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The importance of controlling respirable dust and methane gas levels in underground coal mining cannot be underestimated. While respirable dust can significantly affect the occupational health of underground coal miners, methane gas accumulations pose significant safety concerns for these same workers. Water sprays and machine mounted dust scrubbers offer effective control of respirable dust exposures and methane gas accumulations. Water must not only be applied carefully to avoid dust rollback to the machine operator but must create sufficient turbulence to remove dead zones that could contain high concentrations of methane gas. While the flooded-bed dust scrubber has been generally responsible for decreased worker exposures to respirable dusts, this device has proved effective in controlling methane levels at the face. This paper reviews practical applications of water sprays and dust scrubbers to control respirable dust and methane gas on continuous miner faces.

By J. R. Thoenen

In the summer of 1937 the authors began a series of time studies of the various processes employed in the production of crushed stone. These studies, made at quarries scattered over the eastern and southeastern parts of the United States, have not been completed, but to make results available to thee industry as early as possible it was decided to publish summaries of the studies made to January 1, 1939, as a series of progress reports. The first of these reports dealt with power-shovel loading and was issued as Report of Investigations 3461 in September 1939. The present circular discusses analyses of the time Studies of the haulage systems at the same quarries. OBJECT OF STUDY The pressure of business problems frequently requires the entire attention of quarry management and in consequence internal plant economies often are neglected, Also, operating officials absorbed in their local problems are prone to overlook possible economies that would attract attention immediately were they critically examining another plant. The authors felt that similar studies of many plants by impartial engineers -would disclose possibilities for cost reduction or greater efficiency in internal plant processes.

Jan 1, 1939

By V. Vern Hutchison

This selected list contains 829 entries with citations to Bureau of Mines publications related to petroleum and natural gas, which were released during the 1961-1970 period. Some entries are multiple in nature, resulting in a total of 881 citations.

Jan 1, 1972

By Yael Miron

This report describes laboratory studies by the U.S. Bureau of Mines to determine the suitability of a static oxygen (OJ adsorption test for evaluating the self-heating tendencies of coals. Reliable minimum self-heating temperature (SHT) values from adiabatic oven tests were used as standards for comparison and evaluation. A suite of six coals was tested in the adiabatic oven and in sealed flasks. In the latter tests, both undried and dried samples, in a range of four particle sizes, were examined. Miniature pressure trans-ducers monitored pressures in the flasks, and gas samples taken at the end of the tests quantified all the gases present. An excellent correlation was found between the minimum SHT's and amounts of O2 adsorbed over a 7-day period for dried coals, independent of particle size. In addition, a good correlation was obtained between the minimum SHT's and pressure changes in the flasks at the end of the test for the same coals, also independent of particle size. Based on these results, the sealed flask test can be reliably used to determine the self-heating tendency of a bituminous coal sample.

Jan 1, 1990

By E. D. Calvert

The objective of this research was to examine variations in melting and forging practice for four titanium-base alloys and to determine their effect on the resultant product. Of particular interest was the evaluation of the skull-casting technique. The data should serve as a guide to producers and consumers of titanium products. Physical properties of four titanium-base alloys in ingot form and in sheet form were evaluated and correlated, where possible, with variations in the melting and casting procedure. Consumable-electrode melting was used throughout, but arc current and furnace backfill pressure were varied, and ingots were formed both by melting directly into a water-cooled copper mold and by skull melting followed by pouring into a graphite mold. Alloying metal additions for the alloys tested were (1) 8 percent manganese, (2) 6 percent aluminum and 4 percent vanadium, (3) 6 percent molybdenum and 2 percent aluminum, and (4) 16 percent vanadium and 2.8 percent aluminum.

Jan 1, 1962

This publication summarizes, for potential contractors and other interested parties, the research, development, and demonstration contract projects programed by the Bureau of Mines for fiscal year 1979 (October 1, 1978-September 30, 1979) under its Mine Health and Safety Research program. The objective of these projects is to provide an ordered and sequenced series of advances toward the Bureau's overall goal of providing the system technology required to create a healthier and safer working environment for the Nation's miners.

Jan 1, 1979

By Steven W. Schmauch

The U.S. Bureau of Hines conducted e mineral resource survey of approximately 232,000 acres in part of the Humboldt National Forest, Nevada, during 1989. About 7S percent of the study area was covered with mining claims. About 1,800 samples were collected end analyzed for 16 elements. Geologic structure, including thrust faults, is the most important factor in the localization of mineral deposits in the study area. The Independence mine (formerly Jerritt Canyon), Big Springs, and Wood Gulch are the most well known active properties, all developed on large, low-grade, disseminated gold deposits. These deposits have produced almost 3 million ounces of gold and are known to contain more than 8 million ounces of gold. At least 10 barite deposits in the south end of the range have had significant past production and contain 0.2 million tons of resources. Numerous precious and base metal targets have been identified and in some cases quantified during this study.

Jan 1, 1992

By J. S. Miller

The Bureau of Mines conducted surface tests to determine the feasibility of using liquid explosives for underground rock fracturing. The effects of configuration, confinement, length, critical layer thickness, and fracture-propping sand on detonation and explosive propagation velocity of desensitized nitroglycerin were studied, using polymethyl methacrylate and glass-plate reservoirs through lengths from 3 to 12 ft, with explosive-layer thicknesses from 0.1875 to 0.0312 in and in aluminum tubes 8 ft long with diameters from 2.000 to 0.125 in. Interval and continuous detonation velocity data were obtained. Under the test conditions detonation velocity was dependent upon explosive confinement and fracture-propping sand. The detonation velocity of a confined nitroglycerin explosion in aluminum tubes can be reduced by as much as 85 percent, when the tube contains fracture-propping sand. The shape of the reservoir, whether triangular or rectangular, has little effect on the detonation velocity or explosive propagation. The critical or minimum explosive-layer thickness between glass plates, capable of supporting propagation, was 0.0312 in. The presence of a fracture-propping sand in the sheetlike layers increased the critical explosive layer thickness to 0.0625 in. In nitroglycerin-filled and nitroglycerin-sand filled tubes, the minimum tube diameters successfully tested were 0.125 in and 0.375 in, respectively.

Jan 1, 1969

By H. P. Rue

The Bureau of Mines has recently collected two samples of crude oil from wells in the Greasewood Flat area of northeastern Colorado. Sample 31310 was taken from the Continental Oil Co.'s well Briggs No. 1 which care in or September 27, 1931, with a maximum production of 940 barrels per day. Sample 31311 was taken from tie Reiter-Foster Oil Co. Is well Ida Johnson No. 1 which came in on August 24, 1931 with a maximum production of approximately 1000 barrels per day.

Jan 1, 1932

By J. A. Organiscak

In the United States, respirable coal mine dust exposures are limited to a 2 mg/m3 time weighted average for a working shift. If the silica content of the sample exceeds 5 percent, the 2 mg/m3 standard is reduced according to 10- (% silica) to limit silica dust exposures to 100 µg/m3. Examinations of dust sampling data collected by the federal coal mine inspectorate showed that roof bolter occupations continue to be at risk for overexposure to respirable silica dust. Testing at the Pittsburgh Research Laboratory of the National Institute for Occupational Safety and Health assessed the effectiveness of a canopy air curtain for controlling occupational exposures to respirable silica and coal dusts. Initial testing found that zones of higher velocity airflow shrank as distance beneath the canopy increased. This suggested that protection from occupational dust exposures would likely decrease as distance beneath the canopy increased. Further testing revealed that coal dust reduction efficiencies were most affected by changes in interference air velocity and, to a lesser extent, changes in canopy air quantity. However, respirable silica dust percentages under the canopy were not affected by such changes and, in fact, were not significantly different from silica percentages measured outside the canopy. This implied that the air curtain was equally effective on both respirable coal and respirable silica dust particles.

By N. A. C. Smith, D. D. Stark

"Sulphur is apparently a normal Constituent of crude petroleum, but in most crudes is present in percentages of less than one-half of one per cent. Some crudes, however, contain more, and occurrences have been reported of heavy asphaltic oils with as much as five per cent of sulphur.Occurrences of Sulpher-bearing CrudesIn North America, the fields rest of the Mississippi River are almost entirely free from sulphur oils, the time oil from Northern Ohio and Indiana, and the Potrolia crude in Ontario, being practically the only ones which contain sulohur in amounts over 0.5. per cent. In the Mid-Continent district the production of high sulphur crude in general is small and unim¬portant. The two main excentions are the Healdton field in Oklahoma and the El Dorado field in Arkansas, both of which produce oils with considerable sulphur content. In the Wyoming field, one sand, the Ember Sandstone, pro¬duces a crude of high sulphur content, and it is probable that this crude rill be of considerable importance as production increases. At present, however, very little crude is produced from this formation. In the Gulf Coast conditions are irregular, some crudes being low in sulphur and others comparatively high. The same is largely true of California. The crudes of Mexico contain notable amounts of sulphur, and as they have been of great commercial importance in this country, a typical sample of light Mexican crude was selected for the present study. It is probable that the results obtained poly also (but to a lesser degree) to other sulphur-bearing oils. An analysis of this crude will be found in Table 3, also analyses of other typical sulphur-bearing crudes from different sections of the United States."

Mar 1, 1924

By William H. Schiffbauer

The Bureau of Mines has developed a passive encoder for range knobs, a device that automates the task of obtaining the range settings from devices or instruments to be input to microcomputers. It is easily constructed and installed and will not disrupt the device to which it is being attached. It consists of a custom knob and a small printed circuit board that has light-emitting diodes and magnetic reed switches attached. A ribbon cable connects it to a microcomputer. This encoder eliminates one source of human error in an automated process.

Jan 1, 1983

By A. J. Kraemer

The twenty-fourth of a series of semiannual surveys pertaining to motor gasoline marketed in the United States was made by the Bureau of Mines in August, 1931, The first part of a report giving the results of that survey as they pertain to specification data is given in this paper. A companion report, Part II, is in preparation and will discuss the results off other determinations made on the samples, including octane number ratings on the individual samples (to be made by the Bureau of Standards) and results of the determination of gravity, color, doctor test, and "gum" content by the copper dish method and the Bureau of Mines steam-oven method. The retail price and the tax at the time Each sample was taken will also be retorted. History of Survey The Bureau of Mines made its first survey of motor gasolines sold throughout the United States in 1915,4 a second in 1917,0 and a third in April, 1919.0 These three surveys showed that during each 2-year interval the motor gasoline had become notably less volatile. In order

Jan 1, 1932

By Laurance L. Oden

The Bureau of Mines is developing melting data for binary combinations of the alkaline earth fluorides and yttria to facilitate the formulation of slag compositions. The present report deals with the CaF2-Y203 system for which solidus and liquidus temperatures and solid solubilities were determined. The information is presented as the phase diagram. All specimen compositions were blended from high-purity materials and encapsulated in Mo or Pt20Rh prior toheat treatment. Liquidus temperatures were determined by ceramographic examination of heat-treated and quenched specimens. Solidus temperatures were determined by differential thermal analysis and by electron microprobe analysis of quenched specimens. Terminal solid solubilities were derived by parametric methods. The peritectic system was found to be pseudobinary due to the formation of yttrium oxyfluoride at temperatures near the liquidus. The peritectic point occurs at 7 mole pct Y203 and 1,438° ± 5°C. The terminal solid solubility of Y203 in CaF2 decreases from 7 mole pct at 1,438° C to 1 mole pct at 1,100° C, and the solubility of CaF2 in Y203 decreases from 9.5 to 7 mole pct over the same temperature interval.

Jan 1, 1970

By Donald J. Ninteman

This Bureau of Mines publication is a literature study of the problem of spontaneous oxidation and combustion of sulfides in underground mines. It summarizes the present-day hazards, process mechanisms, and prevention and control techniques of this growing problem in underground mines. The iron sulfides generally have the greatest tendency to oxidize, particularly pyrrhotite. The presence of moisture and oxygen is essential for the oxidation reaction. Highly fractured sulfides, when found with timber or combustible refuse in slowly circulating air, pose the most serious fire hazard. Quenching with water is effective in quickly dealing with local hot spots, but ventilation at high flaw rates is the most effective and economical means for long-term prevention and control.

Jan 1, 1978

By Henry P. Chandler

[Diamond, because of its extreme hardness and abrasion resistance, has an important function in precision engineering and automation. With the increasing; requirements of modern production for fine tolerances, interchange-ability, and speed, it has become even more important. In spite of the supply of other abrasive and hard materials and of ultrasonic, electrospark rued other substitute grinding, methods, world industry seams likely to absorb large quantities of diamond for industrial purposes. An increasing part of the world's needs will be supplied by manufactured diamond, which was introduced commercially by General Electric Co. in 1957. Use of diamond for glass cutting roes bark several centuries, mid diamond drilling of rock became important to the mining industry M the 1870's. Today, diamond drilling is the most extensively used method of exploring the world's ore reserves; diamond drills two also used to determined the nature of bedrock below the foundations of buildings, dams, and bridges. Diamond drill bits are now used extensively in the petroleum industry, and replacement or steel rock bits with diamond drill bits in hard rock formations has affected substantial savings.]

Jan 1, 1964

By Henry P. Chandler

[Diamond, because of its extreme hardness and abrasion resistance, has an important function in precision engineering and automation. With the increasing; requirements of modern production for fine tolerances, interchangeability, and speed, it has become even hors, important in spite of the supply of other abrasive and hard materials and of ultrasonic, electrospspark rued other substitute grinding methods world industry seems likely to absorb large quantities of diamond for industrial purposes. An increasing part of the world's needs will be supplied by manufactured diamond, which was introduced commercially by General Electric Co. in 1957. Use of diamond for glass cutting goes bark several centuries, mid diamond drilling of rock became important to the mining industry M the 1870's. Today, diamond drilling is the most extensively used method of exploring the world's ore reserves; diamond drills two also used to determine the nature of bedrock below the foundations of buildings, dams, and bridges. Diamond drill bits are now used extensively in the petroleum industry, and replacement or steel rock bits with diamond drill bits in hard rock formations has effected substantial savings.]

Jan 1, 1964

By Melvin E. Poad

This Bureau of Mines report presents two phases of a research program to evaluate a single-entry system for longwall development. Organizations participating in the program; which began in July 1971, include the Bureau of Mines, the Mining Enforcement and Safety Administration, and the University of Utah, working under a cooperative agreement with Kaiser Steel Corp. at its Sunnyside mine in Utah. Part 1 of this report describes the present longwall mining practice, including a brief history, and discusses the advantages and disadvantages of a single-entry development system and its introduction in the United States. Part 2 of the report presents the research program; test design, instrumentation for ground and support evaluation, and the test results from the No. 2 mine. Subsequent reports will describe the research conducted in the No. 1 mine.

Jan 1, 1977

The XVIth International Conference on Coal Mine Safety Research was divided into eight half-day technical sessions. In accord with the established practice of these conferences, at each session, presentation of the papers was followed by a discussion period. Questions and comments submitted in writing to the session chairman were answered or discussed by the authors of the relevant papers or by their representatives. These discussions were tape-recorded in the original language of the speaker and subsequently translated into English when necessary. Questions to which no answer was available at the time and a few comments that exceeded the scope of the session have been omitted.

Jan 1, 1975

This Bureau of Mines report describes research on methods of assuring the continued safety of mine electrical power distribution circuits through reliability and quality assessment of the protective devices, innovative inspection techniques for these devices and the circuits themselves, novel applications of trolley line circuit breakers, and computer modeling of distribution systems to determine the proper ratings for cables, power sources, and circuit protective elements. Battery charger safety is included.

Jan 1, 1979