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By Jon C. Volkwein

The Bureau of Mines conducted a series of tests to evaluate the effectiveness of mixing a compressed-air-generated foam with dried whole-grain silica sand to suppress dust in minerals processing plants. Dust at downstream transfer points was monitored with personal gravimetric samplers and with Real-Time Aerosol Monitors (RAM's) that were connected to strip' chart recorders. Results showed dust reductions of 80 to 90 pct on three separate occasions at two different plants. The mechanism by which foam suppresses dust is discussed, as are the constraints on the use of foam, which may include incompatibility of the foam with the mineral product, difficulty in controlling the foam generator, and cost.

Jan 1, 1983

By W. P. Diamond, A. C. Smith, J. A. Organiscak, T. P. Mucho

The U.S. Bureau of Mines conducted a worldwide literature review of bleederless ventilation practices to evaluate their use as a spontaneous combustion control measure in U.S. coal mines. Factors that must be taken into account in the design and use of these systems include seal construction, the use of ventilation control devices, the use of methane-drainage systems in gassy mines, and the ground control plan. Monitoring for the detection of spontaneous combustion and the control of methane when methane-drainage techniques are employed is critical to the successful use of a bleederless ventilation system. This report describes the types of ventilation systems used throughout the world and the spontaneous combustion risks associated with these systems. Methane-drainage systems used in conjunction with bleederless ventilation systems are discussed. Ground control considerations such as pillar design, entry stability, and seal usage are reviewed. Monitoring systems for spontaneous combustion detection, methane-drainage control, and behind seals are examined. Finally, methods for evaluating the spontaneous combustion hazard of a mining operation to determine when the use of a bleederless ventilation system is warranted are reviewed.

Jan 1, 1994

Five conclusions that emerged from ADL's Contractor Noise Measurements Assessment done for the Bureau of Mines and the 7 December 1971 Bureau of Mines Contractors' Round Table Meeting in Boulder, Colorado were: ? a limited amount of good data has been obtained for characterizing the noise environment for electromagnetic (EM) coal mine operational/emergency communications systems; ? significant noise date gaps still exist; ? suitable instrumentation and data analysis methods are available for filling these data gaps; ? the immediate and most important data gaps should be filled by means of a timely field measurement effort that is purposely limited in scope and duration; ? this field measurement effort should preferably be carried out by a team knowledgeable and experienced in coal mine EM noise measurements.

Jan 1, 1972

By P. B. Altringer

The Bureau of Mines conducted laboratory tests to devise a procedure for recovering a marketable grade of tungsten from the brine of Searles Lake, Calif. The brine contains only 56 parts per million of tungsten (70 parts per million of W03). Using ion exchange resins synthesized by Bureau chemists, 98 percent of the tungsten was extracted from the brine and 92 percent of the tungsten was recovered as a marketable iron-tungsten concentrate containing 44 percent tungstic oxide. Although major technical problems have largely been resolved, research is progressing to escalate testing in a process-development unit to provide more reliable data for an economic appraisal.

Jan 1, 1978

By James D. Noll, Jon A. Hummer, Aleksandar D. Bugarski, George H. Jr. Schnakenberg, Steven E. Mischler, Larry D. Patts

The National Institute for Occupational Safety and Health conducted a study to determine the effects of selected, state-of-the-art emission control technologies on the ambient concentrations of particulate matter and gases emitted by underground diesel-powered mining equipment. Tests were conducted in an isolated zone of an underground mine to evaluate the effectiveness of alternative fuel formulations, namely, water-fuel emulsions, blended biodiesel fuels, ultralow sulfur diesel fuel, and #1 diesel; and selected exhaust after treatment devices, namely, diesel oxidation catalysts (DOCs), diesel particulate filter (DPF) systems, and filtration systems designed around high-temperature disposable filter elements. The results showed that using a cold-weather and warm-weather water-fuel emulsion formulation reduced mass concentrations of elemental carbon (EC) by about 70% and 85%, respectively. The 20% and 50% soy biodiesel blends reduced EC by 49% and 66%, respectively. The reductions were slightly less pronounced for the 20% and 50% yellow grease biodiesel blends—33% and 56%, respectively. EC concentrations were unaffected by using ultralow sulfur diesel in place of #1 diesel. Use of the reformulated fuels did not substantially alter the concentrations of nitric oxide and carbon monoxide. However, a measurable increase in the nitrogen dioxide (NO2) peak concentration was observed during the biodiesel tests. The ArvinMeritor (AM) fuel-burner DPF system with a palladium-catalyzed DOC reduced EC concentrations by 92%. The diesel filter elements from Donaldson Co., Inc., and Filter Service & Testing Corp. reduced the EC concentration of the mine air by 92% and 70%, respectively. When the palladium-based DOC was used with the AM DPF, it raised the average and peak downstream NO2 concentrations by a factor of three. Tests of the AM DPF system with a platinum-catalyzed DOC and CAP/ETG catalytic particulate oxidizer system had to be terminated because the elevated NO2 concentrations threatened to overexpose the operator. The tests with only a selected DOC also resulted in increased NO2 concentrations in mine air.

Jan 8, 2006

By J. W. Eckerd, W. S. Sanner, P. L. Woolf, R. E. McKeever

The Bureau of Mines experimental blast furnace was operated successfully with anthracite metallurgical briquets . Tuyère pressures were higher and more erratic than for operations using coke , and furnace " hangs " occurred more frequently . Higher hot - blast temperatures were required to maintain the quality of the metal . By using higher hot blast temperatures , the fuel and production rates and slag volumes were comparable to those obtained for all - coke operation . The anthracite metallurgical briquets exhibited excellent mechanical strength and descended through the shaft of the furnace with little breakage or reduction in size .

Jan 1, 1964

By N. S. Dalal, X. Shi

"Electron spin resonance (ESR) spin trapping methodology has been used to study the reactions of manganese dusts with glutathione, employing a-{4-pyridyl-1-oxide)·N-tert-butyl-nitrone (PBN) and 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as spin traps. The results show evidence for the glutathionyl radical formation in the reactions of both MnO2 and manganese (Ill) acetate with glutathione. Based on these experimental observations, we hypothesise that the mechanism of neurotoxic effects of manganese might be due to the fact that the generation of glutathionyl radicals depletes the glutathione pool and reduces the glutathione shield against free radical products of dopamine metabolism and manganese induced reactive oxygenated species. IntroductionExposure to manganese compounds often occurs as the result of foundries and mining operations (1. 2). Other significant sources of environmental manganese include coal-fired power plants and burning of residual and crude oil (3, 4). Lately gasoline combustion has also started to contribute since manganese (methyl cyclopentadienyl manganese tricarbonyl. 0. 125 g/gallon) is being used instead of lead as an antiknock ingredient in automobile fuels (5. 6). Although manganese is an essential element in certain biological processes it is toxic in excessive amounts. The manganese toxicity is mainly associated with the nervous system (7-9). Symptoms frequently observed in manganese poisoning or manganism are disorientation, memory loss, anxiety, compulsive laughing and crying, mask-like faces, akincsia rigidity and tremor (10). In spite of numerous investigations to understand the mechanism of manganese induced injury. it has not been possible to localize the initial chemical lesion responsible for altered physiology and ultimate cell death. This may perhaps he the reason for failure in developing a successful therapy for manganese intoxication."

Jan 1, 1990

By R. Hogg, T. F. Dumm

"A procedure for evaluating the size/specific gravity distribution of ultrafine coal and the distributions of sulfur and ash with respect to particle size and specific gravity is described. The procedure is essentially an extension of the conventional coal washability technique in which special precautions are taken to ensure particle dispersion in the heavy organic liquids, centrifuges are used to obtain adequate separation rates, and micromesh sieves are used for size separation at fine sizes. An example of the application of this technique to the evaluation of the extent of liberation of sulfur and ash in a coal sample ground to 90Z passing 200 mesh (74 um) is described.INTRODUCTIONIn order to determine the potential for deep cleaning of coal by fine grinding to liberate sulfur and ash-forming minerals, it is necessary to obtain data on the distributions of these species by size and specific gravity. In conventional coal processing operations, this information is obtained by means of a standard ""washability"" analysis. Attempts to extend this procedure to ultrafine coal, however, have generally been unsatisfactory and have often led to unreliable and inconsistent results [11. The present authors have described a modified washability procedure in which cumulative specific gravity fractionation is combined with sub-sieve size analysis (by laser diffraction/light scattering) to determine the particle size/specific gravity distribution of ultrafine coal [2]. Unfortunately, because this technique does not involve separation of the individual fractions, only limited information can be obtained on the specific distributions of sulfur and ash.The objective of the work described in this paper was to develop and evaluate a procedure for size and specific gravity fractionation of ultrafine coal and to use conventional analyses for sulfur and ash to determine their relative distribution in the coal. The procedure is essentially a simple extension of the standard washability analysis [3] but incorporating special precautions for treating ultrafine particles.EXPERIMENTAL Material The material used in the development and evaluation of the ultrafine coal fractionation procedure was a medium volatile bituminous coal from the Lower Kittanning seam. A sample of the coal (nominally - 1/4 inch), obtained from the Penn State Coal Data Base, was ground to 90% passing 200 mesh by the following two-stage grinding procedure: About 2 kg of the as-received coal were ground to about 30Z passing 200 mesh in a Model 4-E Quakertown mill (""coffee grinder""). About 1 kg of this product was then ground to about 90Z passing 200 mesh in a Holmes Model 300 Pulverizer."

Jan 1, 1989

By Philip G. Freeman

The growth-promoting properties of coal-derived humus were tested by a variety of bioassay methods. Humate materials used included leonardite, a form of naturally oxidized lignite, and humic acids extracted from leonardite. It was found that the greatest effects were evident when water-soluble humic acid was applied to excised root tips. No significant short-term effect was noted when water-soluble humic acid was applied to stem or coleoptile sections. Root initiation was promoted in bean stems when high concentrations of coal-derived humate were applied. Gross weight of tomato plants was increased by up to 40 percent when coal-derived humates were added in concentrations of 101 to 104 ppm to the nutrient in a hydroponic growth test of 6 weeks' duration. It is concluded that coal-derived humate promotes the uptake of minerals, specifically iron, by serving as a metal chelate.

Jan 1, 1968

By A. W. Henderson

This investigation was performed to develop chlorination methods for extracting tungsten from scheelite and from an ore concentrate containing a mixture of scheelite and wolframite. On a laboratory scale with proper temperature control using elemental chlorine, over 90 percent extraction of tungsten is achieved. Carbon and sulfur dioxide were studied as reducing agents. The effects of salts such as calcium fluoride and sodium chloride were studied as additives to increase extraction and to reduce impurities in the volatile tungsten chloride product. Sodium chloride reacts with ferric chloride to form a nonvolatile double salt; whereas the chlorides and oxychlorides of tungsten are volatile and consequently condense free of iron. Separation of tungsten from molybdenum from an equal molar mixture was successful by fractionally distilling the oxygen-free chlorides and by selectively condensing the oxychlorides. Yields of 60 and 80 percent, respectively, were achieved for separating the less volatile tungsten chlorides containing less than 0.5 percent molybdenum.

Jan 1, 1965

By D. J. Parker, J. B. Benson, J. H. Bird, F. E. Cash

"INTRODUCTION The organic act that became effective July 1, 1910, imposes two very definite primary obligations upon the Bureau of Mines: (1) The prevention of loss of life and limb and the protection of the health of workers in the mineral industries, and (2) the conservation and scientific utilization of the country's mineral resources.The subject of this publication falls within the scope of both of these responsibilities by reason of the fact that (1) certain safety precautions are involved in combating even surface fires and, (2) although peat is not now, so far as known, utilized commercially or otherwise in this country as a fuel, it is extremely valuable agriculturally in at least one of our States, The justification for the conservation of such low-grade fuel through fire prevention appears warranted because of its present value to agriculture and the possible advantages accruing to future generations as a source of heat and power.Although the Bureau of Mines has published information on the origin and uses of peat, this is the first attempt to give out data concerning the prevention and control of peat-bog fires. Although the information presented here is restricted to the Lake Superior District, California, and Florida, there may be similar conditions in other sections of the country that have not come to the attention of engineers of the Bureau of Nines."

Jul 1, 1947

By G. S. Rice, R. V. Wheeler

"FOREWORDThe cooperative mine safety research program was carried on successfully in the year 1930 in a manner similar to that described in the report for 1929It is believed that the results of such fundamental work as is being done are unquestionably of great benefit in their application in coal-mining operations, in the saving of life and health of minera. The research result compared and checked by investigations in the two organizations, and further by large-scale tests, as in the Experimental Mine, give confidence to mine operators, miners and State mining officials in the findings of the various researches.The annual report of the contact officers of the United. States Bureau of Mines and the British Safety in Mines Research Board to the Director of the Bureau and the Chairman of the Board respectively, follows:Annual Reports for 1930 To: The Director, Bureau of Mines.The Chairman, Safety in Mines Research Board."

Sep 1, 1931

By H. E. Powell

A series of alkyl-dithiocarbamic acid amine salts was prepared and tested as collector for slimed lead minerals contained in the waste material from a commercial lead ore concentrator. The reagents, members of a homologous series differing only in the number of alkyl radicals in their structure, were prepared by reacting stoichiometric amounts of primary amines and carbon disulfide in a cold alcohol solution. Subsequent purification was by recrystallization from absolute ethyl alcohol solution. Evaluation was through froth flotation of a mill tailing containing 0.2 percent lead. Results show that maximum recovery (38 percent) was obtained with the reagent containing 8 alkyl radicals, but that maximum rougher concentrate grade (4.8 percent) was obtained with the reagents of intermediate number of radicals.

Jan 1, 1962

By E. Wittenau

This paper describing the concentrator practice of the Copper Queen Branch of the Phelps Dodge Corporation at Bisbee, Ariz., is one of a series of papers on milling methods and costs being prepared by the United States Bureau of Mines. The Copper Queen Concentrator treats 4,000 tons of copper ore daily by preferential flotation, whereby the copper sulphides are floated and considerable iron pyrite is depressed. During 1929 the heads to the concentrator averaged 2.15 per pent of copper, the recovery was 91.32 per cent of the total copper, and the concentrates produced contained 12.92 per cent of copper.

Jan 1, 1931

By R. E. Collom

The spontaneous explosion of charges of nitroglycerin placed in deep wells situated in parts of the Ranger and Caddo fields of North Texas has aroused considerable inquiry among operators end others as to the probable agency, or combination of conditions, which causes the explosion.The method now followed, under certain physical conditions of a well, of setting a charge of nitroglycerin and allowing it to explode spontaneously was discovered locally by accident. In certain deep wells where formations, overlying productive strata, cave upon withdrawal of casing, it has been the practice to fire the shot electrically. In some of these operations the electric wires are broken or the firing system is otherwise deranged by pulling casing or the caving of hole prior to the time for firing. Sucn accidents make it necessary for the driller carefully to clean cavings out of the hole to a depth close to the top of the charge, after which in the normal practice, an attempt is made to fire the charge by dropping a ""jack-squib"", fitted with a fuse and detonator, down the well. Mr. R. L, Fowler, production manager for the Pierce Oil Corporation, reports that a delayed shot was thus successfully tired through four feet of caved material lying on top of the nitroglycerin shells.When a shot destined to be fired electrically fails, because of the above mentioned accidental conditions to the electric firing system, much time is required for the driller to run casing into the hole and clean out caved material. It was during the time of such uncompleted operations that the spontaneous explosions first noted took place. Having noted these spontaneous explosions the well shooters now intentionally place a charge in deep holes, which because of probable caves would otherwise have to be tired electrically, and wait for the charge to go off. No detonators are placed with the charge.

May 1, 1920

By H. P. LeVan

The Bureau of Mines has developed a technically feasible continuous single-stage leaching and thickening system for extracting manganese from umber by a sulfuric acid-ferrous sulfate process; the cocurrent leaching and thickening system proved simpler to operate and control than the countercurrent leaching and thickening system developed earlier" Related tests investigated the use of a centrifuge to replace thickeners for separating the product liquor from are residues and compared several chemical agents for removing iron from the pregnant manganese leach solutions. Results of Some exploratory autoclaving tests are also given.

Jan 1, 1972

By Charles Vaught, Warren G. Lacefield, Ronald D. Wasielewski, Philip K. Berger, Henry P. Cole, John V. Haley, Shannon L. Price

A comprehensive review of published research was carried out to identify methods for teaching and assessing critical but nonroutine skills needed for coping with emergency situations. Computerized searches of the relevant data bases were carried out, along with identification of relevant articles and materials by personal contact with experts in many fields. The citations listed in this bibliography resulted from this systematic literature search and review. The computer searches and an analysis of this literature are described in technical report 1. Specific methods for assessing critical skills proficiency in aviation, medicine, organization management, the military, and other industrial/ technical workplaces were described. The potential application of these methods for teaching and assessing (1) critical first aid and (2) self-rescue and escape skills to underground coal miners in annual refresher training was explored. Research and development activities that may improve mine health and safety training were suggested. Most of the entries in this bibliography were assembled in 1984 through 1985. Study of these materials contributed to the completion of the project research that followed. This later work is reported in the project technical report 2 and the final report. This bibliography is most useful when combined with examination of technical reports 1 and 2 and the final project report.

Jan 7, 1988

By Efrem R. Reeves

Noise-induced hearing loss (NIHL) is the most common occupational illness in the United States, with 30 million workers exposed to excessive noise levels [NIOSH 1996] every day. Of particular concern is the mining industry; which has the highest prevalence of hazardous noise exposure of any major industry sector [Tak et al. 2009] and is second only to the railroad industry in prevalence of work-ers reporting hearing difficulty [Tak and Calvert 2008]. This document is for operators, safety personnel, and mechanics in the mining industry who are not specialists in noise control engineering or acoustics. Evaluations of successful and unsuccessful attempts at controlling noise on several large, underground metal mining machines are detailed to illustrate the basic principles of noise control. Once personnel understand the guidelines and principles of noise control, they will be able to ¦evaluate the extent of a noise problem; ¦determine the best approach to the problem; and ¦apply the most appropriate solution. Because of the insidious nature of NIHL, it can go unnoticed until a considerable loss of hearing has occurred. In some cases, diagnosis is delayed because an exposed individual claims to have become accustomed to the noise. In reality, that person may have already suffered irreversible hearing loss. Humans can hear sounds in the frequency range from about 20 to 20,000 Hertz (Hz). Within this range, NIHL usually begins in the frequency region around 4,000?6,000 Hz, the upper levels of the speech region. The first noticeable symp-toms include difficulty understanding higher pitched voices, such as the voices of females and children, and difficulty understanding certain consonant sounds, which are primarily high frequency in nature. The extent of NIHL varies depending on the level and duration of noise exposure and on an individual?s susceptibility; despite having similar noise exposure, individuals can experience differing degrees of hearing loss, or none at all. NIHL is almost always preventable. To reduce or eliminate the possibility of NIHL, an individual?s noise environment must be analyzed and appropriate action taken to reduce noise exposure.

Dec 1, 2009

By Elaine Cullen, Launa Mallett, Mike Jenkins, C. M. K. Boldt, Thomas Camm

The material in this Information Circular was presented at the National Institute for Occupational Safety and Health’s (NIOSH) open-industry briefing held during the 2004 Northwest Mining Association conference in Spokane, WA. The open-industry briefing discussed results of recently completed and on-going mine safety- and health-related research conducted at NIOSH’s Spokane and Pittsburgh Research Laboratories on the human side of mining—the miner. The first paper sets the stage for what mining has achieved and what we mean by “getting to zero.” The second paper, “Help Experienced Miners Become Great On-the-Job Trainers,” distinguishes between experienced miners and trainers. This paper provides some key concepts for turning great miners into great trainers. “The Power of Story-Telling in Getting Through to Miners” explains the history and importance of stories in the culture and training of miners. Finally, “Understanding Self in Stressful Working Environments,” describes the personal and social aspects of the working environment, much of which parallels familial theories. The downward trend of deaths in U.S. mining has been remarkable. The number of miners killed or injured each year has decreased steadily over the past 100 years. Some charts show these trends overlain with important events such as World War II and the Mine Safety and Health Act. However, this downward trend in mining fatalities has flattened out. How can you get to zero accidents? Do you concentrate on technological advances and equipment maintenance to avoid malfunctions? Do you concentrate on developing work processes and organizational structures that minimize risk? Do you combine them and take a systems approach that links one to the other with an evaluative loop? Safety efforts in mining have used all of these approaches. What more can we do to get to zero? Getting to zero will require two objectives: A clear and unshakeable belief that it can be done and attention to the human side of mining. Getting to zero is not a new idea; it has been used by mine companies and safety professionals for years as the safety goal. But getting to zero is not so much a physical goal as it is a belief that there are no insurmountable barriers to achieving the goal.

Jan 3, 2006

This Bureau of Mines publication describes the plan used to instrument two longwall gateroads at the Powhatan No. 4 Mine of the Quarto Mining Co. Vibrating wire stressmeters, flat jack U-cells, multipoint extensometer stations, and convergence stations were installed in or on the coal pillars, roof bolts, and roof strata of the gateroad entries. The instruments measure pillar stresses, bolt loadings, and strata movements as the gateroad entries are developed and the longwall panel(s) is mined. The report details only the instrumentation plan of the longwall gateroads and not the evaluation of any subsequent data. This is because a complete analy-sis of the data cannot be made until extraction of the longwall panel(s) is complete.

Jan 1, 1982