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By A. C. Johnson

This report is one of a series being prepared by the Bureau of Mines on exploration, development, mining methods, and costs at various mines in the United States. It describes operations at the Black Rock mine, Wah Chang Mining Corp., Mono County, Calif. The purpose of these reports is to promote development and conservation of our mineral resources by disseminating technologic information on mining methods, practices, and costs. The Black Rock tungsten mine of the Wah Chang Mining Corp. is 33 miles north of Bishop, Calif., in the Benton Range, Mono County, Calif. The property was acquired in August 1950 and a well-planned program of exploration, development, and exploitation resulted in a good production record with low costs. Operations were halted in July 1957, about 6 months after suspension of the tungsten purchase program by the Federal Government.

Jan 1, 1960

By Ali Tabeshian, Ragnhild E. Aune, Reza Beheshti

Today’s lithium-ion batteries (LiBs) are found in more than half of the hybrid-electric and plug-in hybrid vehicles on the marked, all-electric vehicles, and nearly all consumer electronics. As a result, recycling of LiBs will be a strategic necessity in the near future. In the present study, the feasibility of application of conventional aluminum recycling process (secondary aluminum production) as a suitable process for treatment of LiBs was studied. The overall idea is to recover aluminum, copper and lithium from a mixed waste stream of LiBs and aluminum scrap. A two-stage process, consisting of a preheating step and a melting step, were tested on cell phone batteries mixed with pure aluminum in a ratio 1:10 and the distribution of elements between the metal phase and the slag phase evaluated. The obtained results are compared and discussed based on the thermodynamic calculated by the use of the FactSage™ software version

Mar 1, 2017

By Luiz Augusto Ferreira de Campos Viana

O processamento de aços ARBL (Alta Resistência Baixa Liga) para fabricação de bens de capital de dimensões avantajadas pode sobrecarregar máquinas operatrizes de indústrias do setor metal-mecânico. Uma rota alternativa para processamento deste material é a conformação do mesmo a temperaturas elevadas (processamento "a morno"), para redução de seu limite de escoamento e consequente diminuição do esforço nos equipamentos. Entretanto as propriedades mecânicas destes materiais devem ser mantidas após seu retorno à temperatura ambiente. Neste trabalho um aço ARBL temperado e revenido foi submetido a 1, 3, 5, 7 e 9 ciclos térmicos, com a soma do tempo de todos os ciclos térmicos igual a 10 horas e temperatura de 580°C. Em seguida ensaios mecânicos de tração, impacto em corpos de prova Charpy-V e dureza Vickers foram executados. A caracterização microestrutural e análises fratográficas dos corpos de prova de tração e impacto foram realizadas por meio de microscópio eletrônico de varredura (MEV). A análise microestrutural revelou o coalescimento de partículas de cementita em todas as amostras. A resistência mecânica dos corpos de prova submetidos a 1, 3, 7 e 9 ciclos caiu. A energia absorvida no ensaio de impacto aumentou para estas amostras. O corpo de prova submetido a 5 ciclos térmicos apresentou endurecimento secundário. A fratografia de todos os corpos de prova ensaiados a tração revelaram fratura dúctil. O mesmo ocorreu para os corpos de prova submetidos ao ensaio de impacto, exceto para os corpos de prova submetidos a 5 ciclos térmicos. Em nenhum dos casos ocorreu descaracterização do material com quedas nos limites de resistência a valores inferiores aos especificados pelo fabricante.

Aug 16, 2017

By Huldrych W. Kobe

"El presente estudio señala la comparación entre la enargita-ortorrómbica y la luzonita tetragonal como minerales pertenecientes al grupo de los sulfuros. Sin embargo, luego de un riguroso estudio se comprobó que estos minerales no son similares pues no tienen un sistema ontorrómbico. Los minerales que cristalizan en la misma estructura que la luzonita famatinita tienen una celda unitaria doble y son la calcopirita, estanita y otros. Mientras que la tetraedrita-tennantita cristaliza en la estructura de la esfalerita con celda unitaria. A esto, se suma la dificultad de flotación que presenta la luzonita en comparación con la enargita debido al contenido en ciertos elementos en la luzonita. Finalmente se describen propiedades de ambos minerales y se agrega estudios sobre los derivados de las mallas cristalinas, polimorfismo entre el tipo wurtzita y esfalerita y flotación, respectivamente."

Jul 20, 1961

By Arcy R., D&apos George

The Bureau of Mines has developed, on a laboratory scale, a superior Eluex-type circuit for eluting and recovering uranium from ion exchange resins. The improved circuit differs from conventional Eluex practice in that a stage of uranium solvent extraction is coupled with each stage of resin elution rather than the elution and solvent extraction operations being conducted separately. The new system reduces the number of stages, retention time, and resin inventory in the elution circuit to one-fourth or one-fifth that in existing circuits. The system is applicable to both resin-in-pulp and moving-bed-type ion exchange uranium recovery circuits.

Jan 1, 1969

By Tina Maniatis

Applied Biosciences has developed a biological technology for removal of arsenic, nitrate, selenium, and other metals from mining and industrial waste waters.The ABMet® technology was implemented at a closed gold mine site in Canada for removing arsenic from tailings pond water. The system included six bioreactors that began treating water in the spring of 2004. Design criteria incorporated a maximum flow of 567 L/min (150 gallons per minute) and water temperatures ranging from 10°C to 15°C. Influent arsenic concentrations range from 0.5 mg/L to 1.5 mg/L. The ABMet® technology consistently removes arsenic to below detection limits (0.02 mg/L). Data from the full scale system will be presented, as well as regulatory requirements and site specific challenges. Keywords: Arsenic, Sulfate Reduction, Metal Sulfide Precipitate, Biological Water Treatment

Jan 1, 2005

By Davis E. Traut

TiC14, AIC13, and VC14 were coreduced simultaneously via a Kroll-type magnesium reduction to form an alloy sponge as part of a research effort by the Bureau of Mines to produce titanium alloy powder. Reduction tem-peratures of 750°, 850°, and 950° C, a range of chloride feed rates from 34 to 152 Ib/(ft2·h), and crucible diameters of 7-3/4 and 10-1/4 in were tested. Microprobe analyses using a 40-um-diam spot showed no effect on alloy microhomogeneity (distribution of Al and V in the Ti, considered critical as a powder property), due to changes in process variables within these ranges. Statistical analysis of these data for alloy sponge indicated greater variation in the chemical composition (AI and V) than that found in commercial Ti-6Al-4V plate or Plasma Rotating Electrode Process (PREP) powder. Therefore, a one-step approach to pow-der, such as grinding the Ti alloy sponge, would not produce a powder product of acceptable chemical homogeneity. An approach that homoge-nized the sponge, such as with a melting step, would produce an accept-able powder product with respect to chemical homogeneity.

Jan 1, 1987

By Pierre Buteau

Peat/ands distribution in Canada is widely spread thoughout the country and corresponds to a wide spectrum of wetland habitats which overlay peat deposits. The development and the evolution ofpeat/ands and peat deposits are closely linked together, since the vegetal remains of the peat deposits originate from the peatland habitats, and the peatland habitats constitute a response to many factors, including the properties of the substrate, which are the peat deposits. Peat/ands are defined as waterlogged terrains where the production of plant materials usually exceeds the rate of decomposition. The underlying peat deposits consists of organic residues associated to peatland vegetation, more or less decomposed, built up and kept under anaerobic conditions. Peat/ands evolution and distribution are determined primarily by climatic factors, but also by the geomorphology and edaphic conditions. All of these create particular hydrodynamical environments which will vary according to different regional settings, and sequentially to an evolutive time frame.

Jan 1, 2001

By David C. Byrne

PURPOSE: Evaluate practical technological advances in level-dependent hearing protectors and inexpensive personal acoustic monitors. RESEARCH SUMMARY: The results of previous NIOSH research show that miners develop hearing loss much more quickly than nonoccupationally noise-exposed individuals and that miners experience a greater severity of hearing loss than would be expected for nonoccupational noise-exposed persons of the same age and gender. Using hearing thresholds at 4,000 Hz as an indicator, coal miners experience hearing loss 2.5 to 3 times greater than would be expected for persons not exposed to occupational noise. At age 50, 90% of coal miners and 49% of metal/nonmetal miners were found to have a hearing impairment. In comparison, only 9% of a nonoccupationally exposed control group had a hearing impairment at age 50. There are numerous barriers to the prevention of hearing loss among miners. In an effort to overcome some of these obstacles, this work was initiated to evaluate practical technological advances in level-dependent hearing protectors and inexpensive personal acoustic monitors. Experiments will involve analysis of this new technology under both laboratory and field conditions. Laboratory components will consist of controlled studies using an anthropometrically correct test fixture as well as human subjects to evaluate the adequacy/effectiveness of various hearing protective devices. Electroacoustical performance testing of new noise monitors will also be conducted in a laboratory setting. Subsequent field studies will determine the actual usefulness and practicality of the personal protective/monitoring equipment as used in different mining situations. It is anticipated that increased on-the-spot awareness of hazardous noise levels and the availability of better-suited hearing protectors will provide a degree of protection beyond what is currently attained in different mining environments. Therefore, the intent of this project is to identify and adapt new acoustical technologies and products that have a direct application to individual mine workers. With increased knowledge of these technological advances, a greater demand for similar devices will likely occur, which, in turn, will lead to a better understanding and awareness of hearing loss prevention methods throughout the mining community. The ultimate goal is for widespread integration of useful hearing loss prevention products and devices into the daily routines of miners

Jan 2, 2000

By A. E. Flynn

THERE is at the present time a revived interest in amalgamation, due to the number of mines starting up, usually on high-grade ore, and utilizing this relatively cheap and convenient means of recovering gold, more especially in their initial stages of production. The marked increased use of the amalgamation process has revealed a dearth of amalgamators and there is no doubt the art of amalgamation has stood still for a generation or two and is not readily applicable to the modern practice of milling gold ores. Mill operators of long experience are learning the art for the first time and are giving it intelligent study, and considerable testing and research work is now being undertaken Most millmen consider amalgamation a simple process, and so it is when we have a clean ore with coarse gold, specially when stamps are used for crushing. In treating Nova Scotia ores by stamps and amalgamation, recoveries of 95 to 97 per cent are common and easily obtained. So-called 'under-water feed' is almost universally used in Nova Scotia and is quite beneficial. The water is supplied through jets between the dies and below the die surface and maintains this space as a live trap which catches the gold particles before they are overground and spoilt for amalgamation. With this method, the portion of gold recovered in the battery is higher than usual and often amounts to 80 per cent of the total gold in the ore, the remaining 20 per cent being caught on the plate. As a continuous amalgamator, the simple plate cannot be excelled. Some of the modern devices having moving or covered and not very accessible plates, which cannot be readily inspected and dressed to keep them in condition, do not give the best results in service. An exception might be drawn in the case of amalgamation of very heavy ore or concentrate which would bank up unless the plate is carried at such a steep inclination as to weep mercury. Difficulties in stamp-mill amalgamation are encountered when acid water is used or when grease is present. Also, certain sulphides and graphitic and talcose ores give trouble, resulting in poor gold recovery and high mer-cury loss. The older literature on gold milling deals with the common troubles of this type and the old-time amalgamator was well able to take care of day-by-day difficulties. When the difficulties were unsurmountable, the ore was classed as 'refractory' and other processes were used.

Jan 1, 1939

By N. A. Eilertsen, Rolf S. Paine

The Bureau of Mines studied the presplitting technique used for controlling overbreakage in the walls of a vertical shaft at the U.S. Army Corps of Engineers Littleville Dam project near Huntington, Mass. The periphery of the shaft, the dimensions of which were 16-1/2 feet wide by 21 feet long and 52 feet deep, was presplit (cracked) in the solid to a depth of 48 feet prior to full-depth sinking. Presplitting prevented overbreak in a fairly soft schist and provided sound self-supporting walls which required very little scaling.

Jan 1, 1965

By W. H. Morris

I have been requested to present a paper on the slag from the basic Bessemer process, as prepared for fertilizing. Since Professor W. B. Phillips presented at the Birmingham meeting, in May, 1888, an able paper* on this subject, as it had been developed up to that time, there is little for me to add. Perhaps later practice may be best expressed by the homely proverb, " The proof of the pudding is in the eating." As the Pottstown Iron Company is the only concern manufacturing basic Bessemer slag in this country, the writer's personal experience in the use of it may be interesting. Our slag averages: P2O5, 21.37; SiO2,, 5.10; MgO, 5.90; Al2O3, 4.01; MnO, 5.56 ; FeO, 12.00; Na2O and K2O, 0.80; CaO, 45.26; total, 100.00. This gives over 76 per cent. of phosphoric acid and lime. In using this material for several years past on my lawn and garden, I have found it better than anything else I have ever tried ; and I am sure that any of you who had seen my green grass last month (January), wherever the ground was bare from snow, as bright as in early fall, would be forced to acknowledge the advantages of this soil-enricher. The grass on my private lawn, and around the company's office, is green the whole winter; and we have raised very good sod, by the use of this phosphate, where, without it, we were unable to get the grass to grow either from seed or by repeatedly sodding. The same statement applies to garden-truck; when the soil was first broken up, a good crop of vegetables was easily raised. My own gardener has had several premiums from Philadelphia seedsmen (notably, last year, the first premium for sugarcorn raised in the first part of July, being the first sample sent them). Our method of applying this material is to grind the slag very finely, so that at least 60 per cent. of it will go through a 150-mesh screen (i.e., say, 22,500 meshes to the square inch), and 90 per cent. through a 100-mesh screen (i.e., 10,000 meshes to the square inch). This fine grinding seems to be the main condition of success.

Jan 1, 1893

By M Grigorescu, J H. Hodgkinson, H Alehossein

A new framework that collates and interprets pre-existing data to assess vulnerability and ultimately plan to avoid or minimise flood-related risk to infrastructure, people, downtime, environment and revenue has been developed. The æClimate Related Adaptation from Terrain Evaluation ResultsÆ (CRATER) method tested at a coal mine in Queensland, provides semi-quantitative information to assist decision makers when designating investment for minimising vulnerability of mining operations to climate. Here we present the processes involved in this three-step approach that uses pre-existing spatial data of the mine site and local knowledge to build a set of visual tools to assist decision-making. The first step of the process is performing multi-criteria evaluation (MCE) within a geographic information system (GIS) on ranked natural conditions at the mine, such as elevation, slope, drainage, soil and vegetation, which is performed to identify critical flood areas. Secondly, a fault-tree analysis identifies how impact can occur and what options there are for impact reduction. Finally, a resource assessment of the mineÆs capacity to adapt reduces the adaptation options to those most suited to the mine. The results are confidential, but for the purpose of introducing the methodology, we present simplified results, particularly of steps 2 and 3. CRATER can also be used for future æwhat-ifÆ flooding scenarios to identify the most suitable locations for roads, buildings or other critical infrastructure. The methodology is transferable to any mine, series of mines or locations along the mining value chain that have sufficient data, providing a practical decision-making tool to identify æno-regretsÆ actions that not only could reduce downtime after or during an event, but in some cases may enhance production between extreme events. We now plan to test this method at a broader scale, to encompass more than one mine in the analysis.CITATION:Hodgkinson, J H, Grigorescu, M and Alehossein, H, 2013. Climate Related Adaptation from Terrain Evaluation Results (CRATER) - interpretation of pre-existing data for mine site flood vulnerability and management, in Proceedings Water in Mining 2013 , pp 259-266 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By Verônica Silva Costa Medeiros

O chamote é um resíduo proveniente da indústria cerâmica, classificado como material não-plástico. Tal rejeito pode ser retornado ao processo de produção de cerâmicas, substituindo parte da matéria-prima convencional. O objetivo deste trabalho foi avaliar a incorporação de chamote nas propriedades físicas e mecânicas de peças cerâmicas sob três temperaturas de queima distintas: 850°C, 950°C e 1050°C. As matérias-primas utilizadas na pesquisa foram caracterizadas quanto à granulometria, limites de consistência e composição química por meio de EDX. Foram propostas três misturas, contendo 0%, 13,33% e 40% do resíduo. Corpos de prova prismáticos foram produzidos por prensagem e, após, realizou-se os ensaios de determinação da retração na queima, índice de absorção de água e resistência à flexão. Os resultados revelam que, quanto maior a temperatura, maior a retração linear na queima e a resistência à flexão em todas as misturas. Em relação à absorção, foram observados menores valores a 1050°C, devido ao processo de vitrificação. Verificou-se que a adição de chamote reduz a retração; no entanto, reduz também a resistência mecânica. Dentre as misturas com resíduo, a composição com 13,33% apresentou melhores resultados, sobretudo sob a temperatura de 1050°C.

Oct 30, 2017

By Charles W. Goodale, William A. Akers

The treatment of silver-ores of too low a grade to justify either smelting or preliminary roasting, and yet not " free" enough to permit of raw amalgamation, has ever been a serious problem. As bearing upon it, the operations of the Combination Mining and Milling Company of Black Pine, Deer Lodge county, Montana, during the past year may not be without interest. It is not claimed that the process to be described is not susceptible of great improvement, nor is any claim of originality made for it; but its use is, as yet, not very general, and it seems to offer a means of profitably working the large class of partially-decomposed argentiferous ores which, by reason

Jan 1, 1890

By Lars A. Bergstrom

High-voltage direct -current transmission is a relatively new technology. The successful development and operation of AC/DC converters, capable of handling large power blocks, have made HVDC transmission generally accepted by utility engineer s and planners around the world. HVDC technology still has significant development potential and, as a result, it is expected that equipment costs will escalate at a substantially slower rate than those of conventional AC equipment. This development will also result in still more compact terminal stations. This paper reviews two modern HVDC installations. In Zaire in Africa. a 1700-km overhead DC line rated at 500 kv, will supply power to the copper mining district in the Shaba region. Another HVDC link connects Norway and Denmark through a submarine cable rated at 250 kv. This is the longest HVDC cable in the world, 127 km, and the water depth , maximum 530 m, is also much greater than for any previous similar cable. The reasons for selecting HVDC are discussed, and the design and layouts are presented.

Jan 1, 1978

By Charles Albert Ashburner

The coal-fields of the United States have been variously classified as to their geographical positions. In 1887 I proposed slight changes to the classification generally used, for more convenient description of our coal-fields in my report on the statistical history of coal in the States during 1886 for the United States Geological Survey. This new classification seems to meet all practical requirements and has been generally adopted. The coal-areas are grouped in two divisions—the anthracite division and the bituminous division. The anthracite division, in a commercial sense, may be said to include the anthracite districts of Pennsylvania alone, although small amounts of anthracite are mined in Colorado and have been

Jan 1, 1890

By Enrique Pasquel Carbajal

El presente texto describe los resultados realizados por el Centro de Investigación tecnológica del Cemento y del Concreto (CIDETEC) sobre el empleo de microalfiler de carbonato de calcio como adición mineral para mejorar las propiedades reológicas en estado fresco y endurecido del shockrete empleado en las labores de sostenimiento en la industria minera. Asimismo, se señalan la aplicación de esta tecnologías en proyectos mineros como Cobriza, Andaychagua, San Cristobal y Pallancata.

Sep 12, 2011

By William D. Riley

In order to evaluate the corrosion resistance of zirconium in mineral extraction processes, such as a clay-hydrochloric acid leaching process for extracting alumina, the Bureau of Mines conducted corrosion studies in HCl-AlC13-FeC13 environments. A series of weight loss and electrochemical tests were conducted at 25° and 65° C in aluminum chloride (AlC13) plus hydrochloric acid (HCl) solutions containing 0 to 1,000 ppm ferric ion. It was determined that zirconium, which normally exists in a passive state in chloride-containing solutions, undergoes pitting attack in solutions containing more than 100 ppm of ferric ion. It is also shown that an oxide film prepared in air at high temperature offers protection in acid solutions containing levels of ferric ion from 300 to 1,000 ppm.

Jan 1, 1981

By Fredy Llerena B.

El presente trabajo describe la geología del depósito minero Candelaria, perteneciente al distrito minero de Castrovirrey, Huancavelica. Dicho depósito está asociado a la actividad ígnea de centros y domos volcánicos del terciario medio o superior, mientras que la veta Candelaria está constituida por tetrahodrita, enargita, boulangerita, bournouita, jamesonita, esfalerita, galena, bismutinito, chalcopirita y como minerales de ganga, pirita, cuarzo, barita, oropimente, regelgar, marcasita, arsenopirita, así como hay lazos cimoidea. De otro lado, las intersecciones de vetas favorecen la mineralización y el Domo Volcánico Candelaria es favorable a la mineralización al igual que los tufos.

Oct 14, 1980