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This chapter summarizes data on crude nonfuel mineral production for the United States, its island possessions, and the Commonwealth of Puerto Rico. Also included are tables that show the principal nonfuel mineral commodities exported from and imported into the United States and that compare world and U.S. mineral production. 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. Although crude mineral production may be measured at any of several stages of extraction and processing, the stage of measurement used in this chapter is what is normally 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.

Jan 1, 1988

Electrical trailing cable used to power coal mining machinery is frequently damaged in usage because of tensile strain or crushing effect of mining machines running over the cable. One of the repair problems is finding the exact location of a short or open in this cable so it may be spliced or otherwise repaired. The U.S. Bureau of Mines and FMC corporation signed Contract No. H0 122011 in August, 1971, to develop instrumentation for finding faults in coal mine trailing cable. This report describes performance of several existing instruments as trailing cable fault locators and also construction details and performance records of several cable fault location instruments that FMC designed, built and tested as part of this project.

Jan 1, 1973

By Rolland L. Blake

Petrographic methods of examination were used by the Bureau of Mines on a suite of samples of ultramafic rock from Soapstone Ridge, Ga., located about 8 miles south-southeast of Atlanta. The samples were analyzed to determine (1) their potential for releasing regulatory particles upon crushing and grinding and (2) their concentration of fibrous particles that approach the dimensions of amphibole and serpentine asbestos minerals. Such particles might be generated during grading and excavation for housing and industrial development and could become a health concern. Light optical microscopy, scanning electron microscopy, and X-ray diffraction were the techniques used to examine the samples. Six of the twelve samples contained amphibole as a major mineral; in five, it was a moderate to minor mineral. One sample contained no amphiboles, and serpentine was not observed or identified by X-ray diffraction in any of the samples. In nine of the samples, the amphiboles exhibited a habit that was either prismatic or acicular, but not asbestiform. Two of the samples did contain asbestos, occurring as small veins or fracture fillings, which represented only a minor percentage of the total sample. Similar petrographic screening is recommended for examining any rock deposit or mine location to delineate hazardous and nonhazardous mineral areas.

Jan 1, 1982

By Robert L. Lagace, Alfred G. Emslie

This report presents a mathematical model for the propagation of UHF radio waves in the large cross-section tunnels of a room and pillar limestone mine, and describes the analysis of a small amount of propagation data obtained in a limestone mine. The model and analysis is based on the waveguide mode theory developed earlier for the transmission of UHF waves in coal mine tunnels, with allowance for propagation losses due to refraction into the tunnel walls, to scattering by wall roughness, and to long range random tilt of the walls. Propagation around corners and through pillars is also examined based on a ray theory approach, together with the beneficial effects of placing reflectors at intersections to significantly reduce corner losses. The theory is found to be in fair agreement with the data; however, additional in-mine measurements are needed to provide a more conclusive test of the model.

Jan 1, 1979

By Robert A. Harrow

This report documents the results of the development and installation of an illumination system for an underground coal mine Shortwall Mining Section. Also presented are the techniques used for the above ground test and evaluation of the lighting system prior to installation underground which resulted in the issuance of a Statement of Test and Evaluation (STE) from the Mine Safety and Health Administration, Technical Support, Beckley, West Virginia.

Jan 1, 1979

By D. Harrington, C. W. Owings

Each year at least one and in some years several explosions are reported as having resulted from firing of mudcapped shots in coal mines; undoubtedly a number of small or local explosions occur that are not reported; in addition there are numerous accidents, some of them fatal, attributable to this reprehensible blasting practice. It is surprising that so few explosions and other accidents from this cause occur since the practice of firing mudcapped, Even in gassy "adobe," "dobe," "sand blast," or "bulldozed" shots is widespread. mines where general blasting is safeguarded by being done with permissible explo- sives, rocks or bowlders frequently are blasted with mudcapped shots of dynamite; even if permissible explosives are used, this type of shooting is dangerous. The usual method of preparing a mudcapped shot is to place the explosive, either in loose or cartridge form, with the detonator or "cap" on top of a piece of rock or coal and cover it with several handfuls of moist clay, loam, sand, or When the shot is road dust; in many cases there is no covering of any kind. fired a dense cloud of dust, together with an intensively hot fleme, are thrown into suspension, and if the dust is explosive or ignitable an explosion or igni- tion is likely to result practically simultaneously. The presence of gas greatly increases the explosibility of the dust, as well as the probability of an ignition. Every shot, of any known explosive, fired in a coal mine without having the charge properly confined in a drill hole and tamped with incombustible stemming to the collar of the hole, is capable of initiating an explosion that may cause the death of every man in the mine. Attention has recently been directed to this unsafe practice by an explo- sion resulting from a flagrant disregard of safe blasting practices in one of our The mine had been idle for several years most productive coal-mining regions. and was being prepared for reopening on a different system of mining. Six to 10 inches of bottom coal had been left in place during former mining operations, but in the new system it was felt desirable to remove the bottom coal left in certain parts of the mine. Instead of drilling holes in the coal, loading them, and fir- ing in the usual safe manner, five or six charges of dynamite were placed on top of the coal in each of several rooms; and while the men were at the mouth of the

Aug 1, 1929

Develop a metal substitute which is more plentiful and less expensive than the metals currently being used in high performance, permanent magnets, while maintaining the quality of the magnet. The New Alloy The rare-earth metal used in most high performance magnets is samarium, an expensive metal of limited availability. Cobalt is also used in high performance magnets, but supplies of this metal also are limited because it is not domestically mined and must be imported. The Bureau of Mines embarked on research to find a less costly domestic: metal source for use in industrial magnets. The alloy found most promising consists of mischmetal, a relatively abundant, naturally occurring mixture of rare-earths, which can be used as a replacement for samarium. Additives of copper, magnesium and iron used in combination with mischmetal aid in replacing some of the cobalt needed for the magnets.

Jan 1, 1983

By Lester G. Morrell

UPTREND in value of mineral production in the Commonwealth of Australia continued in 1963, again pacing the country's general economic growth rate. Increases occurred in output of most raw and processed mineral products, including bauxite, copper, iron ore, pig iron, steel, lead, zinc, cement, gypsum, pyrite, coal, and refined petroleum products. Although the economy of Australia has been traditionally based on wool and agricultural products, in recent years the country has become highly industrialized. Nearly one-third of the 3.6 million total civilian labor force is engaged in manufacturing. Employment in mines and quarries occupies 1.4 percent of the national labor force.

Jan 1, 1964

By M. D. Aldridge

This document reports the results of a two-year research effort aimed at improving communication systems used in coal mines. This work was conducted under a program whose original goal not only involved the development of practical and effective electronic systems for operational communications, but also for monitoring, at a central location, remote instruments at key positions in a mine. About half way through the originally proposed three year effort, the program was redirected to phase out the communication effort at the end of two years and to concentrate the program" resources on the investigation of new monitoring system concepts developed by this research. Thus, the work reported here is incomplete relative to the originally pro- posed program. However, the work was carried to the point of providing sufficient evidence to aid in the comparison of certain new communication concepts. For the concepts chosen for this study, the work was stopped short of hardware development and field testing, Several reports in the form of Master's theses and a Doctoral Dissertation have resulted from this research. They each report in considerable detail the results of several individual" contributions to this program. In preparing this report, an attempt has been made to provide a complete description of the significant results but with- out burdening the reader with the minute details. These more detailed reports are referenced heavily for the convenience of those interested. PRESENT COMMUNICATION METHODS Two types of communication systems are presently used In coal mines. They are: 1, Various forms of telephone systems, and 2. Carrier current radio systems using the trolley line as the interconnection circuit. Carrier current radio is used almost exclusively for control of rail trafflc by the dispatcher. Almost all other communication uses the telephone system, Telephone lines generally extend to areas where trolley lines are not present such as the outside offices and warehouse. Therefore the telephone system provides the primary means of voice communication. Telephones - Telephone systems employed in American coal mines fall into three categories. 1. Paging type telephone systems - these systems have individual stations which use battery powered transistor audio amplifiers to boost signal levels for normal communication. When in the page mode,

By Thomas J. Peters

In 1979 and 1980, the U.S. Bureau of Mines and U.S. Geological Survey conducted a mineral survey of the 15,600 acre (6,310 ha) Freel Peak RARE II area (No. 5271) in the Lake Tahoe Management Unit. This study by the Bureau of Mines indicates that potential for economic mineral resources in the area is slight. The only mineralized structures in the area consists of two quartz veins. One quartz vein, at the Mountain Top Mine (fig. 1), located by Fred Denner in 1932, is estimated to contain 2,000 tons (1,800 t) of silver and copper-bearing resources. Chip samples from the vein averaged 0.61 oz silver per ton (20.91 g/t), and 1.59 percent copper. The narrow vein is not economically mineable. The other quartz vein is poorly exposed and contains traces of molybdenum. A second reported molybdenum occurrence could not be substantiated.

Jan 1, 1982

By R. W. Welker

A technique was developed for sampling and analyzing airborne dusts in diesel-operated, underground, metal, and nonmetal mines. Samples were taken using personal respirable samplers, operated as area samplers, and an 11-stage cascade impactor. Real-time particle size distribution and concentration measurements were made with a quartz crystal micro-balance cascade impactor and a portable electrical aerosol analyzer. The materials characterized were minerals (by XRD), elements (by XRF), particle size distribution and concentration (gravimetrically), and organic constituents (by HPLC). The method was used to characterize dusts generated at the chute pulling operations on the main haulage level of an underground tungsten mine. Analysis showed that respirable dust concentration ranged from 0.8 to 2.3 mg/m3. It consisted of silica (3-7%); organic constituents from diesel exhaust (0.11-0.31 mg/m3 equivalent airborne concentration); and mineral dust (39-100%). The remainder was diesel exhaust particles. It was concluded that size selective sampling may be used to estimate the ratio of diesel exhaust to nondiesel dusts in the respirable fraction.

Jan 1, 1982

By G. Ahnell

Throughout portions of four (4) heavily mined Appalachian states subdivided by the Mine Safety and Health Administration (MSHA) as: District 3 -Northern West Virginia and Maryland; District'" -Southern West Virginia; District 5 -Virginia; and District 6 -Eastern Kentucky, active coal mine waste embankments associated with mechanical and/or chemical coal processing facilities of various levels of coal preparation were inventoried. For each site plant specifications, disposal techniques, embankments' characteristics, and coal source data were accumulated. Mapping at 1: 24, 000 and 1: 250,000 scale and Disposal Site Characterization forms were developed to present the findings. Associated abandoned surface and underground openings near each site were also indicated as well as locational data for each site and the areas environmental conditions - temperature, precipitation and vegetation types. A state-of-the-art review of coal preparation, waste disposal, and alternative uses of coal waste is also included.

Jan 1, 1982

Determine the site specific flow behavior of leachants and groundwater during development, production, and restoration phases of an in situ leaching operation. Approach A computer program has been developed which simulates the hydrologic activity associated with in situ mining. Various user options enable modeling of many of the site specific geologic conditions and well field specifications that affect the hydrology of solution mining. How It Works In situ hydrology is modeled, using a closed-form solution to the three-dimensional, partial differential equation that describes changes in hydraulic head as a result of pumping from leachant Injection and recovery wells. Model capabilities include arbitrary well patterns and pumping schedules, partially penetrating well screens, directionally anisotropic permeability and natural groundwater flow, in either

Jan 1, 1981

By Donald R. Johnson

Apparatus providing simultaneous differential thermal analysis, thermo-gravimetry, and evolved gas analysis, has been developed by the Bureau of Mines specifically for thermal study of oil shale and other solid, natural fuels. The apparatus is described in detail, and simultaneous analyses on a single sample of an oil shale mineral, nahcolite, and a thermal analysis demonstration compound, calcium oxalate monohydrate, are presented to demonstrate the instrument's capabilities.

Jan 1, 1970

By G. L. Fitzpatrick

A portable optical instrument for performing multispot laser vibrometry is described. The instrument is capable of measuring arrival times, surface motion frequency, and surface velocity and displaying these quantities in various useful ways. Sigma Research is currently pursuing the development of such optical measuring systems for the evaluation of structures in rock by non-contact interferometry methods. This work was sponsored by the U.S. Department of Interior (U.S. Bureau of Mines) under a Small Business Innovation Research (SBIR) contract number J0145075. The goal of the work was to develop a portable tripod mounted measuring system which can be set up at arbitrary distances (up to 30 meters) from a surface and project four in-line laser sample beams on this surface. A light receiving telescope gathers the scattered light from these four spots and provisions are made to mix this light with a reference beam from the laser. Four photodiodes are employed to determine the resultant interference signals which characterize the motion (particle velocity, frequency, amplitude) of the four illuminated spots on the surface under sudy. Information of this type can then be used to characterize the elastic or mechanical properties of the surface in question. In some cases (if more than four spots are involved) this surface information could be back propagated to draw inferences about the internal state of the material volume bounded by this surface.

Jan 1, 1987

By W. A. Calhoun

This report gives results of metallurgical investigations performed by the Bureau of Mines on mineral samples taken during April 1959, from Hawaiian bauxite deposits on the islands of Kauai, Maui, and Hawaii. The bauxite samples were tested at the Bureau's Rolla Metallurgy Research Center, Rolla, Mo., to determine if alumina could be extracted. The results were encouraging. Extraction of the alumina by the American Bayer type digest of crude ore samples from Kauai, Maui, and Hawaii recovered 78.8, 73.1, and 70.0 percent, of the total alumina, respectively. These recoveries were increased to 82.8, 85.5, and 79.5 percent by modifying the treatment, which consisted essentially of calcination and weak caustic desilication to provide a residue. The residue was then treated with calcium oxide and digested in a strong caustic solution to extract the alumina.

Jan 1, 1962

By M. W. Von Bernewitz

Fay's glossary3/ of terms contains the following definition of "black sand": Heavy grains of various minerals which have a dark color and. are usually found accompanying gold in alluvial deposits, for example, magnetite, chromite, ilmenite, cassiterite, tourmaline, and others. The Bureau of Mines is issuing this report in answer to the many inquiries from individuals and firms as to how they may treat or sell the heavy black sands that accumulate in the sluice boxes of beach and river placering and to warn such individuals and firms against becoming too enthusiastic over the chances of striking it rich. For a half century or longer much money, energy, and time have been wasted in devising, building, and trying numerous machines to recover gold and platinum, also gem stones, from sand that generally has not been worth the effort. Volumes have been written on the subject, and thousands of letters of inquiry have been received by agencies of the State and Federal Governments. The demand for information has been so great that all of the Bureau's publications dealing wholly or partly with black sands are out of print. They are listed at the end of this report.

Jan 1, 1938

By N. S. Shan

This report presents the results of a study to determine compaction criteria for coal waste embankments. The purpose of this study is to evaluate the costs and resulting effects on the engineering proper-ties of coal waste materials, utilizing different compaction methods, equipment passes, and lift thickness. Based on the results of the study, a cost efficient compaction method that will attain the desired results will be recommended to the coal mining industry. The report describes a comprehensive literature search into the compaction of coal waste materials, field compaction programs, laboratory investigations, analysis of test data as well as conclusions and recommendations for establishing the compaction criteria. The findings obtained in this investigation are intended to supply much needed information and to justify the guidelines that have been recommended.

Jan 1, 1981

By Bill M. Stewart, Phil W. Patton, Curtis C. Clark

Back injuries from handling materials in underground mines continue to be a major safety problem. In spite of the ingenuity of many people and the development of numerous mechanized aids, the number of materials-handling injuries remains second only to the number of roof fall injuries in underground coalmines. Relocation and repositioning of electrical cable, conveyor belt parts, and roof bolt sup-plies in particular are the sources of significant numbers of back injuries. To help reduce such injuries, researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health are examining Mine Safety and Health Administration accident data to determine correlations between materials-handling tasks and the number of back injuries. Also being investigated are new technologies used in underground mines in the United States. Equipment is being developed or modified that would replace the necessity of doing lifting tasks manually. A Coleman manipulator was tested, and modifications were made to make it more suitable for underground mine use. To reduce or eliminate the need to manually clean off materials that commonly plug grizzly openings, a track-guided pincher arm device was developed. Oversized rock can be broken with the pincher arms in the up position, and the arms can be lowered to grab and remove debris. The arm can also be used in a sweeping action to remove cohesive fines that may bridge grizzly openings.

By R. V. Ramani

This report is volume 3 of an eleven-volume final report for a Grant completed by The Pennsylvania State University for the Bureau of Mines to develop a dynamic general purpose computer simulation model for underground coal mining. The simulator developed under the Grant has a wide range of possible applications in the design and evaluation of underground coal mining systems from the standpoints of health and safety, productivity, and mine environment. The Master Design Simulator consists of nine free-standing function-oriented subsystem models linked together into an integrated, comprehensive model of an entire mining system. The subsystems comprising the Master Design Simulator include geology and reserves, methane generation, roof support, subsidence, production, rail haulage, cost, water generation,' and ventilation. This volume of the final report describes the Methane Generator subsystem of the Master Design Simulator. This subsystem is used to determine methane emission rates into the mine environment. These flow rates are then used by the simulator in planning primary and secondary ventilation systems, planning a methane drainage system, and analyzing complex ventilation networks. Both steady state and unsteady state gas flows are included, and have been modeled as second order nonlinear partial differential equations. Finite difference equations are used to obtain numerical solutions to the models using a central differencing scheme. An application of the model is presented. The appendices include derivation of the gas flow equations used in the model as well as a users manual for the computer program.

Jan 1, 1974