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By Allen D. Look, Norman King

For many years, much thought and effort have been devoted to the achievement of safety in the use of explosives by those interested in the preservation of human life and the protection of property. As a result, we now have adequate rules pertaining to the safe use of explosives , which, if observed, would prevent many, perhaps ail , of the explosives accidents that yet occur . Although the rules respecting the use of explosives are believed to be well - known, many accidents occur because they are disregarded . The mental awareness aroused by a tragic accident usually will cause safety precautions to be taken for a while ; however , this awareness gradually disappears unless a sincere effort is made permanently to prevent similar accidents . Frequently, because safe methods are more irksome than unsafe methods , the lessons taught by accident experience are forgotten in a short time , vigilance is relaxed , and there is a gradual return to unsafe , easy methods of performing work. If the preservation of human life is important , the unfortunate experiences of others and the lessons taught by them should be applied to reduce unnecessary loss of life . The value of a life lost as the resuit of accident should be calculated not only from the monetary and humanitarian standpoint but also according to what the accident could contribute in the way of saving other lives and suffering . This saving of other lives can and will , if the lessons from unfortunate accidents are applied , convert a loss to a gain a gain of such magnitude that the accident victim could be considered

May 1, 1944

By C. Richard Groves

As the level of technology applied in the electrical measurement, control, and display portions of mine hoist systems continues to advance, the issues and concerns associated with the ramifications of the application of microprocessor technology on the safety-related aspects of these systems become paramount. This report, in part tutorial, addresses several aspects of these concerns. Beginning with discussions of microprocessor-based system architectures, the report addresses some existing and anticipated uses of this technology in mine hoist systems and discusses safety related considerations associated with the areas of data derivation; control and display panels; and system reliability issues. The report concludes with electrical maintenance and inspection considerations associated with the safety assurance of microprocessor based mine hoist systems.

Jan 1, 1986

By Michael J. Sapko, Kenneth L. Cashdollar

In This Chapter [Methane ignition as initiation source for much larger secondary coal dust explosions Rock dusting requirements to prevent coal dust explosions Dangers of hybrid mixtures of methane and coal dust] Although methane explosions are dangerous, those that involve coal dust are even more so. If exploding methane disperses and ignites the coal dust that has accumulated on the mine ribs and floor, the burning coal dust immeasurably increases the strength of the explosion. Such methane-dust explosions are prevented by inerting the coal dust in a way that prevents the exploding methane from igniting it. This chapter discusses the dust hazard and how it is pre-vented in U.S. coal mines. METHANE IGNITION AS INITIATION SOURCE FOR MUCH LARGER SECONDARY COAL DUST EXPLOSIONS The typical scenario for coal mine explosions starts with the ignition of a flammable methane-air atmosphere near the face. The turbulent winds from the primary methane explosion then disperse the coal dust. If there is insufficient rock dust (usually limestone), a secondary coal dust explosion then propagates throughout large sections of the mine. These scenarios have been studied extensively at the Bruceton Experimental Mine (BEM) and the Lake Lynn Experimental Mine (LLEM) of the NIOSH Pittsburgh Research Laboratory. The minimum quantity of methane required to initiate a coal dust explosion was studied in 1930 in the BEM [Rice et al. 1933; Nagy 1981] and then later in the LLEM, whose cross-sectional area (130 ft2) is over twice that of the BEM [Sapko et al. 1987a]. Studies conducted in the BEM closely simulated conditions that existed in operating mines in the early 20th century. The later tests in the 20-ft-wide entries of the LLEM simulated the geometries of modern mines with advanced roof support technology. The data from the BEM tests show that 13 ft3 was the minimum quantity of methane at the face that, when ignited, would disperse and ignite coal dust. In the BEM, this amount of methane was mixed with air to form a total flammable volume of about 140 ft3 of a 9% methane-in-air mix-ture. In the wider entries of the LLEM, about 37 ft3 of methane was required to disperse pure coal dust and start a self-sustained coal dust explosion. This amount of methane was mixed with

Jan 6, 2006

By H. A. Watson

Laboratory tests on three commercial methane detectors, two combustion- type detectors and one interferometer-type detector, were made by the Bureau of Mines to determine their response to certain single and multiple flammable gases mixed with normal and abnormal air atmospheres. Although both types of detectors responded accurately to methane-normal air mixtures, they did not show correct concentrations for other single flammable gases in air. Uniquely, the response of the interferometer-type detector to hydrogen was in a negative direction. The effects of individual gases in multiple flammable gas mixtures were approximately additive. In oxygen-deficient atmospheres the methane response of the interferometer-type detector erred on the high side, but only in very low oxygen concentrations were the combustion-type detectors affected-- showing low, erratic methane readings.

Jan 1, 1966

By K. E. Stanfield

Oil-yield results are presented for 65 oil-shale sections in Piceance Creek Basin, Colorado, sampled during the period 1957 through 1963. Including previously published data, oil-yield results for 203 sampled sections have now been released by the Bureau of Mines to aid in appraising the shale oil potential of the basin. Oil yields of core samples (135 sets) were regarded as reliable bases for appraising the Mahogany-zone interval, but only 5 sets of cores sampled the deeper, lower-zone oil shales. Drill cuttings (68 sets) sampled the lower-zone oil shales, but their oil yields are principally indicative and should be confirmed by analyses of cores. More complete core sampling of the lower-zone oil shales is needed.

Jan 1, 1967

By J. J. Drost

This Bureau of Mines investigation studied the effect of thermal treatments upon concentratability of a western Mesabi Range nonmagnetic taconite ore and is a sequel to Bureau of Mines RI 7567. Magnetic tube tests were used to develop the data needed to calculate separation efficiency, the primary measure of concentratability. A horizontal tube furnace was employed to heat treat and reduce the hematitic ore samples. The two variables studied were roasting temperature and cooling method. The manner of cooling, either by slow cooling or quenching in water, produced no significant difference in concentratability. Roasting temperatures employed ranged from 500° to 1,000° C, and a temperature of 650° C effected the best concentratability. The temperature of 650° C correlated with the most effective roasting temperature for grindability.

Jan 1, 1973

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Jan 1, 1975

By Richard L. Unger

The U.S. Bureau of Mines has designed, fabricated, and tested a prototype track maintenance vehicle for underground coal mines. The vehicle uses a stiff rotating brush to clean the track so that a visual inspection is possible. It is also equipped to measure track gauge and cross-level. The objective of this report was to describe the track maintenance vehicle and detail the results of investigations into present underground track inspection procedures and cleaning technologies, which led to the development of the prototype. Recommendations are made concerning the integration of components of this prototype vehicle into current track cleaning and inspection systems used in underground mines.

Jan 1, 1984

By C. A. Herbert

Timber decay is due largely if not wholly to a fungus growth on the timber from which it derives' food; a warm, moist atmosphere is necessary for rapid growth. The decay is spread from infected timber to sound timber by countless microscopic spores or seeds given off by the fungus growth and carried by air currents or by long, cottonlike threads, which spread from timber to timber. Haulage roads in most mines in the central coal fields are also return aircourses; hence moisture and temperature conditions are ideal for the rapid decay of mine ties and mine timber. Possibly the return air, which contains a higher percentage of carbon dioxide than normal outside air, also stimulates the growth of fungi. Those familiar with coal mining have observed the more pronounced growth of fungi and decay of timber in poorly ventilated worked-out sections of mines where the air is moist and where usually the percentage of carbon dioxide in the air is considerably above normal.

Jan 1, 1934

By BUREAU OF MINES

TABLE OF CONTENTS

Sep 1, 1932

By Michael J. Klishis

Accident rates continue to show that underground mining jobs areamong the most hazardous occupations in the United States and roof bolter operators continue to have one of the highest accident incident rates (MSHA, 1991) despite efforts by labor, government, and industry to reduce and eliminate work-related hazards. In the last two decades we have seen technical innovations such as the ATRS, and there has been an increased emphasis on hazard awareness through programs such as MSHA's REAP, but bolter operators continue to be injured and killed. Researchers at West Virginia University examined risk in the roof bolter's job and developed new approaches to accident and injury prevention. The study concentrated on the workers' job performance, machinery and the work environment to identify miner's risk and hazard exposure while bolting.

Jan 1, 1993

By Raja V. Rarnani, Robert L. Frantz

More than 100 scientists from diverse professional backgrounds have contributed their expertise to the Dust Center as investigators. Approximately 50 researchers served as principal investigators, with responsibility for directing the work on Center projects, from experimental design and implementation in mines and in laboratories to coordination of efforts within the research infrastructure of the Center. The professional biographies which follow demonstrate the breadth and depth of research capabilities brought to the Center by its principal investigators.

Jan 1, 1995

By R. J. Pokora

This Bureau of Mines report is an applications manual that can be used by the nonmetallic mining industry for guidance in installing noise control materials into crushing and screening plants. These noise control modifications were installed and successfully tested at three operating quarries. This report identifies the major noise sources that can be encountered in crushing and screening plants, and discusses the applicable noise control materials and techniques that a plant operator can utilize on a retrofit basis to reduce equipment noise.

Jan 1, 1984

By Effie T. Kurt, Jack Wright, J. W. Watkins, Cynthia Pearson

"The analysis of water produced with crude petroleum has interested oil producers since inception of the industry. Records of the first analysis of mineralized water produced from an oil-productive formation are obscure, and references to the first use of brine analyses to assist in solving problems of petroleum production are not available in the technical literature. However, many early reports of the Federal Bureau of Mines 5-8/ and. Federal Geological Survey, 9-11/ as well as articles in engineering and geological placed special emphasis on journals ,12-l4/ the importance, interpretation, and application of water analyses.One of the earliest applications of water analyses, and still a major one today, is for identification of intrusive waters in oil wells. This may be done by comparing the chemical constituents of a sample of water indigenous to the oil-productive formation with those of samples from upper, water-bearing formations within the same general area. Some earlier investigators recognized the need for analyzing samples of all waters encountered in drilling operations. Ambrose15/ stated, in part, ""In wells being drilled, the engineer should grasp every opportunity to get a true sample of water from each sand. . .,"" and, ""The waters of each oil field are chemically different from those of another field."" The validity of the latter observation and the importance of the former one have been borne out by comparing the results of analyses of many samples and noting the differences in relative concentrations of like constituents of waters from the same geological formation in different localities or oil pools."

Apr 1, 1957

By Dale W. Richardson

Ductile hafnium was not obtained consistently by the conventional Kroll process. The bimetal reduction modification produced a more ductile hafnium by lowering the impurities, especially oxygen, in the sponge metal. Hafnium oxide was chlorinated in the presence of carbon to form anhydrous hafnium tetrachloride, which was reduced by sodium and magnesium in an inert atmosphere to produce sponge hafnium metal. After vacuum distillation to remove the byproducts, the sponge was arc-melted into ingot and rolled into strip. Metallic impurities were decreased by evaporating the hafnium tetrachloride from a fused salt. An excessive amount (over 1,200 parts per million (p.p.m.)) of aluminum was contained in some of the hafnium oxide, much of which remained as aluminum chloride in the hafnium tetrachloride during chlorination. Evaporation of the hafnium tetrachloride from a fused NaCI-KCI mixture during the Mg-Na reduction greatly lowered its aluminum content, as most of the aluminum and some of the other metallic impurities were retained by the fused salt.

Jan 1, 1961

By Hanns J. Billmayer

This report, which covers the period from June 15, 1974 to May 30, 1975, describes the work performed in compliance with the requirements of Contract No. H0242065 and modifications 1, 2, and 3 thereto. The purpose of the original contract was to equip the second shuttle car in the Jewell Ridge No. 12 mine, section 6R, with a refined design canopy and seats. In addition, several refinements and improvements were to be designed and installed at the same location on the cutter and the loader. However, during October 1974 in response to a request from the Technical Project Officer, the contract was modified to eliminate all of the cutter and loader tasks and substitute the design, fabrication, and installation of an improved canopy on the no. 2 roof drill in the above mentioned section of the Jewell Ridge No. 12 mine.

Jan 1, 1975

By R. A. Beall, S. L. Ausmus

The development of a completely water - free expendable graphite mold material , useful for reactive metal castings , has been detailed . Mixing and curing variables have been evaluated both by physical testing of the material itself and by castings of titanium , zirconium , and hafnium . The blend of powdered graphite , cornstarch , dextrin , cereal binder , linseed oil , and Carbowax -4000 is a successful mix when mulled in a carbon dioxide atmosphere , and properly cured and fired . The primary advantage of this material is its adaptability to standard foundry techniques ; i . e . , core blowing and hand ramming . Temperatures in the curing and firing cycles do not exceed 960 ° C , and no vacuum firing is required .

Jan 1, 1964

By J. P. Dunford

This U.S. Bureau of Mines report describes the development of a yielding steel post for underground mine support. The report covers concept development, laboratory tests, modifications, and field evaluations. The objective of this work was to develop a stiff support member capable both of supporting high loads and yielding when excessive amounts of mine entry closure were present. The 6-to 7-ft steel post was designed to yield nearly 2 ft while maintaining a 45-ton (force) load. The post is a three-piece unit consisting of top and bottom telescoping legs and a separate foot bracket. It develops its load-carrying characteristics when the lower pipe, with an attached interference ring, is forced into the larger top pipe. Laboratory tests were used to determine critical loads and post performance for various post lengths. Field tests showed that the posts could perform in actual mining conditions. The post has the ability to provide support in highly yielding ground and also, because of its slender profile, enhance ventilation and provide more area for travelways and escapeways. The design is simple enough to allow for fabrication at most mine shop facilities.

Jan 1, 1989

By A. S. Swanson

The Babb fault vein in Crittenden and Livingston Counties, Ky. (fig. 1), is one of an extensive series of such veins in the Western Kentucky and Southern Illinois fluorspar district. First operated in 1904, the production to May 1, 1944, was estimated at 143,000 tons of fluorite ore. There are five mines (fig. 2) on the Babb fault zone - Guill ,Kentucky Babb, Delhi-Babb, Eagle-Babb and Howard-Barnes. The Bureau of Mines developed four of these properties by core drilling from July 9, 1943, to May 1, 1944. During that period a total of 8,177.8 feet of diamond drilling was completed in 28 holes.

Jan 1, 1950

By A. M. Gaudin

A study of the consumption of reagents used in flotation gives useful data as to the market which employment of the flotation process creates for the manufacturers of the necessary chemicals and oils, and furnishes a useful clue to the trends in flotation practice influencing the choice of reagents used and the' extent to which new reagents are displacing less suitable older reagents. In the present investigation an attempt has been made to cover both of these phases of the consumption of reagents in flotation. Unfortunately, however, the data collected in tie various districts have not been equally informative; some operators have reported very completely both the consumption of reagents and the metallurgical results obtained therewith, while others were apparently unable to supply these figures in sufficient detail to meet the requirements of this investigation. RESULTS OF INVESTIGATION Table 1 gives the tonnage of ore treated by flotation, as reported. This table shows that flotation has been most largely used in the concentration of copper ores, next in complex lead-zinc ores, followed by lead ores, zinc ores, miscellaneous ores, and copper-iron ores.

Jan 1, 1929