Search Documents

This Information Circular from the National Institute for Occupational Safety and Health (NIOSH) documents and supplements the information presented in a series of workshops held during 2002 and 2003. The primary intended audience consists of all who are involved in developing and conducting miners? training. According to the Mine Safety and Health Administration (MSHA), mine operators reported 240,000 full-time equivalent workers and independent contractors reported 42,000 full-time equivalent workers working on mine property during the year 2000. Unfortunately, these workers have a relatively high risk of suffering serious work-related injuries and illnesses. The mining industry has the highest rate of occupational fatalities among all U.S. industries. The fatality rate is 30 deaths per 100,000 workers compared to 4.6 for all private industry(Morbidity and Mortality Week Report, 2001; NIOSH, 2002).Compared to workers in other industries, miners also have a relatively high rate of nonfatal lost-time injuries, and their injuries tend to be more severe (Bureau of Labor Statistics, 1999). Many miners are also exposed to significant health hazards, including coal and silica dust, diesel exhaust, and noise. More than 1000 U.S. miners die of lung disease each year(NIOSH, 1999).

Jan 1, 2002

By Jeffrey M. Listak

This report describes a study, conducted jointly by BethEnergy Mines Inc. and the Bureau of Mines, to assess the effects of longwall front abutment loading on various supplemental support materials utilized in a predriven recovery room. The purpose of the predriven recovery room is to reduce longwall equipment transfer time by eliminating the premove preparation associated with conventional recovery methods. In addition, the room provides a large area in which face salvage equipment can maneuver. Results of four recovery-room study areas show the progression and influence of the front abutment on the longwall panel and supports and their subsequent behavior. The best performance (i. e. the support that most facilitated recovery) of support material was achieved through the use of a concrete mixture which had a sand content of 35 percent by volume. The longwall transfer time was reduced by 30 percent which translates to a production advantage of 37,000 raw tons of coal per panel.

Jan 1, 1989

By J. T. Dunham

The Bureau of Mines studied by dilatometry the effect of titanium on the thermal expansivity of hot-rolled zinc and Zn-l percent Cu alloy. The titanium content of the alloys was varied up to 0.3 percent. Expansion coefficients were determined from measurements made both parallel and perpendicular to the plane of the rolled sheet. Titanium reduced expansion parallel to the plane of the sheet, especially in the rolling direction, but increased expansion perpendicular to the sheet. Basal-plane pole figures showed that the degree of preferred orientation increased with the titanium content in the alloy, and that anisotropic expansion can be correlated to sheet texture.

Jan 1, 1965

By C. B. Kenahan

A summary of Bureau of Mines research on recycling, reuse, and disposal of mineral-, metal-, and energy-based wastes is presented, accompanied by an extensive bibliography of related publications. The Bureau's waste recycling and disposal program is directed toward the following four main areas of research and development: (1) extraction of mineral, metal, and energy values from urban refuse; (2) upgrading and recycling of automotive and related ferrous and nonferrous scrap; (3) recovery, utilization, and stabilization of mine and mill processing wastes, and (4) recovery and reuse of values from industrial waste products. This publication updates Bureau of Mines Information Circular 8529, which was issued August 1971.

Jan 1, 1973

By Jheison Lopes dos Santos

Neste trabalho, pela primeira vez, o sistema cerâmico Al2O3-Nb2O5-LiF teve suas propriedades mecânicas investigadas. Foram investigadas diferentes composições, em peso, para o composto (Al2O3–4%Nb2O5)–nLiF, com n variando entre 0 e 1,50%, a três temperaturas de sinterização diferentes (1300, 1350 e 1400 ºC). Como caracterização mecânica, avaliou-se a microdureza Vickers para todas as composições. A adição de LiF que apresentou os maiores valores de densificação teve seus módulos de Young e de cisalhamento, e as velocidades de ondas elásticas determinadas. Os resultados mostraram que todas as adições de LiF elevaram a microdureza do composto Al2O3–4%Nb2O5. Este fato pode estar relacionado com a densificação e fases obtidas após a sinterização. A adição de 0,5% de LiF ao composto cerâmico Al2O3-4% Nb2O5, promovendo maior densificação, quando sinterizado a 1300 ºC obteve valores de propriedades elásticas comparáveis aos obtidos por Al2O3–4%Nb2O5 sem LiF, sinterizado a 1400 ºC. Os resultados relevaram ainda uma coerente correlação entre dureza, módulo de elasticidade e densificação. Dessa forma, a adição de fluoreto de lítio ao sistema cerâmico alumina-nióbia possibilitou a redução em pelo menos 100 ºC na temperatura de sinterização, com propriedades mecânicas comparáveis.

Oct 30, 2017

By Carroll W. DeKock

Thermodynamic data for selected metal sulfates were critically evaluated and compiled as part of the Bureau of Mines program to provide a scientific base for use in developing new technology and predicting the feasibility of new processes. Values for Cp°, S°, H° - H°298, -(G° - H°298)/T, ?Hf°, ?Gf°, and log Kf as a function of temperature are given in tabular form. Thermodynamic data were compiled for VOSO4, Cr2(SO4)3, MnSO4, FeSO4, Fe2(SO4)3, CoSO4, NiSO4, Cu2SO4, CuSO4, CuO-CuSO4, ZnSO4, and ZnO-2ZnSO4, together with their stable hydrates.

Jan 1, 1982

The Industrial Minerals Division met jointly with the Materials and Equipment Division of the American Ceramic Society at State College, Pa, Sept 24-26 Headquarters were at the Nittany Lion Inn Thurs- day afternoon was devoted to a tour of inspection of the Bell Mine, American Lime and Stone Co , Bellefonte, Pa The party returned to State College for dinner and in the evening the Division's executive committee held a brief session There were four technical sessions Friday morning, Mining, afternoon, Beneficiation, Saturday morning, Industrial Minerals and Beneficiation There was an informal banquet at the Nittany Lion Inn Friday night with 93 present Edward Steidle was toastmaster Brief talks were made by President F C Flint and Secretary Ross Purdy, of the American Ceramic Society, Oliver Bowles, Chairman, Industrial Minerals Division, Adrian Morse, assistant to the president, Pennsylvania State College, and George Otis Smith, past president A I R'I E

Jan 1, 1937

The problem of ventilating an advancing drive which finally reached 5,550 ft from the fresh air base in rock with virgin temperature of 83°F was solved economically by the use of two 15 h.p. electric fans forcing ventilating air through 281/2 in. dia. fiexible polythene tubing of wall thickness 0·010 in. The saving in cost over conventional metal duct was estimated to be £3· 24 per ft of drive.INTRODUCTIONAs described by Dutton (1965) and Newton (1965) the existing 1,480' ft level drive at the South Mine, Broken Hill, was extended in two stages. The first extension was 3,790 ft, the face then being 4,790 ft from the fresh air inlet. Later, after a vertical ventilation connection was made 1,000 ft back from the face, the drive was extended a further 4,550 ft. The rate of face advance in both stages was about 15 ft per day (3 shifts of 5 ft), 5 days per week. Drive size was 8 ft by 9 ft 6 in. high.The Mines Inspection Act of New South Wales requires 6 hr shifts (instead of the normal 7 in Broken Hill) to be worked if the wet bulb temperature exceeds 80°F. Virgin rock temperature on the 1,480 ft level was 83°F. Inlet air temperature varied with seasons from 58 to 72,oF wet bulb.To adequately ventilate the face, a flow of air of about 11,000 c.f.m. was thought to be necessary.Re-entry time was about 75 min, being governed by the 7 hr length of shift (3 shifts per day) and travelling time.Blasting was permitted only at the end of the shift, in accordance with local industrial restrictions.

Jan 1, 1965

By Mozart Henrique Teixeira

As reservas de minério de ferro da Mineração Usiminas S.A. (MUSA) estão localizadas no extremo oeste do QF e ocupam a porção ocidental da Serra do Curral (Alkmin, 2009 [1]), também chamada Serra Azul e inseridas no Supergrupo Minas / Formação Cauê. Abrangem as Minas Oeste, Central e Leste. Atualmente a classificação geológica industrial adotada pela empresa leva em consideração o teor de ferro, contaminantes e compacidade (granulometria) das rochas. Os minérios são separados em dois domínios litológicos, hidratado e silicoso. Estes domínios apresentam comportamento granulo-químico fortemente heterogêneo tanto lateral como em profundidade (Teixeira, 2015 [2]), este comportamento confere ao planejamento da lavra elevado grau de dificuldade em relação às estimativas de massas e teores no que se refere à separação dos estéreis e minérios. Até novembro de 2015 o Planejamento de Lavra de Curto Prazo utilizava modelos de blocos atualizados mensalmente para a liberação de planos de lavra mensais e estimativas de teores do ROM, porém, ao longo do mês os desvios de teor na alimentação da planta e dificuldades na execução da geometria planejada eram frequentes. Diante disto, com foco na redução destes desvios, passou-se a gerar os modelos de blocos semanalmente para confecção de programações de lavra semanais e diárias com expectativa de liberação de estimativas de massas e teores com maior grau de confiança e melhor previsibilidade das características granuloquímicas dos produtos finais. Para a elaboração dos modelos semanais foram adotados novos métodos nas ferramentas de topografia, amostragem de frentes de lavra e mudança na rotina do mapeamento geológico, que passaram a ser executados semanalmente. Os resultados obtidos foram as reduções de desvios de teores na alimentação dos processos unitários das plantas e na produção de granulados.

Oct 30, 2017

This paper summarizes seven years of Italian ex­perience with the use of large calibration chambers for the calibration, under closely controlled stress and strain conditions, of some in situ testing devices which are used in sand deposits. At the present time two calibration chambers are operating in Italy, one at E.N.E.L.-C.R.I.S. (Milan) (*) and the other at I.S.M.E.S. (Berga­mo) (**). Both chambers can accomodate cylindrical samples 1.2 m in diameter and 1.5 m in height. A detailed description of these chambers can be found in Bellotti, et. al (1982).

Jan 1, 1987

The Annual General Meeting of the South African Institute of Mining and Metallurgy was held in Kelvin House on Wednesday, 22nd August, 1979. Dr M. G. Atmore (President) was in the chair and declared the meeting open at 16h00. Obituaries President: It is my sad duty to announce the death of the following Members of the Institute : Brigadier R. S. G. Stokes, Honorary Life Fellow and Past President ; J. A. Arthur, C. L. Cartwright, R. B. Greaves, A. A. Haynes, G. Ross, M. W. Richards, W. T. Stobart, E. Veres, G. V. White, and A. G. Williams, Life Fellows; A. J. H. Pole, D. T. McMurray, P. G. O. Pretorius, A. E. D. Rubidge, A. M. Seccombe, and R. R. Uren, Fellows; R. E. Oltman, R. B. Richardson, and G. P. Rundle, Members; S. F. Dench and S. van Wyk, Associates. As a mark of respect to the memory of the deceased, and in sympathy with the bereaved, please rise and observe a few moments' silence. Minutes President: May we confirm the minutes of our last Annual General Meeting, which was held on 23rd August, 1978, as published in the November issue of the Journal? Agreed.

Jan 1, 1979

By Flaviana Dias Rocha Pimenta

Com o objetivo de adequar a logística interna ás particularidades e variabilidade das demandas de movimentação interna de produto, a VBR (Vallourec Tubos do Brasil S.A) estudou em parceria com o operador logístico TRADIMAQ um novo modelo de equipamento que atendesse todas as regras internas de segurança e as diversas restrições em sua operação. O presente trabalho tem como objetivo apresentar as diferenças entre o modelo anterior utilizado para a movimentação interna e o atual modelo implementado no final de 2015, bem como todas as alterações necessárias entre o projeto conceitual e o equipamento em operação atualmente.

Aug 17, 2017

By Honeycombe R. W K, Greenwood J. N

Powder metallurgy has been developed rapidly in the last twenty years by overseas metallurgists. The technique of making the powders and their subsequent pressing and sintering into useful forms has' only been introduced into Australia under the stress of war-time economic conditions.The technique involved has very little in common with our usual methods of fabricating engineering alloys by melting the ingredients to a homogeneous mass, followed by casting to shape or casting to ingot form and shaping by application of pressure-so-called mechanical working. On the other hand, the technique includes operations, such as milling and sizing, familiar to the primary metallurgists.The compacting of metal or other powders finds important application in two outstanding fields of engineering production: (a) in making porous bearings and contact brushes, in which such a material as powdered graphite can be incorporated; (b) in making cutting tool tips of hard -carbides, which have a melting point too high to make casting feasible, and which would be too brittle in the cast condition in any case. In both these cases; the final article can be made of the desired shape and size (subject to shrinkage allowances) whilst the compact is in a soft and readily machined condition a consideration of great importance in connection with the hard carbides.In order to develop the necessary equipment and technique and at the same time to assisil in the war effort, it was decided to divert the research work of the Metallurgy Department of the University of Melbourne to the problems associated with the production of hard carbides from local raw materials and the sintering of such into tips for cutting tools. Since this work was started at least two industrial concerns have started to produce these materials in the Commonwealth.The work. to date has included (a) the purification of crude cobalt oxide from Risdon and the reduction of this to metal Particles of less than 10 p. diameter; (b) the production of tungsten powder from King Island scheelite and its conversion into tungsten carbide with particle size less than 4 p. diameter; (c) the sintering of the latter product, using the former as a bond; (d) the production of titanium carbide from titanium dioxide; (e) the separation of columbium and tantalum oxides from a Northern Territory tantalite, and the conversion of these into the respective carbides.

Jan 1, 1942

AIME 1953 DIRECTORY SUPPLEMENT COMMITTEES NOMINATING E. H. Rose, Chairman R. E. Byler J. F. Myers Grover Molt S. W. Engelmann S. J. Swainson EDUCATION A. C. Dorenfeld, Chairman G. P. Lutjen A. E. McHugh H. Rush Spedden T. G. Chapman T. M. Morris T. Barker S. R. B. Cooke W. O. McClintock

Jan 1, 1953

By Bruce Richardson

A contractor-manufactured 4.75m (15'-7") diameter EPB shield excavated a 115m (375 ft) long tunnel under the San Antonio River as part of the Salado Creek to Dos Rios Pipeline Interconnect Project in San Antonio, Texas. Lignite, limestone concretions, and sandstone in the face of the tunnel required the use of disc cutters. Less than 7.6m (25 ft) of sand and gravel hydraulically connected the top of the tunnel to the channel of the river. Fully lagged steel ribs with filter fabric were used for initial ground support and water control. This and other contractor manufactured TBMs in the 1.2 to 4.75m (4 to 16 ft) range are presented with descriptions of the jobsites, equipment, performances, and problems.

Jan 1, 2008

By L. A. Neumeier

The Bureau of Mines evaluated the properties of a Zn-0.75 pct Cu-0.12 pct Ti alloy extruded at temperatures between 400° and 720° F. The extrusions were made with a reduction ratio of 28-to-l and at relatively slow speed. Rod was also extruded at 560° and 640° F with a reduction of 255-to-l. With increased extrusion, temperature, extrusion pressures decreased substantially and creep resistance of the rod improved significantly. Coefficients of thermal expansion were low in the long rod dimension. Microstructures, hardness, and tensile properties were also evaluated, and a limited evaluation was made of bend ductility at 32° F for the rod extruded with the 255-to-1 reduction.

Jan 1, 1969

By E. V. Leont'eva, V. R. Vafin, A. G. Kladova, N. L. Medyanik, A. P. Ponomarev

"The thermochemical technology for recovery gold, silver from mature flotation tailings of pyrite ores by two-stage sintering with chlorine-ammonium reagents and leaching of bakes with water is developed. The economic effect of the technology implementation is calculated. KEYWORDS Gold and silver recovery, mature flotation tailings, pyrite ores, chlorine-ammonium reagents, leaching INTRODUCTION The relevance of processing the technogenic reserves of ore mining and concentration wastes accumulated over the long operation periods of mineral deposits is beyond doubt. Hundreds of tons of precious and non-ferrous metals that were not recovered during the primary processing are concentrated in the accumulated wastes. For example, tailing storage facilities (TSF) at the mineral processing plants in the Southern Urals region of Russia hold more than one hundred tons of gold and thousands of tons of silver in the mature flotation tailings (MFT) of copper pyrite ores. Secondary processing of technogenic materials is facilitated by the fact that they are preprocessed — ground and compactly deposited on the surface, but complicated by the low (compared to ores) grade, uneven distribution of the valuable minerals, altered and unstable material composition of the mineral feed. This leads to low recovery rates of valuable metals by conventional physicochemical processing methods. It is necessary to develop innovative methods of deep integrated processing of industrial wastes, based on the study of the material composition of specific technogenic mineral resources and based on ensuring the environmental safety of the resulting secondary waste. MATERIALS AND METHODS The object of this study are the MFT of Uchaly Concentrator in the Republic of Bashkortostan, Russia, which processes copper pyrite and copper-zinc ores. According to the data of particle size, chemical, X-ray phase, and optical microscopic analyzes, samples of the MFT are characterized by considerable particle fineness (the fraction of the size class -41 µm is 89-90%), low grade of gold (1.7-2.0 g/t) and silver (18.0-19.5 g/t), comparable grades of iron (23.0-26.8%) and sulfur (28.1-28.7), but different grades of copper (0.12 - 0.73%) and zinc (0.34-1.26%). The most common mineral in the samples is pyrite (50 - 56%), found in intergrowth with grains of other sulfides (0.1-4%) - sphalerite, tennantite, chalcopyrite, covellite. Quartz and aluminosilicates are the dominant rock minerals (21-36%). Based on the results of the phase analysis, it was established that approximately 70% of the gold in the samples is found in a form that is resistant to cyanidation — it is locked in sulfides (52-56%) and quartz and coated by films. Along with sulfides and rock minerals, common gold and silver minerals (chalcogenides, intermetallides, native gold) in the form of submicro- and nano-sized precipitates are also associated with intergrowth of a complex structure. These features of the material composition allow classifying the MFT of the pyrite ores as a mature feed material and emphasize the need for chemical non-cyanide methods to recover gold and silver from the mature minerals and associations they are found in."

Jan 1, 2018

By Chester L. Arnold, Reinhardt Thiessen, Alexander Lowy

"INTRODUCTION Peat is the accumulated mass of plant materials that remain after partial decay under specific conditions. In the swampy peat bogs dead material which falls on the surface immediately is attacked by fungi and aercbic bacteria. Decay under these conditions is rapid, but of relatively short duration, since the constant addition of new material soon forces the older layers below the water level, in this position, without access to oxygen, the plant constituents are attacked mainly by anaerobic bacteria, and decomposition proceeds slowly. The largest part of peat is contributed by the woody tissues of plants, the chief constituents of which are cellulose and lignin, together with a small proportion of hemicelluloses. During the normal process of biological decay celluloses disappear more rapidly than lignin. The result is a complex substance known as humin, from which the humic acids may be extracted.In 1826, Sprengel 5 found that when decayed plant materials were extracted with alinnli and the resulting black liquid acidified with mineral acid a brown gelatinous precipitate was formed. To this product, which was a brown amorphous powder when dry, he gave the name ""humic acid'. Since that time, chemists have used the name rather loosely to designate products which have been isolated by very diverse means from soils, decayed woods, peat, lignite, and coal. An excellent review of the early work on humic acids was published by Baumann 6 in 1909. This publication aroused the interest of Oden, who then investigated the humic acids. An account of Oden’s work, as a good survey of the literature, is contained in his monograph “Die Huminsauren”. 7"

Nov 1, 1934

By D. A. Paice

Direct current electrical systems are used in most coal mines primarily to power the main haulage trains and secondarily to feed other equipment and passageway lighting. Electrical power is supplied from rotary machines or static rectifier equipment and is distributed through the mine by open trolley wires and feeder cables. The rails of the haulageway are used as a current return path. This exposed power distribution system is very vulnerable to conditions which lead to undesired leakage currents and short circuits and, consequently, the possibility of fires or other hazards to personnel. Present techniques and equipment have been utilized in so far as practical to improve the safety of the dc electrical system; however, there still appears a need for further improvement. Because of this need, this program was sponsored by the Bureau of Mines to investigate two specific technical areas related to improvement of dc electrical system safety. One area included the determination of the characteristics of mine electrical systems and their protection requirements and the verification of the adequacy of available protective devices for mine service. Despite the widespread application of industrial protective equipment in mines, there was little detailed technical information available related specifically to the performance of this equipment in service. Our task was not only to develop useful information regarding mine system protection, but also to define and verify the adequacy of the protective devices available. The second area of investigation called for development of a practical technique for detecting low level electrical fault or leakage currents. Conventional protective devices

Jan 1, 2012

By V. McLemore, N. Dunbar, K. Donahue

There are three principle lines of evidence that indicate the clay minerals found in the Goathill North (GHN) rock pile at the Molycorp mine are predominantly a product of hydrothermal alteration, not weathering. The unweathered drill core and samples from GHN have similar types and abundances of clay-mineral groups based on XRD analysis. Chemical analyses from the electron microprobe reveal similar chemical compositions for the hydrothermal alteration clays in drill-core samples and clays found in the rock pile. Textural evidence gathered from petrographic and microprobe examination also suggests a hydrothermal origin for clay minerals.

Jan 1, 2007