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By Steven J. Page

Since 1982 standard calibration materials recommended for respirable crystalline silica analysis by the Mine Safety and Health Administration (MSHA) P7 Infrared Method and the National Institute for Occupational Safety and Health (NIOSH) X-ray Diffraction (XRD) Analytical Method 7500 have undergone minor changes in size distribution. However, a critical assumption has been made that the crystalline silica in ambient mine atmosphere respirable dust samples has also remained essentially unchanged in particle size distribution. The objective of this work, therefore, is to compare recent particle size distributions of underground coal mine dust and the silica component of these dusts with estimated aerodynamic particle size distributions of calibration standard materials MIN-U-SIL 5, Berkeley 5, and SRM 1878 used by two crystalline silica analysis techniques. This work provides resolution to a previously reported discrepancy involving the proper sample dilution for the particle sizing method used. Dust impactor sampling data for various locations in 13 underground coal mines were collected between 1991 and 1998 and analyzed for the respirable mass median aerodynamic diameters. The data suggest that the MSHA P7 Method will underestimate the silica content of the sample by at most 8.5 % in the median size range of 0.9–3.6 µm and that it is unlikely one would obtain any significant error in the MSHA P7 Method analysis when the method uses Berkeley 5, MIN-U-SIL 5, or SRM 1878 as a calibration standard material. The results suggest that the NIOSH Analytical Method 7500 would be more appropriate for a dust sample that is representative of the total (no cyclone classifier) rather than the respirable airborne dust, particularly since the mass fraction in the size range below 4 µm is usually a small percentage of the total airborne dust mass. However, the NIOSH Analytical Method 7500 is likely to underestimate the silica content of an airborne respirable dust sample by only 5–10 %. The results of this study also suggest that any changes that may have occurred in the median respirable size of airborne coal mine dust are not significant enough to cause any appreciable error in the current methods used for respirable crystalline silica analysis.

Aug 3, 2005

By D. Harrington

This circular presents part I of a review of the literature on effects of breathing dusts, with special reference to silicosis, largely in the minim; and allied industries. The literature on this subject is so extensive that no attempt has been made to include all published material but only to assemble some of the more outstanding data on several aspects of the subject. Parts II and III will deal with prevention and treatment of dust diseases and some of the economic and legal aspects of dust diseases in industry, with special reference to mining. Dust diseases arc much before the public at present, and there is good reason to believe that the information on the subject available to the layman is extremely meager; even those rated as experts usually have a more or less theoretical conception of the diseases, their causation, remedies, and prevention, rather than actual experience with them. Until recently little attention has been given to prevention, and the usual attitude of the engineer, upon whom the main reliance for prevention ultimately must devolve, has been to let "sleeping dogs lie" or, more definitely, to "let well enough alone." However, the "laissez faire" attitude no longer is tenable, and in the past few years numerous conditions have caused those engaged in industry, including mining, to bring the subject before the public with a view to ascertaining the facts upon which to formulate remedial measures, primarily preventive.

Jan 1, 1935

By R. D. Brown

This Bureau of Mines report describes a new methodology for identifying and sorting scrap metals using two modern portable instruments: a thermoelectric sorter and a hand-held emission spectroscope. The method, tested on a 27-sample stainless steel and superalloy array, makes it possible to group and/or identify a typical mixture of high-value metal scrap in two or three steps, whereas as many as seven or eight steps are needed to perform the same separations using chemical spot tests. A portable fluorescent X-ray analyzer identified 19 of the 27 alloys in the sample array by name or type; these alloys are included in the microprocessor memory. The remaining alloys were identified by using the analyzer in its elemental analysis mode and comparing the results wit.h alloy specification chemistry.

Jan 1, 1984

By V. A. Danielson

The Bureau of Mines studied waste disposal methods a1 a coal mine in Kentucky and another in Alabama to develop cost estimates, to provide better knowledge of current practices, and to guide consideration of alternate disposal methods. Costs of the existing waste disposal systems at each mine were estimated using present-day costs of equipment and labor. Costs of waste disposal systems using alternate equipment were also estimated. Although total disposal costs were essentially the same for both operations, reclamation costs will differ because of different reclamation practices.

Jan 1, 1969

By J. H. Jacobs

In late 1946, research was begun at the Bureau of Mines Electrometallurgical Laboratory at Boulder City, Nev., to determine the possibility of electrowinning manganese from chloride electrolytes on a continuous basis. All phases of electrodeposition were investigated on a small scale it the laboratory, and the results were reported by Jacobs and Churchward. These results indicated that a chloride process had certain possible advantages over the sulfate process that made it worthwhile to continue the investigation on a semi-pilot-plant basis, and this paper reports the results of this work. Research and development work on a process for electrowinning manganese from low-grade ores has been carried on intermittently by the Bureau of Mines since 1936. A process was developed, using sulfate electrolyte, that has been extensively described in the literature.

Jan 1, 1951

By R. A. Cattell

Every finding of the year's work, obtained under stress to meet present objectives, contributed to postwar needs, because the very nature and constitution of petroleum and natural gas require that research be conducted along the same general lines whether the results are applied in peace or war. More than 40 reports were submitted to the Petroleum Administration for War and others concerned with (1) evaluation of crude oils to determine their content of aviation-gasoline base stock, (2) evaluation of base stocks for blending with high-octane, synthetically manufactured components, (3) analyses of naphthas to determine their content of various types of hydro-carbons, such as benzene and toluene, and (4) the improvement of quality of marginal base stocks to meet future requirements of aviation gasoline. This upgrading of marginal stocks is being attained by selective distillation and chemical and catalytic removal of sulfur compounds. Asphalts were studied with respect to the characteristics of their various constituents in order to compound them, in the same way that aviation fuels now are being "built" to meet exacting requirements. The work previously initiated to give the industry fundamental data on thermodynamics of hydrocarbons progressed satisfactorily, and the heats of combustion of 10 hydrocarbons in the lubricating oil -range of petroleum were determined. Thermodynamic data requiring highly specialized techniques are so broad in application that their commercial usefulness is not yet fully appreciated.

Jan 1, 1946

By Oliver Bowles

Manufacture of lime is one of the oldest industries. Plants are distributed widely and furnish an essential raw material for numerous commodities. Use of lime in hundreds of manufacturing and chemical processes, by the building trades, and in agriculture has created a demand for large production and has necessitated exhaustive research on methods of manufacture and uses. The bibliography of publications on lime is extensive; but, for the most part, each publication has dealt with individual operations. The purpose of this paper is to present a general picture of the industry as a whole. The abundant literature has been abstracted and quoted freely, and the National Lime Association has furnished valuable data for certain sections. Publications containing more-detailed information on the various branches of the industry are referred to in the footnotes and bibliography.

Jan 1, 1952

By Albert L. Brautigam, Michael R. Yenchek, Jeffrey Shawn Peterson, James C. Cawley

The National Institute for Occupational Safety and Health investigated how the starting of induction motors may cause nuisance tripping of short-circuit protection on coal mine power systems. This research had a dual purpose: 1) to identify how motor-start waveforms differ from those for short circuits and 2) to devise a method to provide short-circuit protection without intentional time delays to account for motor starts. This technology will help ensure that surface temperatures of energized electrical apparatus will not exceed gas or dust ignition thresholds when short circuits occur.

By K. B. Lindsey

Geologically, the Williston Basin is a large structural depression of sedimentary rock in Montana, North Dakota, and South Dakota and Manitoba and Saskatchewan, Canada. The approximate It-mite of the basin are shown on figure 1; it is roughly circular with a diameter of about 400 miles and contains approximately 120,000 square miles. Although the petroleum potentialities in this area had long been recognized, it had not been vigorously prospected by the petroleum industry because of its geographic location, rigorous winters, depths to possibly productive zones, difficult geological problems, and the fact that more seemingly favorable areas were available for prospecting. With the discovery of oil near Edmonton, Alberta, in the prolific Devonian reefs, an incentive was given to explore for oil in the southeast extension of the same sedimentary trough, the Williston Basin. The Virden field discovery in southwestern Manitoba in January 1951 was a direct result of this southeastward movement. Discovery of this shallow field was followed soon after by discovery of' deep production on the Nesson anticline in North Dakota at Clarence Iverson No. 1 well. North Dakota then became the twenty-seventh petroleum-producing State.

Jan 1, 1954

By Ralph Husack

The Bureau of Mines investigated the effect of gamma radiation on reactions between Pennsylvania anthracite and fluorine and chlorine. In the tests with fluorine about 90 percent of the coal reacted at 350° C to form volatile products whether or not irradiation was employed. Up to 0.8 ml of liquid products per gram of anthracite was collected. Among the 25 com-pounds indicated by gas chromatography, fluoroform and l,l-difluoroethylene were tentatively identified from their relative retention times and perfluoro-cyclopentane from its infrared spectrum. In addition, a clear, hard, wax, probably a fluorocarbon, was formed at 45° C in both the presence and absence of radiation. With chlorine there was no significant difference due to radiation, and preliminary tests indicated that the chlorine reacted more with the organic matter of anthracite at 200° C than with inorganic matter. At 400° C the results were inconclusive because of excessive corrosion in the reaction vessel.

Jan 1, 1966

By L. B. Berger

Tests and observations of a Diesel-powered locomotive used for under-ground haulage, in a-clay mine were made by representatives-of the Bureau of Mines .primarily to determine the composition of the exhaust gases produced by the engine under actual haulage conditions-and to determine the effects of the operation on the quality of the mine atmosphere. In addition to ascertaining these conditional t proved interesting to analyze the test, data in regard to certain other performance, characteristics of the engine. This report presents results of tests of the mine locomotive, prefaced by a brief resume of the performance characteristics of Diesel engines to facilitate discussion.

Jan 1, 1948

By Dorothy M. Richardson

The Bureau of Mines has participated in the American Petroleum Institute Research Project 48A (API-RP48A) program on the Separation and Identification of Sulfur Compounds in Crude Petroleum. The lack of reference compounds or infrared spectral data has made difficult the identification of individual sulfur compounds boiling above 140° C. The recent acquisition of 24 alkylthiophnnes has made possible a limited study of this important class of sulfur compounds. The infrared spectra of 2-monoalkylthiophenes and 2,5-dialkylthiophenes for the 2 to 15p range are reported. Correlations for determining the 2-alkyl and 2,5-dialkyl substituted thiophenes are derived from this information. The 2-alkylthiophenes show a unique pattern in the 5.50 to 6.54 region, while the 2,5-dialkylthiophenes show a distinctive pattern in the 5.6µ to 6.7µ region. A skeletal vibration occurs in the 9.5 to 10.0µ region for all of the thiophenes investigated. These data will aid the infrared spectroscopist in the identification of compounds of the type reported.

Jan 1, 1961

By Carl L. Bieniewski

U.S. molybdenum production increased fivefold from 18.2 million pounds in 1946 to 90.5 million pounds in 1966, and constituted 87.3 percent of the total free world supply in the 1946-66 period. Mining development in other free world countries in the next few years may reduce the magnitude of the U.S. position, although similar development planned for the United States may counteract some of the relative gains by those countries. In 1966 two-thirds of the reported molybdenum consumption in the United States by end uses was as an alloying element in steel. Molybdenum also has important use as an alloying element in iron and high-temperature alloys. Consumption of molybdenum metal for making fabricated parts has increased in the past few years, especially in the space and nuclear industries. Molybdenum compounds are used mainly for making pigment, catalysts, and lubricants. Based on producer reports of shipments of primary products to domestic customers, U.S. consumption of molybdenum increased from 16.5 million pounds of molybdenum in 1946 to 65.6 million pounds in 1966. U.S. molybdenum reserves are now estimated to be 5.9 billion pounds of recoverable molybdenum, an increase of 2.1 billion pounds above previous estimates. Molybdenum ores account for 71.4 percent of the reserves, copper ores for 22.3 percent and copper-molybdenum, tungsten, and uranium ores for 6.3 percent. Several methods for predicting future demand are illustrated and estimates of demand using these methods were made for 1975. Based on present capacities and announced company plans for future developments, estimates of annual production were made for 1967 through 1975 for the United States, Canada. Chile, Peru, and the free world. These data indicate that molybdenum production in 1975 for the free world is expected to be 246 million pounds with the United States producing 68.2 percent and Canada, Chile, and Peru 30.3 percent.

Jan 1, 1970

By Wilbur I. Duvall, S. L. Windes, Leonard Obert

"Previous investigations, too numerous to be listed in entirety, have been performed to determine the physical properties of rock. When considered according to their objectives, most of these investigations can be grouped as follows: First, the geologic group (1,2),4/ in which the purpose was to obtain information on the physical properties of the rocks that make up the earth's crust. Particular emphasis has been placed on the determination of the elastic constants--that is, Young's modulus, the modules of rigidity, and Poisson's ratio – as these quantities determine the propagation characteristics of seismic waves. Second, the structural properties group (3 - 11), in which the physical properties of architectural or monumental stone, concrete and aggregate rock, road blocks (cobblestone), and the like were desired. The tests have been quite general and include, besides the elastic properties; the compressive and tensile strength, and the toughness, hardness, and weathering properties of many types of rocks.To .a lesser degree, investigations have been carried out to determine the physical properties of mine rock. A few reports (12 - 14) present data on the crushability and grindability of mine rock, and a large number of papers discuss grinding and crushing procedures and methods of analyzing the data (for example, see references 15 - 17). Some of the latter group also have given the results of tests on mine rock; however, comparatively few include an adequate petrographic description or information on other physical properties of the rock. A few papers,(18 - 22) have reported studies of the strength of rock specimens in respect to the strength of parts of mine structures, such as pillars, roof, arches, etc. Other papers (23 - 26) have discussed investigations on such subjects as primary and secondary crushing, diamond and pneumatic rock drilling, explosive breaking and shattering of rock, rate of drifting and miring, and other allied problems. The majority of these reports have given no more than a cursory, description of the rocks and have included no statement regarding the physical properties. When statements have been given regarding the physical properties, they have usually referred only to isolated tests, making correlations between variations in the physical properties and variations in the .test under consideration difficult, if not impossible. Some reports have included handbook values on such characteristics as the crushing strength, hardness, and toughness. This practice is not satisfactory, because these values are usually given for col¬lective types of rocks, such as granites, limestones, and marbles, and it is known that the variations of the physical properties within these groups is often larger than the differences between the groups."

Aug 1, 1946

By D. J. Dollhopf

The specific objective of this three year study is to investigate the means of reestablishing non-polluted hydrologic systems in areas where surface mining directly impacts shallow ground-water resources. The research area chosen for the study is located near Colstrip, Montana it a new mine site where chemical analysis of core samples from the overburden suggested that excessive concentrations of several elements would he encountered during the mining process. This report discusses local vegetation; soils; and regional geology, and hydrology. Stratigraphic cross sections and regression analyses were used to study the litho-chemical relationships in the overburden. Cross sections indicated Inimical material may be related to both rock tune and position within the overburden profile. In overburden zoness where clay content was high, there was a greater probability that Pb, Cu, Ni, and Mn concentrations would also be higher than average; similarly, the likelihood of overburden exceeding a suspect level became less as the sand content increased. Highest value, of conductance were usually found within a few meters of the surface. High concentrations of clay, nickel, and zinc were frequently found directly above and below the Rosebud coal. Regression analysis indicated overburden SAR was predictable with only a Na analysis. A strong relationship also existed in the overburden between conductance, Ca, and Mg.

Jan 1, 1977

By Robert S. Becker

The results of a laboratory investigation of coal cutting mechanics and noise is presented. These experiments were performed using a linear cutting apparatus that operates over a broad cutting speed range. The influence of several coal cutting parameters on the noise, force, productivity, and specific energy associated with linear cuts is ascertained. Some basic theoretical aspects of coal cutting mechanics and noise generation are discussed, and the results of the laboratory experiments are used to Formulate analytical models of the coal cutting forces and noise. The analytical model For coal cutting noise is then generalized to account for the more important effects of rotary cutting. Based on the generalized model, an estimate of the sound pressure level at an operator's position is made for a typical continuous mining machine. It is concluded that by employing linear rather than rotary cuts, using deeper depths of cut, slower cutting speeds, and more efficient cutting tools, it is possible to reduce the level of coal cutting noise, as well as Provide benefits to other important areas of underground health and safety.

Jan 1, 1980

By S. P. Sandoval

Previous research by the U.S. Bureau of Mines demonstrated that nonionic surfactants increased the leaching rate of copper in the flask leaching of chalcopyrite with ferric sulfate if sufficient ferric sulfate was present. This research was continued by the Bureau in Part 2 to further explore the application of nonionic surfactants to the dump leaching of chalcopyrite. A polyoxyethylene lauryl ether was selected as the superior nonionic surfactant tested at 25° and 50° C. The addition of the surfactant increased copper leaching by 116 pct at 25° C and 1.0 pct solids and by 61 pct at 50° C and 0.5 pct solids at Fe 3+ concentrations greater than 1 g/L. At 0.1.0 g/L Fe 3+ and below, the addition of the surfactant produced as much as a 35 pct decrease in leaching. Each of the nonionic surfactants studied was found to be heavily adsorbed by a typical chalcopyrite ore, which poses a serious barrier to the application of nonionic surfactants in an actual chalcopyrite dump.

Jan 1, 2010

By Chas. F. Jackson

This paper is one of a series dealing with special mining problems and forming part of a general study of mining, methods and costs being conducted under direction of the Bureau of Mines. A considerable part of the material assembled and discussed in this paper has been gathered from articles on individual mines written by consulting engineers to the bureau who are engaged in active mine operation at the properties described, while other data have been taken from the technical press or gathered from personal observations. OBJECT AND SCOPE OF PAPER C. F. Jackson4 ha[-] pointed out that underground transportation (tramming, haulage, and hoisting) absorbs an appreciable percentage of the total underground cost of most mines, averaging for different methods of mining 12.9 to 28.4 per cent of the total underground cost. In general the percentage of cost accounted for by transportation was shown to be highest for the low-cost mining methods.

Jan 1, 1931

By Lloyd A. Morley

The primary goal of this research report is to discuss safety considerations involved in the use of lead-acid batteries for traction purposes in underground coal mines. In order to arrive at the objective, the topic of battery safety has been divided into two specific areas. The first deals with the fact that batteries emit hydrogen gas during and after the charge cycle. Hydrogen gas can be the source of dangerous explosions or mine fires. The second major topic deals with the electrical nature of the battery and battery-charging systems, which also provides a source of mine fires as well as electrocution hazards. In addition to the discussion on battery safety, a literature review has been undertaken to acquaint the reader with some basic concepts inherent to the battery usage process. The result of this research is a set of design specifications and procedural recommendations directed at improving the safety factors inherent in any underground battery usage scheme.

Jan 1, 1977

By Paul Meadows

The Buckrange reservoir, Stephens field, Ark., is approaching the economic limit of production under present operating conditions. Over 100 million barrels of oil remaining in the reservoir will not be recovered by primary producing methods. The Bureau of Mines, in cooperation with the Arkansas Oil and Gas Com-mission, made the petroleum-engineering study presented in this report to aid operators in evaluating secondary-recovery possibilities in the reservoir and in planning secondary-recovery programs if their initiation is decided. The Stephens field, in Columbia, Nevada, and Ouachita Counties, Ark., is about 12 miles northeast of Magnolia, Ark., and 15 miles west of the Smackover field. Surface elevations in the area average about 240 feet above sea level.

Jan 1, 1956