. O-Ring sealing arrangements for ultra-high vacuum systems

    Science.gov (United States)

    Kim, Chang-Kyo; Flaherty, Robert

    1981-01-01

    An all metal reusable O-ring sealing arrangement for sealing two concentric tubes in an ultra-high vacuum system. An O-ring of a heat recoverable alloy such as Nitinol is concentrically positioned between protruding sealing rings of the concentric tubes. The O-ring is installed between the tubes while in a stressed martensitic state and is made to undergo a thermally induced transformation to an austenitic state. During the transformation the O-ring expands outwardly and contracts inwardly toward a previously sized austenitic configuration, thereby sealing against the protruding sealing rings of the concentric tubes.

  7. Lead isotope studies of the Guerrero composite terrane, west-central Mexico: implications for ore genesis

    Science.gov (United States)

    Potra, Adriana; Macfarlane, Andrew W.

    2014-01-01

    New thermal ionization mass spectrometry and multi-collector inductively coupled plasma mass spectrometry Pb isotope analyses of three Cenozoic ores from the La Verde porphyry copper deposit located in the Zihuatanejo-Huetamo subterrane of the Guerrero composite terrane are presented and the metal sources are evaluated. Lead isotope ratios of 3 Cenozoic ores from the El Malacate and La Esmeralda porphyry copper deposits located in the Zihuatanejo-Huetamo subterrane and of 14 ores from the Zimapan and La Negra skarn deposits from the adjoining Sierra Madre terrane are also presented to look for systematic differences in the lead isotope trends and ore metal sources among the proposed exotic tectonostratigraphic terranes of southern Mexico. Comparison among the isotopic signatures of ores from the Sierra Madre terrane and distinct subterranes of the Guerrero terrane supports the idea that there is no direct correlation between the distinct suspect terranes of Mexico and the isotopic signatures of the associated Cenozoic ores. Rather, these Pb isotope patterns are interpreted to reflect increasing crustal contribution to mantle-derived magmas as the arc advanced eastward onto a progressively thicker continental crust. The lead isotope trend observed in Cenozoic ores is not recognized in the ores from Mesozoic volcanogenic massive sulfide and sedimentary exhalative deposits. The Mesozoic ores formed prior to the amalgamation of the Guerrero composite terrane to the continental margin, which took place during the Late Cretaceous, in intraoceanic island arc and intracontinental marginal basin settings, while the Tertiary deposits formed after this event in a continental arc setting. Lead isotope ratios of the Mesozoic and Cenozoic ores appear to reflect these differences in tectonic setting of ore formation. Most Pb isotope values of ores from the La Verde deposit (206Pb/204Pb = 18.674-18.719) are less radiogenic than those of the host igneous rocks, but plot within the

  8. New isotopic evidence bearing on bonanza (Au-Ag) epithermal ore-forming processes

    Science.gov (United States)

    Saunders, James A.; Mathur, Ryan; Kamenov, George D.; Shimizu, Toru; Brueseke, Matthew E.

    2016-01-01

    New Cu, S, and Pb isotope data provide evidence for a magmatic source of metal(loid)s and sulfur in epithermal Au-Ag deposits even though their ore-forming solutions are composed primarily of heated meteoric (ground) waters. The apparent isotopic discrepancy between ore metals and ore-forming solutions, and even between the ore and associated gangue minerals, indicates two different sources of epithermal ore-forming constituents: (1) a shallow geothermal system that not only provides the bulk of water for the ore-forming solutions but also major chemical constituents leached from host rocks (silica, aluminum, potassium, sodium, calcium) to make gangue minerals and (2) metals and metalloids (As, Te, Sb, etc.) and sulfur (±Se) derived from deeper magma bodies. Isotopic data are consistent with either vapor-phase transport of metal(loids) and sulfur and their subsequent absorption by shallow geothermal waters or formation of metallic (Au, Ag, Cu phases) nanoparticles at depth from magmatic fluids prior to encountering the geothermal system. The latter is most consistent with ore textures that indicate physical transport and aggregation of nanoparticles were significant ore-forming processes. The recognition that epithermal Au-Ag ores form in tectonic settings that produce magmas capable of releasing metal-rich fluids necessary to form these deposits can refine exploration strategies that previously often have focused on locating fossil geothermal systems.

  9. Lake retention of manufactured nanoparticles

    NARCIS (Netherlands)

    Koelmans, A.A.; Quik, J.T.K.; Velzeboer, I.

    2015-01-01

    For twenty-five world lakes and three engineered nanoparticles (ENP), lake retention was calculated using a uniformly mixed lake mass balance model. This follows similar approaches traditionally used in water quality management. Lakes were selected such that lake residence times, depths and areal hy

  10. Lake retention of manufactured nanoparticles

    NARCIS (Netherlands)

    Koelmans, A.A.; Quik, J.T.K.; Velzeboer, I.

    2015-01-01

    For twenty-five world lakes and three engineered nanoparticles (ENP), lake retention was calculated using a uniformly mixed lake mass balance model. This follows similar approaches traditionally used in water quality management. Lakes were selected such that lake residence times, depths and areal hy

  11. Salting our freshwater lakes.

    Science.gov (United States)

    Dugan, Hilary A; Bartlett, Sarah L; Burke, Samantha M; Doubek, Jonathan P; Krivak-Tetley, Flora E; Skaff, Nicholas K; Summers, Jamie C; Farrell, Kaitlin J; McCullough, Ian M; Morales-Williams, Ana M; Roberts, Derek C; Ouyang, Zutao; Scordo, Facundo; Hanson, Paul C; Weathers, Kathleen C

    2017-04-25

    The highest densities of lakes on Earth are in north temperate ecosystems, where increasing urbanization and associated chloride runoff can salinize freshwaters and threaten lake water quality and the many ecosystem services lakes provide. However, the extent to which lake salinity may be changing at broad spatial scales remains unknown, leading us to first identify spatial patterns and then investigate the drivers of these patterns. Significant decadal trends in lake salinization were identified using a dataset of long-term chloride concentrations from 371 North American lakes. Landscape and climate metrics calculated for each site demonstrated that impervious land cover was a strong predictor of chloride trends in Northeast and Midwest North American lakes. As little as 1% impervious land cover surrounding a lake increased the likelihood of long-term salinization. Considering that 27% of large lakes in the United States have >1% impervious land cover around their perimeters, the potential for steady and long-term salinization of these aquatic systems is high. This study predicts that many lakes will exceed the aquatic life threshold criterion for chronic chloride exposure (230 mg L(-1)), stipulated by the US Environmental Protection Agency (EPA), in the next 50 y if current trends continue.

  12. Helium, lead and sulfur isotope geochemistry of the Gejiu Sn-polymetallic ore deposit and the sources of ore-forming materials

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Studies on the helium, lead and sulfur isotopic composition were performed of the Gejiu super-large Sn-polymetallic ore deposit. The results indicated that the ore-forming materials came from different sources and the deposit is a product of superimposed mineralization. The deposit is characterized by multi-source and multi-period mineralization, which experienced submarine hydrothermal deposition and Late Yanshanian magmatic hydrothermal mineralization. It is held that the Gejiu super-large Sn-polymetallic ore deposit is a multi-genesis deposit.

  13. Analytical fingerprint for tantalum ores from African deposits

    Science.gov (United States)

    Melcher, F.; Graupner, T.; Sitnikova, M.; Oberthür, T.; Henjes-Kunst, F.; Gäbler, E.; Rantitsch, G.

    2009-04-01

    Illegal mining of gold, diamonds, copper, cobalt and, in the last decade, "coltan" has fuelled ongoing armed conflicts and civil war in a number of African countries. Following the United Nations initiative to fingerprint the origin of conflict materials and to develop a traceability system, our working group is investigating "coltan" (i.e. columbite-tantalite) mineralization especially in Africa, also within the wider framework of establishing certified trading chains (CTC). Special attention is directed towards samples from the main Ta-Nb-Sn provinces in Africa: DR Congo, Rwanda, Mozambique, Ethiopia, Egypt and Namibia. The following factors are taken into consideration in a methodological approach capable of distinguishing the origin of tantalum ores and concentrates with the utmost probability: (1) Quality and composition of coltan concentrates vary considerably. (2) Mineralogical and chemical compositions of Ta-Nb ores are extremely complex due to the wide range of the columbite-tantalite solid solution series and its ability to incorporate many additional elements. (3) Coltan concentrates may contain a number of other tantalum-bearing minerals besides columbite-tantalite. In our approach, coltan concentrates are analyzed in a step-by-step mode. State-of-the-art analytical tools employed are automated scanning electron microscopy (Mineral Liberation Analysis; MLA), electron microprobe analysis (major and trace elements), laser ablation-ICP-MS (trace elements, isotopes), and TIMS (U-Pb dating). Mineral assemblages in the ore concentrates, major and trace element concentration patterns, and zoning characteristics in the different pegmatites from Africa distinctly differ from each other. Chondrite-normalized REE distribution patterns vary significantly between columbite, tantalite, and microlite, and also relative to major element compositions of columbites. Some locations are characterized by low REE concentrations, others are highly enriched. Samples with

  14. 42 CFR 421.200 - Carrier functions.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Carrier functions. 421.200 Section 421.200 Public...) MEDICARE PROGRAM MEDICARE CONTRACTING Carriers § 421.200 Carrier functions. A contract between CMS and a carrier specifies the functions to be performed by the carrier. The contract may include any or all of...

  15. Cancer of the lung in iron ore (haematite) miners

    Science.gov (United States)

    Boyd, J. T.; Doll, R.; Faulds, J. S.; Leiper, J.

    1970-01-01

    Boyd, J. T., Doll, R., Faulds, J. S., and Leiper, J.(1970).Brit. J. industr. Med.,27, 97-105. Cancer of the lung in iron ore (haematite) miners. The mortality of Cumberland iron-ore miners has been studied by examining the death certificates of 5 811 men resident in two local authority areas (Ennerdale R.D. and Whitehaven M.B.) who died between 1948 and 1967. Comparison of the iron miners' experience with (1) that of other local men and (2) the relevant national experience has provided an assessment of the suspected occupational risk of lung cancer associated with haematite mining. During the 20-year period there were 42 deaths attributed to lung cancer among iron mine employees resident in the study area: 36 of these occurred in miners working underground, which was significantly greater than that expected from local non-mining (20·6 deaths) or national (21·5 deaths) experience. In contrast to these findings, there was no evidence of any excess mortality from lung cancer among surface workers and, for iron miners as a whole, mortality from other cancers was close to the national experience. A parallel analysis of mortality among coal miners showed a deficit of deaths from lung cancer in line with other studies. The patterns of other respiratory mortality in the two local mining groups were also in line with previous experience, and confirmed the existence of a substantial silicotic hazard associated with haematite mining in Cumberland. These findings strengthen previous necropsy evidence and indicate that West Cumberland iron-ore miners who work underground experience an occupational hazard of lung cancer. They suggest that the miners suffer a lung cancer mortality about 70% higher than `normal'. The risk may be due to radioactivity in the air of the mines (average radon concentration of 100 p Ci/litre) or to a carcinogenic effect of iron oxide. PMID:5448525

  16. Identification of contamination in a lake sediment core using Hg and Pb isotopic compositions, Lake Ballinger, Washington, USA

    Science.gov (United States)

    Gray, John E.; Pribil, Michael J.; Van Metre, Peter C.; Borrok, David M.; Thapalia, Anita

    2013-01-01

    Concentrations and isotopic compositions of Hg and Pb were measured in a sediment core collected from Lake Ballinger, near Seattle, Washington, USA. Lake Ballinger has been affected by input of metal contaminants emitted from the Tacoma smelter, which operated from 1887 to 1986 and was located about 53 km south of the lake. Concentrations and loadings of Hg and Pb in Lake Ballinger increased by as much as three orders of magnitude during the period of smelting as compared to the pre-smelting period. Concentrations and loadings of Hg and Pb then decreased by about 55% and 75%, respectively, after smelting ended. Isotopic compositions of Hg changed considerably during the period of smelting (δ202Hg = −2.29‰ to −0.38‰, mean −1.23‰, n = 9) compared to the pre-smelting period (δ202Hg = −2.91‰ to −2.50‰, mean −2.75‰, n = 4). Variations were also observed in 206Pb/207Pb and 208Pb/207Pb isotopic compositions during these periods. Data for Δ199Hg and Δ201Hg indicate mass independent fractionation (MIF) of Hg isotopes in Lake Ballinger sediment during the smelting and post-smelting period and suggest MIF in the ore smelted, during the smelting process, or chemical modification at some point in the past. Negative values for Δ199Hg and Δ201Hg for the pre-smelting period are similar to those previously reported for soil, peat, and lichen, likely suggesting some component of atmospheric Hg. Variations in the concentrations and isotopic compositions of Hg and Pb were useful in tracing contaminant sources and the understanding of the depositional history of sedimentation in Lake Ballinger.

  17. Thermal stress in North Western Australian iron ore mining staff.

    Science.gov (United States)

    Peiffer, Jeremiah J; Abbiss, Chris R

    2013-05-01

    Demand for Australian mined iron ore has increased employment within this sector, thus exposing increased numbers of workers to the harsh Australian climate. This study examined the influence of hot (>30°C wet bulb globe temperature) environmental temperatures, consistent with working in North Western Australia, on iron ore mining staff. Core temperature, hydration status, perceived exertion, mood, and fatigue state were measured in 77 participants at three time points (pre-, mid-, and post-shift) during a normal 12-h shift at an open-cut iron ore mining/processing site (n = 31; Site1) and an iron ore processing/shipping site (n = 46; Site2). A significant effect for time was observed for core temperature with greater mean core temperatures measured mid-shift (37.5±0.4°C) and post-shift (37.6±0.3°C) compared with pre-shift values (37.0±0.5°C). All mean core temperature measures were lower than ISO7933 thresholds (38°C) for thermal safety. Mean hydration measures [urine-specific gravity (USG)] were greater at Site1 (1.029±0.006) compared with those at Site2 (1.021±0.007). Furthermore, both pre- and post-shift measures from Site1 and the post-shift measures from Site2 were greater than the threshold for dehydration (USG = 1.020). No differences were observed for mood or perceived exertion over time; however, measures of fatigue state were greater post-shift compared with pre- and mid-shift values for both sites. Our findings indicate that the majority of mine workers in North Western Australia are able to regulate work rate in hot environments to maintain core temperatures below ISO safety guidelines; however, 22% of workers reached or exceeded the safety guidelines, warranting further investigation. Furthermore, hydration practices, especially when off-work, appear inadequate and could endanger health and safety.

  18. CHAIN EXTENDER AND EMULSIFIER APPLICATION IN IRON ORE FLOTATION

    Directory of Open Access Journals (Sweden)

    José Pedro da Silva

    2013-06-01

    Full Text Available The present study aims to evaluate the reverse flotation performance of iron ore, using collector (amine, in the presence and absence of chain extender (diesel oil and emulsifier (sodium lauryl sulfate.Six tests were realized with duplicate. Tests using amine, diesel oil and sodium lauryl sulphate show the better results, with metallurgical recovery of 91.82% and the concentrate silica equal 1.68%. Thus, it is found that the use of emulsifier and chain extender together with the amine, shows better results in the flotation, in terms of metal recovery and selectivity, when compared to using only amine or amine and diesel oil.

  19. Thermal Decomposition of Copper Ore Concentrate and Polyethylene Composites

    Science.gov (United States)

    Szyszka, Danuta; Wieckowska, Jadwiga

    2016-10-01

    Thermal analyses (TGA and DTA) of the composite, comprised of 10% polyethylene (PE) scrap and 90% copper ore concentrate, enabled determination of the temperature range and decomposition degree of the organic matters in argon atmosphere. Products of pyrolysis were qualitatively and quantitatively determined. The results were compared to those obtained for products of pyrolysis of the composite in air. Products of pyrolysis were identified by means of the gas chromatography (GC) method alone or supported with results of mass spectrometry analyses (GC-MS).

  20. TECHNOLOGICAL CHARACTERISTICS OF THE ZLATÁ BAŇA ORES

    Directory of Open Access Journals (Sweden)

    Košuth Marián

    1997-10-01

    Full Text Available The main processing interest of examined Zlatá Baňa polymetalic ores was focused on copper-lead-zinc minerals with precious metals and trace elements. Gold occurrin a native form or as an isomorphism in pyrite. The role of inclusions of own Ag-minerals was inflated by geologist, but a prevailing amount of silver is isomorphous in galena and argentotetrahedrite. Almost no possibility to concentrating discrete silver minerals was proved technologically. In galena, an interesting content of Se and Te was registered. Among trace elements, a higher content of cadmium folows exclusively the content of zinc in blende.

  1. Topological aperiodicity for product systems over semigroups of Ore type

    DEFF Research Database (Denmark)

    Kwasniewski, Bartosz; Szymanski, Wojciech

    2016-01-01

    We prove a version of uniqueness theorem for Cuntz-Pimsner algebras of discrete product systems over semigroups of Ore type. To this end, we introduce Doplicher-Roberts picture of Cuntz-Pimsner algebras, and the semigroup dual to a product system of 'regular' C*-correspondences. Under a certain...... aperiodicity condition on the latter, we obtain the uniqueness theorem and a simplicity criterion for the algebras in question. These results generalize the corresponding ones for crossed products by discrete groups, due to Archbold and Spielberg, and for Exel's crossed products, due to Exel and Vershik...

  2. Sandbox experiments on Uraninite Ore: ERT and SP measurments.

    Science.gov (United States)

    Singh, R. K.

    2015-12-01

    Nuclear energy, considering its own intrinsic merits, would be a leading source for meeting the energy requirement in present and future scenario. Concealed Uranium deposits under sedimentary cover, with poor surface indications calls for reorientation of survey with large inputs involving integrated geophysical approach. Sand Box experiments have been carried out over Uraninite ore. The tank is a glass fish tank (height 39 cm, length 75 cm, width 30 cm). It was filled with sand up to 35 cm high. The sand was saturated from below to minimize the entrapment of the gas bubbles. The average size for sand grains is ~ 0.295mm. The formation factor of the sand is 3.5, with a negligible surface conductivity because of the coarse nature of the sand grains. The dimension of considered Uraninite ore sample is 4cm x 4cm x 4cm. The depth of top of the ore sample is kept at 3cm. In this paper both resistivity and self-potential measurements were carried out for possible detection of Uraninite. The resistivity measurements were made with 64 non-polarizable electrodes using Electrical Resistivity Tomography (ERT) equipment of FlashRes Universal developed by ZZ Resistivity Imaging Pty. Ltd. We have used screws of length 3cm as electrodes. The separation between these electrodes are ~ 1cm. The resistivity tomography results clearly outlines the target Uraninite body. The resistivity tomography results also detects small heterogeneities associated with air bubbles possibly due to unsaturated pore spaces. SP measurements were made using two non-polarizing Pb/PbCl2 electrodes and a Fluke 289 voltmeter (sensitivity 0.001 mV, internal impedance 100 MOhm). The reference electrode was located on the corner of the sandbox. The other electrode was used to scan the electrical potential at the surface of the sand. SP measurements were made with a spacing of 3 cm over the same ERT profile. The SP results also shows a dip (or a low SP anomaly) over the target ore body sample. Thus, both SP and

  3. 2016 Lake Michigan Lake Trout Working Group Report

    Science.gov (United States)

    Madenjian, Charles P.; Breidert, Brian; Boyarski, David; Bronte, Charles R.; Dickinson, Ben; Donner, Kevin; Ebener, Mark P.; Gordon, Roger; Hanson, Dale; Holey, Mark; Janssen, John; Jonas, Jory; Kornis, Matthew; Olsen, Erik; Robillard, Steve; Treska, Ted; Weldon, Barry; Wright, Greg D.

    2017-01-01

    This report provides a review on the progression of lake trout rehabilitation towards meeting the Salmonine Fish Community Objectives (FCOs) for Lake Michigan (Eshenroder et. al. 1995) and the interim goal and evaluation objectives articulated in A Fisheries Management Implementation Strategy for the Rehabilitation of Lake Trout in Lake Michigan (Dexter et al. 2011); we also include data describing lake trout stocking and mortality to portray the present state of progress towards lake trout rehabilitation.

  4. Mineralogical Study of Zard Koh and Kulli Koh Iron Ore Deposits of Pakistan

    Directory of Open Access Journals (Sweden)

    SULTAN AHMED KHOSO

    2017-10-01

    Full Text Available Zard Koh and Kulli Koh are two recently discovered iron ore deposits, existing in the Chagai district, Balochistan, Pakistan. PSM (Pakistan Steel Mill Limited is interested to utilize these ore deposits at priority. Purpose of the present study was to assess the mineralogy of the Zard Koh and Kulli Koh iron ore deposits, as it plays a vital role in the selection of an appropriate processing method. The mineralogical study of ore deposits was carried out by XRD (X-Ray Diffraction, XRF (X-Ray Fluorescence, SEM (Scanning Electron Microscope attached with EDS (Energy Dispersive Spectroscope and SM (Stereomicroscope techniques. Results indicated that the Zard Koh ore is mainly composed of 60.15% maghemite, 23.57% pyrite, 4.07% chlorite, 10.30% grossular and 1.65% admontite minerals. The chemical analysis revealed that Zard Koh iron ore contains an average of 54.27% Fe, 12.73% S, 8.70% Si, 3.07% Al, 4.07% Ca, and 2.16% Mg. Similarly, the mineralogical study of the Kulli Koh iron ore indicated that, ore is containing 51.16% hematite, 29.24% quartz, 8.89% dravite, and 8.76% kaolinite minerals. Elemental analysis of different samples indicated that Kulli Koh iron ore contains an average composition of 40.23% Fe, 20.67% Si, 3.44% Ca, 3.81% Al and 3.25% Mg. Mineralogical study of the Zard Koh and Kulli Koh iron ore deposits suggested that these ore deposits can be beneficiated costeffectively by using magnetic separation techniques.

  5. Idea of Identification of Copper Ore with the Use of Process Analyser Technology Sensors

    Science.gov (United States)

    Jurdziak, Leszek; Kaszuba, Damian; Kawalec, Witold; Król, Robert

    2016-10-01

    The Polish resources of the copper ore exploited by the KGHM S.A. underground mines are considered as one of the most complex in the world and - consequently - the most difficult to be processed. The ore consists of three lithology forms: dolomites, shales and sandstones but in different proportions which has a significant impact on the effectiveness of the grinding and flotation processes. The lithological composition of the ore is generally recognised in-situ but after being mined it is blended on its long way from various mining fields to the processing plant by the complex transportation system consisting of belt conveyors with numerous switching points, ore bunkers and shafts. Identification of the lithological composition of the ore being supplied to the processing plant should improve the adjustments of the ore processing machinery equipment aiming to decrease the specific processing (mainly grinding) energy consumption as well as increase the metal recovery. The novel idea of Process Analyser Technology (PAT) sensors - information carrying pellets, dropped into the transported or processed bulk material which can be read directly when needed - is investigated for various applications within the DISIRE project (a part of the SPIRE initiative, acting under the Horizon2020 framework program) and here is adopted for implementing the annotation the transported copper ore for the needs of ore processing plants control. The identification of the lithological composition of ore blended on its way to the processing plant can be achieved by an information system consisting of pellets that keep the information about the original location of the portions of conveyed ore, the digital, geological database keeping the data of in-situ lithology and the simulation models of the transportation system, necessary to evaluate the composition of the blended ore. The assumptions of the proposed solution and the plan of necessary in-situ tests (with the special respect to harsh

  6. Hydrography - Lakes Assessments - Non Attaining

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This layer shows only non attaining lakes of the Integrated List. The Lakes Integrated List represents lake assessments in an integrated format for the Clean Water...

  7. Boat Dwellers of Weishan Lake

    Institute of Scientific and Technical Information of China (English)

    JENNIFER; LIM

    1998-01-01

    IN the south of Shandong Province, Weishan Lake is the largest freshwater lake in northern China. Under the bright blue sky, it gleams like a large mirror. "As the sun is about to set, Weishan Lake is quiet…" Humming

  8. Mineralogical and geochemical characteristics of the Noamundi-Koira basin iron ore deposits (India)

    Science.gov (United States)

    Mirza, Azimuddin; Alvi, Shabbar Habib; Ilbeyli, Nurdane

    2015-04-01

    India is one of the richest sources of iron ore deposits in the world; and one of them is located in the Noamundi-Koira basin, Singhbhum-Orissa craton. The geological comparative studies of banded iron formation (BIF) and associated iron ores of Noamundi-Koira iron ore deposits, belonging to the iron ore group in eastern India, focus on the study of mineralogy and major elemental compositions along with the geological evaluation of different iron ores. The basement of the Singhbhum-Orissa craton is metasedimentary rocks which can be traced in a broadly elliptical pattern of granitoids, surrounded by metasediments and metavolcanics of Greenstone Belt association. The Singhbhum granitoid is intrusive into these old rocks and to younger, mid Archaean metasediments, including iron formations, schists and metaquartzites and siliciclastics of the Precambrian Iron Ore Group (Saha et al., 1994; Sharma, 1994). The iron ore of Noamundi-Koira can be divided into seven categories (Van Schalkwyk and Beukes 1986). They are massive, hard laminated, soft laminated, martite-goethite, powdery blue dust and lateritic ore. Although it is more or less accepted that the parent rock of iron ore is banded hematite jasper (BHJ), the presence of disseminated martite in BHJ suggests that the magnetite of protore was converted to martite. In the study area, possible genesis of high-grade hematite ore could have occurred in two steps. In the first stage, shallow, meteoric fluids affect primary, unaltered BIF by simultaneously oxidizing magnetite to martite and replacing quartz with hydrous iron oxides. In the second stage of supergene processes, deep burial upgrades the hydrous iron oxides to microplaty hematite. Removal of silica from BIF and successive precipitation of iron resulted in the formation of martite- goethite ore. Soft laminated ores were formed where precipitation of iron was partial or absent. The leached out space remains with time and the interstitial space is generally filled

  9. Basic Stand Alone Carrier Line Items PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Carrier Line Items Public Use Files (PUF) with information from Medicare Carrier claims. The CMS BSA Carrier Line...

  10. 40Ar-39Ar Dating of Quartz from Ore in the Baiyangping Cu-Co Polymetallic Ore-Concentrated Area, Lanping Basin, Yunnan

    Institute of Scientific and Technical Information of China (English)

    何明勤; 刘家军; 李朝阳; 李志明; 刘玉平; 杨爱平; 桑海清

    2004-01-01

    40Ar-39Ar fast neutron activation age spectrum of quartz in ore collected from the Baiyangping Cu-Co polymetallic ore-concentrated area, Lanping Basin, is saddle-shaped. The plateau age, minimum appearance age and isochron age shown on the spectra are 56.53±0.43 Ma, 55.52±1.78 Ma and 55.90±0.29 Ma respectively. The age data are consistent with each other within 1σ uncertainties. Because the given initial 40Ar/36Ar value of 294.7±1.14 is very close to Nier's value (295.5±5), both plateau and isochron ages may be considered as the forming time of quartz. So the age of 55.90-56.53 Ma represents the forming age of ore deposits. It is obvious that the ore deposits were formed during the Early Himalayan period.

  11. Remobilisation features and structural control on ore grade distribution at the Konkola stratiform Cu-Co ore deposit, Zambia

    Science.gov (United States)

    Torremans, K.; Gauquie, J.; Boyce, A. J.; Barrie, C. D.; Dewaele, S.; Sikazwe, O.; Muchez, Ph.

    2013-03-01

    The Konkola deposit is a high grade stratiform Cu-Co ore deposit in the Central African Copperbelt in Zambia. Economic mineralisation is confined to the Ore Shale formation, part of the Neoproterozoic metasedimentary rocks of the Katanga Supergroup. Petrographic study reveals that the copper-cobalt ore minerals are disseminated within the host rock, sometimes concentrated along bedding planes, often associated with dolomitic bands or clustered in cemented lenses and in layer-parallel and irregular veins. The hypogene sulphide mineralogy consists predominantly of chalcopyrite, bornite and chalcocite. Based upon relationships with metamorphic biotite, vein sulphides and most of the sulphides in cemented lenses were precipitated during or after biotite zone greenschist facies metamorphism. New δ34S values of sulphides from the Konkola deposit are presented. The sulphur isotope values range from -8.7‰ to +1.4‰ V-CDT for chalcopyrite from all mineralising phases and from -4.4‰ to +2.0‰ V-CDT for secondary chalcocite. Similarities in δ34S for sulphides from different vein generations, earlier sulphides and secondary chalcocite can be explained by (re)mobilisation of S from earlier formed sulphide phases, an interpretation strongly supported by the petrographic evidence. Deep supergene enrichment and leaching occurs up to a km in depth, predominantly in the form of secondary chalcocite, goethite and malachite and is often associated with zones of high permeability. Detailed distribution maps of total copper and total cobalt contents of the Ore Shale formation show a close relationship between structural features and higher copper and lower cobalt contents, relative to other areas of the mine. Structural features include the Kirilabombwe anticline and fault zones along the axial plane and two fault zones in the southern limb of the anticline. Cobalt and copper behave differently in relation to these structural features. These structures are interpreted to have

  12. Iron ore Development and supplies from Third world: A Potential for Sustainable Development.

    Directory of Open Access Journals (Sweden)

    Abdurrauf A. Ibrahim

    2014-12-01

    Full Text Available This paper discuss the qualitative leaching of iron ore in hydrochloric acid and multi gravity separation method as new strategies for reducing lost of iron during production. The focus of the paper is on the potential of iron ore development and supplies from Third world for Sustainable Development and to enter and sustain in the export global competitive Market..

  13. Methods of Dust Air Flows Reduction at Ore Transfer Facilities of Mining and Processing Plants

    Directory of Open Access Journals (Sweden)

    Gulmira K. Saparova

    2013-01-01

    Full Text Available The article describes the most typical schemes of ore stationary transfers. Aspirate units, depending on dust intensity are divided into three groups. Typical schemes of stationary transfers were presented. On the ground of the research, the classification of ore transfer facilities types at mining and processing plants was offered

  14. Market Structure Differences Impacting Australian Iron Ore and Metallurgical Coal Industries

    Directory of Open Access Journals (Sweden)

    Kurt Lawrence

    2015-07-01

    Full Text Available Steelmaking relies on iron ore and metallurgical coal as main ingredients, the trade of which is hypothesized to theoretically change in tandem. However, strong correlation is not evident in historical trade prices of steelmaking inputs. To determine causes to this occurrence, the market factors that influence the Australian iron ore and metallurgical coal industries were studied. Data was collected over the past decade for worldwide resource production and trade quantities of crude steel, iron ore, and metallurgical coal. The data was analysed to reveal trends, allowing examination of the macroeconomic trade of metallurgical coal and iron ore with relation to worldwide and country specific steel production. It was determined that the influential growth of China’s steel production has spurred the growth of worldwide iron ore demand, which was met with increased production and supply, from Australia. The increased metallurgical coal demand has been met with increased production within China locally. Measures of supply elasticity were created for worldwide iron ore and metallurgical coal trade, where comparisons between Australia’s industries to the relevant greatest competitor were examined. The results, along with respective resource production data, highlighted the elevated competitive position that Australian iron ore producers enjoy compared to metallurgical coal producers. Trade characteristics revealed the different market structures that iron ore and metallurgical coal industries operate in, prompting a discussion of the effects these markets have on the two Australian industries.

  15. 40 CFR 440.30 - Applicability; description of the uranium, radium and vanadium ores subcategory.

    Science.gov (United States)

    2010-07-01

    ... for the extraction of uranium, radium and vanadium. Only vanadium byproduct production from uranium... uranium, radium and vanadium ores subcategory. 440.30 Section 440.30 Protection of Environment... SOURCE CATEGORY Uranium, Radium and Vanadium Ores Subcategory § 440.30 Applicability; description of...

  16. Relaxation phenomena and jointing in ore bodies under explosive injection treatment

    Science.gov (United States)

    Shevchenko, YuS

    2017-02-01

    Under analysis are relaxation phenomena in ore bodies under leaching. It is shown that liquid and gas–liquid phases make these phenomena last longer, thus it is recommended to apply synergetically interconnected processes of explosive fracture of an ore block and simultaneous injection of active leaching solutions in the generated system of joints.

  17. Tungsten and Molybdenum Ores in China and the Management Policies(Part Ⅰ)

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>China is traditionally a leading producer of tungsten and molybdenum ores in the world. The ores are densely distributed and easy to exploit,and the production accounts for a large share of the world’s total.But China has yet to dominate the market and the advantage that China has long enjoyed is being weakened,giv-

  18. Silicophosphate Sorbents, Based on Ore-Processing Plants' Waste in Kazakhstan

    Science.gov (United States)

    Kubekova, Sholpan N.; Kapralova, Viktoria I.; Telkov, Shamil A.

    2016-01-01

    The problem of ore-processing plants' waste and man-made mineral formations (MMF) disposal is very important for the Republic of Kazakhstan. The research of various ore types (gold, polymetallic, iron-bearing) MMF from a number of Kazakhstan's deposits using a complex physical and chemical methods showed, that the waste's main components are…

  19. The gold contained in imported lead ore concentrate is exempted from import value-added tax

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>According to the No. 14 proclamation issued by Customs Service, as from April 1st 2007, the importation of galena and the lead ore concentrate will enjoy the favorable policy intended for associated gold deposits, i.e. the value-added tax for gold component in the imported galena and lead ore concentrate is exempted,

  20. Simulating Some Complex Phenomena in Hydrothermal Ore-Forming Processes by Reaction-Diffusion CNN

    Institute of Scientific and Technical Information of China (English)

    Xu Deyi; Yu Chongwen; Bao Zhengyu

    2003-01-01

    Complexity phenomena like dynamic and static patterns, order from disorder, chaos and catastrophe were simulated by the application of 2-D reaction-diffusion CNN of two state variables and two diffusion coefficients transformed from Zhabotinksii model. They revealed somehow the mechanism of hydrothermal ore-forming processes, and answered several questions about the onset of ore forming.

  1. Application of neodymium isotope ratio measurements for the origin assessment of uranium ore concentrates

    NARCIS (Netherlands)

    Krajko, J.; Varga, Z.; Yalcintas, E.; Wallenius, M.; Mayer, K.

    2014-01-01

    A novel procedure has been developed for the measurement of 143Nd/144Nd isotope ratio in various uranium-bearing materials, such as uranium ores and ore concentrates (UOC) in order to evaluate the usefulness and applicability of variations of 143Nd/144Nd isotope ratio for provenance assessment in nu

  2. Reduction of Low-grade Manganese Dioxide Ore Pellets by Biomass Wheat Stalk

    Institute of Scientific and Technical Information of China (English)

    Honglei ZHANG; Guocai ZHU; Hong YAN; Yuna ZHAO; Tiancheng LI; Xiujuan FENG

    2013-01-01

    An investigation on reducing low-grade manganese dioxide ore pellets was carried out by using wheat stalk as reductant.The main impact factors of reduction percent such as particle size,biomass/ore ratio,heating rate,nitrogen flow rate,temperature and time in reduction process were discussed.The morphology and component of manganese dioxide ore particle at different stages were also analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS).The results show the increase of the reduction temperature and time,biomass/ore ratio,and the decrease of particle size,heating rate and nitrogen flow rate can significantly enhance reduction efficiency.The reduction kinetic of the manganese ore is controlled by three-dimensional mass diffusion of gaseous reductive volatiles passing from the surface to the core of the ore particles.The activation energy E and frequency factor A were calculated to be 24.15 kJ.mol-1 and 166 min-1,respectively.Biomass pyrolysis volatiles adsorbed onto the surface of the ore particle leads to serious variation of the microstructures and chemical composition of the manganese ore particles.

  3. Preparation of ore blocks for mine leaching by reagent explosion injection

    Science.gov (United States)

    Shevchenko, YuS

    2017-02-01

    The current drilling-and-blasting operations fail to prepare intact ore body underlying a production horizon for subsequent mining and leaching. It is found that the required preparation quality is possible by means of advanced implementation of ore body discontinuity and filling of the resultant system of joints with active leaching solutions.

  4. Depreciation in Ambient Air Quality in Iron Ore Mining Region of Goa

    Directory of Open Access Journals (Sweden)

    Gurdeep Singh

    2015-04-01

    Full Text Available Goa is one of the most famous international tourist destinations of the world. Export of Iron ore extracted from the midland of Goa is a major economic activity. However, there is a serious concern of air pollution due to iron ore mining activities. In order to assess the impact of mining activities on the environmental regime, the air quality depreciation index was adopted for this study due to its realistic and meaningful presentation of deterioration in ambient air quality. The index had been applied to the ambient air quality monitoring results of thirty four locations in the iron ore mining region of Goa. To envisage upon the deterioration in air quality due to various activities, eight stations were selected around mines, twelve in the buffer zone (within 4 Km radius of the core mining activities and fourteen along the ore transportation routes for monitoring of SPM, PM10, SO2 and NOX. The deterioration of air quality in the iron ore mining region of Goa is clearly apparent as the depreciation in air quality was found < -1 from the most desired value of 0 at all the stations. In general, the air quality was found most depreciated along the ore transportation routes, which is also evidenced by a considerable load of particulate matters observed. This infers that ore transportation is the most devastating activity in the iron ore mining region of Goa and accordingly mitigation plan should be adopted.

  5. Accelerating column leaching trial on copper sulfide ore

    Institute of Scientific and Technical Information of China (English)

    WANG Hongjiang; WU Aixiang; ZHOU Xun; WANG Shaoyong; ZHANG Jie

    2008-01-01

    The main measures to accelerate leaching sulfide ore are large spraying intensity,manual oxygen supply,temperature control and acclimated bacteria.The indoor experiment accelerating sulfide ore leaching detected the temperature during leaching process,dissolvability of oxygen,bacterial concentration,Cu concentration and slag grade.At the same time,this paper also analyzed the effect of four factors,which are bacterial diversity cultivation stage,spraying intensity,air supply,and whether to control temperature,on the leaching efficiency of copper.The results indicate that the oxygen content of leach solution has a close relationship with temperature but it is rarely affected by air supply.The bacterial concentration preserves from 106 to 107 mL-1,and temperature has a great effect on the bacterial activity under the condition of proper temperature and oxygen supply,and the lack of nutrition prevents the bacterial concentration from rising in the late stage.The relationships of the copper leaching efficiency to temperature,air feed,and spraying intensity are directly proportional.The leaching efficiencies of the cultivated bacteria and acclimation bacteria are 1.2 and 1.4 times as large as that of the original bacteria.

  6. Application of natural analog studies to exploration for ore deposits

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, D.L. [Consulting Economic Geologist, Reno, NV (United States)

    1995-09-01

    Natural analogs are viewed as similarities in nature and are routinely utilized by exploration geologists in their search for economic mineral deposits. Ore deposit modeling is undertaken by geologists to direct their exploration activities toward favorable geologic environments and, therefore, successful programs. Two types of modeling are presented: (i) empirical model development based on the study of known ore deposit characteristics, and (ii) concept model development based on theoretical considerations and field observations that suggest a new deposit type, not known to exist in nature, may exist and justifies an exploration program. Key elements that are important in empirical model development are described, and examples of successful applications of these natural analogs to exploration are presented. A classical example of successful concept model development, the discovery of the McLaughlin gold mine in California, is presented. The utilization of natural analogs is an important facet of mineral exploration. Natural analogs guide explorationists in their search for new discoveries, increase the probability of success, and may decrease overall exploration expenditure.

  7. Phytostabilization of iron ore tailings through Calophyllum inophyllum L.

    Science.gov (United States)

    Chaturvedi, Nilima; Dhal, N K; Reddy, Palli Sita Rama

    2012-12-01

    The phytostabilization of waste material generated during mining and processing of iron ore through Calophyllum inophyllum L. have been investigated. Iron ore tailings and its varying composition with garden soil were taken to study plant growth, chlorophyll content and metal uptake pattern of Calophyllum inophyllum L. These studies indicate that 100% survival of plant species was noted in all the treatments without any toxicity symptoms. The increase in growth parameters and chlorophyll content along with the high metal accumulation in plant tissues suggests that Calophyllum inophyllum L. may be a potential tool for phytoremediation. The accumulation of Pb (1662 microgm/gm) and Fe (2313 microgm/gm) was observed to be maximum in the plant tissues followed by Cu, Zn, Cr, and Ni. The TF values for most of the heavy metals was observed to be > 1 which indicates that the plant can efficiently translocate these toxic metals to its above ground parts. Removal of more than 30% of the most of the heavy metal like Fe, Pb, and Cu & Zn has been observed in all the treatments during one year of observation. The overall study clearly suggests that the plant can be used as an efficient tool for restoration of mining wastes and other similarly contaminated sites.

  8. Analyzing the international exergy flow network of ferrous metal ores.

    Science.gov (United States)

    Qi, Hai; An, Haizhong; Hao, Xiaoqing; Zhong, Weiqiong; Zhang, Yanbing

    2014-01-01

    This paper employs an un-weighted and weighted exergy network to study the properties of ferrous metal ores in countries worldwide and their evolution from 2002 to 2012. We find that there are few countries controlling most of the ferrous metal ore exports in terms of exergy and that the entire exergy flow network is becoming more heterogeneous though the addition of new nodes. The increasing of the average clustering coefficient indicates that the formation of an international exergy flow system and regional integration is improving. When we contrast the average out strength of exergy and the average out strength of currency, we find both similarities and differences. Prices are affected largely by human factors; thus, the growth rate of the average out strength of currency has fluctuated acutely in the eleven years from 2002 to 2012. Exergy is defined as the maximum work that can be extracted from a system and can reflect the true cost in the world, and this parameter fluctuates much less. Performing an analysis based on the two aspects of exergy and currency, we find that the network is becoming uneven.

  9. Analyzing the International Exergy Flow Network of Ferrous Metal Ores

    Science.gov (United States)

    Qi, Hai; An, Haizhong; Hao, Xiaoqing; Zhong, Weiqiong; Zhang, Yanbing

    2014-01-01

    This paper employs an un-weighted and weighted exergy network to study the properties of ferrous metal ores in countries worldwide and their evolution from 2002 to 2012. We find that there are few countries controlling most of the ferrous metal ore exports in terms of exergy and that the entire exergy flow network is becoming more heterogeneous though the addition of new nodes. The increasing of the average clustering coefficient indicates that the formation of an international exergy flow system and regional integration is improving. When we contrast the average out strength of exergy and the average out strength of currency, we find both similarities and differences. Prices are affected largely by human factors; thus, the growth rate of the average out strength of currency has fluctuated acutely in the eleven years from 2002 to 2012. Exergy is defined as the maximum work that can be extracted from a system and can reflect the true cost in the world, and this parameter fluctuates much less. Performing an analysis based on the two aspects of exergy and currency, we find that the network is becoming uneven. PMID:25188407

  10. Content Distribution for Telecom Carriers

    Directory of Open Access Journals (Sweden)

    Ben Falchuk

    2006-08-01

    Full Text Available Distribution of digital content is a key revenue opportunity for telecommunications carriers. As media content moves from analog and physical media-based distribution to digital on-line distribution, a great opportunity exists for carriers to claim their role in the media value chain and grow revenue by enhancing their broadband “all you can eat” high speed Internet access offer to incorporate delivery of a variety of paid content. By offering a distributed peer to peer content delivery capability with authentication, personalization and payment functions, carriers can gain a larger portion of the revenue paid for content both within and beyond their traditional service domains. This paper describes an approach to digital content distribution that leverages existing Intelligent Network infrastructure that many carriers already possess, as well as Web Services.

  11. Geology and ore fluid geochemistry of the Jinduicheng porphyry molybdenum deposit, East Qinling, China

    Science.gov (United States)

    Li, Hongying; Ye, Huishou; Wang, Xiaoxia; Yang, Lei; Wang, Xiuyuan

    2014-01-01

    Jinduicheng deposit is a giant Mesozoic porphyry Mo system deposit in the East Qinling molybdenum belt, Shaanxi Province, China. The mineralization is associated with the I-type Jinduicheng granite porphyry. Both the porphyry stock and country rocks underwent intense hydrothermal alteration. The alteration, with increasing distance from the parent intrusion, changes from silicification, through potassic and phyllic assemblages, carbonation, to propylitic assemblages. Molybdenite, the dominant ore mineral, occurs in veinlets, most of which are hosted by the altered country rocks, with less than 25% of the ore in the porphyry body. The hydrothermal system comprises four stages, including pre-ore quartz and K-feldspar; two ore stages of quartz, K-feldspar, molybdenite, and Pb- And Zn-bearing sulfides; and post-ore quartz and carbonate. Six main types of primary fluid inclusions are present in hydrothermal quartz, including two-phase aqueous, one-phase aqueous, three-phase CO2-bearing, CO2-dominated fluid inclusions, gas inclusions, and melt inclusions. The homogenization temperatures of fluid inclusions range from 210 to 290 °C in the pre-ore stage, 150-310 °C in ore stage I, 150-360 °C in the ore stage II, and 195-325 °C in the post-ore stage quartz. Estimated salinities of the ore-forming fluids range from 6.9 to 13.5, 4.3 to 12.3, 6.2 to 12.4, and 3.4 to 9.9 wt.% NaCl equiv. in stages 1-4, respectively. The δ34S values of pyrite in the two ore stages range from 2.8‰ to 4.3‰, whereas the δ34S values of molybdenite range from 2.9‰ to 6.2‰. The data suggest both magmatic and crustal sources of sulfur. The δD and δ18O values for the hydrothermal fluids are -57.2‰ to -84.4‰ and 8.0‰ to -3.2‰, respectively. The fluid inclusion and stable data indicate that the pre-ore hydrothermal fluids were mostly of magmatic origin, but the fluids responsible for ore deposition were mixed magmatic and meteoric, and eventually meteoric water dominated the system

  12. LIFETIME PREDICTION FOR MODEL 9975 O-RINGS IN KAMS

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, E.; Skidmore, E.

    2009-11-24

    The Savannah River Site (SRS) is currently storing plutonium materials in the K-Area Materials Storage (KAMS) facility. The materials are packaged per the DOE 3013 Standard and transported and stored in KAMS in Model 9975 shipping packages, which include double containment vessels sealed with dual O-rings made of Parker Seals compound V0835-75 (based on Viton{reg_sign} GLT). The outer O-ring of each containment vessel is credited for leaktight containment per ANSI N14.5. O-ring service life depends on many factors, including the failure criterion, environmental conditions, overall design, fabrication quality and assembly practices. A preliminary life prediction model has been developed for the V0835-75 O-rings in KAMS. The conservative model is based primarily on long-term compression stress relaxation (CSR) experiments and Arrhenius accelerated-aging methodology. For model development purposes, seal lifetime is defined as a 90% loss of measurable sealing force. Thus far, CSR experiments have only reached this target level of degradation at temperatures {ge} 300 F. At lower temperatures, relaxation values are more tolerable. Using time-temperature superposition principles, the conservative model predicts a service life of approximately 20-25 years at a constant seal temperature of 175 F. This represents a maximum payload package at a constant ambient temperature of 104 F, the highest recorded in KAMS to date. This is considered a highly conservative value as such ambient temperatures are only reached on occasion and for short durations. The presence of fiberboard in the package minimizes the impact of such temperature swings, with many hours to several days required for seal temperatures to respond proportionately. At 85 F ambient, a more realistic but still conservative value, bounding seal temperatures are reduced to {approx}158 F, with an estimated seal lifetime of {approx}35-45 years. The actual service life for O-rings in a maximum wattage package likely lies

  13. Technology of Polish copper ore beneficiation – perspectives from the past experience

    Directory of Open Access Journals (Sweden)

    Wieniewski Andrzej

    2016-01-01

    Full Text Available The paper describes the main types of existing copper deposits in the world and the most common enrichment technologies. The characteristic elements of the current flowsheet of the Polish ore beneficiation were discussed together with the reasons for using them. The paper presents a perspective flowsheet based on more than 50-years of experience in beneficiation of Polish copper ore. The main elements of proposed technology are: leaving in justified cases the division of ore into fractions of increased sandstone and carbonate ores content, flotation in the milling circuit as part of the effective preparation of the ore to rougher flotation, intensive rougher flotation, classic cleaning system, processing of the middlings with grinding system in new type mills, classification and flotation with outlet of final tailings.

  14. Isotopic tracing of ore-forming source materials for Dexing porphyry copper deposit of Jiangxi, China

    Institute of Scientific and Technical Information of China (English)

    Peng QIAN; Jianjun LU

    2008-01-01

    Dexing copper deposit is the biggest porphyry copper deposit in China. By researching isotopes of C,Si and Cu from the samples of Tongchang and Fujiawu ore-field, the authors found that δ13CPDB values of siderite were close to the δ13CPDB value of original magma; δ30Si values of the samples at the ore-forming stage were close to the δ30Si value range of magma, δ30Si values of partial samples were far away from it; Cu isotopic compositions of massive chalcopyrite formed at the early ore-forming stage are higher than that of veinal chalcopyrite formed at the later ore-forming stage. The results show that ore-forming materials were mainly derived from the porphyry body, and part of them were from wall rock materials.

  15. Iron ore tailings used for the preparation of cementitious material by compound thermal activation

    Institute of Scientific and Technical Information of China (English)

    Zhong-lai Yi; Heng-hu Sun; Xiu-quan Wei; Chao Li

    2009-01-01

    In the background of little reuse and large stockpile for iron ore railings, iron ore tailing from Chinese Tonghua were used as raw material to prepare cementitious materials. Cementitious properties of the iron ore tailings activated by compound thermal ac-tivation were studied. Testing methods, such as XRD, TG-DTA, and IR were used for researching the phase and structure variety of the iron ore tailings in the process of compound thermal activation. The results reveal that a new cementitious material that contains 30wt% of the iron ore tailings can be obtained by compounded thermal activation, whose mortar strength can come up to the stan-dard of 42.5 cement of China.

  16. Genetic characteristics of fluid inclusions in sphalerite from the Silesian-Cracow ores, Poland

    Science.gov (United States)

    Kozlowski, A.; Leach, D.L.; Viets, J.G.

    1996-01-01

    Fluid inclusion studies in sphalerite from early-stage Zn-Pb mineralization in the Silesian-Cracow region (southern Poland), yielded homogenization temperatures (Th) from 80 to 158??C. Vertical thermal gradient of the parent fluids was 6 to 10??C, and the ore crystallization temperature ranges varied from recrystallization of ores, and Th distribution in single fissure fillings were considered. The ore-forming fluids were liquid-hydrocarbon-bearing aqueous solutions of Na-Ca-Cl type with lower Ca contents in the south and higher Ca contents in the north of the region. The ore-forming fluids had salinities from nul to about 23 weight percent of NaCl equivalent. Three types of fluids were recognized, that mixed during ore precipitation: a) ascending fluids of low-to-moderate salinity and high, b) formation brines of high salinity and moderate Th, and c) descending waters of low salinity and low-to-moderate Th.

  17. Butyl rubber O-ring seals: Revision of test procedures for stockpile materials

    Energy Technology Data Exchange (ETDEWEB)

    Domeier, L.A.; Wagter, K.R.

    1996-12-01

    Extensive testing showed little correlation between test slab and O-ring performance. New procedures, comparable to those used with the traditional test slabs, were defined for hardness, compression set, and tensile property testing on sacrificial O-ring specimens. Changes in target performance values were made as needed and were, in one case, tightened to reflect the O-ring performance data. An additional study was carried out on O-ring and slab performance vs cure cycle and showed little sensitivity of material performance to large changes in curing time. Aging and spectra of certain materials indicated that two sets of test slabs from current vendor were accidently made from EPDM rather than butyl rubber. Random testing found no O-rings made from EPDM. As a result, and additional spectroscope test will be added to the product acceptance procedures to verify the type of rubber compound used.

  18. EXPERIMENTAL STUDY ON THE LOAD DECAY AND ITS EFFECT ON LEAK RATE OF O-RING

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Experimental studies on load decay and leak rate of O-rings made of two kinds of silicone rubber are conducted. The results show that the characteristic of load decay is relative to the material and temperature of O-rings; the rate of load decay increases with the rise of temperature; the effects of load decay on leak rate of O-rings are negligible at room temperature, but they are notable at high temperature, and they are related to the material of O-rings. On the basis of study on the theory of load decay and analysis to the results of experiments, a theoretical model is developed to describe the load decay characteristic of O-rings, and it matches the experimental data very well. By the study of time-temperature equivalence of load decay, the interconvertting equation of test data of load decay at different temperatures is obtained.

  19. Thermodynamic Analysis of the Selective Reduction of a Nickeliferous Limonitic Laterite Ore by Hydrogen

    Science.gov (United States)

    Elliott, R.; Pickles, C. A.

    2017-09-01

    Nickeliferous limonitic laterite ores are becoming increasingly attractive as a source of metallic nickel as the costs associated with recovering nickel from the sulphide ores increase. Unlike the sulphide ores, however, the laterite ores are not amenable to concentration by conventional mineral processing techniques such as froth flotation. One potential concentrating method would be the pyrometallurgical solid state reduction of the nickeliferous limonitic ores at relatively low temperatures, followed by beneficiation via magnetic separation. A number of reductants can be utilized in the reduction step, and in this research, a thermodynamic model has been developed to investigate the reduction of a nickeliferous limonitic laterite by hydrogen. The nickel recovery to the ferronickel phase was predicted to be greater than 95 % at temperatures of 673-873 K. Reductant additions above the stoichiometric requirement resulted in high recoveries over a wider temperature range, but the nickel grade of the ferronickel decreased.

  20. Discovery of the superlarge gallium ore deposit in Jungar, Inner Mongolia, North China

    Institute of Scientific and Technical Information of China (English)

    DAI Shifeng; REN Deyi; LI Shengsheng

    2006-01-01

    Mineralogy and geochemistry of No.6 Coal from the Heidaigou Mine of the Jungar Coalfield of North China were studied using instrumental neutron activation analysis, inductively coupled-plasma mass spectroscopy, X-ray fluorescence spectrometry, and scanning electron microscope equipped with an energy-dispersive X-ray spectrometer. The results show that gallium concentration is as high as 44.8 μg·g-1 in the whole coal-channel sample, and varies from 30.1 μg·g-1 to 76.0 μg·g-1 (mean 51.9 μg·g-1) in the main minable benches of No.6 Coal. Such high concentration of Ga in the coal is far higher than the industrial grade (30 μg·g-1). The thickness of the main minable benches accounts for 81.9% of the whole coal bed. The laboratory high-temperature ashes (550℃) of the main minable coal benches also contain a high concentration of Ga, varying from 62.2 μg·g-1 to 178 μg·gμ1, with an average of 89.2 μg·g-1. The boehmite significantly enriched in No.6 Coal is the main carrier of the high Ga in the coal. Average concentration of Ga in boehmite is 0.09%. The average content of boehmite is 6.1% in the whole coal and 7.5% in the main minable benches. Boehmite is derived from the bauxite in the weathered crust of the underlying Benxi Formation in the north of the basin during the peat accumulation. The colloidal idrargillite had been shortly transported from the weathered crust to the peat mire, and owing to the compaction of the overlying strata during the peat accumulation and early diagenesis, the idrargillite colloid had begun to be dehydrated, leading to boehmite formation. A preliminary estimation showed that the ensured and prospected reserves of Ga in No.6 Coal are up to 6.3×104t and 8.57×105t, indicating a superlarge gallium ore deposit. The particular paleogeography of the Jungar Coalfield and the peculiar carrier of Ga in coal suggest that this Ga ore deposit is unique in the world. Rare earth elements are also enriched in coal and laboratory ashes

  1. Role of minerals properties on leaching process of weathered crust elution-deposited rare earth ore

    Institute of Scientific and Technical Information of China (English)

    肖燕飞; 刘向生; 冯宗玉; 黄小卫; 黄莉; 陈迎迎; 吴文远

    2015-01-01

    Granite belonged to intrusive rock and volcanic was extrusive rock. There may be many differences in their degree of weathering and mineral chemical composition. The present study investigated the minerals properties and the leaching mechanism of the granitic weathered crust elution-deposited rare earth ore from Longnan Rare Earth Mine area (LN ores) and volcanic weathered crust elution-deposited rare earth ore from Liutang Rare Earth Mine area (LT ores). The X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) were used to characterize the phase of rare earth ores. The particle size distributions and main composition of the ore were also presented in this paper. The leaching mechanisms of two kinds of rare earth ores were analyzed with different kinetics models and could be described by the shrinking-core model. They were all inner diffusion-controlled leaching processes. The leaching equation of the kinetics of the LN ores could be expressed as:4 LN LN 1.096 10 2/3 0.377 8.314 0 2 3=0.1061 (1 ) Tr e tη η×−−− − −, leaching equation of kinetics of LT ores was 3 LT LT 4.640 10 2/3 0.411 8.314 0 32 3=8.33 101 (1 ) Tr e tη η×−− −×− − −. The rare earth leaching rate of LT ores was always lower in the same condition, and it would need more time and more (NH4)2SO4 consump-tion to achieve the same rare earth leaching efficiency, which would lead to more serious ammonia-nitrogen pollution. Therefore, magnesium salt was proposed as the leaching agent to eliminate ammonia-nitrogen pollution and further studies would be taken in the future.

  2. The Mechanism on Biomass Reduction of Low-Grade Manganese Dioxide Ore

    Science.gov (United States)

    Zhang, Honglei; Zhu, Guocai; Yan, Hong; Li, Tiancheng; Zhao, Yuna

    2013-08-01

    The mechanism on biomass reduction of low-grade manganese dioxide ore was studied by investigating influence factors on manganese recovery degree, such as the reaction temperature, time, biomass/ore ratio, compositions of biomass, nitrogen flow rate, and particle size of raw materials, and it was further identified through analysis of gas composition in the outlet gas, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) for the reduced sample. The results show that the reduction process involved mainly two steps: (1) The biomass was first pyrolyzed to release reductive volatiles and (2) manganese oxide ore was reacted with the reductive volatiles. By an analysis of gas composition in the outlet gas, it was also found that the ratio of biomass/ore had an important effect on the reduction mechanism. With a low biomass/ore ratio of 0.5:10, the reducing reaction of the reductive volatiles with manganese dioxide ore proceeded mainly in two stages: (1) The condensable volatiles (tar) released from biomass pyrolysis reacted with manganese oxide ore to produce reductive noncondensable gases such as hydrogen, carbon monoxide, and some light hydrocarbons; and (2) the small molecule gases further participated in the reduction. XRD pattern analysis on the reduced manganese dioxide ore revealed that the process of biomass reduction of manganese ore underwent in phases (MnO2 → Mn3O4 → MnO). The kinetics study showed the reduction process was controlled by a gas-solid reaction between biomass volatiles and manganese oxide ore with activation energy E of 53.64 kJ mol-1 and frequency factor A of 5.45 × 103 minutes-1.

  3. 20 CFR 404.1084 - Gain or loss from disposition of property; capital assets; timber, coal, and iron ore...

    Science.gov (United States)

    2010-04-01

    ...; capital assets; timber, coal, and iron ore; involuntary conversion. 404.1084 Section 404.1084 Employees... from disposition of property; capital assets; timber, coal, and iron ore; involuntary conversion. (a... disposal of iron ore mined in the United States, even if held primarily for sale to customers, if section...

  4. 78 FR 47317 - Ore Knob Mine Superfund Site; Laurel Springs, Ashe County, North Carolina; Notice of Settlement

    Science.gov (United States)

    2013-08-05

    ... AGENCY Ore Knob Mine Superfund Site; Laurel Springs, Ashe County, North Carolina; Notice of Settlement... Protection Agency has entered into a settlement with Herbert N. Francis concerning the Ore Knob Mine... comments by site name ``Ore Knob Mine Superfund Site'' by one of the following methods:...

  5. Great Lakes Teacher's Guide.

    Science.gov (United States)

    Reid, Ron

    The Great Lakes are one of the world's greatest reservoirs of fresh water, the foundation of Ontario's economic development, a primary force in ecological systems, and a base for pleasure and recreation. They are also a magnificent resource for the teachers of Ontario. Study of the Great Lakes can bring to life the factors that shape the ecology…

  6. Marine lakes of Indonesia

    NARCIS (Netherlands)

    Becking, Leontine Elisabeth

    2012-01-01

    The objective of this thesis was to obtain insight into the processes that play a role in biodiversity patterns of tropical marine species by using marine lakes as a model. Marine lakes are landlocked water bodies that maintain a marine character through narrow submarine connections to the sea. Two

  7. The Great Lakes.

    Science.gov (United States)

    Seasons, 1987

    1987-01-01

    The Great Lakes are one of the world's greatest reserviors of fresh water, the foundation of Ontario's economic development, a primary force in ecological systems, and a base for pleasure and recreation. These lakes and their relationship with people of Canada and the United States can be useful as a subject for teaching the impact of human…

  8. Marine lakes of Indonesia

    NARCIS (Netherlands)

    Becking, Leontine Elisabeth

    2012-01-01

    The objective of this thesis was to obtain insight into the processes that play a role in biodiversity patterns of tropical marine species by using marine lakes as a model. Marine lakes are landlocked water bodies that maintain a marine character through narrow submarine connections to the sea. Two

  9. Lake trout in northern Lake Huron spawn on submerged drumlins

    Science.gov (United States)

    Riley, Stephen C.; Binder, Thomas; Wattrus, Nigel J.; Faust, Matthew D.; Janssen, John; Menzies, John; Marsden, J. Ellen; Ebener, Mark P.; Bronte, Charles R.; He, Ji X.; Tucker, Taaja R.; Hansen, Michael J.; Thompson, Henry T.; Muir, Andrew M.; Krueger, Charles C.

    2014-01-01

    Recent observations of spawning lake trout Salvelinus namaycush near Drummond Island in northern Lake Huron indicate that lake trout use drumlins, landforms created in subglacial environments by the action of ice sheets, as a primary spawning habitat. From these observations, we generated a hypothesis that may in part explain locations chosen by lake trout for spawning. Most salmonines spawn in streams where they rely on streamflows to sort and clean sediments to create good spawning habitat. Flows sufficient to sort larger sediment sizes are generally lacking in lakes, but some glacial bedforms contain large pockets of sorted sediments that can provide the interstitial spaces necessary for lake trout egg incubation, particularly if these bedforms are situated such that lake currents can penetrate these sediments. We hypothesize that sediment inclusions from glacial scavenging and sediment sorting that occurred during the creation of bedforms such as drumlins, end moraines, and eskers create suitable conditions for lake trout egg incubation, particularly where these bedforms interact with lake currents to remove fine sediments. Further, these bedforms may provide high-quality lake trout spawning habitat at many locations in the Great Lakes and may be especially important along the southern edge of the range of the species. A better understanding of the role of glacially-derived bedforms in the creation of lake trout spawning habitat may help develop powerful predictors of lake trout spawning locations, provide insight into the evolution of unique spawning behaviors by lake trout, and aid in lake trout restoration in the Great Lakes.

  10. Paleoenvironments, Evolution, and Geomicrobiology in a Tropical Pacific Lake: The Lake Towuti Drilling Project (TOWUTI)

    Science.gov (United States)

    Vogel, Hendrik; Russell, James M.; Bijaksana, Satria; Crowe, Sean; Fowle, David; Haffner, Douglas; King, John; Marwoto, Ristiyanti; Melles, Martin; von Rintelen, Thomas; Stevenson, Janelle; Watkinson, Ian; Wattrus, Nigel

    2014-05-01

    drying between ~33,000 and 16,000 yr BP when high-latitude ice sheets expanded and global temperatures cooled. This in combination with the observed little direct influence of precessional orbital forcing and exposure of the Sunda Shelf implies that central Indonesian hydroclimate varies strongly in response to high-latitude climate forcing: a hypothesis we aim to test across multiple glacial-interglacial cycles through scientific drilling. Indeed, numerous high-amplitude reflectors in the upper 150 m of lacustrine fill suggest repeated cycles of moisture-balance variations in the tropical Pacific. In summary drilling in Lake Towuti will help to: (1) Document the timing, frequency, and amplitude of orbital- to millennial-scale changes in surface hydrology and terrestrial temperature in the Indo-Pacific Warm Pool across multiple glacial-interglacial cycles; (2) Understand how variations in terrestrial hydrology and temperature in central Indonesia respond to changes in the mean state of the ENSO system, the monsoons, high-latitude forcing, and insolation; (3) Analyze the long-term stability and resilience of rainforest vegetation to changes in climate, greenhouse gases, and fire frequency; (4) Study the extent, biogeography, and metabolism of microbial life in the sediments of a non-sulfidic, ferrginous basin, and their relationships to carbon cycling, redox metal deposition, and the concentration of metal ore minerals; (5) Study the effects of climate-driven changes in the aquatic environment on both lacustrine microbial populations, and the geobiosphere within the lake's sediment; (6) Determine the age of Lake Towuti, and the ensuing rates of speciation of Towuti's endemic fauna and flora; (7) Identify the timing of past lake level fluctuations in Towuti, changes in hydrological connections among the Malili Lakes, and how these influenced biological colonization events, habitat stability, and modes of speciation (sympatric, allopatric). Important milestones concerning

  11. AGING PERFORMANCE OF MODEL 9975 PACKAGE FLUOROELASTOMER O-RINGS

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, E.; Daugherty, W.; Skidmore, E.; Dunn, K.; Fisher, D.

    2011-05-31

    The influence of temperature and radiation on Viton{reg_sign} GLT and GLT-S fluoroelastomer O-rings is an ongoing research focus at the Savannah River National Laboratory. The O-rings are credited for leaktight containment in the Model 9975 shipping package used for transportation of plutonium-bearing materials. At the Savannah River Site, the Model 9975 packages are being used for interim storage. Primary research efforts have focused on surveillance of O-rings from actual packages, leak testing of seals at bounding aging conditions and the effect of aging temperature on compression stress relaxation behavior, with the goal of service life prediction for long-term storage conditions. Recently, an additional effort to evaluate the effect of aging temperature on the oxidation of the materials has begun. Degradation in the mechanical properties of elastomers is directly related to the oxidation of the polymer. Sensitive measurements of the oxidation rate can be performed in a more timely manner than waiting for a measurable change in mechanical properties, especially at service temperatures. Measuring the oxidation rate therefore provides a means to validate the assumption that the degradation mechanisms(s) do not change from the elevated temperatures used for accelerated aging and the lower service temperatures. Monitoring the amount of oxygen uptake by the material over time at various temperatures can provide increased confidence in lifetime predictions. Preliminary oxygen consumption analysis of a Viton GLT-based fluoroelastomer compound (Parker V0835-75) using an Oxzilla II differential oxygen analyzer in the temperature range of 40-120 C was performed. Early data suggests oxygen consumption rates may level off within the first 100,000 hours (10-12 years) at 40 C and that sharp changes in the degradation mechanism (stress-relaxation) are not expected over the temperature range examined. This is consistent with the known long-term heat aging resistance of

  12. Formation conditions of high-grade gold-silver ore of epithermal Tikhoe deposit, Russian Northeast

    Science.gov (United States)

    Volkov, A. V.; Kolova, E. E.; Savva, N. E.; Sidorov, A. A.; Prokof'ev, V. Yu.; Ali, A. A.

    2016-09-01

    The Tikhoe epithermal deposit is located in the Okhotsk-Chukotka volcanic belt (OChVB) 250 km northeast of Magadan. Like other deposits belonging to the Ivan'insky volcanic-plutonic depression (VTD), the Tikhoe deposit is characterized by high-grade Au-Ag ore with an average Au grade of 23.13 gpt Au and Au/Ag ratio varying from 1: 1 to 1: 10. The detailed explored Tikhoe-1 orebody is accompanied by a thick (20 m) aureole of argillic alteration. Pyrite is predominant among ore minerals; galena, arsenopyrite, sphalerite, Ag sulfosalts, fahlore, electrum, and küstelite are less abundant. The ore is characterized by abundant Sebearing minerals. Cu-As geochemical specialization is noted for silver minerals. Elevated Se and Fe molar fractions of the main ore minerals are caused by their formation in the near-surface argillic alteration zone. The veins and veinlets of the Tikhoe-1 ore zone formed stepwise at a temperature of 230 to 105°C from Nachloride solution enriched in Mg and Ca cations with increasing salinity. The parameters of the ore-forming fluid correspond to those of epithermal low-sulfidation deposits and assume the formation of high-grade ore under a screening unit of volcanic rocks. In general, the composition of the ore-forming fluid fits the mineralogy and geochemistry of ore at this deposit. The similarity of the ore composition and parameters of the ore-forming fluid between the Tikhoe and Julietta deposits is noteworthy. Meanwhile, differences are mainly related to the lower temperature and fluid salinity at the Julietta deposit with respect to the Tikhoe deposit. The fluid at the Julietta deposit is depleted in most components compared with that at the Tikhoe deposit except for Sb, Cd, and Ag. The results testify to a different erosion level at the deposits as derivatives of the same ore-forming system. The large scale of the latter allows us to predict the discovery of new high-grade objects, including hidden mineralization, which is not exposed at

  13. Lake metabolism scales with lake morphometry and catchment conditions

    DEFF Research Database (Denmark)

    Stæhr, Peter A.; Baastrup-Spohr, Lars; Jensen, Kaj Sand;

    2012-01-01

    We used a comparative data set for 25 lakes in Denmark sampled during summer to explore the influence of lake morphometry, catchment conditions, light availability and nutrient input on lake metabolism. We found that (1) gross primary production (GPP) and community respiration (R) decline with lake...... area, water depth and drainage ratio, and increase with algal biomass (Chl), dissolved organic carbon (DOC) and total phosphorus (TP); (2) all lakes, especially small with less incident light, and forest lakes with high DOC, have negative net ecosystem production (NEP ... decreases with lake area and water depth as a consequence of lower input of nutrients and organic matter per unit water volume; (4) the influence of benthic processes on free water metabolic measures declines with increasing lake size; and (5) with increasing lake size, lake metabolism decreases...

  14. Bacterial Carriers for Glioblastoma Therapy

    Directory of Open Access Journals (Sweden)

    Nalini Mehta

    2017-03-01

    Full Text Available Treatment of aggressive glioblastoma brain tumors is challenging, largely due to diffusion barriers preventing efficient drug dosing to tumors. To overcome these barriers, bacterial carriers that are actively motile and programmed to migrate and localize to tumor zones were designed. These carriers can induce apoptosis via hypoxia-controlled expression of a tumor suppressor protein p53 and a pro-apoptotic drug, Azurin. In a xenograft model of human glioblastoma in rats, bacterial carrier therapy conferred a significant survival benefit with 19% overall long-term survival of >100 days in treated animals relative to a median survival of 26 days in control untreated animals. Histological and proteomic analyses were performed to elucidate the safety and efficacy of these carriers, showing an absence of systemic toxicity and a restored neural environment in treated responders. In the treated non-responders, proteomic analysis revealed competing mechanisms of pro-apoptotic and drug-resistant activity. This bacterial carrier opens a versatile avenue to overcome diffusion barriers in glioblastoma by virtue of its active motility in extracellular space and can lead to tailored therapies via tumor-specific expression of tumoricidal proteins.

  15. Low-cost carriers fare competition effect

    NARCIS (Netherlands)

    Carmona Benitez, R.B.; Lodewijks, G.

    2010-01-01

    This paper examines the effects that low-cost carriers (LCC’s) produce when entering new routes operated only by full-service carriers (FSC’s) and routes operated by low-cost carriers in competition with full-service carriers. A mathematical model has been developed to determine what routes should b

  16. Standard practices for sampling uranium-Ore concentrate

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 These practices are intended to provide the nuclear industry with procedures for obtaining representative bulk samples from uranium-ore concentrates (UOC) (see Specification C967). 1.2 These practices also provide for obtaining a series of representative secondary samples from the original bulk sample for the determination of moisture and other test purposes, and for the preparation of pulverized analytical samples (see Test Methods C1022). 1.3 These practices consist of a number of alternative procedures for sampling and sample preparation which have been shown to be satisfactory through long experience in the nuclear industry. These procedures are described in the following order. Stage Procedure Section Primary Sampling One-stage falling stream 4 Two-stage falling stream 5 Auger 6 Secondary Sampling Straight-path (reciprocating) 7 Rotating (Vezin) 8, 9 Sample Preparation 10 Concurrent-drying 11-13 Natural moisture 14-16 Calcination 17, 18 Sample Packaging 19 Wax s...

  17. Spatial data mining system for ore-forming prediction

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The authors designed the spatial data mining system for ore-forming prediction based on the theory and methods of data mining as well as the technique of spatial database, in combination with the characteristics of geological information data. The system consists of data management, data mining and knowledge discovery, knowledge representation. It can syncretize multi-source geosciences data effectively, such as geology,geochemistry, geophysics, RS. The system digitized geological information data as data layer files which consist of the two numerical values, to store these files in the system database. According to the combination of the characters of geological information, metallogenic prognosis was realized, as an example from some area in Heilongjiang Province. The prospect area of hydrothermal copper deposit was determined.

  18. Molybdenum removal from copper ore concentrate by sodium hypochlorite leaching

    Institute of Scientific and Technical Information of China (English)

    Liu Youcai; Zhong Hong; Cao Zhanfang

    2011-01-01

    The removal of molybdenum from a copper ore concentrate by sodium hypochlorite leaching was investigated. The results show that leaching time, liquid to solid ratio, leaching ternperature, agitation speed, and sodium hypochlorite and sodium hydroxide concentrations all have a significant effect on the removal of molybdenum. The optimum process operating parameters were found to be: time, 4 h: sodium hydroxide concentration, 10%; sodium hypochlorite concentration, 8%; liquid to solid ratio, 10:1; temperature, 50℃; and,agitation speed, 500 r/min. Under these conditions the extraction of molybdenum is greater than 99.9% and the extraction of copper is less than 0.01%. A shrinking particle model could be used to describe the leaching process. The apparent activation energy of the dissolution reaction was found to be approximately 8.8 kJ/mol.

  19. Amalgamated Products of Ore and Quadratic Extensions of Rings

    CERN Document Server

    Johnson, Garrett

    2012-01-01

    We study the ideal theory of amalgamated products of Ore and quadratic extensions over a base ring R. We prove an analogue of the Hilbert Basis theorem for an amalgamated product Q of quadratic extensions and determine conditions for when the one-sided ideals of Q are principal or doubly-generated. We also determine conditions that make Q a principal ideal ring. Finally, we show that the double affine Hecke algebra $H_{q,t}$ associated to the general linear group GL_2(k) (here, k is a field with characteristic not 2) is an amalgamated product of quadratic extensions over a three-dimensional quantum torus and give an explicit isomorphism. In this case, it follows that $H_{q,t}$ is a noetherian ring.

  20. Removal of phosphorus from iron ores by chemical leaching

    Institute of Scientific and Technical Information of China (English)

    JIN Yong-shi; JIANG Tao; YANG Yong-bin; LI Qian; LI Guang-hui; GUO Yu-feng

    2006-01-01

    Alkali-leaching and acid-leaching were proposed for the dephosphorization of Changde iron ore, which contains an average of 1.12% for phosphorus content. Sodium hydroxide, sulfuriced, hydrochloric and nitric acids were used for the preparation of leach solutions. The results show that phosphorus occurring as apatite phase could be removed by alkali-leaching, but those occurring in the iron phase could not. Sulfuric acid is the most effective among the three kinds of acid. 91.61% phosphorus removal was attained with 1% sulfuric acid after leaching for 20 min at room temperature. Iron loss during acid-leaching can be negligible, which was less than 0.25%.The pH value of solution after leaching with 1% sulfuric acid was about 0.86, which means acid would not be exhausted during the process and it could be recycled, and the recycle of sulfuric acid solution would make the dephosphorization process more economical.

  1. The North American iron ore industry: a decade into the 21st century

    Science.gov (United States)

    Jorgenson, John D.; Perez, A. A

    2011-01-01

    During the 20th century, the iron ore mining industries of Canada and the United States passed through periods of transformation. The beginning of the 21st century has seen another period of transformation, with the failure of a number of steel companies and with consolidation of control within the North American iron ore industry. Canadian and United States iron ore production and the market control structure involved are changing rapidly. Consolidation of ownership, formation of foreign joint ventures, divestitures of upstream activities by steelmakers, and industry changes to ensure availability of feedstocks all played a role in recent developments in the North American iron ore industry. Canadian and U.S. iron ore operations and their strong linkage to downstream production, although isolated, must also be considered within the context of the changing global economy. Projects using new technology to produce direct reduced iron nuggets of 96-98% iron content and other projects designed to produce steel at minesites may once again change the face of the iron ore industry. Social and environmental issues related to sustainable development have had a significant effect on the North American iron ore industry.

  2. Culturable microorganisms associated with Sishen iron ore and their potential roles in biobeneficiation.

    Science.gov (United States)

    Adeleke, Rasheed; Cloete, T E; Khasa, D P

    2012-03-01

    With one of the largest iron ore deposits in the world, South Africa is recognised to be among the top ten biggest exporters of iron ore. Increasing demand and consumption of this mineral triggered search for processing technologies, which can be utilised to "purify" the low-grade iron ore minerals that contain high levels of unwanted potassium (K) and phosphorus (P). This study investigated a potential biological method that can be further developed for the full biobeneficiation of low-grade iron ore minerals. Twenty-three bacterial strains that belong to Proteobacteria, Firmicutes, Bacteroidetes and Actinobateria were isolated from the iron ore minerals and identified with sequence homology and phylogenetic methods. The abilities of these isolates to lower the pH of the growth medium and solubilisation of tricalcium phosphate were used to screen them as potential mineral solubilisers. Eight isolates were successfully screened with this method and utilised in shake flask experiments using iron ore minerals as sources of K and P. The shake flask experiments revealed that all eight isolates have potentials to produce organic acids that aided the solubilisation of the iron ore minerals. In addition, all eight isolates produced high concentrations of gluconic acid followed by relatively lower concentrations of acetic, citric and propanoic acid. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) analyses also indicated extracellular polymeric substances could play a role in mineral solubilisation.

  3. Microwave enhanced recovery of nickel-copper ore: communition and floatability aspects.

    Science.gov (United States)

    Henda, R; Hermas, A; Gedye, R; Islam, M R

    2005-01-01

    A study describing the effect of microwave radiation, at a frequency of 2450 MHz, on the processes of communication and flotation of a complex sulphide nickel-copper ore is presented. Ore communication has been investigated under standard radiation-free conditions and after ore treatment in a radiated environment as a function of ore size, exposure time to radiation, and microwave power. The findings show that communication is tremendously improved by microwave radiation with values of the relative work index as low as 23% at a microwave power of 1.406 kW and after 10 s of exposure time. Communication is affected by exposure time and microwave power in a nontrivial manner. In terms of ore floatability, the experimental tests have been carried out on a sample of 75 microm in size under different exposure times. The results show that both ore concentrate recoveries and grades of nickel and copper are significantly enhanced after microwave treatment of the ore with relative increases in recovered concentrate, grade of nickel, and grade of copper of 26 wt%, 15 wt%, and 27%, respectively, at a microwave power of 1330 kW and after 30 s of exposure time.

  4. Selective Removal of Iron from Low-Grade Ti Ore by Reacting with Calcium Chloride

    Science.gov (United States)

    Kang, Jungshin; Okabe, Toru H.

    2017-02-01

    Recently, titanium metal production by molten salt electrolysis using CaCl2 as molten salt and TiO2 or rutile (94 to 96 pct TiO2) as feedstock has been drawing attention. However, when a low-grade Ti ore (mainly FeTiO3) is used as feedstock, removal of iron (Fe) from the ore is indispensable. In this study, the influence of reaction temperature, reaction time, particle size of the ore, and source country for the ore on the removal of iron by selective chlorination using CaCl2 was assessed. Experimental results showed that the mass percent of iron in the ore decreased from 49.7 to 1.79 pct under certain conditions by selective removal of iron as FeCl2. As a result, high-grade CaTiO3 was produced when the ore particles smaller than 74 µm reacted with CaCl2 at 1240 K (967 °C) for 8 to 10 hours. Therefore, this study demonstrates that the removal of iron from the ore is feasible through the selective chlorination process using CaCl2 by optimizing the variables.

  5. Strontium isotope geochemistry of the Lemachang independent silver ore deposit, northeastern Yunnan, China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Sr isotope geochemical studies (the 87Sr/86Sr and ?18O-87Sr/86Sr systems) on the wall rocks and ores from the Lemachang independent Ag deposit in northeastern Yunnan provide strong evidence that the ore-forming fluids had flown through radiogenetically Sr-enriched rocks or strata prior to their entry into the locus of ore precipitation, and water-rock interaction is the main mechanism of Ag ore precipitation. The radiogenetically Sr-enriched source region may be the Proterozoic basement (the Kunyang and Hekou groups). Moreover, the theoretical modeling of the Sr isotopic system indicates that the ore-forming fluids contain as much as 3×10?6 Sr with isotopic composition of Sr being 0.750 and that of oxygen 7.0‰. The ore-forming temperatures were estimated at 150-250℃ for the carbonate rock-type ores and at 200-260℃ for the clastic rock-type.

  6. Strontium isotope geochemistry of the Lemachang independent silver ore deposit, northeastern Yunnan, China

    Institute of Scientific and Technical Information of China (English)

    邓海琳; 李朝阳; 涂光炽; 周云满; 王崇武

    2000-01-01

    Sr isotope geochemical studies (the 87Sr/86Sr and δ18O-87Sr/86Sr systems) on the wall rocks and ores from the Lemachang independent Ag deposit in northeastern Yunnan provide strong evidence that the ore-forming fluids had flown through radiogenetically Sr-enriched rocks or strata prior to their entry into the locus of ore precipitation, and water-rock interaction is the main mechanism of Ag ore precipitation. The radiogenetically Sr-enriched source region may be the Proterozoic basement (the Kunyang and Hekou groups). Moreover, the theoretical modeling of the Sr isotopic system indicates that the ore-forming fluids contain as much as 3×10-6 Sr with isotopic composition of Sr being 0.750 and that of oxygen 7.0‰. The ore-forming temperatures were estimated at 150-250℃ for the carbonate rock-type ores and at 200-260℃ for the clastic rock-type.

  7. Magnetic mineralogy of the Hongqiling Cu-Ni sulphide deposit:Implications for ore genesis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Pyrrhotite is one of the common ore minerals in Cu-Ni sulphide deposits, but only monoclinic pyrrhotite is ferromagnetic at room temperature. X-ray and EPA analyses reveal that most pyrrhotite forming sideronitic texture in the Hongqiling Cu-Ni sulphide deposit is monoclinic, but that in the massive ore is a mixture of monoclinic and hexagonal pyrrhotites. Differential thermal and magneticthermogravimetric analyses of massive ore indicate a magnetic transition and heat absorption at 323℃, suggesting that this temperature is the thermomagnetic and phase transition point of pyrrhotite. For massive pyrrhotite ores heated at 400℃ for 30 h and then quenched by cool water, the monoclinic pyrrhotite (mpo) transforms completely into the hexagonal pyrrhotite (hpo). However, all the pyrrhotites resulting from slow cooling of the sample in air are mpo. These results indicate that transformation between hpo and mpo depends upon the cooling rate. Therefore, massive ores in this deposit might have been formed via rapid cooling of ore melts. On the other hand, it is significant to study the effect of the ratio of the magnetite in total ores on the genesis of magmatic Cu-Ni suphide deposits.

  8. Selective Removal of Iron from Low-Grade Ti Ore by Reacting with Calcium Chloride

    Science.gov (United States)

    Kang, Jungshin; Okabe, Toru H.

    2016-09-01

    Recently, titanium metal production by molten salt electrolysis using CaCl2 as molten salt and TiO2 or rutile (94 to 96 pct TiO2) as feedstock has been drawing attention. However, when a low-grade Ti ore (mainly FeTiO3) is used as feedstock, removal of iron (Fe) from the ore is indispensable. In this study, the influence of reaction temperature, reaction time, particle size of the ore, and source country for the ore on the removal of iron by selective chlorination using CaCl2 was assessed. Experimental results showed that the mass percent of iron in the ore decreased from 49.7 to 1.79 pct under certain conditions by selective removal of iron as FeCl2. As a result, high-grade CaTiO3 was produced when the ore particles smaller than 74 µm reacted with CaCl2 at 1240 K (967 °C) for 8 to 10 hours. Therefore, this study demonstrates that the removal of iron from the ore is feasible through the selective chlorination process using CaCl2 by optimizing the variables.

  9. A novel stress distribution analytical model of O-ring seals under different properties of materials

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Di; Wang, Shao Ping; Wang, Xing Jian [School of Automation Science and Electrical Engineering, Beihang University, Beijing (China)

    2017-01-15

    The elastomeric O-ring seals have been widely used as sealing elements in hydraulic systems. The sealing performance of O-ring seals is related to stress distribution. The stresses distribution depends on the squeeze rate and internal pressure, and would vary with properties of O-ring seals materials. Thus, in order to study the sealing performance of O-ring seals, it is necessary to describe the analytic relationship between stress distribution and properties of O-ring seals materials. For this purpose, a novel Stress distribution analytical model (SDAM) is proposed in this paper. The analytical model utilizes two stress complex functions to describe the stress distribution of O-ring seals. The proposed SDAM can express not only the analytical relationship between stress distribution and Young’s modulus, but also the one between stress distribution and Poisson’s ratio. Finally, compared results between finite element analysis and the SDAM validate that the proposed model can effectively reveal the stress distribution under different properties for O-ring materials.

  10. Iron-Ore Sintering Process Optimization / Optymalizacja Procesu Aglomeracji Rudy Żelaza

    Directory of Open Access Journals (Sweden)

    Fröhlichová M.

    2015-12-01

    Full Text Available The work deals with examination of the influence of the ratio between iron ore concentrate and iron ore on quality of produced iron ore sinter. One of the possibilities to increase iron content in sinter is the modification of raw materials ratio, when iron ore materials are added into sintering mixture. If the ratio is in favor of iron ore sinter, iron content in resulting sintering mixture will be lower. If the ratio is in favor of iron ore concentrate and recycled materials, which is more finegrained, a proportion of a fraction under 0.5 mm will increase, charge permeability property will be reduced, sintering band performance will decrease and an occurrence of solid particulate matter in product of sintering process will rise. The sintering mixture permeability can be optimized by increase of fuel content in charge or increase of sinter charge moisture. A change in ratio between concentrate and iron ore has been experimentally studied. An influence of sintering mixture grain size composition, a charge grains shape on quality and phase composition on quality of the produced iron sinter has been studied.

  11. STUDY ON BIOLEACHING OF PRIMARY CHALCOPYRITE ORE WITH THERMOACIDOPHLIC ARCHAE

    Institute of Scientific and Technical Information of China (English)

    P. Zou; W.B. Zhang; T. Lei; J.K. Wang

    2006-01-01

    A high temperature-tolerating thermoacidophilic archae (TA) was isolated from water samples collected from a hot sulfur-containing spring in the Yunnan Province, China, and was used in bioleaching experiments of a low-grade chalcopyrite ore. The TA grow at temperatures ranging from 40 to 80℃, with 65℃ being the optimum temperature, and at pH values of 1.5 to 4.0, with an optimum pH value of 2.0. The bioleaching experiments of the chalcopyrite ore were conducted in both laboratory batch bioreactors and leaching columns. The results obtained from the bioreactor experiments showed that the TA bioleaching rate of copper reached 97% for a 12-day leaching period, while the bioleaching rate was 32.43% for thiobacillus ferrooxidans (Tf) leaching for the same leaching time. In the case of column leaching, tests of a two-phase leaching (196 days), that is,a two-month (56 days) Tf leaching in the first phase, followed by a 140-day TA leaching in the second phase were performed. The average leaching rate of copper achieved for the 140-day TA leaching was 195mg/(L· d), while for the control experiments, it was as low as 78mg/(L· d) for the Tf leaching, indicating that the TA possesses a more powerful oxidizing ability to the chalcopyrite than Tf. Therefore, it is suggested that the two-phase leaching process be applied to for the heap leaching operations, whereas, the TA can be used in the second phase when the temperature inside the heap has increased, and the primary copper sulfide minerals have already been partially oxidized with Tf beforehand in the first phase.

  12. Ecology under lake ice.

    Science.gov (United States)

    Hampton, Stephanie E; Galloway, Aaron W E; Powers, Stephen M; Ozersky, Ted; Woo, Kara H; Batt, Ryan D; Labou, Stephanie G; O'Reilly, Catherine M; Sharma, Sapna; Lottig, Noah R; Stanley, Emily H; North, Rebecca L; Stockwell, Jason D; Adrian, Rita; Weyhenmeyer, Gesa A; Arvola, Lauri; Baulch, Helen M; Bertani, Isabella; Bowman, Larry L; Carey, Cayelan C; Catalan, Jordi; Colom-Montero, William; Domine, Leah M; Felip, Marisol; Granados, Ignacio; Gries, Corinna; Grossart, Hans-Peter; Haberman, Juta; Haldna, Marina; Hayden, Brian; Higgins, Scott N; Jolley, Jeff C; Kahilainen, Kimmo K; Kaup, Enn; Kehoe, Michael J; MacIntyre, Sally; Mackay, Anson W; Mariash, Heather L; McKay, Robert M; Nixdorf, Brigitte; Nõges, Peeter; Nõges, Tiina; Palmer, Michelle; Pierson, Don C; Post, David M; Pruett, Matthew J; Rautio, Milla; Read, Jordan S; Roberts, Sarah L; Rücker, Jacqueline; Sadro, Steven; Silow, Eugene A; Smith, Derek E; Sterner, Robert W; Swann, George E A; Timofeyev, Maxim A; Toro, Manuel; Twiss, Michael R; Vogt, Richard J; Watson, Susan B; Whiteford, Erika J; Xenopoulos, Marguerite A

    2017-01-01

    Winter conditions are rapidly changing in temperate ecosystems, particularly for those that experience periods of snow and ice cover. Relatively little is known of winter ecology in these systems, due to a historical research focus on summer 'growing seasons'. We executed the first global quantitative synthesis on under-ice lake ecology, including 36 abiotic and biotic variables from 42 research groups and 101 lakes, examining seasonal differences and connections as well as how seasonal differences vary with geophysical factors. Plankton were more abundant under ice than expected; mean winter values were 43.2% of summer values for chlorophyll a, 15.8% of summer phytoplankton biovolume and 25.3% of summer zooplankton density. Dissolved nitrogen concentrations were typically higher during winter, and these differences were exaggerated in smaller lakes. Lake size also influenced winter-summer patterns for dissolved organic carbon (DOC), with higher winter DOC in smaller lakes. At coarse levels of taxonomic aggregation, phytoplankton and zooplankton community composition showed few systematic differences between seasons, although literature suggests that seasonal differences are frequently lake-specific, species-specific, or occur at the level of functional group. Within the subset of lakes that had longer time series, winter influenced the subsequent summer for some nutrient variables and zooplankton biomass. © 2016 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

  13. Yellowstone Lake Nanoarchaeota

    Directory of Open Access Journals (Sweden)

    Scott eClingenpeel

    2013-09-01

    Full Text Available Considerable Nanoarchaeota novelty and diversity were encountered in Yellowstone Lake, Yellowstone National Park, where sampling targeted lake floor hydrothermal vent fluids, streamers and sediments associated with these vents, and in planktonic photic zones in three different regions of the lake. Significant homonucleotide repeats (HR were observed in pyrosequence reads and in near full-length Sanger sequences, averaging 112 HR per 1,349 bp clone and could confound diversity estimates derived from pyrosequencing, resulting in false nucleotide insertions or deletions (indels. However, Sanger sequencing of two different sets of PCR clones (110 bp, 1349 bp demonstrated that at least some of these indels are real. The majority of the Nanoarchaeota PCR amplicons were vent associated; however, curiously, one relatively small Nanoarchaeota OTU (70 pyrosequencing reads was only found in photic zone water samples obtained from a region of the lake furthest removed from the hydrothermal regions of the lake. Extensive pyrosequencing failed to demonstrate the presence of an Ignicoccus lineage in this lake, suggesting the Nanoarchaeota in this environment are associated with novel Archaea hosts. Defined phylogroups based on near full-length PCR clones document the significant Nanoarchaeota 16S rRNA gene diversity in this lake and firmly establish a terrestrial clade distinct from the marine Nanoarcheota as well as from other geographical locations.

  14. Yellowstone lake nanoarchaeota.

    Science.gov (United States)

    Clingenpeel, Scott; Kan, Jinjun; Macur, Richard E; Woyke, Tanja; Lovalvo, Dave; Varley, John; Inskeep, William P; Nealson, Kenneth; McDermott, Timothy R

    2013-01-01

    Considerable Nanoarchaeota novelty and diversity were encountered in Yellowstone Lake, Yellowstone National Park (YNP), where sampling targeted lake floor hydrothermal vent fluids, streamers and sediments associated with these vents, and in planktonic photic zones in three different regions of the lake. Significant homonucleotide repeats (HR) were observed in pyrosequence reads and in near full-length Sanger sequences, averaging 112 HR per 1349 bp clone and could confound diversity estimates derived from pyrosequencing, resulting in false nucleotide insertions or deletions (indels). However, Sanger sequencing of two different sets of PCR clones (110 bp, 1349 bp) demonstrated that at least some of these indels are real. The majority of the Nanoarchaeota PCR amplicons were vent associated; however, curiously, one relatively small Nanoarchaeota OTU (71 pyrosequencing reads) was only found in photic zone water samples obtained from a region of the lake furthest removed from the hydrothermal regions of the lake. Extensive pyrosequencing failed to demonstrate the presence of an Ignicoccus lineage in this lake, suggesting the Nanoarchaeota in this environment are associated with novel Archaea hosts. Defined phylogroups based on near full-length PCR clones document the significant Nanoarchaeota 16S rRNA gene diversity in this lake and firmly establish a terrestrial clade distinct from the marine Nanoarcheota as well as from other geographical locations.

  15. Numerical Modelling of Ore-forming Dynamics of Fractal Dispersive Fluid Systems

    Institute of Scientific and Technical Information of China (English)

    邓军; 方云; 杨立强; 杨军臣; 孙忠实; 王建平; 丁式江; 王庆飞

    2001-01-01

    Based on an analysis of the fractal structures and mass transport mechanism of typical shear-fluid-ore formation system, the fractal dispersion theory of the fluid system was used in the dynamic study of the ore formation system. The model of point-source diffusive illuviation of the shear-fluid-ore formation system was constructed, and the numerical simulation of dynamics of the ore formation system was finished. The result shows that: (1) The metallogenic system have nested fractal structure. Different fractal dimension values in different systems show unbalance and inhomogeneity of ore-forming processes in the geohistory. It is an important parameter to symbolize the process of remobilization and accumulation of ore-forming materials. Also it can indicate the dynamics of the metallogenic system quantitatively to some extent. (2) In essence, the fractal dispersive ore-forming dynamics is a combination of multi-processes dominated by fluid dynamics and supplemented by molecule dispersion in fluids and fluid-rock interaction. It changes components and physico-chemical properties of primary rocks and fluids, favouring deposition and mineralization of ore-forming materials. (3) Gold ore-forming processes in different types of shear zones are quite different. (1) In a metallogenic system with inhomogeneous volumetric change and inhomogeneous shear, mineralization occurs in structural barriers in the centre of a shear zone and in geochemical barriers in the shear zone near its boundaries. But there is little possibility of mineralization out of the shear zone. (2) As to a metallogenic system with inhomogeneous volumetric change and simple shear, mineralization may occur only in structural barriers near the centre of the shear zone. (3) In a metallogenic system with homogeneous volumetric change and inhomogeneous shear, mineralization may occur in geochemical barriers both within and out of the shear zone.

  16. Thickening and rheological properties of slurries as functions of the oxidized nickel ore composition

    Science.gov (United States)

    Serova, N. V.; Olyunina, T. V.; Lysykh, M. P.; Ermishkin, V. A.; Smirnova, V. B.

    2016-07-01

    The thickening and rheological properties of ore slurries and pulps after autoclave sulfuric acid leaching are analyzed as a function of the phase composition of oxidized nickel ore. Experiments have been carried out with samples of ferrous, silicate and combined ores. The initial concentration of the ore slurries is ˜28%. Higher values of thickening properties (thickening rate of 1.3 m/day, thickened layer concentration of 54%) are exhibited by the ferrous ore slurry and the pulp after its leaching (thickening rate of 0.9 m/day, thickened layer concentration of 42%). The thickening rate of silicate ore slurry is 0.15-0.2 m/day, the thickened layer concentration is 40-45%. The thickening properties of the pulp after autoclave sulfuric acid leaching of silicate ore strongly depend on the consumption of sulfuric acid. The thickening properties of combined ore and pulps after its leaching deteriorate with increase in the content of silicon dioxide in the ore. In terms of the rheological properties, all slurries are pseudoplastic systems. Poorly thickening slurries are characterized by a high dynamic yield stress (up to 7 Pa) and apparent plastic and effective viscosities. The effective viscosity at the equivalent shear rate corresponding to the mixer rotation rate in laboratory autoclave reaches 34 × 10-3 Pa s. Boundary values are determined in rheological constants with regard to the thickening properties. For instance, if the dynamic yield point is 1.0 Pa, the thickening rate decreases from 0.075 m/day to zero. The thickening and rheological properties are found to depend on the particle size of solid phase and its surface properties.

  17. Ecology of playa lakes

    Science.gov (United States)

    Haukos, David A.; Smith, Loren M.

    1992-01-01

    Between 25,000 and 30,000 playa lakes are in the playa lakes region of the southern high plains (Fig. 1). Most playas are in west Texas (about 20,000), and fewer, in New Mexico, Oklahoma, Kansas, and Colorado. The playa lakes region is one of the most intensively cultivated areas of North America. Dominant crops range from cotton in southern areas to cereal grains in the north. Therefore, most of the native short-grass prairie is gone, replaced by crops and, recently, grasses of the Conservation Reserve Program. Playas are the predominant wetlands and major wildlife habitat of the region.More than 115 bird species, including 20 species of waterfowl, and 10 mammal species have been documented in playas. Waterfowl nest in the area, producing up to 250,000 ducklings in wetter years. Dominant breeding and nesting species are mallards and blue-winged teals. During the very protracted breeding season, birds hatch from April through August. Several million shorebirds and waterfowl migrate through the area each spring and fall. More than 400,000 sandhill cranes migrate through and winter in the region, concentrating primarily on the larger saline lakes in the southern portion of the playa lakes region.The primary importance of the playa lakes region to waterfowl is as a wintering area. Wintering waterfowl populations in the playa lakes region range from 1 to 3 million birds, depending on fall precipitation patterns that determine the number of flooded playas. The most common wintering ducks are mallards, northern pintails, green-winged teals, and American wigeons. About 500,000 Canada geese and 100,000 lesser snow geese winter in the playa lakes region, and numbers of geese have increased annually since the early 1980’s. This chapter describes the physiography and ecology of playa lakes and their attributes that benefit waterfowl.

  18. ON SOME KEY GEOLOGICAL PROBLEMS RELATED TO THE LINGLONG-JIAOJIA ORE-CENTRALIZED DISTRICT IN SHANDONG PROVINCE, CHINA

    Institute of Scientific and Technical Information of China (English)

    WANG Jincao; XIA Bin; TANG Jingru

    2003-01-01

    The Lingtong-Jiaojia ore-centralized district is controlled by the tectonic stress field characterized bY the combination of extension and strike-slip, and the dip, dip angle, pitch and pitch angle of the ore bodies are all constrained by the dynamic conditions of the tectonics. The metallotectonic series for the ore-centralized district belong to the type of a combination of extension and strike-slip and can be subdivided into four sub-series. The ore-forming process in the brittle regime can be disintegrated into two stages, i.e., the embryonic fracture stage and the megascopic fracture stage, and ore-forming process is rather common in the ore-centralized district at the former stage. Moreover, several key structural patterns and their features were discussed and a preliminary assessment about the ore-forming prospect in this district was made in the paper.

  19. A study on iron ore transportation model with penalty value of transportation equipment waiting

    Directory of Open Access Journals (Sweden)

    Kailing Pan

    2017-03-01

    Full Text Available As some steel enterprises are at a disadvantage in the choice of the mode of transportation, this paper made further studies of the characteristics of the iron ore logistics, taking comprehensive consideration of optimizing the waiting time under the conditions with limited loading capacity and setting up a procedural model of the iron ore logistics system with minimum cost of transportation, storage, loading, unloading, and transportation equipment waiting. Finally, taking the iron ore transport system of one steel enterprise as example, the solution and the validity of the model were analyzed and verified in this paper.

  20. Da identidade açoriana ao consumo da marca Açores

    OpenAIRE

    Negalha, Raquel Raposo

    2015-01-01

    Dissertação de Mestrado, Sociologia, 24 de Setembro de 2015, Universidade dos Açores. O presente Projeto de Dissertação insere-se na área da sociologia do consumo intitulada Da Identidade Açoriana ao Consumo da Marca Açores. A pertinência da mesma prende-se com o facto de o Projeto “Marca Açores” desenvolvido pela Sociedade para o Desenvolvimento dos Açores (SDEA) ser uma novidade para as empresas que se encontram interessadas em incutir o selo da mesma nos seus produtos de modo a que este...

  1. Application of LANDSAT satellite imagery for iron ore prospecting in the Western Desert of Egypt

    Science.gov (United States)

    Elshazly, E. M.; Abdelhady, M. A.; Elghawaby, M. A.; Khawasik, S. M.

    1977-01-01

    Prospecting for iron ore occurrences was conducted by the Remote Sensing Center in Bahariya Oasis-El Faiyum area covering some 100,000 km squared in the Western Desert of Egypt. LANDSAT-1 satellite images were utilized as the main tool in the regional prospecting of the iron ores. The delineation of the geological units and geological structure through the interpretation of the images corroborated by field observations and structural analysis led to the discovery of new iron ore occurrences in the area of investigation.

  2. Innovative application of mathematical methods in evaluation of ore raw materials for production of iron

    Directory of Open Access Journals (Sweden)

    P. Besta

    2014-01-01

    Full Text Available Current principles of evaluation of ore raw materials are usually based on a comparison of selected isolated criteria. Today‘s sophisticated technological level of blast furnace process requires the introduction of raw material indicators that provide global characteristics of their quality. This can´t be realized with isolated parameters only. The evaluation should incorporate the key characteristics of iron ore and convert them into a uniform evaluation parameter. This article analyzes the use of mathematical methods in the evaluation of the quality of ore raw materials.

  3. AMS of natural 236U and 239Pu produced in uranium ores

    Science.gov (United States)

    Wilcken, K. M.; Barrows, T. T.; Fifield, L. K.; Tims, S. G.; Steier, P.

    2007-06-01

    The rare isotopes 236U and 239Pu are produced naturally by neutron capture in uranium ores. Here we measure 236U and 239Pu by accelerator mass spectrometry (AMS) in the same ore samples for the first time. To ensure efficient extraction of both elements and isotopic equilibrium between the 239Pu in the ore and a 242Pu spike, we developed a new sample preparation protocol. AMS has clear advantages over previous methods because it achieves better discrimination against molecular interferences with higher sensitivity and shorter counting times. Measurements of 236U and 239Pu hold considerable promise as proxy indicators of neutron flux and uranium concentration.

  4. TWO-DIMENSIONAL AXISYMMETRIC MODELING OF COMBUSTION IN AN IRON ORE SINTERING BED

    DEFF Research Database (Denmark)

    Lafmejani, Saeed Sadeghi; Davazdah Emami, Mohsen; Panjehpour, Masoud;

    2013-01-01

    A twodimensional model, based on conservation of mass, momentum and energy equations, is represented in this paper in which the coke combustion process, for iron ore sintering in a packed bed, is simulated numerically. The aforementioned packed bed consists of iron ore, coke, limestone and moisture...... of species are solved numerically by using a computational fluid dynamics code in a discrete solving domain. Modeling of iron ore sintering has complex and various features like coke combustion, complicated physical changes of solid phase particles and different modes of heat transfer, for example convection...

  5. Manufacturing and Application of Metalized Ore-Coal Pellets in Synthetic Pig Iron Smelting

    Science.gov (United States)

    Nokhrina, O. I.; Rozhikhina, I. D.; Khodosov, I. E.

    2016-08-01

    The article presents research data on manufacturing and application of metalized ore-coal pellets in synthetic pig iron smelting. A technology of pellets metallization by means of solid-phase reduction of iron from oxides using hematite-magnetite iron ore and low-caking coal as raw materials is described. Industrial testing of replacing 10, 15, and 20% of waste metal by the metalized ore-coal pellets in the coreless induction furnace IST-1 is described. Optimal temperature and time conditions of feeding the metalized pellets into the furnace in smelting pig iron of SCh-40-60 grade are determined.

  6. Sedimentary carbonate-hosted giant Bayan Obo REE-Fe-Nb ore deposit of Inner Mongolia, China; a cornerstone example for giant polymetallic ore deposits of hydrothermal origin

    Science.gov (United States)

    Chao, E.C.T.; Back, J.M.; Minkin, J.A.; Tatsumoto, M.; Junwen, Wang; Conrad, J.E.; McKee, E.H.; Zonglin, Hou; Qingrun, Meng; Shengguang, Huang

    1997-01-01

    Detailed, integrative field and laboratory studies of the textures, structures, chemical characteristics, and isotopically determined ages and signatures of mineralization of the Bayan Obo deposit provided evidence for the origin and characteristics favorable for its formation and parameters necessary for defining giant polymetallic deposits of hydrothermal origin. Bayan Obo is an epigenetic, metasomatic, hydrothermal rare earth element (REE)-Fe-Nb ore deposit that is hosted in the metasedimentary H8 dolostone marble of the Middle Proterozoic Bayan Obo Group. The metasedimentary sequence was deposited on the northern continental slope of the North China craton. The mine area is about 100 km south of the suture marking Caledonian subduction of the Mongolian oceanic plate from the north beneath the North China craton. The mineralogy of the deposit is very complex, consisting of more than 120 different minerals, some of which are epigenetic minerals introduced by hydrothermal solutions, and some of which are primary and secondary metamorphic minerals. The major REE minerals are monazite and bastnaesite, whereas magnetite and hematite are the dominant Fe-ore minerals, and columbite is the most abundant Nb mineral. Dolomite, alkali amphibole, fluorite, barite, aegirine augite, apatite, phlogopite, albite, and microcline are the most widespread gangue minerals. Three general types of ores occur at Bayan Obo: disseminated, banded, and massive ores. Broad zoning of these ore types occurs in the Main and East Orebodies. Disseminated ores are in the outermost zone, banded ores are in the intermediate zone, and massive ores are in the cores of the orebodies. On the basis of field relations, host rocks, textures, structures, and mineral assemblages, many varieties of these three types of ores have been recognized and mapped. Isotopic dating of monazite, bastnaesite, aeschynite, and metamorphic and metasomatic alkali amphiboles associated with the deposit provides constraints

  7. Geochemistry, mineralogy, and chemical modeling of the acid crater lake of Kawah Ijen Volcano, Indonesia

    Science.gov (United States)

    Delmelle, Pierre; Bernard, Alain

    1994-06-01

    rockforming elements are produced by dissolution of approximately 60 g of andesite per kg of acid solution. Complete neutralization of the acid lake waters by reaction with the wallrock produces a theoretical alteration assemblage equivalent to that observed in volcano-hosted, acid-sulfate epithermal ore deposits.

  8. FY2017 status report: Model 9975 O-ring fixture long-term leak performance

    Energy Technology Data Exchange (ETDEWEB)

    Daugherty, W. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-07-27

    A series of experiments to monitor the aging performance of Viton® GLT and GLT-S O-rings used in the Model 9975 shipping package has been ongoing since 2004 at the Savannah River National Laboratory. One approach has been to periodically evaluate the leak performance of O-rings being aged in mock-up 9975 Primary Containment Vessels (PCVs) at elevated temperature. Other methods such as compression-stress relaxation (CSR) tests and field surveillance are also on-going to evaluate O-ring behavior. Seventy tests using PCV mock-ups with GLT O-rings were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determine if they continue to meet the leak-tightness criterion defined in ANSI standard N14.5-97. Due to material substitution, a smaller test matrix with fourteen additional tests was initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. Leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The 300 °F GLT O-ring fixtures failed after 2.8 to 5.7 years at temperature. The remaining GLT O-ring fixtures aging at 300 ºF were retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 9 to 10.5 years, or in GLT O-ring fixtures aging at 270 ºF for 5.7 years. These aging temperatures bound O-ring temperatures anticipated during normal storage in K-Area Complex (KAC). Leak test failures have been experienced in all of the GLT-S O-ring fixtures aging at 300 ºF and above. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 and 250 ºF for 6.9 to 7.5 years. Data from the O-ring fixtures are generally consistent with results from compression stress relaxation testing, and provide confidence in the predictive models based on those results

  9. The potential for ore and industrial minerals in the Forsmark area

    Energy Technology Data Exchange (ETDEWEB)

    Lindroos, Hardy [MIRAB Mineral Resurser AB, Uppsala (Sweden); Isaksson, Hans; Thunehed, Hans [GeoVista AB, Luleaa (Sweden)

    2004-03-01

    A survey has been made of existing information concerning the potential for ore and industrial minerals in and near the candidate area for a deep repository in Forsmark. A deep repository for spent nuclear fuel should not be located in a rock type or an area where mineral extraction might be considered in the future, since this would make it impossible to exploit this natural resource. Avoiding such areas reduces the risk that people in the future will come into contact with the deep repository through mineral prospecting or mining activities. The survey has made use of all the geoscientific information that was compiled in the more regional investigations in Oesthammar Municipality in 1996-97. In cooperation with the Geological Survey of Sweden (SGU), a new, more detailed mineral resources map has been prepared. The map shows areas with an ore potential that may be unsuitable or unfavourable for siting of a deep repository. The results of the recently completed geophysical helicopter surveys of the Forsmark area are presented in a special chapter. The judgement of the area's ore potential is in part based on the geophysical evaluation of these measurements. Furthermore, the survey obtained information from ongoing deep drillings from the site investigation in Forsmark. In order to better be able to judge the ore potential, the survey has initiated a geochemical investigation of activated soil samples, plus an ore geology sampling of a section in the deep borehole KFM02A, where a hydrothermally altered zone was detected in 2003.The first results from these samplings are presented in the report, which also discusses prospecting efforts in the area as well as relevant Swedish mining legislation. Some suggestions are made for further ore geology investigations. The mineral resources map shows that there is an elongate northwest-southeast zone south and southwest of the candidate area which has a potential for skarn iron ore, and possibly for copper and zinc

  10. 75 FR 2923 - Motor Carrier Safety Advisory Committee Public Meeting

    Science.gov (United States)

    2010-01-19

    ... Federal Motor Carrier Safety Administration Motor Carrier Safety Advisory Committee Public Meeting AGENCY: Federal Motor Carrier Safety Administration (FMCSA), DOT. ACTION: Notice of Motor Carrier Safety Advisory Committee Meeting. SUMMARY: FMCSA announces that its Motor Carrier Safety Advisory Committee (MCSAC)...

  11. 75 FR 72863 - Motor Carrier Safety Advisory Committee Public Meeting

    Science.gov (United States)

    2010-11-26

    ... Federal Motor Carrier Safety Administration Motor Carrier Safety Advisory Committee Public Meeting AGENCY: Federal Motor Carrier Safety Administration, DOT. ACTION: Notice of Motor Carrier Safety Advisory Committee Meeting. SUMMARY: FMCSA announces that the Agency's Motor Carrier Safety Advisory Committee...

  12. 76 FR 12214 - Motor Carrier Safety Advisory Committee Public Meeting

    Science.gov (United States)

    2011-03-04

    ... Federal Motor Carrier Safety Administration Motor Carrier Safety Advisory Committee Public Meeting AGENCY: Federal Motor Carrier Safety Administration, DOT. ACTION: Notice: Announcement of Motor Carrier Safety Advisory Committee meeting; request for comment. SUMMARY: The Federal Motor Carrier Safety...

  13. 75 FR 29384 - Motor Carrier Safety Advisory Committee Public Meeting

    Science.gov (United States)

    2010-05-25

    ... Federal Motor Carrier Safety Administration Motor Carrier Safety Advisory Committee Public Meeting AGENCY: Federal Motor Carrier Safety Administration (FMCSA), DOT. ACTION: Notice of Motor Carrier Safety Advisory Committee meeting. SUMMARY: FMCSA announces that its Motor Carrier Safety Advisory Committee (MCSAC)...

  14. Structural and alteration controls on gold mineralization the of the amphibolite facies Detour Lake Deposit, Canada

    Science.gov (United States)

    Dubosq, Renelle; Schneider, David

    2016-04-01

    The 15M oz Detour Lake deposit is a Neoarchean orogenic gold ore body located in the northern most region of the Abitibi district within the Superior Province. The mine is an open pit design in the high strain zone of the Sunday Lake Deformation Zone (SLDZ). The ductile-brittle SLDZ parallels the broadly E-W Abitibi greenstone belt and the deposit is situated in a dilation zone between volcanoclastic rocks of the Caopatina Assemblage and Lower Detour Lake Formation, consisting of ultramafic talc-chlorite-sericite schist. The Upper Detour Lake Formation consists of pillowed and massive flows and hyloclastic units crosscut by minor felsic to intermediate dykes. All of the formations are sub-vertical, north-dipping units with stretching lineations indicating dip-slip motion. The Detour deposit differs from other classic ore deposits in the dominantly greenschist facies Abitibi Subprovince by possessing an amphibolite facies metamorphic assemblage of actinolite-biotite-plagioclase-almandine. Consequently, the typical indicator minerals used to identify alteration and mineralization, such as secondary biotite, may not be useful. Petrological and geochemical analyses have revealed at least four populations of biotite: 1) large euhedral crystals located within quartz-carbonate veins, 2) small, euhedral zoned crystals present as alteration haloes, 3) very small, anhedral to subhedral indistinct crystal present in mafic volcanic host rock, and 4) large euhedral crystals defining the main metamorphic foliation in the metasediments. Extensive examination of mineral assemblages, alteration products, and vein structure in rock core across barren and mineralized zones has documented over a dozen vein types which can be grouped into two main categories: 1) sulfidized quartz-carbonate veins associated with biotite alteration and 2) late carbonate veins. Gold grades do not prove to be dependent on vein type but rather on the host rock composition: the highest ore grades are present

  15. Can lake sensitivity to desiccation be predicted from lake geometry?

    Science.gov (United States)

    Torabi Haghighi, Ali; Menberu, Meseret Walle; Aminnezhad, Mousa; Marttila, Hannu; Kløve, Bjørn

    2016-08-01

    Declining lake levels (Aral Sea syndrome) can be caused by changes in climate, increased water use or changed regulation patterns. This paper introduces a novel lake geometry index (LGI) to quantify lake hydrological characteristics. The index was developed using a large representative dataset of lake hypsographic characteristics from 152 lakes and man-made reservoirs. Using the LGI index, lakes can be classified into five groups: groups 1-4 when LGI is 0.5-2.5, 2.5-4.5, 4.5-6.5 and 6.5-8.5, respectively, and group 5 when LGI is >8.5. Naturally shallow and vast lakes and wetlands fall into the first group and deep man-made reservoirs in narrow valleys are in group 5. The response of three different lake systems (LGI 0.75, 2.75 and 6.5) to different water flow scenarios was then simulated using the water balance equation. From this, the index 'potential lake area' (Apot) was developed to show lake responses to changed hydro-climatological conditions. Apot and LGI can be used to classify lakes into open or closed systems. Simulations showed that lakes with low LGI have a shorter response time to flow and climate changes. As a result, the impact of water balance restoration is faster for lakes with low LGI than for lakes with high LGI. The latter are also more vulnerable to climate variation and change.

  16. Source identification and mass balance studies of mercury in Lake An-dong, S. Korea

    Science.gov (United States)

    Han, J.; Byeon, M.; Yoon, J.; Park, J.; Lee, M.; Huh, I.; Na, E.; Chung, D.; Shin, S.; Kim, Y.

    2009-12-01

    In this study, mercury and methylmercury were measured in atmospheric, tributary, open-lake water column, sediment, planktons and fish samples in the catchments area of Lake An-dong, S. Korea. Lake An-dong, an artificial freshwater lake is located on the upstream of River Nak-dong. It has 51.5 km2 of open surface water and 1.33 year of hydraulic residence time. It is a source of drinking water for 0.3 million S. Koreans. Recently, the possibilities of its mercury contamination became an issue since current studies showed that the lake had much higher mercury level in sediment and certain freshwater fish species than any other lakes in S. Korea. This catchments area has the possibilities of historical mercury pollution by the location of more than 50 abandoned gold mines and Young-poong zinc smelter. The objective of this study was to develop a mercury mass balance and identify possible mercury sources in the lake. The results of this study are thus expected to offer valuable insights for the sources of mercury loading through the watershed. In order to estimate the mercury flux, TGM, RGM and particulate mercury were measured using TEKRAN 2537 at the five sites surrounding Lake An-dong from May, 2009 with wet and dry deposition. The fate and transport of mercury in water body were predicted by using EFDC (Environmental Dynamic Fluid Code) and Mercury module in WASP7 (Water quality analysis program) after subsequent distribution into water body, sediments, followed by bioaccumulation and ultimate uptake by humans. The mercury mass balance in Young-poong zinc smelter was also pre-estimated by measuring mercury content in zinc ores, emission gases, sludge, wastewater and products.

  17. ISS qualified thermal carrier equipment

    Science.gov (United States)

    Deuser, Mark S.; Vellinger, John C.; Jennings, Wm. M.

    2000-01-01

    Biotechnology is undergoing a period of rapid and sustained growth, a trend which is expected to continue as the general population ages and as new medical treatments and products are conceived. As pharmaceutical and biomedical companies continue to search for improved methods of production and, for answers to basic research questions, they will seek out new avenues of research. Space processing on the International Space Station (ISS) offers such an opportunity! Space is rapidly becoming an industrial laboratory for biotechnology research and processing. Space bioprocessing offers exciting possibilities for developing new pharmaceuticals and medical treatments, which can be used to benefit mankind on Earth. It also represents a new economic frontier for the private sector. For over eight years, the thermal carrier development team at SHOT has been working with government and commercial sector scientists who are conducting microgravity experiments that require thermal control. SHOT realized several years ago that the hardware currently being used for microgravity thermal control was becoming obsolete. It is likely that the government, academic, and industrial bioscience community members could utilize SHOT's hardware as a replacement to their current microgravity thermal carrier equipment. Moreover, SHOT is aware of several international scientists interested in utilizing our space qualified thermal carrier. SHOT's economic financing concept could be extremely beneficial to the international participant, while providing a source of geographic return for their particular region. Beginning in 2000, flight qualified thermal carriers are expected to be available to both the private and government sectors. .

  18. Halls Lake 1990

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salt marsh habitats along the shoreline of Halls Lake are threatened by wave erosion, but the reconstruction of barrier islands to reduce this erosion will modify or...

  19. Sunk Lake Natural Area

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Sunk Lake Natural Area Management Plan guides the long-range development of the Natural Area by identifying and integrating appropriate habitats, management...

  20. Lake Transect : 1986

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document summarizes transect surveys that were done at four different lakes on St. Vincent National Wildlife Refuge in 1986. Lists of the plant species found at...

  1. Lake Transect : 1988

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document summarizes transect surveys that were done at four different lakes on St. Vincent National Wildlife Refuge in 1988. Lists of the plant species found at...

  2. Lake Transect : 1989

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document summarizes transect surveys that were done at four different lakes on St. Vincent National Wildlife Refuge in 1989. Lists of the plant species found...

  3. History of Lake Andes

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Information about the history and management of Lake Andes is compiled in this report. It is intended to help future refuge managers become acquainted with the...

  4. Lake Level Reconstructions

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past lake levels, mostly related to changes in moisture balance (evaporation-precipitation). Parameter keywords describe what was measured in this data...

  5. Great Lakes Ice Charts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Charts show ice extent and concentration three times weekly during the ice season, for all lakes except Ontario, from the 1973/74 ice season through the 2001/2002...

  6. Chase Lake Wetland Management District, Chase Lake National Wildlife Refuge, Chase Lake Prairie Project: Annual narrative report: 1997

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Chase Lake WMD, Chase Lake NWR, Chase Lake Prairie Project, and Halfway Lake NWR outlines Refuge accomplishments during the 1997...

  7. Hot carrier degradation in semiconductor devices

    CERN Document Server

    2015-01-01

    This book provides readers with a variety of tools to address the challenges posed by hot carrier degradation, one of today’s most complicated reliability issues in semiconductor devices.  Coverage includes an explanation of carrier transport within devices and book-keeping of how they acquire energy (“become hot”), interaction of an ensemble of colder and hotter carriers with defect precursors, which eventually leads to the creation of a defect, and a description of how these defects interact with the device, degrading its performance. • Describes the intricacies of hot carrier degradation in modern semiconductor technologies; • Covers the entire hot carrier degradation phenomenon, including topics such as characterization, carrier transport, carrier-defect interaction, technological impact, circuit impact, etc.; • Enables detailed understanding of carrier transport, interaction of the carrier ensemble with the defect precursors, and an accurate assessment of how the newly created defects imp...

  8. Is Lake Tahoe Terminal?

    Science.gov (United States)

    Coats, R. N.; Reuter, J.; Heyvaert, A.; Lewis, J.; Sahoo, G. B.; Schladow, G.; Thorne, J. H.

    2014-12-01

    Lake Tahoe, an iconic ultra-oligotrophic lake in the central Sierra Nevada, has been studied intensively since 1968, with the goal of understanding and ultimately controlling its eutrophication and loss of clarity. Research on the lake has included a) periodic profiles of primary productivity, nutrients, temperature, and plankton; b) Secchi depth; c) nutrient limitation experiments; d) analysis of sediment cores; e) radiocarbon dating of underwater in-place tree stumps; g) analysis of long-term temperature trends. Work in its watershed has included a) monitoring of stream discharge, sediment and nutrients at up to 20 stream gaging stations; b) monitoring of urban runoff water quality at selected sites; c) development of a GIS data base, including soils, vegetation, and land use. Based on these studies, we know that a) primary productivity in the lake is limited by phosphorus, and continues to increase; b) the loss of clarity continues, but at a declining rate; c) the lake has been warming since 1970, and its resistance to deep mixing is increasing; d) historically the lake level drops below the outlet elevation about one year in seven; e) 6300 to 4300 yrs BP lake level was below the present outlet elevation long enough for large trees to grow; f) the date of the peak snowmelt runoff is shifting toward earlier dates; g) after accounting for annual runoff, loads of nutrients and suspended sediment have declined significantly in some basin streams since 1980. Downscaled outputs from GCM climatic models have recently been used to drive hydrologic models and a lake clarity model, projecting future trends in the lake and watersheds. Results show a) the temperature and thermal stability will likely continue to increase, with deep mixing shutting down in the latter half of this century; b) the lake may drop below the outlet for an extended period beginning about 2085; c) the annual snowpack will continue to decline, with earlier snowmelt and shift from snowfall to rain; d

  9. WHISKER LAKE WILDERNESS, WISCONSIN.

    Science.gov (United States)

    Schulz, Klaus J.

    1984-01-01

    The mineral-resource potential of the Whisker Lake Wilderness in northeastern Wisconsin was evaluated. Only a strip along the southwest corner of the wilderness is assessed as having probable mineral-resource potential. If mineral deposits exist, they probably are of the massive sulfide type. The geologic terrain precludes the presence of fossil fuel resources. Sand and gravel and peat in swampy lowlands are the only resources of the Whisker lake Wilderness.

  10. Temporal and spatial distribution of Au-Ag polymetallic ore deposits and source of ore-forming materials in the Zhangjiakou-Xuanhua mantle-branch metallogenetic zone

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Zhangjiakou-Xuanhua area is a mineral resource-concentrated area for gold-silver polymetallic ore deposits. The temporal and spatial distribution and origin of mineral resources have been argued for a long time. Based on the comprehensive studies of geochronology and sulfur, lead, oxygen, carbon and noble gas isotopes, it is considered that the temporal and spatial distribution of mineral resources in this area is obviously controlled by the Zhangjiakou-Xuanhua mantle branch structure, as is reflected by the occurrence of gold deposits in the inner parts and of Ag-Pb-Zn polymetallic ore deposits in the outer parts. The mineralization took place mainly during the Yanshanian period. Ore-forming materials came largely from the deep interior of the Earth, and hydrothermal fluids were derived predominantly from Yanshanian magmatism.

  11. Resilience and Restoration of Lakes

    Directory of Open Access Journals (Sweden)

    Kathryn L. Cottingham

    1997-06-01

    Full Text Available Lake water quality and ecosystem services are normally maintained by several feedbacks. Among these are nutrient retention and humic production by wetlands, nutrient retention and woody habitat production by riparian forests, food web structures that cha nnel phosphorus to consumers rather than phytoplankton, and biogeochemical mechanisms that inhibit phosphorus recycling from sediments. In degraded lakes, these resilience mechanisms are replaced by new ones that connect lakes to larger, regional economi c and social systems. New controls that maintain degraded lakes include runoff from agricultural and urban areas, absence of wetlands and riparian forests, and changes in lake food webs and biogeochemistry that channel phosphorus to blooms of nuisance al gae. Economic analyses show that degraded lakes are significantly less valuable than normal lakes. Because of this difference in value, the economic benefits of restoring lakes could be used to create incentives for lake restoration.

  12. Pump-lockage ore transportation system for deep sea flexible mining system

    Institute of Scientific and Technical Information of China (English)

    XU Hai-liang; YIN Ping-wei; XU Shao-jun; YANG Fang-qiong

    2008-01-01

    Based on characteristics of deep sea flexible mining system, a new pump-lockage ore transportation system was designed. According to Bernoulli equation and two-phase hydrodynamics theory, parameters of the new system were obtained and four ore transportation systems were analyzed. The results indicate that the pump head of 1000 m mining system is 100-150 m and that of 5 000 m mining system is 660-750 m. In addition, based on similarity theory, a model of the new transportation system was made,which can simulate more than 5 000 m actual ore transportation system. So both theory and experiment prove that the new pump-lockage ore transportation system is an ideal design for deep sea flexible mining system.

  13. REE Characteristics of Microfine Disseminated Gold Ores in Danzai,Guizhou

    Institute of Scientific and Technical Information of China (English)

    陈庆年; 周丕康; 等

    1998-01-01

    Described in this paper are the fundamental characteristics of mineralization of gold ores in the Sandu-Danzhai Hg-Sb-Au ore belt of Guizhou Province,Through systematic sampling of the industrial orebody and alteration zone,the total amount of the rare-earth elements,that of the light rare-earth elements,Eu depletion and other parameters are clarified.There have been distinguished two types of REE distribution patterns:the"Clay type"and the "quartz type" .High-grade orebodies are closely related with silicification,illitization and pyritization.The seven-component diagram of the REEs of even numbers in the periodic table(Bal-asov,1966)is capable of distinguishing ore-bearing from ore-barren deposits.

  14. The study of volume ultrasonic waves propagation in the gas-containing iron ore pulp.

    Science.gov (United States)

    Morkun, V; Morkun, N; Pikilnyak, A

    2015-02-01

    The results of research of the volume ultrasonic waves propagation in the gas-containing iron ore slurry using ultrasonic phased array technology is presented. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Liberation of Oolitic Hematite Grains From Iron Ore,Dilband Mines Pakistan

    Directory of Open Access Journals (Sweden)

    Muhammad Ishaque Abro

    2011-04-01

    Full Text Available Dilband Mine is one of the main iron ore deposits of Balochistan Pakistan, containing about 200milion tones of ore. The Dilband iron ore is mainly composed of oolitic-hematite along with the quartz, calcite, fluorapatite, kaolin, and chlinochlore gangue minerals. The basic objective of the paper is to report the operating conditions of comminuting step where maximum liberation of oolitic hematite from the matrix enriched with calcite and fluorapatite minerals has been possible. Besides this quantitative and qualitative analysis of particles based on concentrate, middlings, and tailings susceptibility of particles is proposed. Comminution circuit for Dilband iron ore is designed on the basis of work index, grade and percent distribution of oolitic-hematite particles in concentrate, middlings and tailings.

  16. SEVENTH INTERIM STATUS REPORT: MODEL 9975 PCV O-RING FIXTURE LONG-TERM LEAK PERFORMANCE

    Energy Technology Data Exchange (ETDEWEB)

    Daugherty, W.

    2012-08-30

    A series of experiments to monitor the aging performance of Viton® GLT O-rings used in the Model 9975 package has been ongoing since 2004 at the Savannah River National Laboratory. Seventy tests using mock-ups of 9975 Primary Containment Vessels (PCVs) were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determine if they meet the criterion of leak-tightness defined in ANSI standard N14.5-97. Fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. High temperature aging continues for 23 GLT O-ring fixtures at 200 – 270 ºF. Room temperature leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The remaining GLT O-ring fixtures aging at 300 ºF have been retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 54-72 months, which is still bounding to O-ring temperatures during storage in K-Area Complex (KAC). Based on expectations that the fixtures aging at 200 ºF will remain leak-tight for a significant period yet to come, 2 additional fixtures began aging in 2011 at an intermediate temperature of 270 ºF, with hopes that they may reach a failure condition before the 200 ºF fixtures. High temperature aging continues for 6 GLT-S O-ring fixtures at 200 – 300 ºF. Room temperature leak test failures have been experienced in all 8 of the GLT-S O-ring fixtures aging at 350 and 400 ºF. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 - 300 ºF for 30 - 36 months. For O-ring fixtures that have failed the room temperature leak test and been disassembled, the O-rings displayed a compression set ranging from 51 – 96%. This is greater than seen to date for any packages inspected during KAC field

  17. 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...

  18. Experimental Study on the Properties of Concrete Mixed with Iron Ore Tailings

    National Research Council Canada - National Science Library

    Tian, Zhong-xi; Zhao, Zeng-hui; Dai, Chun-quan; Liu, Shu-jie

    2016-01-01

    .... Firstly, the raw materials of mixing were analyzed, and the test ratio was determined. Secondly, the workability and mechanical property of concrete specimens with different amounts of iron ore tailings as replacement were tested...

  19. The applications of microwave energy to improve grindability and extraction of gold ores

    CERN Document Server

    Huang, J H

    2000-01-01

    decomposed than pyrite at the same exposure conditions. Scanning electron microscope (SEM), optical microscope, and X-ray diffraction results indicated that the alterations during microwave treatment were complex. Some intermediate products (e.g. Fe sub ( sub 1 sub - sub x sub ) S) were formed before the sulphides were completely oxidised into hematite (Fe sub 2 O sub 3). Oxidation developed from the surfaces into the cores of the microwaved particles. Metallic particles were also formed during microwave exposure. Lihir gold ore, in which gold was finely disseminated in pyrite and marcasite, was an extremely refractory gold ore. Without pretreatment, only 37 approx 39% of the gold could be extracted with sodium cyanide. However, this was improved after the head ores or floatation concentrates were pretreated by microwave radiation. 74.5 approx 81.2% of the gold was extracted from the microwave treated head ore. The hydrometallurgical pretreatment of pyrite and marcasite in a microwave field and a conventional...

  20. SUSTAINABILITY IN PELLETIZING IRON ORE THROUGH THE INDUSTRIAL ECOLOGY AND CLEANER PRODUCTION PROGRAM

    National Research Council Canada - National Science Library

    Cristiano Farias Coelho; Gudelia Morales

    2013-01-01

      This study aims to analyze the practices of a pelletizing iron ore industry with respect to adoption of pollution prevention measures, suggested by applying the concepts of Cleaner Production and Material Flow Analysis...

  1. Tectonic ore-controlling in the middle southern segment of Da Hinggan Ling, Northeast China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Studies on geotectonic evolution, regionally geological characteristics and ore-forming and ore-controlling structures have shown that since the Mesozoic the Da Hinggan Ling region has entered the typical intercontinental orogenic stage, which appears to be closely related to mantle plume activities. Da Hinggan Ling is a typical mantle branch structure and possesses obvious magmatic-metamorphic complexes in the core, detachment slip beds in the periphery and overlapped fault depression basins. Moreover, all these are the principal factors leading to ore formation and ore controlling in the region. This paper also further explores the mechanism of mineralization in the middle-southern segment of Da Hinggan Ling,summaries the rules of mineralization, puts forward the models of mineralization and points out the oresearch orientations in the future time.

  2. The implementation and evaluation of a behaviour-based safety intervention at an iron ore mine

    National Research Council Canada - National Science Library

    GP Möller; Sebastiaan Rothmann

    2014-01-01

    .... The aim of this study was to determine to what extent the safety culture and safety performance in an iron ore mine were affected by the implementation of a behaviour-based safety intervention...

  3. Control of relay structure on mineralization of sedimentaryexhalative ore deposit in growth faults of graben systems

    Institute of Scientific and Technical Information of China (English)

    XI Xiao-shuang; TANG Jing-ru; KONG Hua; HE Sho-xun

    2005-01-01

    Based on the study of ore deposits and orebody structures of two sedimentary-exhalative ore deposits,i. e. , Changba and Xitieshan Ore Deposits, it is found that the structural patterns of metallogenic basin of seafloor exhalative sulfide deposits in the ancient graben systems are controlled by relay structures in normal faults. The shapes of metallogenic basins are composed of tilting ramp, fault-tip ramp and relay ramp, which dominate migration of gravity current of ore-hosted fluid and shape of orebody sedimentary fan in the ramp. By measuring and comparing the difference of length-to-thickness ratios of orebody sedimentary fan, the result shows that the occurrence of the ramp has a remarkable impact on the shape of orebody.

  4. Test of oxidation behavior of sulfide ores at ambient temperature for fire control

    Institute of Scientific and Technical Information of China (English)

    WU Chao; LI Zi-jun; LI Ming; WU Guo-min

    2007-01-01

    The coincidence of relevant factors, e.g. oxygen absorption quantity, weight increment, water soluble iron ions and sulfate ion of sulfide ore samples in the oxidation process, was tested through experiment. Based on a large number of tests for a group sample of sulfide ores from a mine, some important conclusions were obtained. The results obtained by the investigation indicate that there is no general interpretation relative to the oxygen absorption and the formation products of sulfate ion and water soluble iron ions during the oxidation process of sulfide ores at ambient temperature. However, the weight increment of the sulfide ore samples in the oxidation process at ambient temperature has a linear relationship with the quantity of oxygen absorption.

  5. New data on the age of gold mineralization of the Lugokan ore cluster (Eastern Transbaikalia)

    Science.gov (United States)

    Redin, Yu. O.; Dultsev, V. F.; Nevolko, P. A.; Ponomarchuk, A. V.

    2016-08-01

    The Lugokan ore cluster is located in the southeastern part of Transbaikalia within the Aga-Borzya structural-formational zone of the Mongol-Okhotsk orogenic belt. The 40Ar/39Ar dating of K-bearing minerals of syngenetic to ore parageneses has been carried out applying stepwise heating technique: it has been demonstrated that the earliest gold-ore mineral associations are Au-pyrite-arsenopyrite (163 ±1.9 Ma) and Au-chalcopyrite (160 ±2 Ma). The later parageneses encompass the Au-polymetallic (156.3 ± 1.8 Ma) and Au-Bi (155.9 ± 4.5 Ma) one. By their ages and position in the general scheme of the Late Jurassic magmatism of Eastern Transbaikalia, the Lugokan's ore cluster gold-bearing mineral associations corresponds to the time of intrusion of the Shakhtama pluton (161 Ma) and the Porphyry Complex (159-155 Ma).

  6. Some geological problems of bedded manganese ore deposits. Sojo mangankosho no chishitsugakuteki shomondai

    Energy Technology Data Exchange (ETDEWEB)

    Momoi, H. (Ehime University, Ehime (Japan). Faculty of Science)

    1991-09-15

    This paper summarizes the bedded manganese ore deposits in Japan and in the world. Chert-hosted bedded manganese ore deposits in the Chichibu terrane and similar terranes of the inner zone of Southwest Japan are characterized by numerous small deposits composed of rhodochrosite and manganese silicate ores. They are Triassic to Middle Jurassic in age. The deposits in Japan are, together with those of Coast Ranges in western part of North America, typical in the mobile belts of the world. On the other hand, giant bedded manganese deposits represented by Nikopol, South Ukraine and Groote Eylandt, Australia, occur in the inner parts of stable continents and in platforms and consist of manganese dioxide and rhodochrosite. The deposits in mobile belts and those in stable continents are very contrasting in the scale of deposits, distribution, ore, age, depositional environment and other features. 85 refs., 2 figs., 3 tabs.

  7. Extraction of a Low Grade Zinc Ore using Gravity and Froth Flotation ...

    African Journals Online (AJOL)

    ADOWIE PERE

    used to leach base metals from sulphide concentrated with metal ... (1993). The flotation agents are known as collectors, ... lime, oleic acid, propanol, turpentine etc.) of an ore ... using Camry 25k5055 digital weighing balance. Grain Size ...

  8. Experimental Study on the Properties of Concrete Mixed with Iron Ore Tailings

    National Research Council Canada - National Science Library

    Tian, Zhong-xi; Zhao, Zeng-hui; Dai, Chun-quan; Liu, Shu-jie

    2016-01-01

      The objective of this study is to evaluate the modified performance of concrete with mixing of iron ore tailings in order to solve the shortage of natural sand and make full use of industrial waste...

  9. Prospecting and exploration of deposits of ores, useful minerals and rocks (Vademecum 1)

    Energy Technology Data Exchange (ETDEWEB)

    Prokop, F.W.; Streck, W.; Sagheer, M.; Tschoepke, R.W.; Walther, H.W.; Pietzner, H.; Stadler, G.; Vogler, H.; Werner, H.

    1981-01-01

    Geologists and practical men are given instructions for prospecting and exploring deposits of ores, industrial minerals and useful rocks. The improvements and innovations of the prospecting and exploration technologies as well as the production and processing methods are considered.

  10. Aging of Weapon Seals – An Update on Butyl O-ring Issues

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Mark H.

    2011-07-13

    During testing under the Enhanced Surveillance Campaign in 2001, preliminary data detected a previously unknown and potentially serious concern with recently procured butyl o-rings on several programs. All butyl o-rings molded from a proprietary formulation throughout the period circa 1999 through 2001 had less than a full cure. Engineering judgment was that under curing is detrimental and could possibly lead to sub-optimum performance or, in the worst case, premature seal failure. An aging study was undertaken to ensure that suspect o-rings installed in the stockpile will retain sufficient sealing force for a minimum ten-year service life. A new prediction model developed for this study indicates suspect o-rings do not need to be replaced before the ten-year service life. Long-term testing results are reported on a yearly basis to validate the prediction model. This report documents the aging results for the period September 2002 to January 2011.

  11. Chlorination of nickel ore by gaseous chlorine in the presence of active additives

    Directory of Open Access Journals (Sweden)

    Ilić Ilija B.

    2003-01-01

    Full Text Available Paper presents a thermodynamic analysis of chemical reactions occurring during chlorination with and without additives for both nickel oxides and nickel ferrites, which are component parts of nickel ore. The experimental research investigated the influence of temperature in the range from 600 up to 1000 °C and time (up to 3 h on the chlorination degree of nickel ores with and without additives. It was found that the introduction of additives such as C, S, BaS and NaCl intensified the chlorination of nickel ore. The results can be applied and may help determine the optimal conditions for the chlorination of low-grade ferrous nickel ores.

  12. Leaching of molybdenum and arsenic from uranium ore and mill tailings

    Science.gov (United States)

    Landa, E.R.

    1984-01-01

    A sequential, selective extraction procedure was used to assess the effects of sulfuric acid milling on the geochemical associations of molybdenum and arsenic in a uranium ore blend, and the tailings derived therefrom. The milling process removed about 21% of the molybdenum and 53% of the arsenic initially present in the ore. While about one-half of the molybdenum in the ore was water soluble, only about 14% existed in this form in the tailings. The major portion of the extractable molybdenum in the tailings appears to be associated with hydrous oxides of iron, and with alkaline earth sulfate precipitates. In contrast with the pattern seen for molybdenum, the partitioning of arsenic into the various extractable fractions differs little between the ore and the tailings. ?? 1984.

  13. Ore-Bearing Formations of the Precambrian in South China and Their Prospects

    Institute of Scientific and Technical Information of China (English)

    HE Jurui; WANG Aiguo; RUI Xingjian; LI Chunhai

    2004-01-01

    In the Precambrian System of the Yangtze and Cathaysian plates six ore-bearing formations can be identified: the Cu-Pb-Zn-bearing formations in volcanic rocks of marine facies of the Neoarchean-Paleoproterozoic, CuAu-bearing formations and Pb-Zn-bearing formations in volcanic rocks of marine facies of the Mesoproterozoic, Pb-Znbearing formations in volcaniclastic rock and carbonate rock of the Neoproterozoic, Fe-Mn-bearing formations in the volcaniclastic rock of the Neoproterozoic, and Ni-Cr-serpentine-bearing formations in ophiolite and ultrabasic rock of the Meso- and Neoproterozoic. They were mostly formed in the marginal rift valleys of the Yangtze and Cathaysian plates,where occur stratabound and stratiform ore deposits, thermal deposits and porphyry polymetallic deposits. The six regions with ore-bearing formations have good prospects for ore deposits.

  14. Microporosity of BIF hosted massive hematite ore, Iron Quadrangle, Brazil

    Directory of Open Access Journals (Sweden)

    CÉSAR A.C. VARAJÃO

    2002-03-01

    Full Text Available Massive hematite ore (MHO is a special high-grade iron ore, used as lump ore in the process of obtaining direct reduction iron (DRI. The influence of porosity on the reducibility of MHO from the Capitão do Mato Mine (Iron Quadrangle, Brazil was investigated using optical and scanning electron microscopes on drill core and open pit samples. Hematite is the main component of the samples and occurs as granular crystals (10 mum, microplates (1 mum and euhedral martite (10 to 30 mum. Quartz, maghemite, kenomagnetite and goethite are minor components. Primary micropores (Å to 1 mum are associated with microplaty crystals that fill cavities between granular hematite. Secondary micropores (Å to 5 mum related to euhedral martite crystals, are the most important. The total porosity of weathered samples, measured using nitrogen adsorption and mercury injection, attains values up to 11%, whereas unweathered samples have a porosity less than 2.5%. Reducibility is strongly enhanced by porosity, but inhibited by structure (bedding.O minério de hematita compacta (MHC é um tipo de minério de ferro de alto grau usado como minério granulado na obtenção do ferro via redução direta (DRI. A influência da porosidade sobre a redutibilidade do MHC da Mina de Capitão do Mato (Quadrilátero Ferrífero, Brasil, foi investigada em amostras de furos de sonda e de afloramentos da mina, usando-se microscópio óptico e eletrônico de varredura. Hematita é o principal componente mineralógico e ocorre sob diferentes formas: granular (10 mim, microtabular (1 mim e euédrico (10 a 30 mim. Quartzo maghemita, kenomagnetita e goethita são componetes menores. Microporos primários (Å to 1 mim associam-se a cristais de hematita microtabular, que preenchem espaços entre cristais de hematita granular. Microporos secundários (Å to 5 mim, relacionados com os cristais de martita euédrica, são os mais importantes. A porosidade total das amostras do MHC, medida atrav

  15. Is Lake Chabot Eutrophic?

    Science.gov (United States)

    Pellegrini, K.; Logan, J.; Esterlis, P.; Lew, A.; Nguyen, M.

    2013-12-01

    Introduction/Abstract: Lake Chabot is an integral part of the East Bay watershed that provides habitats for animals and recreation for humans year-round. Lake Chabot has been in danger of eutrophication due to excessive dumping of phosphorous and nitrogen into the water from the fertilizers of nearby golf courses and neighboring houses. If the lake turned out to be eutrophified, it could seriously impact what is currently the standby emergency water supply for many Castro Valley residents. Eutrophication is the excessive richness of nutrients such as nitrogen and phosphorus in a lake, usually as a result of runoff. This buildup of nutrients causes algal blooms. The algae uses up most of the oxygen in the water, and when it dies, it causes the lake to hypoxify. The fish in the lake can't breathe, and consequently suffocate. Other oxygen-dependant aquatic creatures die off as well. Needless to say, the eutrophication of a lake is bad news for the wildlife that lives in or around it. The level of eutrophication in our area in Northern California tends to increase during the late spring/early summer months, so our crew went out and took samples of Lake Chabot on June 2. We focused on the area of the lake where the water enters, known on the map as Honker Bay. We also took readings a ways down in deeper water for comparison's sake. Visually, the lake looked in bad shape. The water was a murky green that glimmered with particulate matter that swirled around the boat as we went by. In the Honker Bay region where we focused our testing, there were reeds bathed in algae that coated the surface of the lake in thick, swirling patterns. Surprisingly enough, however, our test results didn't reveal any extreme levels of phosphorous or nitrogen. They were slightly higher than usual, but not by any significant amount. The levels we found were high enough to stimulate plant and algae growth and promote eutrophication, but not enough to do any severe damage. After a briefing with a

  16. Tewaukon – Clouds LakeLake Elsie – Storm Lake and Wild Rice Refuges Narrative Reports : 1939-1956 : From Sand Lake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These narrative reports summarize refuge activities from 1939 to 1956 for Lake Tewaukon Refuge, Clouds Lake Refuge, Lake Elsie Refuge, Storm Lake Refuge, Wild Rice...

  17. TOXAPHENE STUDY OF GREAT LAKES TRIBUTARY SEDIMENTS

    Science.gov (United States)

    The Product is the paper "Pulp and Paper Mills as Sources of Toxaphene to Lake Superior and Northern Lake Michigan" published in the Journal of Great Lakes Research, 25(2):383-394 International Association of Great Lakes 1999.

  18. Mineralogical-Geochemical Peculiarities of Ores in Pyritaceous Fields of Filizchai Type in the Greater Caucasus

    Directory of Open Access Journals (Sweden)

    NOVRUZ A. NOVRUZOV

    2010-12-01

    Full Text Available Pyritaceous fields of the south slope of the Greater Caucasus confined to the Lower-Middle Jurassic sandy clayey deposits are: polygenic polychrone formations which were formed by a complex of hydrothermal sedimentary, hydrothermal metasomatic and hydrothermal metamorphogenic processes of ore formation. Filizchai pyritaceous polymetallic field is the largest in the region and can be characterized by diversity of texture-mineralogical types of ores, rich mineral composition and with geochemical spectrum. Some of the admixture components (Cd, In, Tl, Ga, Ge, Se, Hg are only in isomorphic forms in ores, others (Te, Bi, Au, Ag, Co, Sn, As along with it characterize in their own minerals. The Co is mainly concentrated in pyrite, pyrrhotine; Ag, Bi and also Te – in galenite and chalcopyrite; Se – in pyrite, pyrrhotine and galenite; in sphalerite (mainly in marmatite and chalcopyrite; Cd, Ga, Ge – in sphalerite, mainly in cleiophane; Au – in pyrite and chalcopyrite; Tl – in galenite and colloform pyrite. In all sulphides selenium prevails over tellurium (excepting the late chalcopyrite and cobalt over nickel. Maximum amount of cobalt is confined to pyrite from pyritaceous polymetallic ores and late generation of pyrrhotine. The nature of the connection between chemical elements in ores coordinates with determined stages of minerals formation. The main productive stage of ore formation bringing the main mass of gold, silver, rare and other precious components of ores are sulphosalt polymetallic stage of sulphur ploymetallic stage. Comparative analysis of absolute content of gold, silver and values of gold-silver relation in pyrite fields ores of region with appropriate values in meteorite standard indirectly indicates the relationship between gold-silver mineralization and assimilation crust source.

  19. Mechanochemical activation of iron ore-based catalysts for the hydrogenation of brown coal

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, P.N.; Kuznetsova, L.I.; Chumakov, V.G.; Moiseeva, G.A. [Rossijskaya Akademiya Nauk, Krasnoyarsk (Russian Federation). Inst. of Chemistry and Chemical Technology

    2000-10-01

    Genesis of pyrrhotite catalysts from different iron ore concentrates and pure iron oxides was investigated using the method of mechanochemical treatment in a planetary mill. The dispersion and fine crystalline structure of oxide and pyrrhotite particles were studied as the function of mechanical load, sulfiding temperature and mode of preparation. Methods for the preparation of high performance iron ore-based catalysts for brown coal hydrogenation have been developed. (orig.)

  20. Pilot scale direct flotation of a phosphate ore with silicate-carbonate gangue.

    OpenAIRE

    2012-01-01

    The present pilot scale study addresses the direct flotation route for the concentration of a phosphate ore bearing a silicate-carbonate gangue. The target was to selectively separate apatite from a phosphate ore bearing silicate/carbonate gangue using flotation columns. Based on the results of a previous laboratory scale investigation, a reagents scheme was selected and tested, using, under alkaline conditions, corn starch and a natural collector extracted from the distillation of coconut oi...

  1. Dephosphorization of High-Phosphorus Iron Ore Using Different Sources of Aspergillus niger Strains.

    Science.gov (United States)

    Xiao, Chunqiao; Wu, Xiaoyan; Chi, Ruan

    2015-05-01

    High-phosphorus iron ore is traditionally dephosphorized by chemical process with inorganic acids. However, this process is not recommended nowadays because of its high cost and consequent environmental pollution. With the current tendency for development of a low-cost and eco-friendly process, dephosphorization of high-phosphorus iron ore through microbial process with three different sources of Aspergillus niger strains was studied in this study. Results show that the three strains of A. niger could grow well in the broth, and effectively remove phosphate from high-phosphorus iron ore during the experiments. Meanwhile, the total iron in the broth was also increased. Acidification of the broth seemed to be the major mechanism for the dephosphorization by these strains. High-pressure liquid chromatography analysis indicated that various organic acids were secreted in the broth, which caused a significant drop of the broth pH. Scanning electron microscopy of ore residues revealed that the high-phosphorus iron ore was obviously destroyed by the actions of these strains. Ore residues by energy-dispersive X-ray microanalysis and Fourier transform infrared spectroscopy indicated that the phosphate was obviously removed from the high-phosphorus iron ore. The optimization of the dephosphorization by these strains was also investigated, and the maximum percentages of phosphate removal were recorded at temperature 27-30 °C, initial pH 5.0-6.5, particle size 0.07-0.1 mm, and pulp density of 2-3% (w/v), respectively. The fungus A. niger was found to have good potential for the dephosphorization of high-phosphorus iron ore, and this microbial process seems to be economic and effective in the future industrial application.

  2. Evaluation of the effectiveness of the filtration leaching for uranium recovery from uranium ore

    OpenAIRE

    2015-01-01

    The physical and chemical processes taking place in filtration leaching of uranium from uranium ore sample by sulphuric acid solution have been studied by modern physico-chemical methods (X-ray diffraction, scanning electron spectroscopy, electron probe microanalysis, optical emission spectroscope, ICP OES). Column leaching test was carried out for ore samples obtained from a uranium in-situ leaching (ISL) mining site using deluted sulphuricacid to study the evolution of various elements conc...

  3. Chemical and mineralogical characterization of chromite ore processing residue from two recent Indian disposal sites.

    Science.gov (United States)

    Matern, Katrin; Kletti, Holger; Mansfeldt, Tim

    2016-07-01

    Chromite ore processing residue (COPR) is a hazardous waste. Nevertheless, deposition of COPR in uncontrolled surface landfills is still common practice in some countries. Whereas old (between at least 40 and 180 years) COPR from the temperate zone has been intensively investigated, information on COPR in other regions is restricted. Relatively young (ore processing and preventing the migration of Cr(VI) into water bodies are the main challenges when dealing with these COPR.

  4. Flotation of cobalt bearing minerals from a mixed copper-cobalt oxidized ore

    OpenAIRE

    2012-01-01

    M.Tech. (Extraction Metallurgy) The techniques for the flotation of mixed copper and cobalt bearing oxide ores using the sulphidization method in order to recover the oxidized copper and cobalt bearing minerals have been well documented by previous researchers. These processes have been successfully implemented in many of the metallurgical plant operations in the Democratic Republic of Congo (DRC). The mixed copper and cobalt oxidised ores from this region present significant chal-lenges t...

  5. Influence of Mechanical Activation on Acid Leaching Dephosphorization of High-phosphorus Iron Ore Concentrates

    Institute of Scientific and Technical Information of China (English)

    De-qing ZHU; Hao WANG; Jian PAN; Cong-cong YANG

    2016-01-01

    High pressure roll grinding (HPRG)and ball milling were compared to investigate the influence of me-chanical activation on the acid leaching dephosphorization of a high-phosphorus iron ore concentrate,which was man-ufactured through magnetizing roasting-magnetic separation of high-phosphorus oolitic iron ores.The results indica-ted that when high-phosphorus iron ore concentrates containing 54·92 mass% iron and 0·76 mass% phosphorus were directly processed through acid leaching,iron ore concentrates containing 55·74 mass% iron and 0·33 mass%phosphorus with an iron recovery of 84·64% and dephosphorization of 63·79% were obtained.When high-phosphor-us iron ore concentrates activated by ball milling were processed by acid leaching,iron ore concentrates containing 56·03 mass% iron and 0·21 mass% phosphorus with an iron recovery of 85·65% and dephosphorization of 77·49%were obtained.Meanwhile,when high-phosphorus iron ore concentrates activated by HPRG were processed by acid leaching,iron ore concentrates containing 58·02 mass% iron and 0·10 mass% phosphorus were obtained,with the iron recovery reaching 88·42% and the dephosphorization rate reaching 88·99%.Mechanistic studies demonstrated that ball milling can reduce the particle size,demonstrating a prominent reunion phenomenon.In contrast,HPRG pretreatment contributes to the formation of more cracks within the particles and selective dissociation of iron and P bearing minerals,which can provide the favorable kinetic conditions to accelerate the solid-liquid reaction rate.As such,the crystal structure is destroyed and the surface energy of mineral particles is strengthened by mechanical ac-tivation,further strengthening the dephosphorization.

  6. Analysis of Mineralization System and Prediction of New-Type Ore Deposits

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The discovery of new-type ore deposits, an important approach to guarantee the mineral resources supply in the 21st century, often brings about a gigantic increase in the mineral resources reserves. The analysis of mineralization system is of great importance to the discovery of new-type ore deposits. ① The understanding of the relationship among various ore deposit types within a mineralization system in a region can help us to locate the unknown ore deposit types from the known ore deposit types, evidence that has been proved in the mineral prospecting history of ore belts in the middle and lower reaches of the Yangtze River, China. ② The understanding of the spatial structure of a mineralization system, especially of the vertical zonation, is helpful for the discovery of the concealed ore deposit types. ③ Clarifying the temporal structure of a mineralization system, including the iteration relationship between the mineral deposit types in the mineralization, leads to the location of the missing mineralization chains from the known mineralization chains (mineral deposit type), a method often proved to be effective in the magmatic-hydrothermal mineralization system. ④ Clarifying the factors restraining the diversity of mineral deposit types in mineralization system leads to the discovery of the potential of new-type mineral deposits in relevant region. ⑤ Studying new mineralization setting and new ore-forming processes leads to discovery of new-type mineral deposit. More probabilities of discovery of new-type mineral deposits are present in biogenic mineralization system, deep-sea mineralization system, low-temperature mineralization system, tectonic mineralization system and superimposed mineralization system.

  7. Pelletized vs. natural iron ore technology: energy, labor, and capital changes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kakela, P.

    1978-09-01

    Total energy requirements per ton of iron-in-ore for natural and pelletized ore were calculated by a hybrid energy analysis. Energy requirements for ore preparation were subsequently considered as one energy input (embodied) to blast furnaces. Total energy requirements per ton molten iron were calculated for each year from 1955 through 1975 to identify changes attributable to the shift in iron ore preparation. Four results were found. (1) In practice, the lean ores are energetically superior. Pelletized ore requires more energy at the mine than natural ore, but pellets produce offsetting energy savings in the blast furnace. (2) Labor changes followed a similar pattern: man-hours per ton of molten iron increased at the mine with pelletization, but decreased at the blast furnance. Net labor required per ton of molten iron has decreased with pelletization. (3) Capital investments per ton of molten iron have increased greatly at iron ore mines with pelletization and decreased moderately at blast furnaces. New capital investment per ton of molten iron has increased with pelletization. (4) In the iron and steel industry, relatively low-priced energy held a substantial advantage over high-priced labor between 1950 and 1969. The industry, however, discovered that capital investments in pellet plants could save both labor and energy up to 1963; after 1963 capital and energy weresubstituted for labor. A sharp reversal of substitutional advantage occurred in 1970; energy jumped to the most costly factor. Thus capital presently shows a strong substitutional advantage over high-priced energy and intermediately-priced labor.

  8. Indonesia Prohibited Export of Laterite Nickel Ore, China’s Nickel Industry Responded Calmly

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>On January 12,the Indonesia government implemented new mining regulation to prohibit export of laterite nickel ore and other crude ores.This may cause certain impact on China’s nickel industry which is in a rapid development period.What countermeasures to adopt has become the hot spot and focal point of the nickel industry and iron & steel industry including stainless steel industry.Recently,when receiving interview from reporters of the

  9. Glacial lake inventory and lake outburst potential in Uzbekistan.

    Science.gov (United States)

    Petrov, Maxim A; Sabitov, Timur Y; Tomashevskaya, Irina G; Glazirin, Gleb E; Chernomorets, Sergey S; Savernyuk, Elena A; Tutubalina, Olga V; Petrakov, Dmitriy A; Sokolov, Leonid S; Dokukin, Mikhail D; Mountrakis, Giorgos; Ruiz-Villanueva, Virginia; Stoffel, Markus

    2017-08-15

    Climate change has been shown to increase the number of mountain lakes across various mountain ranges in the World. In Central Asia, and in particular on the territory of Uzbekistan, a detailed assessment of glacier lakes and their evolution over time is, however lacking. For this reason we created the first detailed inventory of mountain lakes of Uzbekistan based on recent (2002-2014) satellite observations using WorldView-2, SPOT5, and IKONOS imagery with a spatial resolution from 2 to 10m. This record was complemented with data from field studies of the last 50years. The previous data were mostly in the form of inventories of lakes, available in Soviet archives, and primarily included localized in-situ data. The inventory of mountain lakes presented here, by contrast, includes an overview of all lakes of the territory of Uzbekistan. Lakes were considered if they were located at altitudes above 1500m and if lakes had an area exceeding 100m(2). As in other mountain regions of the World, the ongoing increase of air temperatures has led to an increase in lake number and area. Moreover, the frequency and overall number of lake outburst events have been on the rise as well. Therefore, we also present the first outburst assessment with an updated version of well-known approaches considering local climate features and event histories. As a result, out of the 242 lakes identified on the territory of Uzbekistan, 15% are considered prone to outburst, 10% of these lakes have been assigned low outburst potential and the remainder of the lakes have an average level of outburst potential. We conclude that the distribution of lakes by elevation shows a significant influence on lake area and hazard potential. No significant differences, by contrast, exist between the distribution of lake area, outburst potential, and lake location with respect to glaciers by regions. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Geochemical Characteristics, Genesis of Concealed Cu-rich Ore Body in the Jinchuan Deposit, Northwestern China, and Its Prospecting

    Institute of Scientific and Technical Information of China (English)

    GAO Yalin; TANG Zhongli; ZHANG Mingjie; TIAN Yulong; XIAO Lizhong

    2009-01-01

    The Jinchuan deposit is hosted by the olivine-rich ultramafic rock body, which is the third-largest magmatic sulfide Ni-Cu deposit in the world currently being exploited. Seeking new relaying resources in the deep and the border of the deposit becomes more and more important. The ore body, ore and geochemistry characteristics of the concealed Cu-rich ore body are researched. Through spatial analysis and comparison with the neighboring Ⅱ1 main ore body, the mineralization rule of the concealed Cu-rich ore body is summed up. It is also implied that Cu-rich magma may exist between Ni-rich magma and ore pulp during iiquation differentiation in deep-stage chambers, which derives from deep-mantle Hi-MgO basalt magma. It is concluded that the type of ore body has features of both magmatic liquation and late reconstruction action. It has experienced three stages: deep liquation and pulsatory injection of the Cu-and PPGE-rich magma, concentration of tectonic activation, and the later magma hydrothermai superimposition. In addition, the Pb and S isotopes indicate the magma of I6 concealed Cu-rich ore body originates predominantly from mantle; however, it is interfused by minute crust material. Finally, it is inferred that the genesis of the Cu-Ni sulfide deposit is complex and diverse, and the prospect of seeking new deep ore bodies within similar deposits is promising, especially Cu-rich ore bodies.

  11. Shear Alteration, Mass Transfer and Gold Mineralization: An Example from Jiaodong Ore Deposit Concentrating Area, Shandong, China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Taking the gold ore deposit concentrating area of Jiaodong area in Shandong, China for an example, based on geological analysis, and applying Gresens' equation, Grant's isocon diagram and O'hara microelement calculation method, a thorough study on shear alteration, mass transfer and gold mineralization was carried out. The authors also made mathematic simulation and geochemical analysis. The work reveals temporal-spatial changing regularities of temperature field and velocity field of fluids, and also reveals fluid transport-chemical reaction coupling metallogenic dynamics of the Jiaojia gold ore concentrating area. During shear-alteration process of the Jiaodong gold ore concentrating area, all kinds of components transferred with different amounts, fluid-rock ratio was rather high and volume strain was of dilation type. Fast flow of ore-forming fluid favors the occurrence of mixed fluid. Shear-fractured zones are places where there was strong transportationreaction coupling mineralization. Ore bodies were located in dilation space of shear structure where there was the greatest fluid flux. After the emplacement of the rock body, a convex heat field was formed around the rock body. It is one of the main metallogenic forces. The major reason for mineralization is the mobilization, migration and enrichment of ore-forming elements induced by shear compressive-extensional tectonism. Inclusion gold dominant Iow-grade ores were formed in the early ore-forming stage, while high-grade ores, which contained fissure gold and polymetallic veinlets, were formed in late ore-forming stage.

  12. In vitro adverse effects of iron ore dusts on human lymphoblastoid cells in culture.

    Science.gov (United States)

    Wang, He; Wang, Jing J; Sanderson, Barbara J S

    2013-01-01

    The aim of this study was to investigate the adverse effects produced by four types of iron (Fe) ore dust using cultured human cells. Genotoxicity and cytotoxicity induced by Fe ore dusts were determined by assays including cytokinesis block micronucleus (CBMN), population growth, and methyl tetrazolium (MTT). Four iron ore dusts were tested, namely, 1002 Limonite & Goethite (1002), HG2 hematite (HG2), HG1 Soutlem Pit (HG1), and HG4. WIL2 -NS cells were incubated for 10 h with extracts from a range of concentrations (0, 75, or 150 μg/ml) of Fe ore dust. Significant decreases in percent cell viability were seen at 150 μg/ml HG2 and 1002 as measured by MTT, with viability that decreased to 75 and 73%, respectively, compared to untreated controls. The cell population regrew to a different extent after Fe ore dust was removed, except for HG1, where population remained declined. An approximately twofold significant increase in the frequency of micronucleated binucleated cells (MNBNC) was seen with 1002, HG2, and HG1 at 150 μg/ml. A significant rise in apoptosis induction was observed at 150 μg/ml HG1. Data indicate that Fe ore dusts at 150 μg/ml produced cytotoxicity and genotoxicity.

  13. Nanocrystalline Iron-Ore-Based Catalysts for Fischer-Tropsch Synthesis.

    Science.gov (United States)

    Yong, Seok; Park, Ji Chan; Lee, Ho-Tae; Yang, Jung-Il; Hong, SungJun; Jung, Heon; Chun, Dong Hyun

    2016-02-01

    Nanocrystalline iron ore particles were fabricated by a wet-milling process using an Ultra Apex Mill, after which they were used as raw materials of iron-based catalysts for low-temperature Fischer-Tropsch synthesis (FTS) below 280 degrees C, which usually requires catalysts with a high surface area, a large pore volume, and a small crystallite size. The wet-milling process using the Ultra Apex Mill effectively destroyed the initial crystallite structure of the natural iron ores of several tens to hundreds of nanometers in size, resulting in the generation of nanocrystalline iron ore particles with a high surface area and a large pore volume. The iron-ore-based catalysts prepared from the nanocrystalline iron ore particles effectively catalyzed the low-temperature FTS, displaying a high CO conversion (about 90%) and good C5+ hydrocarbon productivity (about 0.22 g/g(cat)(-h)). This demonstrates the feasibility of using the iron-ore-based catalysts as inexpensive and disposable catalysts for the low-temperature FTS.

  14. Extraction of copper from an oxidized (lateritic) ore using bacterially catalysed reductive dissolution.

    Science.gov (United States)

    Nancucheo, Ivan; Grail, Barry M; Hilario, Felipe; du Plessis, Chris; Johnson, D Barrie

    2014-01-01

    An oxidized lateritic ore which contained 0.8 % (by weight) copper was bioleached in pH- and temperature-controlled stirred reactors under acidic reducing conditions using pure and mixed cultures of the acidophilic chemolithotrophic bacterium Acidithiobacillus ferrooxidans. Sulfur was provided as the electron donor for the bacteria, and ferric iron present in goethite (the major ferric iron mineral present in the ore) acted as electron acceptor. Significantly more copper was leached by bacterially catalysed reductive dissolution of the laterite than in aerobic cultures or in sterile anoxic reactors, with up to 78 % of the copper present in the ore being extracted. This included copper that was leached from acid-labile minerals (chiefly copper silicates) and that which was associated with ferric iron minerals in the lateritic ore. In the anaerobic bioreactors, soluble iron in the leach liquors was present as iron (II) and copper as copper (I), but both metals were rapidly oxidized (to iron (III) and copper (II)) when the reactors were aerated. The number of bacteria added to the reactors had a critical role in dictating the rate and yield of copper solubilised from the ore. This work has provided further evidence that reductive bioprocessing, a recently described approach for extracting base metals from oxidized deposits, has the potential to greatly extend the range of metal ores that can be biomined.

  15. Ore Petrography Using Optical Image Analysis: Application to Zaruma-Portovelo Deposit (Ecuador

    Directory of Open Access Journals (Sweden)

    Edgar Berrezueta

    2016-06-01

    Full Text Available Optical image analysis (OIA supporting microscopic observation can be applied to improve ore mineral characterization of ore deposits, providing accurate and representative numerical support to petrographic studies, on the polished section scale. In this paper, we present an experimental application of an automated mineral quantification process on polished sections from Zaruma-Portovelo intermediate sulfidation epithermal deposit (Ecuador using multispectral and color images. Minerals under study were gold, sphalerite, chalcopyrite, galena, pyrite, pyrrhotite, bornite, hematite, chalcocite, pentlandite, covellite, tetrahedrite and native bismuth. The aim of the study was to quantify the ore minerals visible in polished section through OIA and, mainly, to show a detailed description of the methodology implemented. Automated ore identification and determination of geometric parameters predictive of geometallurgical behavior, such as grade, grain size or liberation, have been successfully performed. The results show that automated identification and quantification of ore mineral images are possible through multispectral and color image analysis. Therefore, the optical image analysis method could be a consistent automated mineralogical alternative to carry on detailed ore petrography.

  16. Geological structure, composition of ores and age of the Bamsk gold deposit, Amur region, Russia

    Institute of Scientific and Technical Information of China (English)

    Vitaly A. Stepanov

    2004-01-01

    The Bamsk gold-ore deposit is located in the Amur region, the Far East of Russia. It is confined to the Early Cretaceous volcanic-plutonic uplift of central type, located in the Stanov folded-clumpy Pre-Cambrian system. The deposit is presented by a series of gold-bearing quartz and carbonate-quartz vein-stringer zones. They are confined to the super-intrusive zone of the Nevachansk subvolcanic intrusion of sienite-porphyric composition. The mineralization is being controlled by zone of fractures developed in the autochthone ofthe Bamsk fault. Quartz, carbonates and sericite prevail in the composition of ores. The quantity of ore minerals doesn't exceed 1%~5%. Pyrite, chalcopyrite, galena and native gold are widely spread. Sheelite, gold and silver tellurides, sulphobismuthites, acanthite, sphalerite and cinnabar are less developed. Four stages of mineralization have been distinguished. Gold-sulphide-sulphosalt ore with tellurides of gold and silver is productive for gold. The following set of elements is typomorphic for the ores of the deposit: Au, Ag, Cu, Bi,Mo, Pb and Sb (W1, Pb1, Mo) -Cu- (Ag, Bi, Sb, Mn, W1, Pb2) form the vertical series of zoning. Rocks, enclosing the mineralization are exposed to the processes of listvenitization-beresitization. The processes of gumbeization and argillization are less manifested. The age of the gold mineralization, determined by Rb-Sr method on ore-accompanying minerals, is 130.6 Ma.

  17. Correlations among factors of sulfide ores in oxidation process at ambient temperature

    Institute of Scientific and Technical Information of China (English)

    吴超; 李孜军; 周勃

    2004-01-01

    Spontaneous combustion is one of the serious problems in the mining of sulfide ore deposits. The relevant factors, e. G. Oxygen absorption quantity, mass increase, contents of water soluble iron ions and sulfate ion of sulfide ore samples in the oxidation process were investigated both in theory and experiment. The results from the investigation show that there is no general interpretation relation among the oxygen absorption quantity, the contents of sulfate ion and water soluble iron ions during the oxidation process of sulfide ores at ambient temperature.However, there is a linear relationship between the mass increase of the sulfide ore samples in the oxidation process at ambient temperature and the quantity of oxygen absorption. Therefore, the simple and cheap mass scaling method is suitable for predicting the oxygen absorption performance of sulfide ores at ambient temperature in place of the expensive and complicated chemical method used hitherto. Furthermore, combined with other items of breeding-fire test, the mass increase potential can also be used to predict the spontaneous combustion tendency of sulfide ores.

  18. Sintering of manganese ore in natura with different additions on activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Lima, M.M.F.; Mapa, T.F.M.; Lima, R.M.F. [Universidade Federal de Ouro Preto (UFOP), MG (Brazil)

    2016-07-01

    Full text: The shortage of high grade manganese ore and the importance of economically viable processes suggest a necessity of the recovery of ore residues. So, this work presents a route to obtain by-products of economic interest from manganese ore residues in bench scale. The objective was the sintering of manganese ore in natura using a particle size below 0,037μm with different additions of activated carbon. For this, the fine residues were calcined at 800°C during 60 minutes, homogenized in an agate mortar with 12% humidity and additions of 9 and 12% of activated carbon. After homogenization, the sintering process was carried out at 1145°C and 1155°C during 5, 15 and 30 minutes at natural air. The products sintered were characterized by bulk density, BET surface area, OM, SEM / EDS and diffraction X-rays. During the calcination of the ore, the mass loss was (15.16 ± 0.02)% due to the elimination of volatiles and water. The surface area of the ore was reduced due to the diffusion process that occurred during sintering. While, the bulk density values had little variation, around (3.51 ± 0.06)g/cm³. The analyses of micro-regions EDS showed that the matrix is a silicate with a high Mn content. It was identified yet, other silicates with different proportions of Si, Al, Ti, Na, Mn, Mg and Ca. (author)

  19. Research on degradation of vacuum O-rings under gamma radiation

    CERN Document Server

    Ino, H; Saitô, Y; Kubo, T; Kinsho, M

    2003-01-01

    The high-intensity proton accelerator being constructed by JAERI and KEK will generates greater beam power than conventional accelerators. The radiation emission due to beam losses will therefore increase. Since vacuum O-rings installed in the accelerator will be degraded badly by the radiation, there is need to find an O-ring that has more resistant to radiation. To find an O-ring that has better radiation resistant than that of the fluororubber used for conventional accelerators in general, some O-rings which are expected to have enough resistant to the radiation were irradiated, and estimated a degradation by measurement of outgassing rate, hardness, permeation time of helium gas, and an outward observation. Most of the O-rings were irradiated in an oxygen free atmosphere and in the air. The irradiations were carried out at room temperature in Co-60 gamma irradiation facility until a dose of 1 MGy was reached. The radiation resistance of PURE-RUBBER O-ring showed somewhat better than that of the fluororubb...

  20. A New Direction for Biomining: Extraction of Metals by Reductive Dissolution of Oxidized Ores

    Directory of Open Access Journals (Sweden)

    Kevin B. Hallberg

    2013-01-01

    Full Text Available Biomining, the biotechnology that uses microorganisms to extract metals from ores and concentrates, is currently used exclusively for processing reduced ores and mine wastes. Metals of economic value also occur extensively in oxidized ores, such as nickel laterites. While these are not amenable to oxidative dissolution, the ferric iron minerals they contain can, in theory, be disrupted by iron reduction, causing associated metals to be released. We have harnessed the ability of the facultatively anaerobic, acidophilic bacterium Acidithiobacillus ferroooxidans to couple the oxidation of elemental sulphur to the reduction of ferric iron in the goethite fraction of a limonitic nickel ore at 30 °C. Nickel and other metals (Co, Cr and Mn were effectively solubilised and maintained in solution due to the low pH (1.8 of the leach liquor. The results highlight the potential for the bioprocessing of oxidized, iron-rich ores using an approach that is energy-saving and environmentally-benign compared with metallurgical processes currently applied to the extraction of Ni from lateritic ores.

  1. Evidence of Lake Trout reproduction at Lake Michigan's mid-lake reef complex

    Science.gov (United States)

    Janssen, J.; Jude, D.J.; Edsall, T.A.; Paddock, R.W.; Wattrus, N.; Toneys, M.; McKee, P.

    2006-01-01

    The Mid-Lake Reef Complex (MLRC), a large area of deep (> 40 m) reefs, was a major site where indigenous lake trout (Salvelinus namaycush) in Lake Michigan aggregated during spawning. As part of an effort to restore Lake Michigan's lake trout, which were extirpated in the 1950s, yearling lake trout have been released over the MLRC since the mid-1980s and fall gill net censuses began to show large numbers of lake trout in spawning condition beginning about 1999. We report the first evidence of viable egg deposition and successful lake trout fry production at these deep reefs. Because the area's existing bathymetry and habitat were too poorly known for a priori selection of sampling sites, we used hydroacoustics to locate concentrations of large fish in the fall; fish were congregating around slopes and ridges. Subsequent observations via unmanned submersible confirmed the large fish to be lake trout. Our technological objectives were driven by biological objectives of locating where lake trout spawn, where lake trout fry were produced, and what fishes ate lake trout eggs and fry. The unmanned submersibles were equipped with a suction sampler and electroshocker to sample eggs deposited on the reef, draw out and occasionally catch emergent fry, and collect egg predators (slimy sculpin Cottus cognatus). We observed slimy sculpin to eat unusually high numbers of lake trout eggs. Our qualitative approaches are a first step toward quantitative assessments of the importance of lake trout spawning on the MLRC.

  2. Lake Morphometry for NHD Lakes in Ohio Region 5 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  3. Lake Morphometry for NHD Lakes in California Region 18 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  4. Lake Morphometry for NHD Lakes in Tennessee Region 6 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  5. SATELLITE LAKES OF LAKE VICTORIA BASIN (TANZANIAN SIDE)

    African Journals Online (AJOL)

    Studies on phytoplankton species diversity and abundance were carried out in 8 selected satellite lakes within the Lake ... species of blue green algae such as Spirulina spp. are sources of ... scientific and conservation interests. This study ...

  6. NINTH INTERIM STATUS REPORT: MODEL 9975 PCV O-RING FIXTURE LONG-TERM LEAK PERFORMANCE

    Energy Technology Data Exchange (ETDEWEB)

    Daugherty, W.

    2014-08-06

    A series of experiments to monitor the aging performance of Viton® GLT O-rings used in the Model 9975 package has been ongoing since 2004 at the Savannah River National Laboratory. One approach has been to periodically evaluate the leak performance of O-rings being aged in mock-up 9975 Primary Containment Vessels (PCVs) at elevated temperatures. Other methods such as compression-stress relaxation (CSR) tests and field surveillance are also on-going to evaluate O-ring behavior. Seventy tests using PCV mock-ups were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determine if they continue to meet the leak-tightness criterion defined in ANSI standard N14.5-97. Due to material substitution, fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. High temperature aging continues for 23 GLT O-ring fixtures at 200 – 270 ºF. Room temperature leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The earliest 300 °F GLT O-ring fixture failure was observed at 34 months. The remaining GLT O-ring fixtures aging at 300 ºF have been retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 72 - 96 months, which bounds O-ring temperatures anticipated during storage in K-Area Complex (KAC). Based on expectations that the 200 ºF fixtures will remain leak-tight for a significant period yet to come, 2 additional fixtures began aging in 2011 at 270 ºF, with hopes that they may reach a failure condition before the 200 ºF fixtures, thus providing additional time to failure data. High temperature aging continues for 6 GLT-S O-ring fixtures at 200 – 300 ºF. Room temperature leak test failures have been experienced in all 8 of the

  7. Seeking the mantle contribution for the formation of giant ore deposits: Contemporaneous alkaline lamproites and carbonatites in the Kalmakyr and Muruntau ore districts, Tienshan, Uzbekistan

    Science.gov (United States)

    Seltmann, Reimar; Choulet, Flavien

    2014-05-01

    The decline in discoveries of ore deposits contrasted by the rising demand for e-tech metals requires the global mining industry to continuously seek innovation in exploration. Unravelling the source of metals is among the crucial questions in exploration targeting and geologists have often had to recourse to indirect determinations based on the nature of the magma conveying the metals. The relative contributions of mantle and crust in metallogenic processes and the origin of the magmas from either shallow or deep mantle are not fully understood in the current models of ore genesis. To help to resolve this dilemma, research must establish the link between anorogenic (within-plate) and orogenic processes by using a holistic approach featuring crustal processes, mantle dynamics and crust-mantle interactions that may contribute to the magma fertilization. To achieve this, our study focuses on indicators for the involvement of deep-mantle intrusions (lamproites, lamprophyres, etc.), which have the potential to encapsulate pristine samples of the mantle (xenoliths) during magma ascent [1,2]. The Tienshan belt hosting many giant ore deposits is quite exemplary for understanding mantle-crust interactions and identifying the nature of mantle contribution to ore systems. Sr-Nd-Hf-Pb isotope systematics on granitoids [3] showed a variation of crustal to mixed signatures, indicating involvement of both older crustal sources and mantle-derived material, but the mantle source is not clearly assessed. As objects for our case study in Uzbekistan we choose the Kalmakyr Cu-Au porphyry deposit (~ 315 Ma; Chatkal-Kurama continental arc of Middle Tienshan) and the Muruntau orogenic Au deposit (~290 Ma, Turkestan-Alai / Kyzylkum accretionary complex of South Tienshan) to investigate the impact of associated alkaline magmas on the ore-bearing intrusions and mineralization. Field observations and geochronological data shed light on the spatial and temporal relationships between the

  8. Synthesis process of forsterite refractory by iron ore tailings.

    Science.gov (United States)

    Li, Jing; Wang, Qi; Liu, Jihui; Li, Peng

    2009-01-01

    With mineral resources becoming gradually more deficient, as well as the issue of mine tailings causing environmental pollution, more and more people have realized the great significance of tailings utilization. Iron ore tailings, as a kind of secondary resource, have been developed in recycling industries. The feasibility to produce forsterite refractory from high-silicon iron tailings and high-magnesium raw materials were discussed. Also, the synthesis reaction processes were studied from the results of the laboratory experiments. The experiments showed that the synthesis processes can be separated into three steps when using iron tailings to synthesize forsterite: (1) produce magnesium iron sosoloid (Mg(1-X)Fe(X)O) and magnesium metasilicate (MgSiO3), (2) form the fayalite, and (3) create the forsterite. The synthetic productions are primarily forsterite, hortonolite, and small amounts of magnesium metasilicate (MgSiO3). The hortonolite is wrapped around the surface of the forsterite particles and formed the cementing phase. In addition, the method to produce forsterite refractory and lightweight forsterite refractory from iron tailings were offered.

  9. Morbidity among iron ore mine workers in Goa.

    Science.gov (United States)

    Oliveira, Annet; Cacodcar, Jagdish; Motghare, D D

    2014-01-01

    This study was carried out among workers from an open-cast iron ore mine in South Goa with an objective to assess morbidity among these workers. Investigations were carried out at the Occupational Health Service Clinic of the mining company. Nearly 0.6% workers had pneumoconiosis, 3.2% had abnormal spirometry findings, 38.16% had hearing loss and 27.7% had defective vision respectively. The prevalence of other chronic diseases were as follows: diabetes 5.1%, hypertension 8.3%, dyslipidemia 37.5% and polycythemia 12.7% respectively. Since the findings were not compared with the pre-placement records and as most of the workers are young with duration of exposures <10 years, relationship cannot be definitely determined. The study findings are suggesting an association between the occupation in mining with pneumoconiosis, compromised lung function and hearing loss. However for the other finding further analytical studies are required to see for any association. Airborne respirable dust survey and noise monitoring studies also need to be carried out.

  10. Selective Flocculation Enhanced Magnetic Separation of Ultrafine Disseminated Magnetite Ores

    Directory of Open Access Journals (Sweden)

    Tao Su

    2016-08-01

    Full Text Available Simple magnetic separation for a certain magnetite mine with ultrafine disseminated lean ores has resulted in low performance, as the fine sizes and aggregation of ground mineral particles have caused inefficient recovery of the ultrafine minerals. In this study, we attempt to increase the apparent sizes of target mineral particles, and improve the separation indices, by using a multi-stage grinding-dispersion-selective flocculation-weak magnetic separation process. The results showed that under the conditions of 500 g/t sodium hexametaphospate (SHMP as dispersant, 750 g/t carboxymethyl starch (CMS as flocculant, agitating at 400 rpm for 10 min, with slurry pH 11, and final grinding fineness of 93.5% less than 0.03 mm, the obtained concentrate contained 62.82% iron, with recovery of 79.12% after multi-stage magnetic separation. Compared to simple magnetic separation, the concentrate’s iron grade increased by 1.26%, and a recovery rate by 5.08%. Fundamental analysis indicated that, in a dispersed state of dispersion, magnetite particles had weaker negative surface charges than quartz, allowing the adsorption of negative CMS ions via hydrogen bonding. Consequently, the aggregate size of the initial concentrate increased from 24.30 to 38.37 μm, accomplishing the goal of selective flocculation, and increasing the indices of separation.

  11. Estimated water requirements for the conventional flotation of copper ores

    Science.gov (United States)

    Bleiwas, Donald I.

    2012-01-01

    This report provides a perspective on the amount of water used by a conventional copper flotation plant. Water is required for many activities at a mine-mill site, including ore production and beneficiation, dust and fire suppression, drinking and sanitation, and minesite reclamation. The water required to operate a flotation plant may outweigh all of the other uses of water at a mine site, [however,] and the need to maintain a water balance is critical for the plant to operate efficiently. Process water may be irretrievably lost or not immediately available for reuse in the beneficiation plant because it has been used in the production of backfill slurry from tailings to provide underground mine support; because it has been entrapped in the tailings stored in the TSF, evaporated from the TSF, or leaked from pipes and (or) the TSF; and because it has been retained as moisture in the concentrate. Water retained in the interstices of the tailings and the evaporation of water from the surface of the TSF are the two most significant contributors to water loss at a conventional flotation circuit facility.

  12. Innovative method for boron extraction from iron ore containing boron

    Science.gov (United States)

    Wang, Guang; Wang, Jing-song; Yu, Xin-yun; Shen, Ying-feng; Zuo, Hai-bin; Xue, Qing-guo

    2016-03-01

    A novel process for boron enrichment and extraction from ludwigite based on iron nugget technology was proposed. The key steps of this novel process, which include boron and iron separation, crystallization of boron-rich slag, and elucidation of the boron extraction behavior of boron-rich slag by acid leaching, were performed at the laboratory. The results indicated that 95.7% of the total boron could be enriched into the slag phase, thereby forming a boron-rich slag during the iron and slag melting separation process. Suanite and kotoite were observed to be the boron-containing crystalline phases, and the boron extraction properties of the boron-rich slag depended on the amounts and grain sizes of these minerals. When the boron-rich slag was slowly cooled to 1100°C, the slag crystallized well and the efficiency of extraction of boron (EEB) of the slag was the highest observed in the present study. The boron extraction property of the slow-cooled boron-rich slag obtained in this study was much better than that of szaibelyite ore under the conditions of 80% of theoretical sulfuric acid amount, leaching time of 30 min, leaching temperature of 40°C, and liquid-to-solid ratio of 8 mL/g.

  13. Hydraulic Conductivity of Compacted Laterite Treated with Iron Ore Tailings

    Directory of Open Access Journals (Sweden)

    Umar Sa’eed Yusuf

    2016-01-01

    Full Text Available The objective of this study was to investigate the effect of iron ore tailings (IOT on hydraulic conductivity of compacted laterite. The IOT conforms to ASTM C 618-15 Type F designations. In the present study, soil was admixed with 0–20% IOT and compacted at moulding water content ranging from 10 to 25% using four types of compactive efforts. Hydraulic conductivities of the compacted soil-IOT mixtures were determined using deionized water and municipal solid waste leachate as the permeant fluids, respectively. Deionized water was the reference permeant fluid. Results of this study showed that hydraulic conductivity decreased with increase in IOT content as a result of improvement in mechanical properties of the soil. Permeation of the soil-IOT mixtures with leachate caused the hydraulic conductivity to drop to less than 1 × 10−9 m/s especially at higher compactive efforts. Also, bioclogging of the soil pores due to accumulation of biomass from bacteria and yeast present in the leachate tends to significantly reduce the hydraulic conductivity. From an economic point of view, it has been found from the results of this study that soil specimens treated with up to 20% IOT and compacted at the British Standard Light (BSL compactive effort met the maximum regulatory hydraulic conductivity of less than or equal to 1 × 10−9 m/s for hydraulic barrier system.

  14. Magnetic ores with steel or basalt for concrete radiation shielding

    Energy Technology Data Exchange (ETDEWEB)

    Bashter, I.I. [Zagazig Univ. (Egypt). Faculty of Science; A. El-Sayed, Abdo; M. Samir, Abdel-Azim

    1997-06-01

    This paper is concerned with the study of the leakage spectra of total gamma rays and fast neutrons from two types of heavy concretes made from local magnetite ores. The two types are the steel-magnetite concrete ({rho}=5.11 g/cm{sup 3}) and the basalt-magnetite concrete ({rho}=3.05 g/cm{sup 3}). The radiation source used was a collimated beam emitted from one of the horizontal channels of the ET-RR-1 reactor. Total gamma rays and fast neutrons were measured using a gamma-neutron spectrometer with a stilbene scintillator. Gamma ray or neutron events were rejected by a pulse shape discriminator based on the zero cross over method. The obtained data were displayed in the form of spatial fluxes and energy distributions and attenuation curves. The linear attenuation coefficients for total gamma rays, macroscopic removal cross sections for fast neutrons and half-value layers for gamma rays and neutrons have been obtained for the whole energy range and at different energies. Comparison with other published data has been done when such data are available. For comparison, the steel-magnetite concrete is a much better radiation attenuator than the magnetite and basalt-magnetite concretes, especially for thick shields. (author)

  15. Modeling of time dependent subsidence for coal and ore deposits

    Institute of Scientific and Technical Information of China (English)

    Ryszard Hejmanowski

    2015-01-01

    Coal and ore underground mining generates subsidence and deformation of the land surface. Those defor-mations may cause damage to buildings and infrastructures. The environmental impact of subsidence will not be accepted in the future by the society in many countries. Especially there, where the mining regions are densely urbanized, the acceptance of the ground deformations decreases every year. The only solution is to limit the subsidence or its impact on the infrastructure. The first is not rentable for the mining industry, the second depends on the precise subsidence prediction and good preventing management involved in the mining areas. The precision of the subsidence prediction depends strictly on the mathematical model of the deformation phenomenon and on the uncertainty of the input data. The subsidence prediction in the geological conditions of the raw materials used to be made on the basis of numerical modeling or the stochastic models. A modified solution of the stochastic model by Knothe will be presented in the paper. The author focuses on the precise description of the deposit shape and on the time dependent displacements of the rock mass. A two parameters’ time function has been introduced in the algorithm.

  16. Fatigue reliability for LNG carrier

    Institute of Scientific and Technical Information of China (English)

    Xiao Taoyun; Zhang Qin; Jin Wulei; Xu Shuai

    2011-01-01

    The procedure of reliability-based fatigue analysis of liquefied natural gas (LNG) carrier of membrane type under wave loads is presented. The stress responses of the hotspots in regular waves with different wave heading angles and wave lengths are evaluated by global ship finite element method (FEM). Based on the probabilistic distribution function of hotspots' short-term stress-range using spectral-based analysis, Weibull distribution is adopted and discussed for fitting the long-term probabilistic distribution of stress-range. Based on linear cumulative damage theory, fatigue damage is characterized by an S-N relationship, and limit state function is established. Structural fatigue damage behavior of several typical hotspots of LNG middle ship section is clarified and reliability analysis is performed. It is believed that the presented results and conclusions can be of use in calibration for practical design and initial fatigue safety evaluation for membrane type LNG carrier.

  17. Crude oil as carrier of gold: petrological and geochemical evidence from Lannigou gold deposit in southwestern Guizhou, China

    Institute of Scientific and Technical Information of China (English)

    庄汉平; 卢家烂; 傅家谟; 任炽刚; 邹德刚

    1999-01-01

    Organic matter is related closely to mineralization of Lannigou gold deposit in southwestern Guizhou, China, Regionally, the distribution of organic carbon agrees well with that of faults within which gold deposits are hosted. Studies on organic petrology show that pyrobiturnen, which is related most closely to mineralization, adheres to quartz vein or fills quartz veinlet. Proton-induced X-ray emission (PIXE) analysis shows an evident abundance of Au in pyrobitumen. Pyrobitumen paragenetically associates with pyrite and arsenopyrite which are the main carrier minerals of Au. The thermal simulation experiment indicates that about 99% of Au will be concentrated in oil phase in the coexisting system of oil and brine and rock. The role of crude oil in ore-forming process is: as carrier of Au, crude oil moves upwards, and undergoes thermal decomposition and thermochemical reduction when it encounters the oxidizing fluid within the Trassic turbidity; Au is thus released from crude oil, reduced and precipitat

  18. A Customized Finger Brachytherapy Carrier

    OpenAIRE

    Wadhwa, Supneet Singh; Duggal, Nidhi

    2013-01-01

    In recent years, radiation therapy has been used with increasing frequency in the management of neoplasms of the head and neck region. Brachytherapy is a method of radiation treatment in which sealed radioactive sources are used to deliver the dose a short distance by interstitial (direct insertion into tissue), intracavitary (placement within a cavity) or surface application (molds). Mold brachytherapy is radiation delivered via a custom-fabricated carriers, designed to provide a more consta...

  19. Preventative maintenance of straddle carriers

    Directory of Open Access Journals (Sweden)

    Si Li

    2015-02-01

    Full Text Available Background: Robotic vehicles such as straddle carriers represent a popular form of cargo handling amongst container terminal operators.Objectives: The purpose of this industry-driven study is to model preventative maintenance (PM influences on the operational effectiveness of straddle carriers.Method: The study employs historical data consisting of 21 273 work orders covering a 27-month period. Two models are developed, both of which forecast influences of PM regimes for different types of carrier.Results: The findings of the study suggest that the reliability of the straddle fleet decreases with increased intervals of PM services. The study also finds that three factors – namely resources, number of new straddles, and the number of new lifting work centres – influence the performances of straddles.Conclusion: The authors argue that this collaborative research exercise makes a significant contribution to existing supply chain management literature, particularly in the area of operations efficiency. The study also serves as an avenue to enhance relevant management practice.

  20. Lake Michigan lake trout PCB model forecast post audit

    Science.gov (United States)

    Scenario forecasts for total PCBs in Lake Michigan (LM) lake trout were conducted using the linked LM2-Toxics and LM Food Chain models, supported by a suite of additional LM models. Efforts were conducted under the Lake Michigan Mass Balance Study and the post audit represents th...

  1. Mono Lake Excursion Reviewed

    Science.gov (United States)

    Liddicoat, J. C.; Coe, R. S.

    2007-05-01

    The Mono Lake Excursion as recorded in the Mono Basin, CA, has an older part that is about negative 30 degrees inclination and about 300 degrees declination during low relative field intensity. Those paleomagnetic directions are closely followed by greater than 80 degrees positive inclination and east declination of about 100 degrees during higher relative field intensity. A path of the Virtual Geomagnetic Poles (VGPs) for the older part followed from old to young forms a large clockwise loop that reaches 35 degrees N latitude and is centered at about 35 degrees E longitude. That loop is followed by a smaller one that is counterclockwise and centered at about 70 degrees N latitude and 270 degrees E longitude (Denham & Cox, 1971; Denham, 1974; Liddicoat & Coe, 1979). The Mono Lake Excursion outside the Mono Basin in western North America is recorded as nearly the full excursion at Summer Lake, OR (Negrini et al., 1984), and as the younger portion of steep positive inclination/east declination in the Lahontan Basin, NV. The overall relative field intensity during the Mono Lake Excursion in the Lahontan Basin mirrors very closely the relative field intensity in the Mono Basin (Liddicoat, 1992, 1996; Coe & Liddicoat, 1994). Using 14C and 40Ar/39Ar dates (Kent et al., 2002) and paleoclimate and relative paleointensity records (Zimmerman et al., 2006) for the Mono Lake Excursion in the Mono Basin, it has been proposed that the Mono Lake Excursion might be older than originally believed and instead be the Laschamp Excursion at about 40,000 yrs B.P. (Guillou et al., 2004). On the contrary, we favor a younger age for the Mono Lake Excursion, about 32,000 yrs B.P., using the relative paleointensity in the Mono Basin and Lahontan Basin and 14C dates from the Lahontan Basin (Benson et al., 2002). The age of about 32,000 yrs B.P. is also in accord with the age (32,000- 34,000 yrs B.P.) reported by Channell (2006) for the Mono Lake Excursion at ODP Site 919 in the Irminger Basin

  2. REE Mineralization in Kiruna-type Magnetite-Apatite Ore Deposits: Magmatism and Metasomatism

    Science.gov (United States)

    Harlov, D. E.

    2015-12-01

    Magnetite-apatite ore bodies of the Kiruna type occur worldwide and are generally associated with volcanic rocks or volcanism. They also show strong evidence of extensive metasomatism over a wide P-T range. Notable examples include the Kiirunavaara ore body, northern Sweden (Harlov et al., 2002, Chem. Geol., 191, 47-72); the Grängesberg ore body, central Sweden (Jonsson et al., 2010, NGF abstracts, vol 1, 88-89); the Mineville ore body, Adirondacks, New York, USA (McKeown and Klemc, 1956, U.S. Geol Sur Bull (1956), pp. 9-23); the Pea Ridge ore body, SE Missouri, USA (Kerr, 1998, MS Thesis, Univ. Windsor, Windsor, Ontario, Canada 113 pp); the Jurassic Marcona ore body in south-central Peru (Chen et al., 2010, Econ Geol, 105, 1441-1456); and a collection of ore bodies from the Bafq Region, central Iran (Daliran et al., 2010, Geol. Assoc. Canada, Short Course Notes, v. 20, p.147-159). In these ore bodies, low Th and U monazite, xenotime, allanite, REE carbonates, and/or REE fluorides are commonly associated with the apatite as inclusions, rim grains, or as independent grains in the surrounding mineral matrix. High contrast BSE imaging, coupled with EMPA and LA-ICPMS, indicates that the apatite has experienced fluid-induced alteration in the form of (Y+REE) + Na + Si + Cl depletion implying that it served as the source for the (Y+REE) (e.g. Kiirunavaara, northern Sweden; Harlov et al., 2002). Formation of monazite and xenotime associated with fluorapatite, as inclusions or rim grains, has experimentally been demonstrated to originate from the fluorapatite as the result of fluid-aided, coupled dissolution-reprecipitation processes (Harlov et al., 2005, Contrib. Mineral. Petrol. 150, 268-286). This is explains the low Th and U content of the monazite and xenotime. Fluid sources could range from 700-900 °C, residual, acidic (HCl, H2HSO4) grain boundary fluids, remaining after the last stages of ore body crystallization, to later stage, cooler (< 600 °C) (H2O-CO2-(Na

  3. EIGHTH INTERIM STATUS REPORT: MODEL 9975 PCV O-RING FIXTURE LONG-TERM LEAK PERFORMANCE

    Energy Technology Data Exchange (ETDEWEB)

    Daugherty, W. L.

    2013-09-03

    A series of experiments to monitor the aging performance of Viton® GLT O-rings used in the Model 9975 package has been ongoing since 2004 at the Savannah River National Laboratory. Seventy tests using mock-ups of 9975 Primary Containment Vessels (PCVs) were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determine if they meet the criterion of leak-tightness defined in ANSI standard N14.5-97. Fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. High temperature aging continues for 23 GLT O-ring fixtures at 200 – 270 ºF. Room temperature leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The remaining GLT O-ring fixtures aging at 300 ºF have been retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 61 - 85 months, which is still bounding to O-ring temperatures during storage in KArea Complex (KAC). Based on expectations that the fixtures aging at 200 ºF will remain leaktight for a significant period yet to come, 2 additional fixtures began aging in 2011 at an intermediate temperature of 270 ºF, with hopes that they may reach a failure condition before the 200 ºF fixtures. High temperature aging continues for 6 GLT-S O-ring fixtures at 200 – 300 ºF. Room temperature leak test failures have been experienced in all 8 of the GLT-S O-ring fixtures aging at 350 and 400 ºF. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 - 300 ºF for 41 - 45 months. Aging and periodic leak testing will continue for the remaining PCV fixtures.

  4. Lake Erie Fish Community Data

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Lake Erie Biological Station (LEBS), located in Sandusky, Ohio, is a field station of the USGS Great Lakes Science Center (GLSC). LEBS is the primary federal agency...

  5. Crescent Lake Wilderness Reference Sheet

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Reference sheet includes information about Crescent Lake National Wildlife Refuge, and results of the public hearing for Crescent Lake Wilderness Proposal.

  6. Freshwater lake seabird surveys 2012

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Alaska Peninsula/Becharof NWR complex hosts Becharof Lake, the largest lake within a National Wildlife Refuge system. In addition to this distinction, Becharof...

  7. Great Lakes Environmental Database (GLENDA)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Great Lakes Environmental Database (GLENDA) houses environmental data on a wide variety of constituents in water, biota, sediment, and air in the Great Lakes area.

  8. Functional microbiology of soda lakes

    NARCIS (Netherlands)

    Sorokin, D.Y.; Banciu, H.L.; Muyzer, G.

    2015-01-01

    Soda lakes represent unique permanently haloalkaline system. Despite the harsh conditions, they are inhabited by abundant, mostly prokaryotic, microbial communities. This review summarizes results of studies of main functional groups of the soda lake prokaryotes responsible for carbon, nitrogen and

  9. Responsible implementation of expanded carrier screening.

    Science.gov (United States)

    Henneman, Lidewij; Borry, Pascal; Chokoshvili, Davit; Cornel, Martina C; van El, Carla G; Forzano, Francesca; Hall, Alison; Howard, Heidi C; Janssens, Sandra; Kayserili, Hülya; Lakeman, Phillis; Lucassen, Anneke; Metcalfe, Sylvia A; Vidmar, Lovro; de Wert, Guido; Dondorp, Wybo J; Peterlin, Borut

    2016-06-01

    This document of the European Society of Human Genetics contains recommendations regarding responsible implementation of expanded carrier screening. Carrier screening is defined here as the detection of carrier status of recessive diseases in couples or persons who do not have an a priori increased risk of being a carrier based on their or their partners' personal or family history. Expanded carrier screening offers carrier screening for multiple autosomal and X-linked recessive disorders, facilitated by new genetic testing technologies, and allows testing of individuals regardless of ancestry or geographic origin. Carrier screening aims to identify couples who have an increased risk of having an affected child in order to facilitate informed reproductive decision making. In previous decades, carrier screening was typically performed for one or few relatively common recessive disorders associated with significant morbidity, reduced life-expectancy and often because of a considerable higher carrier frequency in a specific population for certain diseases. New genetic testing technologies enable the expansion of screening to multiple conditions, genes or sequence variants. Expanded carrier screening panels that have been introduced to date have been advertised and offered to health care professionals and the public on a commercial basis. This document discusses the challenges that expanded carrier screening might pose in the context of the lessons learnt from decades of population-based carrier screening and in the context of existing screening criteria. It aims to contribute to the public and professional discussion and to arrive at better clinical and laboratory practice guidelines.

  10. Responsible implementation of expanded carrier screening

    Science.gov (United States)

    Henneman, Lidewij; Borry, Pascal; Chokoshvili, Davit; Cornel, Martina C; van El, Carla G; Forzano, Francesca; Hall, Alison; Howard, Heidi C; Janssens, Sandra; Kayserili, Hülya; Lakeman, Phillis; Lucassen, Anneke; Metcalfe, Sylvia A; Vidmar, Lovro; de Wert, Guido; Dondorp, Wybo J; Peterlin, Borut

    2016-01-01

    This document of the European Society of Human Genetics contains recommendations regarding responsible implementation of expanded carrier screening. Carrier screening is defined here as the detection of carrier status of recessive diseases in couples or persons who do not have an a priori increased risk of being a carrier based on their or their partners' personal or family history. Expanded carrier screening offers carrier screening for multiple autosomal and X-linked recessive disorders, facilitated by new genetic testing technologies, and allows testing of individuals regardless of ancestry or geographic origin. Carrier screening aims to identify couples who have an increased risk of having an affected child in order to facilitate informed reproductive decision making. In previous decades, carrier screening was typically performed for one or few relatively common recessive disorders associated with significant morbidity, reduced life-expectancy and often because of a considerable higher carrier frequency in a specific population for certain diseases. New genetic testing technologies enable the expansion of screening to multiple conditions, genes or sequence variants. Expanded carrier screening panels that have been introduced to date have been advertised and offered to health care professionals and the public on a commercial basis. This document discusses the challenges that expanded carrier screening might pose in the context of the lessons learnt from decades of population-based carrier screening and in the context of existing screening criteria. It aims to contribute to the public and professional discussion and to arrive at better clinical and laboratory practice guidelines. PMID:26980105

  11. 14 CFR Section 04 - Air Carrier Groupings

    Science.gov (United States)

    2010-01-01

    ... Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC... carrier to a specific group of carriers will be reviewed periodically by the Director, Office of Airline... Office of Airline Statistics will issue an updated listing of the carrier groups on an annual basis. A...

  12. Spacelab carrier complement thermal design and performance

    Science.gov (United States)

    Bancroft, S.; Key, R.; Kittredge, S.

    1992-01-01

    The present discussion of the Spacelab carrier complement, which encompasses a Module Carrier, a Module-Pallet Carrier, and a Multiplexer/Demultiplexer Pallet, gives attention to both active and passive thermal performance capabilities, and presents ground testing and analytical results obtained to date. An account is given of the prospective use of a Spacelab Multipurpose Experiment Support Structure.

  13. 7 CFR 33.4 - Carrier.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Carrier. 33.4 Section 33.4 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Definitions § 33.4 Carrier. Carrier means any common...

  14. Microplastic pollution in lakes and lake shoreline sediments - A case study on Lake Bolsena and Lake Chiusi (central Italy).

    Science.gov (United States)

    Fischer, Elke Kerstin; Paglialonga, Lisa; Czech, Elisa; Tamminga, Matthias

    2016-06-01

    Rivers and effluents have been identified as major pathways for microplastics of terrestrial sources. Moreover, lakes of different dimensions and even in remote locations contain microplastics in striking abundances. This study investigates concentrations of microplastic particles at two lakes in central Italy (Lake Bolsena, Lake Chiusi). A total number of six Manta Trawls have been carried out, two of them one day after heavy winds occurred on Lake Bolsena showing effects on particle distribution of fragments and fibers of varying size categories. Additionally, 36 sediment samples from lakeshores were analyzed for microplastic content. In the surface waters 2.68 to 3.36 particles/m(3) (Lake Chiusi) and 0.82 to 4.42 particles/m(3) (Lake Bolsena) were detected, respectively. Main differences between the lakes are attributed to lake characteristics such as surface and catchment area, depth and the presence of local wind patterns and tide range at Lake Bolsena. An event of heavy winds and moderate rainfall prior to one sampling led to an increase of concentrations at Lake Bolsena which is most probable related to lateral land-based and sewage effluent inputs. The abundances of microplastic particles in sediments vary from mean values of 112 (Lake Bolsena) to 234 particles/kg dry weight (Lake Chiusi). Lake Chiusi results reveal elevated fiber concentrations compared to those of Lake Bolsena what might be a result of higher organic content and a shift in grain size distribution towards the silt and clay fraction at the shallow and highly eutrophic Lake Chiusi. The distribution of particles along different beach levels revealed no significant differences.

  15. REE Geochemistry of Sulfides from the Huize Zn-Pb Ore Field, Yunnan Province: Implication for the Sources of Ore-forming Metals

    Institute of Scientific and Technical Information of China (English)

    LI Wenbo; HUANG Zhilong; QI Liang

    2007-01-01

    REE abundances in sulfides from the Huize Zn-Pb ore field were determined with the ICPMS after preconcentration. The REE abundances in 26 sulfide samples (including pyrite, galena and sphalerite) are very low, with the ΣREE ranging from 1.6×10-9 to 166.8×10-9. Their LREE/HREE ratios range from 7.6 to 98, showing LREE enrichment relatively. The δEu values are below 1, indicating that they were deposited from an Eu-depleted and reducing fluid-system. Similar to the ore-hosting carbonate strata, calcite separates from carbonate veinlets filling in the fractures or faults crosscutting the carbonate strata also show clear Eu-depletion. This indicates that the carbonate veinlets and their parent fluid was possibly sourced from the strata and inherited the REE geochemical features of the strata. Therefore, REE-geochemical characteristics of both the sulfides and calcites, which were deposited from an ore-forming hydrothermal system, are similar to those of carbonate strata, and strongly suggest that the ore metals were mainly sourced from carbonate strata.

  16. Technical Report on the Behavior of Trace Elements, Stable Isotopes, and Radiogenic Isotopes During the Processing of Uranium Ore to Uranium Ore Concentrate

    Energy Technology Data Exchange (ETDEWEB)

    Marks, N. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Borg, L. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Eppich, G. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gaffney, A. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Genneti, V. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hutcheon, I. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kristo, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lindvall, R. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ramon, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Robel, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Roberts, S. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schorzman, K. C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sharp, M. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Singleton, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Williams, R. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-07-09

    The goals of this SP-1 effort were to understand how isotopic and elemental signatures behave during mining, milling, and concentration and to identify analytes that might preserve geologic signatures of the protolith ores. The impurities that are preserved through the concentration process could provide useful forensic signatures and perhaps prove diagnostic of sample origin.

  17. SIXTH INTERIM STATUS REPORT: MODEL 9975 PCV O-RING FIXTURE LONG-TERM LEAK PERFORMANCE

    Energy Technology Data Exchange (ETDEWEB)

    Daugherty, W.

    2011-08-31

    A series of experiments to monitor the aging performance of Viton{reg_sign} GLT O-rings used in the Model 9975 package has been ongoing for seven years at the Savannah River National Laboratory. Seventy tests using mock-ups of 9975 Primary Containment Vessels (PCVs) were assembled and heated to temperatures ranging from 200 to 450 F. They were leak-tested initially and have been tested periodically to determine if they meet the criterion of leak-tightness defined in ANSI standard N14.5-97. Fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 F. High temperature aging continues for 33 GLT O-ring fixtures at 200-300 F. Room temperature leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 F and higher temperatures, and in 7 fixtures aging at 300 F. No failures have yet been observed in GLT O-ring fixtures aging at 200 F for 41-60 months, which is still bounding to O-ring temperatures during storage in K-Area Complex (KAC). Based on expectations that the fixtures aging at 200 F will remain leak-tight for a significant period yet to come, 2 additional fixtures began aging within the past year at an intermediate temperature of 270 F, with hopes that they may leak before the 200 F fixtures. High temperature aging continues for 6 GLT-S O-ring fixtures at 200-300 F. Room temperature leak test failures have been experienced in all 8 of the GLT-S O-ring fixtures aging at 350 and 400 F. No failures have yet been observed in GLT-S O-ring fixtures aging at 200-300 F for up to 26 months. For O-ring fixtures that have failed the room temperature leak test and been disassembled, the Orings displayed a compression set ranging from 51-96%. This is greater than seen to date for packages inspected during KAC field surveillance (24% average). For GLT O-rings, separate service life estimates have been made based on the O-ring fixture leak test data and based on compression stress relaxation

  18. Composition and origin of Early Cambrian Tiantaishan phosphorite-Mn carbonate ores, Shaanxi Province, China

    Science.gov (United States)

    Hein, J.R.; Fan, D.; Ye, J.; Liu, T.; Yeh, H.-W.

    1999-01-01

    The Tiantaishan phosphorite-Mn carbonate ores occur in the Early Cambrian Tananpo Formation in complexly folded and faulted rocks located in southern Shaanxi Province. About 65 x 106 tonnes of 17% P2O5 ore reserves exist and Mn-ore reserves are about 8.3 x 106 tonnes of +18% Mn. The stratigraphic sequence in ascending order consists of black phyllite, black to gray phosphorite ore, black phyllite, rhodochrostone ore, Mn mixed-carbonates, and dolostone. Data are presented from microprobe mineral chemistry, whole-rock chemistry, stable isotopes of carbonates, X-ray mineralogy, petrographic and SEM observations, and statistical analysis of chemical data. The dominant ore-forming minerals are hydroxy- and carbonate fluorapatite and Ca rhodochrosite, with Mg kutnahorite and dolomite comprising the Mn mixed-carbonate section. Pyrite occurs in all rock types and alabandite (MnS) occurs throughout the rhodochrostone section. The mean P2O5 content of phosphorite is 31% and argillaceous phosphorite is 16%, while the mean MnO content of rhodochrostone ore is 37%. Phosphorite ores are massive, spheroidal, laminated, and banded, while rhodochrostone ores have oolitic, spheroidal, and granular fabrics. The most distinguishing characteristics of the ores are high total organic carbon (TOC) contents (mean 8.4%) in the phosphorite and high P2O5 contents (mean 2.7%) in the rhodochrostone ore. The atypically high TOC contents in the Tiantaishan phosphorite probably result from very strong productivity leading to high sedimentation rates accompanied by weak reworking of sediments; poor utilization of the organic matter by bacteria; and/or partial replacement of bacterial or algal mats by the apatite. The depositional setting of the ores was the margin of an epicontinental seaway created as a direct consequence of global processes that included break-up of a supercontinent, formation of narrow seaways, creation of extensive continental shelves, overturn of stagnant, metal-rich deep

  19. The Patricia Zn–Pb–Ag epithermal ore deposit: An uncommon type of mineralization in northeastern Chile

    OpenAIRE

    Chinchilla, Darío; Ortega, L.; Piña, Rubén; Merinero, R.; Moncada, D.; Bodnar, Robert J.; Quesada, Cecilio; Valverde, Antonio; Lunar, Rosario

    2015-01-01

    The Patricia ore deposit represents an unusual example of economic Zn–Pb–Ag mineralization at the northernmost end of the Late Eocene–Oligocene metallogenic belt in Chile. It is hosted by volcano-sedimentary units, which are typically tuffaceous and andesitic breccias. The ore body consists of a set of subvertical E-W vein systems developed under a sinistral strike-slip regime that included transtensive domains with generalized extensional structures where the ores were deposited. The deposit...

  20. 49 CFR 376.22 - Exemption for private carrier leasing and leasing between authorized carriers.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Exemption for private carrier leasing and leasing... MOTOR CARRIER SAFETY REGULATIONS LEASE AND INTERCHANGE OF VEHICLES Exemptions for the Leasing Regulations § 376.22 Exemption for private carrier leasing and leasing between authorized carriers....

  1. A Lake Dream in Asia

    Institute of Scientific and Technical Information of China (English)

    Yang Wei

    2009-01-01

    @@ When William Wordsworth,representative of Lake Poets wrote his Ode to Night ingale nearby the Lake District of England at the turn of the nine-teenth century,he never imagined a century later,a similar romantic lake dream has been created in China,Asia.

  2. Interesting Ziandao Lake

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    LOCATED in Chun’an County, Zhejiang Province, Qiandao Lake (Lake of a Thousand Isles) is a state-level scenic spot and a bright pearl of the golden tourism line between Hangzhou’s West Lake and Anhui’s Huangshan Mountain. Last autumn, we went to Chun’an. It took only three to four hours by coach to travel from Hangzhou to Chun’an. Flanked by mountains on the west, the small county faces water on the east. A street goes across the county; it takes less than half an hour to walk from one end to the other. Small restaurants and shops line the western side of the road,

  3. Viruses in Antarctic lakes

    Science.gov (United States)

    Kepner, R. L. Jr; Wharton, R. A. Jr; Suttle, C. A.; Wharton RA, J. r. (Principal Investigator)

    1998-01-01

    Water samples collected from four perennially ice-covered Antarctic lakes during the austral summer of 1996-1997 contained high densities of extracellular viruses. Many of these viruses were found to be morphologically similar to double-stranded DNA viruses that are known to infect algae and protozoa. These constitute the first observations of viruses in perennially ice-covered polar lakes. The abundance of planktonic viruses and data suggesting substantial production potential (relative to bacteria] secondary and photosynthetic primary production) indicate that viral lysis may be a major factor in the regulation of microbial populations in these extreme environments. Furthermore, we suggest that Antarctic lakes may be a reservoir of previously undescribed viruses that possess novel biological and biochemical characteristics.

  4. Mercury isotope fractionation during ore retorting in the Almadén mining district, Spain

    Science.gov (United States)

    Gray, John E.; Pribil, Michael J.; Higueras, Pablo L.

    2013-01-01

    Almadén, Spain, is the world's largest mercury (Hg) mining district, which has produced over 250,000 metric tons of Hg representing about 30% of the historical Hg produced worldwide. The objective of this study was to measure Hg isotopic compositions of cinnabar ore, mine waste calcine (retorted ore), elemental Hg (Hg0(L)), and elemental Hg gas (Hg0(g)), to evaluate potential Hg isotopic fractionation. Almadén cinnabar ore δ202Hg varied from − 0.92 to 0.15‰ (mean of − 0.56‰, σ = 0.35‰, n = 7), whereas calcine was isotopically heavier and δ202Hg ranged from − 0.03‰ to 1.01‰ (mean of 0.43‰, σ = 0.44‰, n = 8). The average δ202Hg enrichment of 0.99‰ between cinnabar ore and calcines generated during ore retorting indicated Hg isotopic mass dependent fractionation (MDF). Mass independent fractionation (MIF) was not observed in any of the samples in this study. Laboratory retorting experiments of cinnabar also were carried out to evaluate Hg isotopic fractionation of products generated during retorting such as calcine, Hg0(L), and Hg0(g). Calcine and Hg0(L) generated during these retorting experiments showed an enrichment in δ202Hg of as much as 1.90‰ and 0.67‰, respectively, compared to the original cinnabar ore. The δ202Hg for Hg0(g) generated during the retorting experiments was as much as 1.16‰ isotopically lighter compared to cinnabar, thus, when cinnabar ore was roasted, the resultant calcines formed were isotopically heavier, whereas the Hg0(g) generated was isotopically lighter in Hg isotopes.

  5. Lake Morphometry for NHD Lakes in Great Lakes Region 4 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  6. Low-cost carriers fare competition effect

    OpenAIRE

    Carmona Benitez, R.B.; Lodewijks, G.

    2010-01-01

    This paper examines the effects that low-cost carriers (LCC’s) produce when entering new routes operated only by full-service carriers (FSC’s) and routes operated by low-cost carriers in competition with full-service carriers. A mathematical model has been developed to determine what routes should be operated by a low-cost carrier with better possibilities to subsist. The proposed model in this paper was set up by analyzing The United States domestic air transport market 2005 year database fr...

  7. Carrier synchronization for STBC OFDM systems

    Institute of Scientific and Technical Information of China (English)

    Cai Jueping; Song Wentao; Li Zan; Ge Jianhua

    2005-01-01

    All-digital carrier synchronization strategies and algorithms for space-time block coding (STBC) orthogonal frequency division multiplexing (OFDM) are proposed in this paper. In our scheme, the continuous pilots (CP) are saved, and the complexity of carrier synchronization is reduced significantly by dividing the process into three steps. The coarse carrier synchronization and the fine carrier synchronization algorithms are investigated and analyzed in detail. Simulations show that the carrier can be locked into tracking mode quickly, and the residual frequency error satisfies the system requirement in both stationary and mobile environments.

  8. The Ore Control Factors and the Ore-prospecting Indicators of the Jianchaling Nickel Ore in Shaanxi Province%陕西煎茶岭镍矿床控矿因素及找矿标志

    Institute of Scientific and Technical Information of China (English)

    李静; 董王仓; 郭立宏; 朱伟; 陈艳; 郑向光

    2014-01-01

    Lying in the Mianxian-Lueyang suture zone,Jianchaling nickel ore-forming belt locates inside the Jinjiahe-Tiantaishan Mn-P-Ni prospecting area in a subzone of Mn-P-Cr-Ni-Au mineralization of Mianxian-Lueyang Hercynian-Indosinian ophiolite rock;the origin of the deposit belongs to magmatic liquation-hydrothermal alteration. The main rock is the Proterozoic metamorphic ultrabasic rock, and early nickel-bearing ultrabasic main rock which was later transformed by acidic rocks is the basic metallogenic place.On the whole,the deposit is a large low-grade nickel sulfide ore deposit,associated with low-grade cobalt.By analyzing the ore geotectonic location,the rock body characteristics and the ore body characteristics,the ore control factors and ore-prospecting indicators are concluded.It is believed that the mineralization is controlled by the magnesium ultrabasic rock and the structural fracture zone, and the intermediate-acidic intrusive rock provided the reforming thermal dynamic power for the magnesium ultrabasic rock.%陕西略阳煎茶岭镍矿位于勉略结合带上,成矿区带属勉略华力西-印支蛇绿杂岩 Mn-P-Cr-Ni-Au成矿亚带之略阳金家河-汉中天台山锰磷镍远景区内;矿床成因为岩浆熔离-热液改造型,赋矿岩体为元古代(Pt3)变质(蚀变)超基性岩,早期含镍超基性主岩体是成矿基本场所,后期中酸性岩对超基性主岩体进行改造,总体上为低品位硫化镍大型矿床,伴生低品位Co。通过对矿床大地构造位置、岩体特征、矿体特征等分析,总结了矿床控矿因素及找矿标志特征,认为该矿床成矿作用主要受镁质超基性岩、构造破碎带控制,中酸性侵入岩提供了镁质超基性岩再造成矿所需的热动力。

  9. The flotation of Roşia Poieni copper ore in column machine, with non-polar oils addition

    Directory of Open Access Journals (Sweden)

    Ciocani V.

    2005-11-01

    Full Text Available The most important natural resource of copper in Romania is the ore deposit of Roşia Poieni. At present, the utilization of Roşia Poieni poorphyry copper ore is possible by extraction in quarry of the mass ore and mineral processing into a technological flux with modest results for the value of metal recovery in concentrate 70-72 % and an average contents of 16,5 % Cu. Our researches were directed to studies regarding test and utilisation of special procedure of flotation – addition of the non-polar oil – applied to advanced grinding ore with column type machines.

  10. Gold—depleted Zone and Its Metallogenic Significance,Yinshan Ore Field,Jiangxi Proveince,China

    Institute of Scientific and Technical Information of China (English)

    华仁民; 陈克荣; 等

    1994-01-01

    Based on gold analyses of 213 samples of the Shuangqiaoshan Group in an area of 225km2 with the Yinshan polymetallic ore district as the center, a depleted zone of gold is recognized around the ore district, suggesting that the Shuangqiaoshan Group may be a source bed for gold .Discus-sions were given concerning the alteration-mineralization features of the Yinshan deposit, the ore-controlling mechanism of the NE-trending fault zone and promising targets for further ore pros-pecting.

  11. Ore Zoning and Dynamics of Ore—Forming Processes of Yinshan Polymetallic Deposit in Dexing,Jiangxi

    Institute of Scientific and Technical Information of China (English)

    张德会; 於崇文; 等

    1997-01-01

    The Yinshan deposit,one of the large-scale Cu-Pb-Zn-Au-Ag polymetallic deposits,may be named a middle-low temperature subvolcanic hydrothermal deposit and referred to as the "transitional deposit"linking mineralization of the epithermal and porphyry coppertypes.In this paper,the characteristics and structures of ore zoning are briefly described.On the basis of the dynamics of ore-forming processes and applying computer numerical simulation technique,the mechanism of ore zoning is discussed and a concealed igneous body controlling ore deposition at depth of the Yinshan mine is predicted.

  12. Technologies for lake restoration

    Directory of Open Access Journals (Sweden)

    Helmut KLAPPER

    2003-09-01

    Full Text Available Lakes are suffering from different stress factors and need to be restored using different approaches. The eutrophication remains as the main water quality management problem for inland waters: both lakes and reservoirs. The way to curb the degradation is to stop the nutrient sources and to accelerate the restoration with help of in-lake technologies. Especially lakes with a long retention time need (eco- technological help to decrease the nutrient content in the free water. The microbial and other organic matter from sewage and other autochthonous biomasses, causes oxygen depletion, which has many adverse effects. In less developed countries big reservoirs function as sewage treatment plants. Natural aeration solves problems only partly and many pollutants tend to accumulate in the sediments. The acidification by acid rain and by pyrite oxidation has to be controlled by acid neutralizing technologies. Addition of alkaline chemicals is useful only for soft waters, and technologies for (microbial alkalinization of very acidic hardwater mining lakes are in development. The corrective measures differ from those in use for eutrophication control. The salinization and water shortage mostly occurs if more water is used than available. L. Aral, L. Tschad, the Dead Sea or L. Nasser belong to waters with most severe environmental problems on a global scale. Their hydrologic regime needs to be evaluated. The inflow of salt water at the bottom of some mining lakes adds to stability of stratification, and thus accumulation of hydrogen sulphide in the monimolimnion of the meromictic lakes. Destratification, which is the most used technology, is only restricted applicable because of the dangerous concentrations of the byproducts of biological degradation. The contamination of lakes with hazardous substances from industry and agriculture require different restoration technologies, including subhydric isolation and storage, addition of nutrients for better self

  13. Lakes on Mars

    CERN Document Server

    Cabrol, Nathalie A

    2014-01-01

    On Earth, lakes provide favorable environments for the development of life and its preservation as fossils. They are extremely sensitive to climate fluctuations and to conditions within their watersheds. As such, lakes are unique markers of the impact of environmental changes. Past and current missions have now demonstrated that water once flowed at the surface of Mars early in its history. Evidence of ancient ponding has been uncovered at scales ranging from a few kilometers to possibly that of the Arctic ocean. Whether life existed on Mars is still unknown; upcoming missions may find critic

  14. Sulfate Saturated Hydrous Magmas Associated with Hydrothermal Gold Ores

    Science.gov (United States)

    Chambefort, I.; Dilles, J. H.; Kent, A. J.

    2007-12-01

    Hydrothermal ore deposits associated with arc magmatism represent important sulfur anomalies. During degassing of magmatic systems the volatile may transport metals and sulfur and produce deposits. The ultimate origin of the magma-derived sulfur is still uncertain. The Yanacocha high-sulfidation epithermal Au deposit, Peru, is hosted by a Miocene volcanic succession (ca. 16 to 8 Ma). Magmatic rocks are highly oxidized >NNO+2 and show a range of composition from andesite to dacite. Two populations of amphibole occur in the Yanacocha dacitic ignimbrite deposits (~7 and 12 wt% Al2O3). Low Al amphiboles crystallized at ~ 1.5-2 kbar and 800°C (Plag-Hb thermobarometry) in equilibrium with plagioclase and pyroxene. High Al amphiboles only contain inclusions of anhydrite associated with apatite (up to 1.2 wt% SO3), and have a higher Cr2O3 content (up to 1000 ppm). We estimate these amphiboles form near the magma's liquidus at P(H2O)> 3kbar and 950 to 1000°C of a basaltic, basaltic andesite ascending magma. Low Al amphibole presents an REE pattern with negative anomalies in Sr, Ti and Eu, characteristic of plagioclase and titanite fractionation in the magma. High Al amphiboles are less enriched in REE and have no Sr, Ti, or Eu anomaly. Rare crystals of high Al amphibole display a low Al rim marked by higher REE contents compared to the core and a negative Eu anomaly. Magmatic sulfate occurrences have been discovered through the 8 m.y. volcanic sequence. Rounded anhydrite crystals are found included within clinopyroxene and both high and low Al amphibole. The rare high Al amphiboles (from the sample RC6) contain up to ~10 vol.%, ~5-80 micrometer-long anhydrite as irregularly shaped (amoeboid) blebs that do not show crystallographic forms and do not follow host cleavages. Extremely rare sulfide inclusions are found in plagioclase (Brennecka, 2006). The major and trace element contents of Yanacocha magmatic anhydrite have been analyzed by electron microprobe and LA

  15. Reevaluation of lake trout and lake whitefish bioenergetics models

    Science.gov (United States)

    Madenjian, Charles P.; Pothoven, Steve A.; Kao, Yu-Chun

    2013-01-01

    Using a corrected algorithm for balancing the energy budget, we reevaluated the Wisconsin bioenergetics model for lake trout (Salvelinus namaycush) in the laboratory and for lake whitefish (Coregonus clupeaformis) in the laboratory and in the field. For lake trout, results showed that the bioenergetics model slightly overestimated food consumption by the lake trout when they were fed low and intermediate rations, whereas the model predicted food consumption by lake trout fed ad libitum without any detectable bias. The slight bias in model predictions for lake trout on restricted rations may have been an artifact of the feeding schedule for these fish, and we would therefore recommend application of the Wisconsin lake trout bioenergetics model to lake trout populations in the field without any revisions to the model. Use of the Wisconsin bioenergetics model for coregonids resulted in overestimation of food consumption by lake whitefish both in the laboratory and in the field by between 20 and 30%, on average. This overestimation of food consumption was most likely due to overestimation of respiration rate. We therefore adjusted the respiration component of the bioenergetics model to obtain a good fit to the observed consumption in our laboratory tanks. The adjusted model predicted the consumption in the laboratory and the field without any detectable bias. Until a detailed lake whitefish respiration study can be conducted, we recommend application of our adjusted version of the Wisconsin generalized coregonid bioenergetics model to lake whitefish populations in the field.

  16. BOD determination parameters; BOD. Da cinque giorni a cinque ore

    Energy Technology Data Exchange (ETDEWEB)

    Scarano, E.; Bottari, E.; Mantarro, M. [Rome Univ. La Sapienza, Rome (Italy). Dipt. di Chimica; Pellegrini, G. E. [Istituto Superiore di Sanita' , Lab. di Micologia, Rome (Italy)

    2001-06-01

    An important parameter of those according the law, with regards waste waters and representing a required analytical determination according the national rules on the check of the good working of a depurator is the biological oxygen demand (BOD). The currently applied method is affected by several limitations. It has low accuracy and precision, is strongly depending on the sampling, is time wasting and its application and performance can present different and hard difficulties of execution. However, the result of the analysis cannot be obtained before of five days. By taking into account all these complications, an alternative method is here proposed. The proposed procedure is less manipulative, is more precise and is able to furnish the result within about 5 hours from the start of the chemical analysis. The proposed method was applied successful to sample of a cesspool water depurator and the good results will be shown in the text. [Italian] Uno dei parametri che deve essere valutato per legge nelle acque di scarico e che costituisce una irrinunciabile determinazione analitica per il controllo del buon funzionamento di un depuratore e' la richiesta biologica di ossigeno (BOD, biological oxygen demand). Il metodo generalmente adoperato risulta limitato da una scarsa accuratezza e precisione, e' fortemente dipendente dalle modalita' di prelievo dei campioni, e' laborioso e certamente e' estremamente lungo. Il risultato si puo' conoscere non prima di cinque giorni. Tenendo presente tutte queste limitazioni, viene proposto un metodo alternativo che, essendo meno manipolativo, con una precisione migliore riesce a dare una risposta nel giro di circa 5 ore dall'inizio dell'analisi. Il metodo e' stato applicato con successo alle acque di un depuratore di acque cloacali e se ne riportano i risultati.

  17. Assessment of soda ash calcination treatment of Turkish trona ore

    Directory of Open Access Journals (Sweden)

    Gezer Sibel

    2016-01-01

    Full Text Available Trona is relatively rare, non-metallic mineral, Na2CO3 · NaHCO3 · 2H2O. The pure material contains 70.3% sodium carbonate and by calcination the excess CO2 and water can be driven off, yielding natural soda ash. The terms soda ash and sodium carbonate are used interchangeably. Trona calcining is a key process step in production of soda ash (sodium carbonate anhydrate from the relatively cheap trona ore. The calcination reaction may proceeds in a sequence of steps. Depending on the conditions, it may result in formation of either sodium carbonate monohydrate (Na2CO3 · H2O, sodium sesquicarbonate or weigschederite (Na2CO3 · 3NaHCO3. The Beypazarı Turkish trona deposit is the second largest deposit in the world with the content of 84% trona. The decomposition of trona appeared to be a single stage process across the temperature range studied (150-200 °C with the representative samples of different size fractions in the draught up metallurgical furnace. The optimum particle size and calcination time were −6.35 mm and 30 minutes, respectively, at calcination temperature of 175 °C in a metallurgical furnace. Microwave-induced dry calcination of trona was possible and 5 minutes of calcination time at a power level of 900 was sufficient for complete calcination of −6.35 mm feed. This includes short time calcinations with the goal of improving economics and simplifying the thermal process.

  18. Non-permeable substrate carrier for electroplating

    Energy Technology Data Exchange (ETDEWEB)

    Abas, Emmanuel Chua; Chen, Chen-An; Ma, Diana Xiaobing; Ganti, Kalyana Bhargava

    2012-11-27

    One embodiment relates to a substrate carrier for use in electroplating a plurality of substrates. The substrate carrier comprises a non-conductive carrier body on which the substrates are to be held. Electrically-conductive lines are embedded within the carrier body, and a plurality of contact clips are coupled to the electrically-conductive lines embedded within the carrier body. The contact clips hold the substrates in place and electrically couple the substrates to the electrically-conductive lines. The non-conductive carrier body is continuous so as to be impermeable to flow of electroplating solution through the non-conductive carrier body. Other embodiments, aspects and features are also disclosed.

  19. Non-permeable substrate carrier for electroplating

    Energy Technology Data Exchange (ETDEWEB)

    Abas, Emmanuel Chua; Chen, Chen-an; Ma, Diana Xiaobing; Ganti, Kalyana; Divino, Edmundo Anida; Ermita, Jake Randal G.; Capulong, Jose Francisco S.; Castillo, Arnold Villamor

    2015-12-29

    One embodiment relates to a substrate carrier for use in electroplating a plurality of substrates. The substrate carrier comprises a non-conductive carrier body on which the substrates are to be held. Electrically-conductive lines are embedded within the carrier body, and a plurality of contact clips are coupled to the electrically-conductive lines embedded within the carrier body. The contact clips hold the substrates in place and electrically couple the substrates to the electrically-conductive lines. The non-conductive carrier body is continuous so as to be impermeable to flow of electroplating solution through the non-conductive carrier body. Other embodiments, aspects and features are also disclosed.

  20. Interdependence between iron ore production and maritime transport

    Directory of Open Access Journals (Sweden)

    A. V. Todorut

    2016-10-01

    Full Text Available The maritime industry plays an important role in international trade, transporting a total of 10,1 billion tons of merchandise in 2015, representing over 80% of all global trade, with dry cargo estimated to account for over two thirds of the total seaborne trade. Bulk carriers supply the raw materials needed by the steel industry and container ships transport the steel products. Demand and supply for seaborne transport is influenced by trends in global economy and worldwide demand for commodities. The paper analyzes the most important economic determinants in the supply of metallurgical raw materials, highlighting the importance of the shipping sector.