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By R. Stefanko

This Final Report covers the work performed for Contract No. H0377043, "Cables for Face Equipment" from August 1, 1977 to April 1, 1981. It reports the findings in three areas of research: cable protection, circuit-breakers, and high-voltage cable couplers. Laboratory and analytical studies have been conducted in the three areas to determine proper circuit-breaker settings, cable sizes, and coupler performance. Also, an extensive field-monitoring program was established to relate in-mine epxerience to laboratory findings. Further, various pieces of equipment was designed for laboratory testing, particularly in the area of cable reeling and unreeling.

Jan 1, 1981

By Vernon Helm, John S. Ball, Welton J. Wenger, William E. Haines

"INTRODUCTION Although the presence of sulfur causes many petroleum’s to be classified as ""low-grade"" because of the difficulties encountered in manufacturing products to meet rigid specifications, the petroleum industry is finding it necessary to use such crude oils to satisfy present needs. As the demand for petroleum products increases, and available reserves diminish, this utilization of high-sulfur crude oils will be accentuated. Programs designed to supplement the supplies of fuel available from petroleum by the manufacture of synthetic fuel from natural gas, shale oil, and coal are in progress. Such fuels, especially shale oil and, less so, oil from the hydrogenation of coal, also contain sulfur compounds which must be effectively removed. Thus, the need for fundamental research on the sulfur compounds that may be expected in petroleum and allied products is becoming greater as the industry is forced to call upon all available resources to meet the demand for petroleum products. In recognition of this need, the Bureau of Mines has inaugurated a long-range program assigned to furnish fundamental data concerning the presence, characteristics, and effects of sulfur compounds in petroleum and its products."

Dec 1, 1946

A mobile vacuum sweeper to remove loose coal and coal dust from underground coal mine workings was designed, built, tested, and evaluated. The design was based on an extensive test program. Pick up and conveying rates vs. air volumes, velocities, and nozzle shapes were determined for coal rubble in a laboratory pneumatic handling system. A gas/solids separation system was developed and tested in the laboratory capable of separating the solids loading from the vacuum system air stream to the very high degree required to preclude degradation of the ambient (mine) air. Two designs were made, one for belt conveyor and one for general district cleanup. The belt cleanup machine was chosen for test and demonstrated in an underground coal mine performing cleanup work in belt haulageways and on ribs.

Jan 1, 1975

By J. M. Provost

1. Estimates have been made for eight coal beds in Marion County, but only the Pittsburgh is important from a production standpoint at this time. The Pittsburgh bed has the largest recoverable reserve, and the Sewickley is second in importance. 2. Known measured and indicated reserves thickness of 14 inches and on 1,800 short tons estimated at 3,141 million tons, as of January lion tons is in beds 28 inches and more thick in all beds, based on a minimum per acre-foot of coal in place, are 1, 1955. Of this total, 2,983 mil-Areas in each bed were omitted from the estimate because available data relative to the bed characteristics were too meager for making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1956

Reports by researchers in government, industry, and universities of the United States are given for various projects on basic coal research concerning, the metamorphism, physical and chemical properties, and reactions of coal, and how many of these studies can lead to better utilization of coal.

Jan 1, 1968

By T. A. Raczek

Materials for stronger ventilation tubing for underground use in hardrock mines were developed. The new material composites were evaluated in performance characteristics and compared to currently used materials. The materials were compared on tear, tensile, puncture and flammability properties. Based on cost versus performance data, a polyester film bonded to a polyester fabric was selected as the candidate material for field testing. Ventilation tubing fabricated from the selected material was field tested in two underground uranium mines for four-month periods. The test results indicated that the new composite showed an increase in useful life in the majority of applications, However, the cost performance ratio was not significantly improved to warrant commercialization of the product. When connected directly to some blowers, the material in close proximity to the blower deteriorated. However, material which was punctured or torn by mechanical means did not have further propagation of the tear. The high tear strength of the material prevented further damage. Improved methods of repairing inflated ventilation tubing were investigated and developed. All the repair methods were portable and self-contained. Repair kits based on adhesives, pressure sensitive tapes, and mechanical means were evaluated. Plier staplers and patch systems based on pressure sensitive adhesive proved to be most functional.

Jan 1, 1980

By Roy L. Wilfong

The thermal decomposition of the ammonium sulfate, carbonate, nitrate, oxalate, and sulfate salts of praseodymium, neodymium, and samarium was investigated thermogravimetrically in the temperature range 25° to 1,500° C. Each salt was decomposed at a heating rate of 2.5° C, per minute. The pyrolytic sequences have been identified and the temperatures of formation of inter-mediates, the minimum oxide formation temperatures, and values for loss on ignition have been determined. The nonstoichiometric ranges between Pr6011 and Pr203 and the extent of these ranges have been determined for oxides derived from the carbonate, nitrate, and oxalate salts of praseodymium. The alum and sulfate salts of praseodymium produced the sesquioxide without forming the intermediate non-stoichiometric oxides. The temperature limits of formation and regions of stability for the alums and sulfates were better defined than were those for the carbonates, nitrates, and oxalates. The minimum oxide formation temperature increased in the order of samarium, neodymium, and praseodymium irrespective of the anion.

Jan 1, 1962

The Bureau of Mines found sulfur hexafluoride (SF6), released from a lecture bottle, to be an ideal gaseous tracer for studying mine ventilation systems. Air samples were collected in glass syringes and analyzed by electron-capture gas chromatography. In these studies, the lower limit of detection was about I part per billion by volume (ppb) of SF6 per part of air. Experiments conducted in a Pennsylvania limestone mine showed this technique useful in evaluating the effectiveness of auxiliary fans, measuring low flow velocities, probing the air circulating near a working face region where ventilation appeared to be poor, and estimating volumetric flow rates in airways of large cross-sectional area and having low flow velocities. This technique was also used in a western vein-type metal mine to measure the amount of return air being recirculated into the intake air due to leakage through old stoped areas.

Jan 1, 1974

By Jacqueline A. McClaskey

The U.S. Bureau of Mines (USBM) Information and Analysis Directorate collects worldwide data on virtually every commercially important nonfuel mineral commodity. These data form the base for tracking and assessing the health of the minerals sector of the U.S. economy. The USBM's data collection activity was instituted by the 47th Congress in an appropriations act of August 7, 1882 (22 Stat. 329), which placed the collection of mineral statistics on an annual basis. The most recent authority for the USBM survey activity is the National Materials and Minerals Policy, Research and Development Act of 1980 (Public Law 96-479, 96th Congress). This act strengthens protection for proprietary data provided to the U.S. Department of the Interior by persons or firms engaged in any phase of mineral or mineral-material production or consumption.

Jan 1, 1995

By William E. Sopper

Heat-dried municipal sludge was applied to a barren burned anthracite refuse bank in 1974. Sludge was applied at rates of 0, 40, 75, and 150 dry metric tons per hectare" Ten species of trees were planted and five species of grasses and legumes were seeded for evaluation. One plot was also irrigated with sewage effluent. The 150 t/ha sludge application rate produced the best overall herbaceous vegetation growth response. The 40 and 75 t/ha sludge application rates produced the best tree seedling growth response. Foliar analyses for trace metals indicated no phytotoxity problems. Analyses of leachate water at the three-foot soil depth indicated that the sludge applications did not impair water quality. Results of the study indicate that treated municipal sludge can be used to revegetate land disturbed by mining activities without adverse effects on the vegetation or water quality.

Jan 1, 1978

This report summarizes a study conducted by The Service Bureau Corporation for the Bureau of Mines. Evaluations reflected herein are the result of an independent investigation by The Service Bureau Corporation of methane considerations during coal mining. The study is oriented toward a systematic analysis of methane control problems during coal mining. Throughout this study an attempt has been made to ensure considerations consistent with the recently enacted Federal Coal Mine Health and Safety Act of 1969. References to reports by The Bureau of Mines and others are made for the purposes of establishing identification between the evaluations contained in this report and on-going research efforts.

Jan 1, 1970

By Robert G. Lundquist

The Bureau of Mines compared longitudinal strain energy output of a percussive drill to energy determined by measuring maximum piston velocity. Strain gages were used to determine the strain-time waveform and its amplitude at seven levels of operating pressure and eight levels of thrust. The longitudinal strain energy was found to be approximately 14 ft lb less than the maximum piston energy at comparable operating conditions.

Jan 1, 1969

By Irvin Pritts

This report describes the design, fabrication, and testing of a prototype instrument which demonstrates the feasibility of determining respirable coal dust concentrations by light reflectance photometry. Coal dust is collected on a filter and the quantity collected is continuously monitored by reflectance-photometry. Light emission and detection is accomplished by reflective object sensors, which have both light source and detector in one chip. The use of a pulsed light source insures low drift characteristics of the measuring circuitry. The collection of the respirable coal dust on filters facilitates accurate calibration and also allows measurement verification, if desired, by well-accepted, gravimetric methods.

Jan 1, 1981

By K. K. Kelley

Thermodynamics data for silicates have applications in the fields of extractive metallurgy, ceramics, and geochemistry. To facilitate these applications, up-to-date tables of heats and free energies of formation are needed. It is the purpose of this report to supply such tables for anhydrous silicates. During the last 15 years the heats of formation of a substantial number of anhydrous silicates have been reliably determined at or near room temperature. This resulted from the development (first by the Bureau of Mines and later by the Geophysical Laboratory of the Carnegie Institution of Washington, by the Institute of Geology of the University of Helsinki, Finland, and by the Department of Geology of the University of Chicago) of accurate solution calorimeters, employing hydrofluoric acid as the reaction medium. Specific references to work of these laboratories will be made in the next section of this report. Also, entropy data at 298.150 K. and high-temperature heat-content values are available for many of these silicates, mainly owing to work of the Bureau of Mines. Most of these entropy and heat-content data have been compiled in Bureau of Mines Bulletins (13, 15).3

Jan 1, 1962

By S. K. Ash

In arriving at economic losses in coal mining due to accidents, a statistician is confronted with many difficulties on account of the lack of information relative to nonfatal accidents. For comparative purposes the ex¬ perience of those countries, States, or companies that keep complete records can be drawn upon and an extimate can be arrived at whereby one State can be compared with another, or one mine compared with another in the same district. Such a comparison for the United States has been compiled by the United States Bureau of Mines. It will be observed in Table 1 that the cost per ton for accidents in the State of Washington for the year 1927 is higher than for any other State, with the exception of Georgia and North Carolina, with a small combined tonnage of 130,089 tons. (The figures for coal production in Table 1 are taken from Bulletin 319, 1930, of the United States Bureau of Mines.) The reasons why the cost of accidents in Washington might be higher than the average are on account of physical conditions such as steep pitches, faults, igneous intrusions, highly explosive coal-dust, extremely friable coals, presence of gravel and water, very gassy coal beds, rugged topographic conditions, inherently bad roof and floor, thick beds, and heavy cover. The nature of the coal beds requires the use of preparation machinery. The mines are often deep, and topographic conditions are such that long and fast haul¬ age becomes necessary. All of these factors not only tend to cause high cost of production, which is manifested largely in a. lower than average daily pro¬ duction, per man, but..they.also affect to some degree a tendency toward a higher than average cost for accidents.

Nov 1, 1931

By Fred S. Karn

Inhibitors are used in coal mines as a precaution against accidental dust explosions. Although rock dust is the usual inhibitor many others have been tested. To facilitate testing a screening process using laser irradiation was proposed. The procedure includes irradiation of a coal-dust mixture followed by mass-spectrometric analysis of the evolved gases and an evaluation of the flammability characteristics of the gases. Carbonate-type inhibitors decreased the percentage of combustibles in the gases generated and inhibitors like NaCI (thermally stable salts) decreased the total gas generated. A suitable test procedure did not result from the investigation, demonstrating the inadequacy of fast heating, non-combustive techniques in rating inhibitors of coal dust explosions.

Jan 1, 1973

By J. Fletcher Smoak

The value of abrasive materials consumed in the United States increased 37% in value over that of 1983 to $439 million; of which, 58% was manufactured abrasives, 36% was industrial diamond (natural and synthetic), and 6% was natural abrasives. Production value of natural abrasives, which consist of crude tripoli, special silica stone, garnet, and emery, increased 4% Production of crude tripoli, a finely disintegrated chert, increased 12% in quantity and 8% in value. Shipments of processed tripoli increased only 3% in quantity but increased 16% in value, with large increases occurring in both major end-use categories. Production of garnet, an abundant iron-aluminum silicate, decreased slightly in quantity and value after posting continued increases in quantity and value since 1980. There was a significant decrease in the quantity and [ ]

Jan 1, 1985

By Virgil J. Stachura

The Bureau of Mines has investigated techniques and instrumentation that measure accurately the airblast overpressures from surface mine blasting. The results include equivalencies between broadband research instrumentation and commercially available impulse precision sound levels meters measuring: root-mean-square, peak, fast, slow, impulse, A and C weighting, C-weighted sound exposure level (CSEL), and "linear" (flat) response. These values were obtained from field measurements and broadband FM tape recordings of production blasts at area and contour coal mines, limestones quarries, and iron mines. Frequency response was determined for 14 commercial systems.

Jan 1, 1981

By G. W. Jones

In cooperation with the Edison Electric Illuminating Co. of Boston, Mass., and the-Boston Consolidated Gas Co., the Bureau of Mines, United States Department of the Interior, has conducted a survey continuously since 1929 to determine the general hazards of combustible gases and vapors in manholes of the Edison Electric Illuminating Co.

Jan 1, 1942

By G. W. Jones

In cooperation with the Edison Electric Illuminating Co. of Boston, Mass., and the-Boston Consolidated Gas Co., the Bureau of Mines, United States Department of the Interior, has conducted a survey continuously since 1929 to determine the general hazards of combustible gases and vapors in manholes of the Edison Electric Illuminating Co.

Jan 1, 1942