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By John F. McCoy

The U.S. Bureau of Mines (USBM) awarded? a contract to Foster-Miller, Inc. to develop guidelines for designing, constructing, stocking, and maintaining rescue chambers in underground mines. This report develops information and recommendations which could be used by a mine operator who desired to install a rescue chamber. Volume I covers the following major areas: atmospheric life support, configuration and construction, chamber location, power and lighting, equipment and supplies, communications, and psychological aspects and training. Volume II contains the following appendices: History of Barricading, Chamber Pressuriztion Considerations, Diffusional Infiltration of Gas, Compressed Air Storage, Location Examples, and Psychological Aspects.

Jan 1, 1983

By H. L. Riley, B. W. Gandrud

"INTRODUCTION The Bureau of Mines, United States Department of the Interior, with the cooperation of the University of Alabama and coal producers, has made a series of washability studies to obtain technically and commercially important data regarding the productive coal beds of the State. Based on the system followed in these studies, this report consists principally of screen-sizing and float-and-sink data on the Clark and Gholson beds at Boothton, Ala. A previous washability study 4/ has been made on the Clark bed at Marvel, Ala.SAMPLING AT MINESThe coal from the Gholson and the Clark beds was sampled at the tipple which receives the output,the Boothten No. 3 and No. 4 mines. These two mines are on the Gholson and Clark beds, respectively, but the coal. from both mines is mixed on the tipple and washed in the same washery. The samples taken were minus 4-inch raw coal. The plus 4-inch raw coal is hand¬picked and not washed. AS the 4-inch screen had a capacity in excess of the output of the mines, it was stopped at the end of each mine-car trip. By Observing from which mine incline each trip was hoisted, a separate sample from each bed was cut from the discharge stream of an endless belt which conveys the through 4-inch raw coal to the bin ahead of the washer. The output from each bed was sampled uniformly over the period of a working shift. The two washability samples weighed approximately 3,000 pounds each."

Dec 1, 1947

By P Kirsch, P Jagals, D Viswanathan, J Shandro, R LaBouchardiere

The planning, design and operation of mines must include the development of positive environmental, community and land-use benefits if it is to achieve good corporate social responsibility and minimise detrimental impacts throughout the life of the mine. Life-of-mine (LOM) planning should, therefore, consider conducting mining activities in the best socially, environmentally and economically acceptable manner, from the commencement of exploration to post-closure of the mine. Current knowledge of LOM activities in relation to public health (life-of-community, or LOC) impacts neither fully captures the full suite of human health and well-being impacts, nor comprehensively informs society on these issues. This knowledge gap is becoming more apparent as public antipathy is increasing towards mining activities within Australia, Canada and globally. The purpose of this paper is to present preliminary and informative results of a literature review to gain insight into the extent of available public health and well-being knowledge associated with mining development. LOM development must also benefit the LOC, in that it must aim to minimise detrimental impacts, and maximise beneficial (including health) impacts on all associated communities. Health planning and programing for mitigation of potential adverse health impacts of mining should extend beyond the scope of work-related injury and illness (resulting from chronic exposure to harmful substances, infectious and lifestyle illnesses), to the health and well-being of workersÆ families and extended associated communities. By mapping the available but rather scarce literature on LOC areas to recognised LOM stages, this review found shortcomings and imbalances regarding research reporting on mining and its health-related impacts in the worker-to-community continuum.CITATION:Kirsch, P, Viswanathan, D, LaBouchardiere, R, Shandro, J and Jagals, P, 2012. Health impacts extend from the life of a mine to the life of a community - Knowledge gaps, in Proceedings Life-of-Mine 2012 , pp 161-168 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By Edward F. Fries

The U.S. Bureau of Mines is conducting research that will lead to computer-assisted mining equipment. This research will facilitate improvements in safety by relocating workers from dangerous areas and will increase production by providing more accurate control with less downtime of equipment. A Bureau-developed microcomputer network enhances this research by permitting a group of diverse computers to interact with a mining machine as well as with each other over a common data link. The network is composed of specially integrated off-the-shelf hardware and industry-standard operating system and programming languages. Using the network, researchers can conduct various experiments with the mining machine using a diverse group of sensors, computers, and micro controllers. This report gives a brief background on the Bureau's work in computer-assisted mining, followed by discussions on the network hardware and architecture and the network packets, and an analysis of network operation.

Jan 1, 1992

By W. G. Hubler

It has been within only the last two or three years that enough progress has been made in preferential flotation to warrant metallurgists in recommending the installation of commercial-sized plants for the treatment of copper-zinc-iron ores. Until the new processes had been worked out successfully, the treatment of this type of ore had proved a stumbling block in the path of metallurgical progress. Separation of lead-zinc ore is comparatively simple. A lead-zinc ore low in iron may be separated and concentrated by gravity con-centration, provided it is not necessary to grind too fine. Owing to the specific gravity of chalcopyrite and sphalerite being so nearly the same, however, their separation by gravity concentration is out of the question. Complex lead-zinc-iron ores in which the several minerals are intimately associated, requiring fine grinding to free them, have been successfully treated by flotation for the past fifteen years. Galena is easily floated, and its flotation, unlike that of chal¬copyrite, is not affected by the reagents used to inhibit the flotation of sphalerite and iron sulphides. When an attempt was made to use the methods of lead-zinc se-paration on copper-zinc ores, it was found that the depressant re-agents added to inhibit the flotation of the iron and zinc minerals would, under certain conditions, depress a large part of the copper. It was also recognized that, in the grinding of copper-zinc ore, soluble salts were generated which were detrimental to flotation unless properly controlled. The main part of this paper will be a discussion of solutions in the grinding circuit in relation to the pro¬duction of soluble salts and their effect on flotation.

Jan 1, 1931

By J. E. Udd, L. B. Geller

"Mine-shaft wire-rope discard regulations include, among other criteria, a limited amount of permissible loss-of-breaking-strength (LBS). Currently, this parameter is estimated on the basis of non-destrutive-testing (NDT) with electro-magnetic (EM) type instruments. This paper analyses the accuracy with which these estimates have, so far, been obtained in practice.It concludes that while certain types of testers have produced better results than others, the desired accuracy level has not been attained. Also discussed are the putative reasons for this situation, and appropriate actions that the mining industry might wish to take."

Jan 1, 1990

By Jorge Madias

A Aceros Arequipa é a maior siderúrgica do Peru. A empresa opera uma planta em Pisco, com uma aciaria para 850.000 t anuais de aço líquido, e uma capacidade de laminação de 1.250.000 t anuais de produtos longos. Um projeto de integração vertical incluindo coqueria non-recovery, sinterização e alto-forno foi considerado. Como parte do projeto, um forno piloto de coqueificação foi instalado, com o intuito de testar carvões próprios e importados e obter a máxima participação de carvão local nas misturas. Foram testados sez carvões peruanos e antracito. Os carvões importados escolhidos foram três da Colômbia e quatro dos Estados Unidos. Levando em conta as baixas propriedades dos carvões próprios, foi introduzida a estampagem da carga. A máxima participação dos carvões locais, mantendo a qualidade requerida, foi obtida com 80% de carvão peruano, e 20% de um carvão columbiano. Pode-se usar até 10% de antracito, junto a 60% de carvão peruano e 30% de carvão colombiano.

Oct 30, 2017

By M Hopkins, A Mutale, A E. Vidal da Silva

The Cliffs Nickel Mine extracts a narrow near vertical nickel vein using a mining method of underhand bench stoping with paste backfill. In 2014, at a depth of 400 m below surface, the Northern block of the mine began to experience squeezing within ore development. At first the deformation was localised, within 30 m of the stoping front, but later became pervasive extending across the Northern block and resulting in a hiatus in mine production. The global mechanism is a progressive pillar failure, where the inter-level pillars in advance of the production front could no longer withstand the induced load and progressively yielded. The local mechanism of failure was observed as crushing of the massive sulphide ore and ‘punching’ of the pillars into the ultramafic hangingwall exhibited as floor and sidewall dilation and unravelling of the mafic footwall. The cause of the global mechanism was attributed to a combination of factors, including: high overall extraction ratio, small vertical pillar heights between ore development, high stress in relation to the low rock mass strength, shallow stope front angle, and insufficient ground support capacity. Following the progressive failure, the remnant rock mass conditions across the northern block were severely degraded, with numerous falls of ground that led to a reassessment of the mine plan. Recovery of the Northern block started in 2016 as a staged process. Development of the safe recovery work methodology involved a number of considerations, such as: production sequencing, development access design, ground support, and development of specific procedural controls. The Northern block was then broken into smaller mining precincts based on tactical factors such as location, ease of access, scale of rock mass damage and nickel content. A specific ground support standard and work methodology are employed, while cycle sheets are used to ensure quality and completeness of work. Large intersections showing signs of deformation have either been bypassed or treated using Rocprops to maintain stability during stope production. This approach has been successful in safely regaining access and restarting production in areas that had previously been removed from the mining reserve.

Mar 15, 2021

By Edward R. Rose

This paper summarizes and emphasizes the potential importance of Canadian rare-earth occurrences, and recommends that efforts to locate and evaluate rare-earth deposits should be increased. Increasing world markets, depending on intensive applied research into the numerous unique and remarkable chemical and physical properties of the rare-earth elements (REE), are developing; their properties and uses are becoming better known; methods of separation are much improved. The REE group comprises a Cerium (Light) subgroup of 7 metals and an Yttrium (Heavy) subgroup of 9 metals. REE are trace elements in many rocks and minerals, and major constituents of more than 50 rare-earth minerals, many of which are difficult to detect and identify. They occur preferentially in acidic and alkaline igneous and metamorphic rocks, including carbonatites, as well as in placer deposits, certain uranium deposits, phosphate rocks and others. The main ores now are bastnaesite (in Precambrian carbonatite), monazite and xenotime (in Recent beach sands) as well as uraninite and brannerite (in Huronian quartz-pebble conglomerate) and loperite (perovskite) and apatite (in alkaline complexes). World resources are summarized. Twenty mines in 1973 produced an estimated world total of about 31,000 tons of contained rare-earth oxides (REO), 19,341 tons of which came from one mine at Mountain Pass, California. A selected fifteen, of 315 or more Canadian occurrences, are briefly described and compared, and their relative merits indicated. Their abundance and variety suggest the possibility of finding high-grade deposits in many geological terranes in Canada.

Jan 1, 1979

By P. Fecko

The objective of the paper was application of bacterial leaching on two brown coal samples from locality Mine Druzba, seams Antonin and Josef (Sokolov brown coal basin, Czech republic). Based on the results of bacterial leaching and petrologic analyses of the given samples, it is possible to say that application of bacterial leaching gived good results. Applying bacterial leaching it is possible to remove from 34% to 47% of total sulphur and from 45% to 64% of pyritic sulphur from the coal.

Jan 1, 2014

By H. L. Liu

With the exploitation of mineral resources, valuable minerals are more and more finer and poorer. Priority reclaiming liberation grind particle under rough grinding, will help to pervert loss of melts, raise dewatering efficiency of concentrate, reduce consumption of reagent. And it is propitious to reduce energy consumption and raise the utilization rate of resources. With the feature of coarse particle?s desorption and deposition, CLF flotation machine has special pulp circulating way, which is not only apply to treat coarse particle but also normal size particle. The paper advanced the history, the design principle, the structure feature and the application of CLF flotation machine.

Jan 1, 2014

By John H. Lichtblau

There are three parties to the oil imports controversy: the domestic oil producers, whose side has just been ably summarized by Mr. Jameson; the oil importers; and the public. Domestic producers and importers are both motivated by economic self-interests, that is by their natural and legitimate desire for profit maximization, in their respective positions. Thus, domestic producers, rightly, regard every barrel of imported crude oil (with the exception of some specialty crudes) as a displacement of a barrel of their own crude. Hence, the lower the import Level the better they like it. Conversely, U .S. refiners whose plants are located at the seaboard or at certain inland waterways generally welcome a higher level of imports because refiner profits are based primarily on the spread between the crude oil price and the refined products price, since crude oil represents by far the refiner?s largest cost factor. The relatively low cost of foreign oil means therefore higher profits to those refiners able to process such oil, This applies particularly to integrated companies whose own domestic oil production is insufficient, to meet their refinery requirements but who have developed ample low-cost foreign oil supplies.

Jan 1, 1962

By Christopher Mark, Anthony T. Iannacchione

Falls of ground continue to be one of the most serious causes of injury to U.S. miners. Of the 256 fatal injuries that occurred in mining between 1996 and 1998, 52 (20%) were caused by falls of ground (Table I). Falls of ground affect some sectors of the mining industry more severely than others. For instance, nearly 40% of the 98 coal mine fatalities between 1996 and 1998 were caused by falls of ground. Underground miners are at much greater risk than surface miners. Nearly half (45 out of 101) of underground mine fatalities were attributed to roof, rib and face falls, while less than 5% of the 155 surface fatalities were caused by falls of highwalls or slopes. Sources of Data All of the injury data examined in this study were derived from MSHA’s Fatal Investigation Reports (www.msha.gov)and the MSHA accident database. Because falls of ground often result in serious injury, MSHA Fatal Alert Bulletins and Fatal Investigation Reports provide a useful snapshot of ground control issues in the mining industry. MSHA requires that mines file a report on every reportable accident that occurs, containing information on the accident’s location, severity, classification, activity, and nature of injury, etc. A short narrative is generally included as well. Accident reports can be searched by many of the above fields. From 1996 to 1998, miners suffered a total of 55,096 injuries, which ranged in severity from death (degree 1) to injuries with no days away from work nor restricted duty (degree 6). Six percent of the total injuries were from falls of ground, including machine accidents where caving rock was coded as the source. As the data in Table II indicate, 98% of all non-fatal fall of ground injuries occurred in underground mines, with underground coal mines accounting for 83% of the total. Table II also shows the distribution non-fatal fall of ground injuries by severity and commodity. The injuries are classified into Lost Time Injuries that resulted in permanent disability (degree 2) or days off work (degrees 3-4), and Injuries Without Lost Time that resulted in no more than restricted duty (degree 5-6). Overall, groundfall injuries appear to be more serious than other types of mining injuries. 65% of all ground fall injuries resulted in lost time compared to 54% of all types of mining injuries.

By R. Hazael, R. Alford, R. Critchley

The ability to compare explosives is fundamental. Numerous methods are used and while simple conversion factors are often used, the use of TNT Equivalency (TNTe) is not a simple subject as explosives exhibit very different equivalencies depending on whether the pressure or impulse are being considered as well as other conditions. The scaled distance has been found to have a significant effect on the TNTe but due to the difficulty of taking measurements at very close ranges, no TNTe have been quoted for charges in direct contact (Z=0). This paper describes the use of a ballistic pendulum to measure the impulse from contact charges and presents some surprising results that require a two-stage propulsion, as originally described by Backofen, to be explained.

Jan 1, 2024

By D. E. Smith, M. K. Murthy

"The commercial potential of a silica-kaolin deposit that occurs on the banks of and close to the Missinaibi River in the District of Cochrane, Ontario, is under evaluation by Algocen Mines Limited. The geological features of the deposit, as well as its probable origin, are described. Mineralogical analysis of the deposit samples indicates that the principal minerals are quartz and kaolinite clay; it is estimated that about 20 per cent of the deposit is kaolin clay. The impurity minerals present are: a slightly magnetic Fe-Ti oxide mineral, goethite, muscovite mica, tour-maline, staurolite, anatase and zircon. Laboratory research studies are in progress to develop and evaluate suit-able methods for the separation of silica sand from kaolin. Results to date indicate that good-quality silica sand with an Fe,03 content in the range of 0.012 to 0.025 per cent can be produced. It appears that the clay portion can also be beneficiated to yield products meeting commercial requirements. It has been possible to beneficiate a portion of theetlay to obtain the particle size distribution now specified by industry. However, research is continuing to develop suitable separation and beneficiation methods which can produce kaolin clay meeting all the commercial requirements."

Jan 1, 1970

By R. S. Dean

The development of metallurgical processes may be divided into periods : First , the discovery of a basic reaction which brings about the production of the desired product from the available raw material ; second , a long stage of mechanical development during which little or no attention is paid to the reaction itself ; and third , a careful study of the reaction . Most metallurgical processes are to -day approaching the end of the second period . This we may illustrate by the steel process . The reaction of carbon with iron ore to produce pig iron and the subsequent refinement of the pig iron by an oxidation reaction is very old . Development in modern times has been almost entirely mechanical , the development of the blast furnace , furnace , the Bessemer process , the Siemens process , and even the Aston process for wrought iron being mechanical improvements almost entirely . Metallurgy is now entering a phase where the reactions are being considered . The question of how far can they be made to proceed is being repeatedly asked . As mechanical processes are improved , we approach a limit to which our basic reactions can be pushed which is determined by the nature of the reactions themselves . We want to know : How far can iron be decarbonized by iron oxide ? How low can the oxygen of copper be reduced by any given reaction? How efficiently can the fuel in a zinc reduction process be used ? The demand for purer metals and lower production costs has forced these and similar questions upon us . How are we to answer them ? The determination of these equilibria or end points of metallurgical reactions by direct means is fraught with difficulty because here we must overcome mechanical difficulties which too often become the limiting factors even in the laboratory and we do nottherefore get the actual limit to which the reaction itself may be carried . Further , there are so many reactions of metallurgical materials that to survey each separately is a job to give pause to any experimenter or group of experimenters .

Dec 1, 1930

By John Carr

The tremendous growth in grinding mill size and horsepower during the '70s demanded advancements in gear cutting technology and equipment for the '80s. Computers are used as an aid in the design and selection of the mill drive system; sophisticated computer graphics are used to create manufacturing drawings; and a new generation of gear cutting machines are used to manufacture the gears. These new gear cutters can generate-cut gears over 40' (12.2 m) in diameter at an AGMA quality level exceeding the currenty acceptable standards. The precision of the resulting gear assures maximum tooth contact, which will result in longer gear set life.

Jan 1, 1981

By Alei Leite Alcantara Domingues

A microscopia óptica é uma ferramenta importante para o entendimento dos processos envolvidos na produção do minério de ferro e seus aglomerados. Nos laboratórios em que esse tipo de análise é feita, tem-se geralmente um microscópio de luz refletida e um operador treinado que leva diversas horas para concluir uma única amostra. Nesse trabalho serão mostrados exemplos de resultados de minérios de ferro, sínter e pelotas obtidos em um sistema de microscopia óptica automática com análise de imagens. No estudo do minério de ferro foram determinados a composição mineralógica quantitativa, morfologia das partículas e tamanho dos cristais. Na microscopia de sínter foram determinados a quantificação de fases, porosidade, textura, recristalização de hematita e morfologia das ferritas. Nas pelotas produzidas com minério de ferro foram feitas análises de quantificação de fases, distribuição e quantificação dos poros e evolução microestrutural dos grãos. A implantação de um sistema de microscopia óptica automática com análise de imagens permite que análises sejam feitas em menor tempo, com maior reprodutibilidade possibilitando que a técnica seja implantada em áreas de produção que exijam respostas mais rápidas.

Oct 30, 2017

By Jan Pan, Deqing Zhu, Xianlin Zhou, Yanhong Luo, Zixing Xue

"Magnetic roasting process, aiming at obtaining magnetite concentrate, is the principle method of exploiting siderite as a raw material in iron and steel industry. Study on preparing DRI from siderite through coal based reduction technology is sporadic. To make the process of how siderite is reduced to iron clear, roasted ore reduced from siderite by lignite under different time periods were analyzed. The results indicated that: at the temperature of 1050°C, siderite was rapidly decomposed into magnetite, and further reduced as Fe30r?FeO?Fe, the later step was slower than the previous one. A fracture of particles was found during the process of thermal decomposition and the reduction of newly formed magnetite. As the reduction proceeded, metallization rate of products increased, and the iron grain grew along with time.IntroductionWith the rapid development of economy, China demands more and more iron ores for the iron and steel industry. China has rich iron ore resources, but 97% of them are below 30% in iron grade, many are refractory and unutilized [1], therefore large quantities of imported iron ores are in a desperate need. China imported 686 million tons of iron ore in 2011 (data from the China Customs), accounting for nearly 60% of the total consumption. To guarantee the healthy development of iron and steel industry, domestic refractory iron ores have to be utilized both economically and environmentally."

Jan 1, 2013

By D. Randolph Berry

The U.S. Bureau of Mines awarded a contract to Foster-Miller Associates, Inc. (FMA) to provide recommendations on the safest, most practical methods for complying with new regulations requiring that all underground coal miners have a self-contained, self-rescuer (SCSR) -a device capable of supplying, in an emergency, 1 hr of self-contained oxygen (no breathing of mine air). This report develops information and recommendations which could be used during the early stages of nationwide compliance, especially in the areas of inspection, testing, and underground storage of SCSRs. Volume I contains an Executive Summary, Introduction, Definitions, Recommended Guidelines for District Managers and Mine Operators, and a Storage Plan Checklist and Sample Form.

Jan 1, 1981