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By D. Ng

A facility to evaluate the fire endurance of mine stoppings was constructed by the Bureau of Mines in the multiple entry section of the Bruceton (PA) Experimental Mine. Stoppings up to 6 by 18 ft can be tested in a manner simulating mine conditions. The stopping is subjected to a 70-min liquid fuel tray fire with an energy output of 75,000 Btu/min. The stopping and adjacent areas are instrumented with thermocouples and heat flux gauges. Data acquisition is by an automatic data logger capable of continuously recording over 100 channels of information. Two 8-in-thick concrete block stoppings and a galvanized steel stopping were tested. A crack developed on the fire side surface of the block stoppings where the flames were most intense. However, the temperatures of the unexposed surfaces of the stoppings never exceeded 800 C and the surfaces were undamaged. The steel stopping retained its structural integrity during the test. The temperature of the unexposed steel surface reached 5000 C, but combustible materials located 1 ft from the surface did not ignite. A 3/4-in-thick coating of construction plaster was applied to the fire side of the previously tested uncoated steel stopping. The quantity of heat energy transmitted across this coated metal stopping was reduced approximately 50%. All stoppings prevented the passage of flame and smoke.

Jan 1, 1988

By Richard L. Rains

The U.S. Bureau of Mines conducted a field study of mines and prospects of the Black Canyon RARE II area (No. 5061), Inyo County, California, from June to October 1981. Geological) geochemical, and geophysical studies were conducted by the U.S. Geological Survey. The Black Canyon RARE II area is east of Owens Valley and 6 mi east of Bishop, California. The principal mineral commodities are gold, silver, lead, zinc, and tungsten. Properties with resources in and adjacent to the area are listed in table 1; the locations are shown on figure 1.

Jan 1, 1983

By K. K. Kelley

"INTRODUCTION The Bureau of Mines nitrogen peroxide process (2) 3/ for extracting manganese from low-grade ores is essentially a two-stage process involving the reversible reactionMnO2 + 2NO2 + 6H2O = Mn (NO3)2 . 6H2O (1).At lower temperatures this reaction proceeds to the rigth and affords a means of dissolving manganece and separating it from unreacted ore. At higher temperatures the reaction proceeds to the left and manganese dioxide is recovered and nitrogen peroxide regenerated for recycling. Evidently, therefore, the energy required for decomposition of manganous nitrate is a matter of practical importance. Similar information for certain other nitrates also is desirable beceuse the nitration step of the process produces appreciable amounts of nitrates of other metals, such as iron, aluminum, magnesium, calcium, and barium, some of which are not broken down in the evaporation and decomposition steps. Thus, a portion of the nitrogen peroxide is not directly available for recycling. Whether or not it is feasible to recover nitrogen peroxide locked in the more-stable nitrates depends partly on the energy required and the conditions necessary for their decomposition.To supply information bearing directly on these subjects, several researches were undertaken at the Pacific Experiment Station: (a) Heats of formation (24, 25, 26) of nitrates of manganese, magnesium, calcium, barium, and aluminum were measured at 298.2° K:; (b) low-temperature specific heats (23), in the range 51° to 298.2° K,, and entropies of nitrates of magnesium, calcium, barium, and aluminumm were determined; and (c) heat contents (21) above 298.2° K. of the nitrates of manganese, magnesium, calcium., and barium were measured. The results of these studies, when correlated by thermodymamic methods, permit evaluation, at any temperature of interest, of the energies required to decomposethe nitrates and furnish information concerning the equilibrium pressure temperature relationships."

Sep 1, 1944

By G. B. Shea

In 192b, there wore 47 fatal accidents in the California petroleum industry, 14.6 per cent more than occurred in 1927 when 41 men lost their lives in the drilling, producing, manufacturing, and marketing divisions of the industry. This increase in the number of fatal accidents for 1928 has caused the first upward trend in the fatality curve of the California petroleum industry since 1923. In no other year during the 6-year period have the fatalities in any one year been greater than those for the preceding year. This fact should be given serious consideration and study by the petroleum industry, and an endeavor should be made to cause the number of fatalities again to decrease and conform to the previous gradual declining trend of the fatality curve. The following chart shows the trend of fatal accidents during the past six years:

Jan 1, 1929

Horizontal holes are drilled underground into coalbeds to control methane flow from ribs and active face areas and to make gas pressure measurements in coalbeds. Gas pressure measurements are made by drilling the same hole incrementally. After each increment, the hole is filled with some type of packers and allowed to reach equilibrium before a gas pressure reading is taken. As the length of hole increases, more packers are required to effect a seal and obtain a reliable pressure measurement. Problems have been encountered in obtaining satisfactory packer seals due to the friable nature of the coalbed. New methods of packing the holes must be used. Therefore, this project was established to evaluate materials and develop a new technique in which a semiliquid and/ or rigid type grout could be placed in the hole to provide satisfactory sealing.

Jan 1, 1972

By C. E. Lapple

To improve mine health and safety conditions, there is need for a portable instrument that mine inspectors can use routinely for rapidly checking concentrations of dust in mine atmospheres. On October 23, 1969, Stanford Research Institute was authorized by the U.S. Bureau of Mines to conduct a study aimed at developing such an instrument under Contract No. H0100186. The results of that study are reported in Technical Report No. 1, "Development of Portable Instrument For Measuring Coal Mine Dust Concentration," August 1970. In that study it was demonstrated on bench-scale that a near-forward optical scattering device gives a linear correlation between mass concentration and optical readout over a range of 2 to 200 mg/m3 with excellent reproducibility. The same correlation was obtained for the Respirable* dust fraction of three different coal dusts within ± 10% and an extreme spread of ± 30%. Based on these results a prototype instrument was designed which was expected to meet all the necessary requirements of a portable instrument for mine use. Because of the excellent results obtained, a further study was authorized by the Bureau of Mines on May 10, 1971 under Contract No. H0111688. The prime objective of this study was to build, calibrate, and deliver to the Bureau of Mines two prototype instruments based on the design previously developed. The emphasis was to be on providing instruments which would meet certain minimum standards of size, weight, response time, sensitivity, ruggedness, reproducibility, permissibility, and cost (ultimate); optimization of the design was to be considered only insofar as it would not significantly delay the development. One instrument was to be delivered after initial calibration of both instruments with Coal Dust PGH. The second instrument was to be used for further calibration with a number of other coal and rock dusts and for assessing other relevant performance characteristics. This report summarizes all the results of this second study.

Jan 1, 1972

By T. C. Green

A two-phase program evaluated commercial proximity warning devices and then served to design and develop an automatic electrostatic field strength measurement device with improved performance. The Phase I program consisted of test and evaluation of three commercial proximity warning devices, all of which operate on the principle of electrostatic field intensity measurement for determining proximity to high voltage power lines. Performance testing of these devices utilized full-scale cranes and power line systems and a scale model facility. The evaluation results were reported in the Phase I report entitled "Evaluation of Proximity Warning Devices" dated 22 February 1980. Under the Phase II program, a microproressor-based data acquisition system was designed and developed to collect and measure field strength at distributed points around the crane boom. This unit (referred to as the Distributed Sensor AC Electrometer) measures the field strength about a crane boom using 17 distributed sensors. Keyboard control is provided for the equipment operator. Measured field strength values are displayed on a line printer and recorded on magnetic tape. Laboratory testing of this unit demonstrated performance characteristics and field strength measurement accuracy within the design goals. A Phase III measurements program is proposed using the AC Electrometer to map the field strength contours about power line configurations.

Jan 1, 1981

By David C. Oyler, Hakan Gurgenli, Gregory M. Molinda

Historically, miners have known that roof rocks originally composed largely of mud were prone to slaking and deterioration when exposed to water and humidity. Mine Safety and Health Administration (MSHA) records show that roof falls are more prevalent in summer and late fall. Field data shows higher bolt loads and increased room convergence in summer months. Laboratory data shows that very high internal pressures can be generated by significant strain in clay-rich rocks. In summer months humidities ranging from 70-100% can cause rock strains up to 7%, and rock pressures of 14,000 psi, more than enough to break apart weak shales and fireclays. The National Institute for Occupational Safety and Health (NIOSH) conducted wet/dry immersion cycling of clay-rich rocks. Results show that the rocks most prone to moisture deterioration are fireclays, claystones, and sandy shales, all of which have disrupted bedding. Of the 7 mudrocks with a weatherability index above 40%, none showed consistent fissile bedding. Black shales were surprisingly resistant to wet/dry water immersion cycling. Generally, mixed rocks (stackrock), typically susceptible to horizontal stress, are more resistant to moisture-deterioration. Mine roof rocks tested with moisture sensitivity ratings above 50% (moisture sensitivity index ranges from 0-100 with 100 being the most sensitive) all came from mines which had roof skin problems and used supplemental support to prevent rock fall injuries. Some roof rocks showed lateral variability of moisture sensitivity values, suggesting the need for more samples in highly varying roof rocks. Swelling strains of mudrocks showed that almost all of the swelling occurred in the first 24 hours after immersion. The wet/dry immersion cycling test used provides an accurate, quick and inexpensive method for estimating the moisture sensitivity of mudrocks. With this information mine operators can begin to anticipate hazardous ground and prepare appropriate roof support.

By Michael J. Potter

Native asphalt was produced by five companies in two States, Texas and Utah. Bituminous limestone, used primarily as a paving material for street and road repair, was produced by White Uvalde Mines and by Azrock Industries Inc., Uvalde County, TX. In June, Azrock Industries was purchased by the R L. White Co. Gilsonite, a solidified hydrocarbon found only in Utah and Colorado, was mined by American Gilsonite Co., a division of Chevron Resources Co. (a subsidiary of Standard Oil Co. of California); by Ziegler Chemical and Mineral Corp.; and by Hydrocarbon Mining Co. (a subsidiary of Oberon Oil Inc., a Utah corporation) from properties in Uintah County, UT. Gilsonite is used for a variety of purposes including automobile bodysealer, light-weight aggregate for cement used in oil well drilling, asphaltic building board, protective coverings, anticorrosive paints, and roofing compounds.

Jan 1, 1985

By Orlando Martino

This regional report covers the mineral industries of Canada and 40 countries and areas in Latin America and the Caribbean Basin. Also included is a brief description of the mineral potential of Antarctica. The Latin American region encompasses an area twice that of the United States. Latin America and Canada have a rich and diversified endowment of mineral fuels, metals, and industrial minerals. Tables 1 and 2 provide a summary view of Latin America and Canada's output of its major mineral commodities in world mineral supply in 1990 and 1991. Table 3 shows the relative importance of a selected group of minerals produced in Latin America in the world mineral economy.

Jan 1, 1993

By Alfred L. Ransome

The plan to develop a standard system of names and definitions of regions and districts in Alaska was borne of the need for a tool to use in statistical and economic studies of the mineral industry of the Territory. The purpose of this report is to present to the mineral industry, and to those individuals interested in the mineral or allied industries in Alaska, the system used by the Bureau of Mines in connection with its legal function of collecting and disseminating mineral statistics. It is hoped that the specific descriptions given will result in a more complete understanding of what is meant by the regional and district names that appear in publications of the Bureau of Mines relative to the mineral industry of the Territory. Problem of Standardization of Names and Definitions The question might be asked, does the naming and defining of regions and districts in Alaska present a problem relative to the establishment of a standard? Is it necessary to establish a standard?

Jan 1, 1954

By James D. Eklund

Towards the goal of improving safety, economy and efficiency of scaling in underground metal/nonmetal mines, Battelle developed a combination prying/hammering scaling tool. A prototype was subjected to limited testing 1) to verify its operational functions and 2) to assess its potential capability in future underground testing.

Jan 1, 1983

By Joseph Sabatini

This report, covering the period January through December 1975, contains abstracts of articles concerning all phases of cost engineering and economics for chemicals processing, raining, and other mineral industries. The abstracts are collected from the following sources: 1. Chemical Engineering 2. Chemical Engineering Progress 3. Chemtech 4. Coal Arse 5. Coal Mining and Processing 6. Combustion 7. Drilling 8. Electrical World 9. Engineering and Mining Journal

Jan 1, 1976

By Meliton M. Garcia

The volume of gases produced in major and trace amounts following the detonation of two water gel and two emulsion explosives in a mine were determined. The volume .of the major gases (CO, CO2, NO, and NO2) was measured immediately following detonation, during the mucking operation, and following the removal of the muck. Tests to identify and quantify the gases produced in trace amounts were performed following the detonation only. The volume of each major gas per pound of explosive (ft /lb) ;ranged as follows: CO, 0.0424-0.3231; CO , 0.6819-1.5632; NO, 0.0129-0.1320; and NO2, 0.0019-0.1111.. An approximate average of 95% of the gases produced was found in the test chamber immediately following the detonation, while less that 2% was found in the chamber following removal of the muck. Benzene was the most significant compound found to occur in trace amounts. Scaling tests performed with a water gel and an emulsion explosive suggest that the volume of the gases per unit mass of explosive detonated diminishes as the amount of explosive per blast increases.

Jan 1, 1986

By W. C. Babcock

This report covers Phase V of .a continuing program to apply a new liquid membrane process called coupled transport to the recovery pf metals from hydrometallurgical leach solutions. During this phase of the program, a membrane system of moderate scale was constructed and field-tested at the Exxon Highlands Mine and Mill Co. site near Douglas, Wyoming. The test unit contained four hollow-fiber membrane modules, each with 100 ft2 of membrane area. In the field tests, about 1000 gallons per day of leach solution was processed. The unit was operated on the leach solution for about 50 days. Leach solution entering the unit contained 100 ppm uranium. This concentration was reduced to about 5 ppm by coupled-transport treatment, and the uranium was concentrated to about 2 wt% as a uranyl carbonate product. Under these conditions, a transmembrane uranium flux of about 2.5 lb/ft2-year was obtained. An economic analysis showed that the cost of recovering uranium from this leach solution via coupled trans-port is about $1.20/lb. At higher concentrations of uranium in the leach solution this cost is reduced. For example, at 1000 ppm the cost of uranium recovery is about $0.30/lb.

Jan 1, 1983

By C. W. Owings, J. J. Forbes

"Although coal-mine explosions rank third among causes of underground fatalities, they receive more wide-spread attention than any other accidents in mines because frequently many persons lose their lives in a single disaster. Each bituminous coal-mine explosion endangers the lives of approximately 100 persons--the average number employed underground in a commercial mine. A critical analysis of coal-mine explosions in a restricted district gives a cross-section of relative existing explosion hazards, of common causes of ignitions of gas and dust, and of effective prevention measures. The Safety Division of the United States Bureau of Mines is collecting data on coal-mine explosions in the various States, and this circular is one of a series analyzing the causes and recommending methods for thy prevention of similar occurrences,The data on this circular are based on records of the United States Bureau of Mines and the West Virginia Department of Mines. Unfortunately practically all of the early records were destroyed by fire in the State House at Charleston, W. Va.; the remaining records were made available to the authors by N. P. Rhinehart, chief of the Department of Mines, and his cooperation is gratefully acknowledged.The earliest available reference to coal in West Virginia is that made by John Peter Lally who in 1742 found ""a great plenty of coals"" near a river later called Coal River. In 1809, Nicholas Roosevelt found coal along the Ohio River and used it on the New Orleans, said to have been the first steamboat west of the Allegheny Mountains. In 1810, Conrad Cotts opened a mine near Wheeling and sold coal for domestic purpose in 1812, a mine was opened on the Ohio River opposite Mason City and produced 1,200 bushels of coal that year. In 1840 the total West Virginia coal production was 298,691 tons; in 1863, the production had increased to 444,468 tons, and in 1883, to 2,335,833 tons. During this period apparently most of the coal was extracted from coal outcropping on the hillsides; little danger of gas ignition existed at that time, but explosions from blown-out shots occurred frequently. On February 22, 1383 the West Virginia legislature enacted legislation providing for a mine inspector to inspect the mines of that State, to prevent mine accidents, and to insure properly ventilated mines.In a special report to the Governor on December 31, 1884 the Inspector of Mines reported:We have 5 shafts, in 4 of which there is more or less gas; and in 1 of our drift mines there was an explosion on the 27th day of March 1880, whereby 2 men were killed and a boy badly burned.Table 1 lists 287 explosions in West Virginia coal mines. Several early explosions were listed in the annual reports of the West Virginia Department of Mines as ""blown-out shots"" or ""powder explosions"". The injuries usually were described; explosives accidents have been eliminated from these and other available data, and only those in which dust or gas were involved have been included in this paper as explosions."

Sep 1, 1934

By Jr. Brinkley

For a theoretical description of power plants that derive their energy from the combustion of a fuel, it is necessary to solve, to an appropriate degree of precision, a hydrodynamic problem that requires for its solution a knowledge of the thermodynamic properties of the working fluid com-posed of the products of the combustion reaction. It is usually a good approximation to assume that the properties of the combustion gas are determined by the conditions of thermal equilibrium, and it is thus possible to employ the methods of Classical thermodynamics for their computation. The thermodynamic properties of fuel gases also are of considerable importance, as they form the basis for the design of appropriate means for their effective utilization. The specification of the operating conditions to produce a gas for use as an intermediate in a chemical process, such as the synthesis of liquid fuels, may be based upon a study of the variation of the composition of the synthesis gas with changes in the various process variables. Although there exists a large number of important scientific and technical applications of the data that can be obtained from the systematic determination of the thermodynamic properties of combustion gases, such application has been greatly handicapped by the extremely tedious and time-consuming computational methods required. The development of large-scale automatic computational equipment makes feasible the initiation of a systematic program for the determination of the thermodynamic properties of combustion gases and for the application of such data to specific problems of scientific and technical importance. As a part of its program of basic research in flame and combustion phenomena, the Explosives and Physical Sciences Division of the Bureau of Mines is engaged in such a program. The present communication is designed to introduce a series of reports presenting the results of this program.

Jan 1, 1951

By Michael Zachariah, Art Miller, David Kittelson, Gib Ahlstrand

This report describes an investigation in which we used iron-doped diesel fuel to generate metal-bearing diesel particles and a subsequent analysis of the particles using transmission electron microscopy (TEM) and energy-dispersive spectroscopy (EDS). For this study, DPM was generated by a 1.5-L diesel engine and the fuel was doped with ferrocene to enhance the level of iron in the system. The exhaust particles were collected on TEM grids and analyzed using the Philips CM12 TEM/EDS instrument. Results show that when the iron-to-carbon (soot) ratio (Fe/C) in the engine is low, the exhaust particles have morphologies similar to those for the undoped case, but at a threshold Fe/C value of 0.013 (for this engine), homogeneously nucleated metallic nanoparticles are formed and begin agglomerating. The number and size of these nanoparticles increase with level of doping. Metal-bearing particles that span a wider size range are also formed. Agglomeration of metallic and carbon particles is observed in two distinct modes: attachment of iron primary particles (5–10 nm in diameter) to carbon agglomerates, and coagulation of iron agglomerates (20–200 nm in diameter) with carbon agglomerates. Results of this work imply that as new engine technologies reduce soot levels in the engine and/or levels of trace metals in the fuel are increased, the generation of metallic nanoparticles may ensue, creating a potential health concern. Keywords: Nanoparticles; Particulate emissions; Metallic particles; Metal emissions

By Stephen D. Smith

The following tables summarize data on crude nonfuel mineral production for the United States, its island possessions, and the Commonwealth of Puerto Rico. Although crude mineral production may be measured at any of several stages of extraction and processing, the stage of measurement used in these tables is what is termed "mine output." It usually refers to minerals or ores in the form in which they are first extracted from the ground, but customarily includes the output from auxiliary processing at or near the mines. Because of inadequacies in the statistics available, some series deviate from the foregoing definition. For copper, gold, lead, silver, tin, and zinc, the quantities are recorded on a mine basis (as the recoverable content of ore sold or treated). However, the values assigned to these quantities are based on the average selling price of refined metal, not the mine value. Mercury is measured as recovered metal and valued at the average New York price for the metal. The values shown are in current dollars, with no adjustments made to compensate for changes in the purchasing power of the dollar.

Jan 1, 1995

By David L. Veith

This Bureau of Mines bibliography of U.S. and Canadian literature pertaining to revegetating coal-mined lands contains 805 references published from 1977 to 1984. Each reference is evaluated by keywords, providing the reader with a means of rapidly sorting through the references to locate only those dealing with the coal mining region and subject of interest. All references are annotated. Other sources of information are given, including Office of Surface Mining (OSM) and State reclamation agencies and other published bibliographies.

Jan 1, 1985