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By Robert A. Westin

Polychlorinated Biphenyls (PCBs) have been widely used as fire resistant dielectri coolants in electrical equipment used in mining applications, including transformers capacitors, electric motors, and electromagnets. In addition, PCBs have been used in hydraulic fluids and heat transfer fluids, and are present in many oil filled transformers. The Environmental Protection Agency recently banned the manufacture of PCBs and equipment using PCBs, and imposed strict requirements on the continued use and disposal of existing PCB equipment. This manual discusses the EPA requirements, suggest ways to decrease the risks resulting from continued use of PCB equipment, and surveys the non-PCB equipment that is available as replacements for the PCB electrical equipment presently used in mines.

Jan 1, 1979

By Walter L. Finlay

The Bureau of Mines has developed prototype instruments promising to improve the ability to warn of imminent roof falls. An unusually good opportunity to test these comparatively under natural caving conditions was afforded by the forecasted caving in August 1977 of a mined-out region of the White Pine Mine. The latter's rock strata closely resemble those in many coal mines. The anticipated cave was of the competent-roof/weak-pillar type. It occurred as, and when, predicted. Automated convergence and bed separation gages agreed well with the standard manual convergence gage measurements. A micro seismic gage was found to be insensitive to the fall and may require different test conditions for effectiveness. A roof resistivity unit was tested under a separate Bureau of Mines contract. (No. H02720J7). An unplanned addition showed interesting potential.

Jan 1, 1978

By V. B. Dale

This is one of a series of reports covering the mineral resources of the Nation. It describes briefly most of the known tungsten deposits in Yuma, Maricopa, Pinal, and Graham Counties, Ariz. Most of those described were examined by the author. An effort was made to determine the position of the various deposits by section, township, and range and to give accurate road direction to each property from a prominent landmark. All available maps have been used in making these determinations, but in unsurveyed areas it was necessary to make approximate projections of subdivisions. The township and range numbers refer to the Gila and Salt River base and meridian.

Jan 1, 1959

By A. R. T. Denues

Liquid oxygen explosives are ordinarily made from a carbonaceous absorbent and from liquid oxygen of high purity. These explosives have a limited but definite field of usefulness; their properties have been described in the literature, which includes several publications of the Bureau of Mines, the most recent dealing with fire-retardant treatments.3/ It seems generally conceded that the outstanding hazards in the use of these explosives are their high inflammability and their relative sensitivity to mechanical action. Each of these topics has been studied, and some interesting practical results have been obtained. Treatments have been described[7] that render liquid-oxygen explosives prepared from granular carbonaceous absorbents practically immune to the action of igniting agents representing or exceeding practical hazards in violence.

Jan 1, 1941

By D. K. Deardorff

The purpose of this work was to investigate the hafnium-carbon phase diagram. Alloys used to study this system were prepared from high-purity components by both consumable-and nonconsumable-electrode arc melting. Data for the diagram were obtained on the alloys by metallography, optical pyrometry, thermal analysis, heat treatment, and X-ray diffraction. The data indicate that a carbide compound occurs over considerable range of composition, and that one of each of the following types of reactions occurs in the hafnium-carbon system: Peritectoid, peritectic, and eutectic. The maximum melting temperature of hafnium carbide is 3,840° C at 49 to 50 atomic percent carbon, and the composition range of hafnium carbide at temperatures of 2,150° to 2,380° C is from 37.0 to 48.5 atomic percent carbon. The hafnium a-S transformation temperature is raised on alloying with carbon from 1,750° to 1,890° C, where a peritectoid reaction isotherm occurs. Alloying hafnium with carbon increases the hafnium melting temperature from 2,190° to 2,250° C, at which temperature a peritectic reaction occurs. Hafnium carbide and carbon react at 3,055° C to form a eutectic of 68.3 atomic percent carbon.

Jan 1, 1967

By Terry L. Muldoon

The report describes the development of preliminary requirement specifications for standardized operating controls for roof bolting machines used in underground coal mining. According to recent statistics, roof bolting continues to be one of the most hazardous occupations in underground coal mining. The two principal hazards to the roof bolter operator are the machine itself and roof falls during the bolting cycle. The lack of standardization of machine controls is a major contributor to this hazardous situation. Observations of roof bolting operations and discussions with roof bolter manufacturers coupled with detailed analyses of roof bolter control design specifications were performed during this study. Detailed roof bolter operator task analyses, commonality of control analyses, and classical link analyses were also performed. The results of these analyses were then used to produce preliminary requirement specifications for standardized controls.

Jan 1, 1980

By Sheridan J. Rodgers

Toxic fumes generated during shot firing were measured in a phosphate rock mine and a copper mine. Fumes generated during firing of explosives in the Bureau of Mines 1350 ft3 test chamber were measured also. The release of fumes from water gels, ammonium-nitrate oil mixtures and nitroglycerin based explosives was studied. Direct reading instruments were used to monitor the fume concentrations. The amount of CO produced per unit weight of nitroglycerin explosives (0.41 ft3/200 grams) was higher than that produced by ammoniumnitrate-oil mixtures (0.24 ft3/200 grams) and water gels (0.16 ft3/200 grams). The amount of NOx produced by nitroglycerin based explosives was also higher than the amount produced by water gels or ammonium nitrate-oil mixtures.

Jan 1, 1976

By E. D. Gardner

Oil shale, a long-considered potential source of motor fuel in the United States, is found over an extensive area in the Green River formation in Colorado, Utah, and Wyoming.4/ Oil has been retorted commercially from shale in Scotland for many years,5/ and work done by the Bureau of Mines and other investigators has shown that it is technically feasible to extract oil from American shales.6/ By refining, the shale oil may be converted into marketable products similar to those manufactured from crude petroleum. The present paper, which was finished in 1936, discusses methods that would be adaptable to mining certain American shales, and the treatment applies specifically to conditions iii the Green River formation on Naval

Jan 1, 1942

By Jr. Gabler

The U.S. Bureau of Mines (USBM) has developed a computerized commodity flow model for strategic and critical materials This flow model is generic and applicable to most commodities and amenable to updating supply, demand, and/or production data change. The original model, with slight modifications, was used to track the flow of chromium. This report follows the flow of chromium through its metallurgical, chemical, and refractory applications, and highlights areas where significant losses occur because of downgrading, export, or disposal. The study indicates that materials containing 451,769 mt of chromium were consumed, including 99,221 mt of chromium from recycling, Chromium losses from all causes in 1989 were estimated to be 345,347 mt from a variety of areas. These areas and their chromium losses are as follows: processing losses, 38,825 mt; processing-downgraded scrap, 18,227 mt; manufacturing losses, 18,128 mt; manufacturing-downgraded scrap, 56,595 mt; prompt scrap exported, 1,531 mt; obsolete scrap exported, 43,443 mt; recovery losses, 155,529 mt; and recycling losses, 13,069 mt. Recycled chromium-containing material accounted for 22 pct of the apparent consumption of chromium in 1989.

Jan 1, 1994

By A. R. T. Denues

[Liquid oxygen explosives are ordinarily made from a carbonaceous absorbent and from liquid oxygen of high purity. These explosives have a limited but definite field of usefulness; their properties have been described in the literature, which includes several publications of the Bureau of Mines, the most recent dealing with fire-retardant treatments.3/ It seems generally conceded that the outstanding hazards in the use of these explosives are their high inflammability and their relative sensitivity to mechanical action. Each of these topics has been studied, and some interesting practical results have been obtained. Treatments have been described that render liquid-oxygen explosives prepared from granular carbonaceous absorbents practically immune to the action of igniting agents representing or exceeding practical hazards in violence.]

Jan 1, 1941

By David E. Kaslow

In sampling dust laden air by drawing the medium into an inlet, some larger particles fail to follow the air and a true sample is not obtained. Inertia prevents particles from accelerating with the air as well as from turning sharp bends; also the particles' weight causes them to fall relative to the air. An analytic solution to the sampling efficiency calculation by Levin gives particle paths and sampling efficiencies for various particle sizes when the inlet can be treated as a point sink. However, the flow field in the neighborhood of an aspirating tube is quite different from a point sink flow. Employing Levin's solution in the outer field, trajectories in actual flow fields have been calculated by computer to locate the critical trajectories separating the entering particles I paths from those paths where the particles hit the tube wall or escape. Sampling efficiencies are presented in terms of 3 variables--a dimensionless particle size coefficient, a dimensionless orifice size coefficient and the tube orientation--for the no-wind case. Over most of the range of sampling conditions, the Stokes drag law can be used and dependence on the variable--particle Reynolds number--can be ignored. A procedure for achieving maximum efficiency in design of a sampler is proposed. Whether these results apply when typical room-sized eddies constitute the ?calm air? environment is not known.

Jan 1, 1974

By Alan A. Campoli

OD March 20, 1989, a meeting was held at the U.S. Bureau of Mines Pittsburgh Research Center at the request of Senator Pete V. Domenici of New Mexico. The purpose of the meeting was to engender a technical relationship between the National Laboratories and the minerals industry. During the meeting, the Director of the Bureau of Mines, T S Ary, suggested that since the Bureau is the focal point for mining research in the United States, it would be appropriate for the agency to act as the liaison between the National Laboratories and the minerals industry. As the first step in this process, the author was selected to perform a 6-month investigation to better define the proper role of the Bureau in this area. As part of the investigation, the mining and mineral-related technology available at 21 major U.S. Department of Energy (DOE) Research Laboratories was reviewed. It was assumed that the broad range of scientific and technical areas covered DOE research would provide fertile ground for mining-related technologies. It was hoped that the applicability of DOE research to this liaison effort would be indicative of Federal laboratories in general.

Jan 1, 2011

By Thomas J. Peters

A mineral survey of the Sill Hill RARE II area (No. 5304), covering 5,200 acres (2,100 ha) of the Cleveland National Forest, San Diego County, California, was conducted by the U.S. Bureau of Mines and the U.S. Geological Survey. This survey was in conformance with the Resource Planning Act (RPA) of 1974, as amended by the National Forest Management Act of 1976, to provide mineral resource information for study area classification. Bureau of Mines personnel made an economic appraisal of mineral deposits by searching pertinent geological and mining publications as well as U.S. Bureau of Land Management, U.S. Forest Service, and U.S. Bureau of Mines files and records. Known mines, prospects, and mineralized localities were examined during 1981, and sampling and mapping were done where warranted. The Geological Survey 'did geologic mapping, geochemical sampling, and geophysical surveys to aid this study.

Jan 1, 1983

By Margaret R. Egan

A study of the combustion emission products of rigid ventilation ducting was completed by the U.S. Bureau of Mines. The ducting was composed of fiberglass-reinforced polyester resin. Four properties of the ducting were evaluated: (1) propensity to ignite, (2) smoke characteristics, (3) gas emissions, and (4) heat release. Particle sizes, obscuration, optical densities, and production constants for gas and smoke were also calculated. These results provide comprehensive data about the emission products, detectability, and relative hazards of fiberglass-reinforced plastic ducting and other mine combustibles under realistic fire conditions.

Jan 1, 1990

By Paul C. Hyndman

The U.S. Bureau of Mines investigations of the three subunits (fig. 1) of the Homestead RARE II area (No. 6291) revealed no evidence of mining activity or mineral deposits in the area. The Iron Dyke Mine, 3 mi (5 km) outside the study area produced ore between 1916 and early 1982 from a volcanogenic massive sulfide deposit in the Permian volcaniclastic Hunsaker Creek Formation of the Seven Devils Group. The Hunsaker Creek Formation does not crop out in the RARE II area, but extends into the area beneath Miocene flows of Columbia River Basalt. The abundant basalt in the area could be used as aggregate or dimension stone, but equivalent deposits exist closer to markets. INTRODUCTION Location and Access The Homestead RARE II area (fig. 1) encompasses 6260 net acres (253U ha), in three units, of the Wallowa-Whitman National Forest in Baker and Wallowa Counties, Oregon. Two small units of 160 and 300 acres (65 and 120 ha) are 5 mi (8 km) north and east of the main study area. Homestead, Oregon, on the Snake River, is about 3 mi (4 km) south of the two small areas, and about 3 mi (4 km) northeast of the main study area. Peripheral access is provided by State Highway 86, U.S. Forest Service Road 39, and ancillary roads and trails.

Jan 1, 1983

By Donald J. Barnes

There are no producing or developing mines in the study area. The only mineral production was stone from a basalt deposit near Indian View Point. Cinders and sand and gravel have been produced from deposits within 1/2 mi (0.8 km) of the boundary. Stone, sand and gravel, and cinder deposits inside the area are not considered resources because equal or better quality material is found closer to markets. The study area has no known oil and gas, coal, geothermal, or other energy related deposits. However, in 1982 application was filed on 25,000 acres (10,125 ha) of petroleum and on 15,000 acres; (6,0/5 ha) of geothermal leases.

Jan 1, 1983

By Sean Gallagher

This report describes research by the Bureau of Mines on alternative materials-handling strategies for reducing the costs and incidence of back injuries in low-seam coal mines. Strategies recommended for redesigning materials-handling tasks include elimination of tasks, mechanization of tasks, and matching lifting tasks to the physical capabilities of underground miners. The report also discusses other methods that can be used by management to reduce the costs associated with back injuries.

Jan 1, 1989

By L. C. IlsLey

"There is an old saying that ""It is too late to lock the stable after the horse is stolen"". Is not this just what is being done by many mine operators today when it comes to buying safe electrical equipment for gaseous and dusty coal mines?The ""open type"" of electrical equipment or even the ""half safe"" type represents the unlocked stable. After the mine disaster, and after men have lost their lives, the lock is put on - that is, safer equipment is installed.For example, an open type of electric coal drill was used in a gaseous mine in West Virginia, This was the probable cause of the death of 27 men. A half safe type of electric coal-cutting machine was used in a gaseous mine in Pennsylvania. This was likely the cause of the death of 36 men. An unapproved, unsafe type of flame safety lamp was used in a gaseous and dusty mine in Utah. This was the all¬eged cause of the death of 171 men. All three disasters happened within the last six months, and seem to have been avoidable if proper equipment had been used.It is understood that more rigid requirements will be enforced in West Virginia. The committee of State mine inspectors made definite recommendation for im¬proving the conditions in the given mine in Pennsylvania. The Industrial Commission of Utah have already issued new orders which will remedy the use of unsafe lamps in that State.These acts and recommendation are all good and will help prevent accidents in those States in the future. Is it not a pity that such recommendations and order were not made a little earlier before the tell of life had been exacted? Is it not a pity that other States will not take these lessons to heart and safeguard their mines before and not after disasters take place?Electric current can cause accidents in five general ways as follows: (1) By shock to persons; (2) by igniting powder; (3) by igniting gas; (4) by igniting coal dust; and (5) by setting fire to inflammable material such as timber and coal. A great many accidents from these causes are preventable if proper care is taken. Most of the accidents caused by sparks and flashes from electrical apparatus would not take place if approved electrical equipment was used. By approved equipment, the writer means equipment that has been tested and formally approved by the Bureau of Mines. So far as known, up to the present time, no disasters have been caused by sparks or flashes from equipment having the Bureau's approval."

Jul 1, 1924

By C. W. Morris

The continuous miner training system provides classroom materials training aids, and a continuous miner simulator to provide a short, intensive instruction and skills development program for training or retraining continuous miner operators. This project included refinement of training objectives, revision of training aids, improvements to the simulator, and evaluation of the entire system. This report describes the revised classroom materials and the validation of the training system.

Jan 1, 1982

LARGE-SCALE production of zirconium by the Northwest Electrodevelopment Laboratory of the Bureau of Mines at Albany, Oreg., is an anomaly that justifies some explanation. The reduction of titanium tetrachloride with magnesium in an inert atmosphere, as perfected by Dr. W. J. Kroll before 1940, aroused renewed interest in zirconium, and in 1945 development work on this metal was initiated at Albany under Dr. Kroll's technical direction. Preliminary results were promising, and in February 1947 a pilot plant with a weekly capacity of 60 pounds of zirconium-metal sponge was put in operation. Shortly thereafter the Oak Ridge National Laboratory of the Atomic Energy Commission requested production of 1 ton of zirconium-metal sheet, with the provision that it have a low hafnium content. The Bureau of Mines was furnished with a. supply of Brazilian baddeleyite ore, containing less than 1 percent hafnium with respect to zirconium, from which was made about. 2,700 pounds of relatively low hafnium zirconium sheet of 0.080-inch thickness for test purposes. This was accomplished by melting zirconium sponge in a graphite crucible, hot-rolling the ingot in an iron sheath, and finishing by cold rolling. Concomitantly the Oak Ridge Laboratory developed a method for separating hafnium from zirconium; and, in cooperation with the Atomic Energy Commission and the Bureau of Ships of the Department of the Navy, a, larger pilot plant was erected to produce zirconium from very low hafnium zirconium tetrachloride furnished by the Commission. Pilot-plant work on producing zirconium tetrachloride from zircon sand and baddeleyite was discontinued. Production of zirconium sponge in the larger pilot plant of 500 pounds per week capacity was begun in June 1949.

Jan 1, 1956