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By Laurance L. Oden

The Bureau of Mines is developing nickel catalysts for converting synthesis gas derived from coal to synthetic natural gas. The present report describes the relationship between the composition of aluminum-nickel alloys in the composition range NiAl3 to Ni2Al3 equilibrated at 840° C and the properties of catalysts obtained from them. Methanation activity was determined in the temperature range of 300° to 360° C in a flowing gas stream containing 1 pct CO, 8 pct H2, and the remainder He. One part per million of H2S was added to the gas stream at 400° C to evaluate the susceptibility of catalysts to sulfur poisoning. The total surface area was measured by the adsorption of nitrogen at liquid nitrogen temperature, and the active surface area was measured by the adsorption of hydrogen at room temperature. Total surface area and active surface area were found to increase with increasing proportion of aluminum-saturated Ni2Al3 in the precursor alloy, but methanation activity and resistance to poisoning by H2S were nearly constant. However, the methanation activity of the catalyst prepared from stoichiometric Ni2Al3 was less than half that of the other catalysts.

Jan 1, 1978

1.1 DEVELOPMENT OF INDUCTANCE MATRICES The basic building block in this analytical work is the development of an equivalent circuit. The equivalent circuit for the cable depends on all of the distributed parameters of the cable although the series inductance and resistance are of primary importance. The cable resistances are generally available from handbooks or from cable manufacturers. On the other hand, the cable inductances are not usually available either from handbooks or from the manufacturer's published data. Thus, it is useful to summarize the derivation of the origin of the inductance matrix from basic principles. 1.1.1 Flux Around a Cylindrical Conductor The flux pattern around a cylindrical current carrying conductor can be found by using symmetry in conjunction with Ampere's Law. From symmetry it is clear that the flux lines which always close on themselves must be concentric circles. Thus, from symmetry alone one can get a qualitative picture of the magnetic field. This is shown in Fig. 1.1 where the inner circle represents the solid round conductor and the outer circle represents a flux line. The quantitative picture will now be developed using Ampere's Law.

Jan 1, 1973

By Jaan Kiusalaas

This report is a self-contained User Manual for a computer program called SPASID -- Subsidence Prediction and System Identification. The program has two primary functions: (i) Precalculation of ground movements due to underground mining operations using the influence function method; (ii) Computation of influence function and site parameters from measured displacements. SPASID is written in FORTRAN and consists of four modules: (i) Preprocessor Module that prepares and maintains surface and mine data bases; (ii) Subsidence Computation Module that predicts movements of the surface; (iii) System Identification Module which is used to calculate the optimal influence function parameters, and (iv) Postprocessor Module for generating graphic displays of subsidence data. The last module is somewhat machine dependent but has internal documentation to indicate potential changes. All of the modules may be run in either batch or interactive mode. The manual does not assume previous knowledge of the influence function method or programming competence.

Jan 1, 1983

By George A. Morgan

Output of mineral products was estimated to be unchanged in 1983 from that of 1982 with the exception of petroleum. The country began production of crude oil from the Seme Oilfield, and all output was exported. Wd and charcoal constituted 72% of Benin's total energy consumption, and imported petroleum products and electric power accounted for the remainder. Cement was produced from imported clinker. The gross domestic product (GDP) was $1,061 million in 1982, the latest year for which information was available.2 COMMODITY REVIEW Gold.-Exploration was underway at Perma by the U.S.S.R. as part of the United Nations development program. Gold had been produced previously at Perma, where a grade of 0.289 troy ounce of gold per ton was reported, An exploitation program for the deposit was to employ about 100 people, and output was targeted to reach 1,600 troy ounces per year. Recoverable reserves were put at 96,000 troy ounces.

Jan 1, 1985

By Wils L. Cooley

The report covers tests and criteria for the establishment of safe grounding systems for coal mines. The work deals primarily with under-ground coal mines, but much is applicable to surface mines as well. Included is an extensive guide to grounding and bonding procedures for mine surface substations. Xit-Rods are evaluated and shown to deviate from manufacturer's claims. An analysis shows that very long cables are difficult to monitor using audio frequency ground-check techniques. A method is developed to detect failing cable splices without removing the cable from service. Simulation and measurement are compared for a technique to detect bad rail bonds, and an assessment is made of grounding techniques for dc face equipment.

Jan 1, 1979

By N. R. Dixon

This report summarizes all work performed under U.S. Bureau of Mines Contract No. J0395028, "Noise Control of Rubber-Tired Front-End Loaders Used in Surface Mining. " Two loaders, a Caterpillar 988 and an International H-400B, were chosen for this program, and the noise sources and acoustic paths that contribute to the operator's noise exposure were identified. Retrofit noise control treatments were designed and installed on these loaders, and noise reductions of more than 10 dBA at the operator position were achieved on both machines. The retrofit packages are low cost and have been field tested in two mines for more than two years. The results of the program were communicated to the mining industry through a series of noise control workshops and a field manual. The workshops were given in nine states across the U.S. and more than 440 manuals were distributed An audio/visual slide presentation was also developed which the program.

Jan 1, 1983

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 D. R. Flinn

A newly developed chemical conditioning technique, which greatly simplifies the preparation of plating baths for the electrodeposition of titanium diboride (TiB2) coatings, is described in this report. The new plating technique was used to prepare samples of titanium diboride (TiB2) coatings on three types of substrate materials. These samples were then evaluated in both low- and high-speed wear-test programs to determine the wear resistance, microhardness, and adhesion of the coatings. In general, it was found that the wear resistance of the coatings is independent of substrate. Scanning electron micrographs have shown that the coating wear surfaces are very smooth, suggesting slow and continuous removal of the coating during the wear test (that is, adhesive wear). Adhesion between the coating and all substrates was excellent. Microhardness results show that the TiB2 coating is harder than alumina, with a hardness value exceeding 5,000 kg/mm2 measured in one test. The results of the wear tests show that TiB2 coatings have relatively poor wear resistance compared with alumina in low-speed unlubricated sliding environments, but exhibit wear properties comparable with alumina in high-speed unlubricated sliding environments.

Jan 1, 1981

By Thomas J. Peters

In 1985, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied a 17,320-acre portion of the 52,143-acre Little High Rock Canyon Wilderness Study Area (CA-020-913/NV-020-008) in order to evaluate its identified mineral resources. The study area is located in Humboldt and Washoe Counties, NV, about 42 miles north from Gerlach. Three areas of epithermal alteration, similar to alteration associated with disseminated gold deposits, were found in the study area. One of the areas occurs along a northeast-trending structural lineament. Southwest of the study area two gold prospects undergoing active exploration, as well JS a gold deposit being prepared for production, occur along the same lineament. The Bureau of Mines examination, however, did not find evidence for gold resources in the study area.

Jan 1, 1987

By William T. Boyd

Foreign mining publications describing successful hydraulic mining installations, and successful domestic hydraulic mining in a gilsonite bed, have prompted the Federal Bureau of Mines to conduct a literature survey of foreign publications to determine if the hydraulic mining method can be applied to domestic coal mining. Most foreign publications do not give detailed data about the water pressures, water capacities, and production and manpower requirements for successful hydraulic mining, However, they do provide enough general data on mining conditions, manpower, and equipment used to show that conditions in many bituminous coal deposits in the United States may be favorable for economical coal extraction, using high-pressure water jets. Therefore, the Bureau proposes to conduct a field investigation to determine the most appropriate natural conditions, water pressures, and equipment for successful hydraulic mining of coal beds in the United States with variable dip, thickness, and hardness. In the past, technical personnel reviewing foreign mining reports assumed that a steeply pitching coal bed was necessary for successful hydraulic mining. Although the structure of the coal bed may be a factor in gaining assistance from overburden pressures or help in an integrated hydraulic mining and transportation system, the coal is broken mainly by the action of high-pressure, water-penetrating cracks, fissures, or cleats; therefore, the slope of the coal bed is not necessarily a determining factor in hydraulic mining.

Jan 1, 1959

By J. P. Schmid

Results of a comprehensive investigation of the impact of underground mine waste disposal on the health and safety of miners are presented. Information was gathered through an extensive search of American and foreign literature and personal communication with professionals in private industry and government. All conceivable health and safety hazards directly or indirectly related to underground mine waste disposal are analyzed, catagorized, and ranked on an industry-wide basis. Positive health and safety effects are analyzed and ranked in a similar way. Both potential and known hazards and positive impacts are included. Recommendations on abatement techniques for the various hazards are presented. Case histories of a fill-related accident in a metal mine and a health hazard associated wtih coal waste backfilling are included and causes and possible abatement procedures are discussed. The rule of management in the promotion of health and safety in backfilling operation is discussed.

Jan 1, 1982

By Jack O. Jones

The Furnish mine, Caharrus County, W. C., was operated intermittently until 1905 as a gold mine. Scheelite was discovered by A. L. Mash in the mine dumps of the Furniss and Phoenix mines, and he later informed the Bureau of Mines of his discovery. The Bureau of Mines, in two projects at the deposit in 1948 and in drilled 12 holes totaling 1,706.6 feet, examined and sampled the underground workings, excavated by bulldozer and hand, 3,155 linear feet of trenches and collected numerous samples for assay. The best scheelite shown; was found in the underground exposure of the Furniss mine.

Jan 1, 1950

By John R. Bartels

This Bureau of Mines report describes the development of a preliminary design for a novel, protected, cab-shuttle car for use in working seam heights down to 40 in. Because of the severe restrictions imposed by low-coal operation, Mine Safety and Health Administration (MSHA) regulations only require canopy protection on shuttle cars operating in seam heights of 42 in or greater. MSHA routinely grants variances for canopy use in seams 48 in high or less. The design was generated by giving the operator needs equal priority as related to machine performance parameters. Cab-shuttle car concepts that led to the recommended design are described, along with criteria and testing used to evaluate their potential effectiveness.

Jan 1, 1988

By Marshal Scherba

Coal seams approximately 7 feet, 9 feet and 20 feet thick at depths of 250, 600 and 1,000 feet respectively were detected using high resolution seismic reflection techniques. Investigation of seismic profiles indicates that good data are required to delineate faulting with only 20 feet of throw but that faulting with 50 feet of vertical displacement can be detected with poor data. Data acquired from dynamite charges fired in water saturated media were clearly superior to that acquired using charges dry tamped in 10 and 20 foot holes.

Jan 1, 1977

This chapter summarizes data on crude mineral production for the United States, its island possessions, and the Common-wealth of Puerto Rico. Included also are tables that show the principal mineral commodities exported from and imported into the United States, and that compare world and U.S. mineral production. Except for the mineral fuel commodities, the detailed data from which these tables were derived are contained in the individual commodity chapters of volume I and in the State chapters of volume II of this edition of the Minerals Yearbook. In October 1977, responsibility for the collection of data on mineral fuels-coal, petroleum, natural gas, and natural gas liquids-was transferred to the newly created Department of Energy. Although chapters covering these commodities will no longer appear in Volume I of the Minerals Yearbook, quantity and value data have been included in most of these summary tables to maintain statistical consistency in State and national value of overall crude mineral output. This shift in responsibility has also resulted in changes to the composition of the "Nonmetals" and "Mineral Fuels" groups in table 1 and table 2. The commodities-asphalt and related bitumens (natural), carbon dioxide (natural), helium, and peat-have been removed from the "Mineral Fuels" group, and are now included under the "Nonmetals" group. There has been no change in the components of the "Metals" group.

Jan 1, 1980

Mercury has been used by mankind since prehistoric times. It has been, and is now, widely used in industry and medicine and has unique properties which make direct substitution difficult or impossible. At present its principal uses are for electrical apparatus, control instruments, electrolytic soda preparation, mildew-proofing paints, pesticides, and medical and dental preparations. Deposits of mercury are less common than those of other base and precious metals, but some of the deposits are very large and have been ample to meet the world's past demands. The price of mercury has had many sharp fluctuations, but in general, the limited number of producers has resulted in a more stable price structure than that of many other commodities. The United States has been one of the main producers of mercury, and from 1850 to 1961 produced 3,247,704 flasks. Yearly production since World War II has varied from 4,535 to 38,067 flasks. An estimate of domestic resources of mercury producible at various price ranges was prepared for each mercury mine by combining specific knowledge of mercury mineralization with estimates of potential, based on geologic information and past production history. The sum of the individual estimates for each price range is shown in a table. A parallel estimate of nationwide production potential was made from a study of past price and production relationships. These were analyzed by plotting yearly production figures against the previous year's price, expressed in dollars of constant purchasing power. An equation was fitted to the data by mathematical means and was used to extend the curve into areas of higher than historic prices. Potential production rates at various price levels were taken from this graph. The estimated yearly production rates were used to make an estimate of total potential based on the premise that production rates and reserves have a proportionate relationship. The rate of developing mercury reserves during the period from January 1944 to January 1962 is considered, and it is shown that if this rate can be continued, the mercury resources of the United States, at a constant dollar price of $500 per flask, are adequate to support a production of 60,000 flasks per year for 30 or more years. This publication contains a history and description of the mercury industry in every State which has had production and individual descriptions of all mercury properties which have reported significant production. Accompanying tables give the important facts about all known mercury occurrences.

Jan 1, 1965

Mercury has been used by mankind since prehistoric times. It has been, and is now, widely used in industry and medicine and has unique properties which make direct substitution difficult or impossible. At present its principal uses are for electrical apparatus, control instruments, electrolytic soda preparation, mildew-proofing paints, pesticides, and medical and dental preparations. Deposits of mercury are less common than those of other base and precious metals, but some of the deposits are very large and have been ample to meet the world's past demands. The price of mercury has had many sharp fluctuations, but in general, the limited number of producers has resulted in a more stable price structure than that of many other commodities. The United States has been one of the main producers of mercury, and from 1850 to 1961 produced 3,247,704 flasks. Yearly production since World War I1 has varied from 4,535 to 38,067 flasks. An estimate of domestic resources of mercury producible at various price ranges was prepared for each mercury mine by combining specific knowledge of mercury mineralization with estimates of potential, based on geologic information and past production history. The sum of the individual estimates for each price range is shown in a table. A parallel estimate of nationwide production potential was made from a study of past price and production relationships. These were analyzed by plotting yearly production figures against the previous year's price, expressed in dollars of constant purchasing power. An equation was fitted to the data by mathematical means and was used to extend the curve into areas of higher than historic prices. Potential production rates at various price levels were taken from this graph. The estimated yearly production rates were used to make an estimate of total potential based on the premise that production rates and reserves have a proportionate relationship. The rate of developing mercury reserves during the period from January 1944 to January 1962 is considered, and it is shown that if this rate can be continued, the mercury resources of the United States, at a constant dollar price of $500 per flask, are adequate to support a production of 60,000 flasks per year for 30 or more years. This publication contains a history and description of the mercury industry in every State which has had production and individual descriptions of all mercury properties which have reported significant production. Accompanying tables give the important facts about all known mercury occurrences.

Jan 1, 1965

In Bureau of Mines research on recycling chrome refractory wastes, used refractories from argon-oxygen decarburization and electric steelmaking furnaces were beneficiated, concentrates were reformed into briquets, and modulus of rupture tests were conducted at 1,350° C. The test results indicated that the beneficiated minus 6-mesh material could be used for producing magnesia-chrome refractories.

Jan 1, 1980

By Donald O. Capstick

A mineral survey of a 5,700-acre portion of the 11,510-acre Upper Deep Creek Wilderness Study Area (ID-111-44B) in southwestern Idaho was conducted by the U.S. Bureau of Mines in 1985. No mining claims have been located, no minerals have been produced, and no resources have been identified in the study area. Three reconnaissance samples of alluvium from the Deep Creek drainage contained $0.21, $0.22, and $2.72 per cubic yard in placer gold, higher than usual for the Owyhee River canyonland area. The samples of near-surface material contained very fine gold in values too low to support large-volume commercial placer operations, but the quantity and size of the particles of gold in the alluvium is expected to increase near bedrock. Consequently, the area may be a target for recreational as well as small commercial suction dredge operations. The physical characteristics of the individual pieces of gold (bright and angular) indicate that it may have recently come from an unidentified nearby source.

Jan 1, 1986

By G. Huang, S. Vytla

Computational fluid dynamics (CFD) is a continually developing numerical technique by which complex fluid flow problems can be solved on computers. To be able to transfer CFD expertise to analyze and design a face-ventilation system, a comprehensive validation study of current CFD tools against mining-related benchmark experiments is required. In the last four years, such studies, funded by National In¬stitute for Occupational Safety and Health (NIOSH) under Grant #R01 CCR415822, were conducted in the Department of Mining Engineering at the University of Kentucky. A wide array of ventilation schemes and mining configurations were considered. Recently, an additional study was performed in cooperation with the NIOSH Pittsburgh Research Laboratory. This study was dedicated to the methane behavior in the empty (containing no equipment) face area with a blowing curtain and a 10. 7-m (35-ft) setback. In this paper, the authors present and discuss the computer-simulation data and compare them with data collected during the laboratory studies at the NIOSH lab.