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By C. J. Thompson

In the course of the work currently conducted by the Bureau of Mines in cooperation with the American Petroleum Institute Research Project 48 on identifying sulfur compounds in petroleum, a micromethod was developed (12)5 for catalytically removing the sulfur atom from sulfur compounds. The product is the residual portion of the molecule; the structure otherwise was unaltered except for hydrogenation of any unsaturated bonds that were present in the original compound. Positive identification of sulfur compounds isolated from crude oils is a difficult problem. Direct comparison of properties of the unknown with those of reference compounds is often impossible because of the limited number of reference sulfur compounds available. However, a relatively large number of pure hydrocarbons is available, and the conversion of the sulfur compound to a hydrocarbon enhances the possibility of identification. The technique also can be used to prepare microquantities of scarce hydrocarbons by hydrogenating compounds that are readily available.

Jan 1, 1962

By H. O. McDonald

The Bureau of Mines reviewed the chemical vapor deposition (CVD) literature on the nonmetal binary and ternary compounds of the group IVB, VB, and VIB elements, with emphasis directed to the following nonmetals: B, C, N, O, and Si. This review examines each of these binary and selected ternary compounds of the group IVB, VB, and VIB elements as coatings and gives some of their preparative methods, uses, and properties. A total of 259 references were found for these compounds of the nine elements. This review was utilized in the Bureau's research to provide abrasion-, erosion-, and corrosion-resistant coatings in order to conserve critical metals and protect various metallic surfaces in metallurgical, mining, and energy conversion systems.

Jan 1, 1983

By K. L. Williams

The Bureau of Mines tested a prototype tapered-element oscillating microbalance (TEOM) dust monitor for measuring respirable coal mine dust. The monitor uses the inertial behavior of a vibrating element to measure the mass of sampled dust. Tests were performed to determine variability, drift, the effect of humidity, placement of collection filter, and element orientation during analysis, and comparability with gravimetric measurements of respirable coal dust. Variability was about 1.6 µg. Over about 26 h at 46 pct relative humidity, drift was very slightly negative. When the relative humidity was increased to 78 pct, all units showed a total positive change less then 40 µg over about 70h. Filter placement variation on the tapered element resulting from in- consistent sizing of the filter mounting bases caused significant error (up to 0.2 mg). In practice, calibration of the system for each new filter will eliminate that error. Orientation of the element during analysis did not introduce significant error, but care is necessary when mounting the canister that houses the element to avoid damping oscillation of the element. Dust tests were performed in an aerosol chamber using coal dust. Measurements made by the TEOM dust monitor agreed to within 10 pct of simultaneous measurements by gravimetric personal samplers.

Jan 1, 1986

By Stephen D. Cramer

The Bureau of Mines conducted a series of in situ linear polarization measurements in high-temperature, high-pressure hypersaline geothermal brines at the Bureau of Mines Geothermal Test Facility in the Imperial Valley of California. The measurements represented an evaluation of the linear polarization technique for obtaining instantaneous corrosion rates of materials of construction in flowing hypersaline hydrothermal fluids that rapidly form scales on exposed surfaces. A special method was devised for use with the linear polarization technique that resulted in obtaining corrosion rates for 1020 carbon steel, 316 and 430 stainless steel, titanium, various nickel-based alloys, and aluminum 6061 under strong scale-forming conditions. The measurements also provided information on scale-deposition rates in various geothermal environments. Exploratory in situ potentiostatic polarization measurements were made in the flowing brines to qualitatively determine scale-deposition effects on the electrochemical measurements.

Jan 1, 1978

By W. J. Wenger

Analytical, geographical, and geological data on 67 samples of crude oils from Utah are presented, along with some correlations and interpretations. Most of the, geologic formations that produce oil in other areas are also productive in Utah; and as in many other locations, the Permian, Pennsylvanian, and Mississippian formations account for the major amount of the total oil produced in the State. Some anomalies and unusual phenomena are noted. Although most Utah oils are low in sulfur, a sample containing the highest percentage of sulfur ever recorded by the Bureau of Mines is among the oils discussed in this paper. Most of the oil from the major producing formations in Utah is low in sulfur; the same formations produce high-sulfur oils in adjoining Rocky Mountain States. Some Utah oils are both waxy and asphaltic, an unusual combination of characteristics. Correlation index curves for some oils are shown suggesting compositional differences in oils from different producing formations. Production statistics trace the rapid rise of oil production in the State after the first commercial discovery in 1947 and indicate a decline in amounts produced since 1959, the year of peak production in Utah.

Jan 1, 1971

By Edward G. Cunney

Track in underground bituminous coal mines was investigated, and technology was taken from other industries in order to obtain information on conditions that impair the safety and efficiency of the track and to develop guidelines and useful information on the construction, inspection and maintenance of mine track. Volume 1 contains information on the investigations, observed track conditions, useful technology from railroads and other industries, derivations of track condition descriptors and recommended limits, conclusions, and recommendations. Volume 2, Guidelines, contains recommended standards and practices for mine track. It includes the relation of track conditions to safe speeds; descriptions and limits for measurable track features such as gage; descriptions of conditions for track components that are normally not measurable, such as subbase soils; construction requirements and techniques, inspection requirements and methods; and methods for managing and performing track maintenance work. As a research product, it does not repeat the summary or derivations. Volume 3, Inspection Handbook, summarizes recommended standards and procedures from Volume 2 and provides related information for' ready reference by inspectors in the mines. As a research product to be used in mines, it does not repeat the summary, derivations or references.

Jan 1, 1977

By J. R. Thoenen

This circular is part IV of the third paper (entitled "Sand and Gravel Excavation") of a series summarizing the technical problems involved in the production and preparation of sand and gravel. Part I discussed the use of power shovels, draglines, and excavator cranes; part II discussed the use of power scrapers, slackline cableway excavators and hydraulic monitors; and part III discussed the use of hydraulic, clamshell, ladder, and dipper dredges. This circular discusses haulage equipment in general, particularly the use of industrial cars with locomotives or hoists as the motive power. Part V, to follow, will discuss the use of other types of haulage equipment.

Oct 1, 1935

By Lisa Steiner, Robin Burgess-Limerick

In 2004, there were 646 underground coal mines in the USA employing 37,445 miners. These mines reported 3556 injuries to MSHA that year - 17% were associated with bolting machines (593 injuries), 8% with continuous miners (283 injuries), and 4% each with Scoop/LHD (1 51 injuries), shuttle cars (134 injuries), and personnel transport (145 injuries). The use of the frequency of reported injuries for the prioritization of risk control strategies has limitations because of the tendency to underestimate the importance of relatively rare but high-consequence events. Injury reports also underestimate the contribution of risk factors such as whole body vibration, which have a long-term cumulative contribution to an elevated risk of injury. However, taking these limitations into consideration, the results of the injury narrative analysis suggest the following hazards as the highest priority for elimination or control: • rock falling from supported roof • inadvertent or incorrect operation of bolting controls • handling continuous miner cable • collisions while driving LHD/Scoop, shuttle cars and personnel transport • rough road while driving or traveling in LHD/Scoop, SC & PT

By J. H. Schuenemeyer

Consider a set of points, some of which are anomalous (larger than a specified cutoff value), located on a plane. Whether some or all of these points are clustered to form one anomaly or more or, alternatively whether these points are scattered at random, may be investigated by measuring perimeters of convex hulls. A convex hull is the smallest convex polygon that will encompass a group of points. (Examples of convex polygons are triangles, rectangles, and all other regular polygons.) A set of anomalous points is selected and the perimeters of the convex hulls of this set and all its subsets are measured and compared with tabulated values of perimeters for each subset size. For a given subset size consider those perimeters which are less than the tabulated perimeter. If the number of convex hulls is greater than the maximum number expected by chance, then the chance that any one of the observed-hulls-is a nonrandom cluster is the ratio of the observed number to the sum of the observed and the maximum number expected by chance. Otherwise, the points are evidently not clustered. If many sample points are anomalous, an alternate model defines various configurations of contiguous points and compares the observed number of configurations per unit area with the expected number. Applications are discussed in several fields of geology and geochemistry-including geochemical exploration surveys and heavy mineral spatial distributions--as well as in mining (dust control) and medical geography.

Jan 1, 1972

By Ivette E. Torres

For a study such as this, which summarizes and amalgamates much information collected, compiled, and utilized by the numerous U.S. Bureau of Mines country specialists and branch chiefs for inclusion in their country and regional reports that comprise the five other sections of 1992 Minerals Yearbook-International Review, it is clearly impossible to cite all sources of information used in its presentation, but some recognition is due. Generally speaking, this study and its related detailed studies on countries and areas would be much more difficult, if not impossible to complete, without the efforts of the personnel of our counterpart national mining and geological agencies throughout the world. Information that they collect, compile, and then publish, either in their own volumes or those of central statistical agencies in their countries, are the foundations on which this work rests. Thus, our appreciation is expressed to the multitude of persons employed by these agencies for their contributions.

Jan 1, 1994

By D. Harrington

[Notwithstanding the fact that it is now fairly generally recognized that widespread explosions can be almost absolutely prevented in coal mines by efficient rock-dusting and that this rock-dusting can be done thoroughly at a cost which should seldom exceed 1 cent per ton of coal mined, a recent survey of the situation by the Safety Division of the U. S. Bureau of Mines, following a similar survey by the Bureau in the fall of 1925, shows that while some progress is being made by our coal-mining people, many entire mining communities are lamentably slow in taking advantage of one of the most effective safeguards available. Much of the information as to the extent of rock-dusting was obtained through the various State inspection departments. Table 1 shows that in the fall of 1925 about 92 coal companies in the United States were using rock-dust ad that in the summer of 1927 the number had increased to 239, or about 160 per cent increase. Similarly, from the fall of 1925 to the summer of 1927 the number of mines using rock-dust increased from 177 to 463, or about 160 per cent increase. This appears to be a decidedly healthy increase, but when it is considered that in 1926 (the last date for which figures are available) there were 7,141 bituminous mines operating and that there were only 463 or 61 par cent, which were even reported to Ice using rock-dust to any extent whatever, the forgoing figures as to progress are by no means impressive or even satisfactory.]

Jan 1, 1928

By M. M. Fine

A satisfactory mean: of beneficiating a Brazilian phosphate rock was developed in a mineral-dressing-research study by the Bureau of Mines. High-grade concentrates well ever the specified minimum grade of 70 percent tricalcium phosphate, were produced, with goad recoveries by agglomerate tabling and flotation. A lower gads but usable secondary product was recovered by sedimentation of the minus-200-mesh fraction of the ore. The ore wan representative of an extensive deposit recently discovered near Recife in the State of Pernambuco, Brazil, which will be exploited in a plant planned to eventually produce at the rate of 500,000 tons of concentrate annually. Although Brazil has been reported to Lave a substantial reserve of phosphate rock,3/ the country has never been more than a small producer of this commodity. From 1945 to 1950 the highest production of phosphate rock attained in Brazil amounted to 10,421 tons. Production in 1949, the most recent year for which figures are available, was 4,553 tons.4/

Jan 1, 1954

By James W. Ballard

The facts are generally accepted that an atmosphere containing large quantities of any dust is objectionable to breathe and that some dusts are more dangerous than others. Therefore, knowledge of the com-position of dusts is important in evaluating the hazard entailed on exposure. At present, free silica, of which quartz is the most abundant form, is considered one of the most significant dusts, from the standpoint of pneumoconiosis, and one State5/ has established permissible limits of air dustiness on the basis of the free-silica content of rock. The amount 06 free silica in materials used for rock dusting also has been limited.6/ Determination of free silica or quartz, therefore, is important.

Jan 1, 1940

This report describes the development, installation and performance of a lonpwall illumination system. The longwall illumination system was installed at the Greenwich Collieries 112, Cockport, Pa. It utilized flourescent luminaires, intrinsically safe power distribution and is the first longwall system installed in Pennsylvania.

Jan 1, 1976

By J. T. Popp, C. M. McCulloch

This Bureau of Mines study reviews the geological factors that affect methane in the Beckley coalbed in southern West Virginia, including overburden, coalbed structure, type of and changes in lithology above and below the Beckley coalbed, and presence of fractures in the coal and rock adjacent to the Beckley. Depending on the depth, the Beckley coalbed emits from 216 to 520 ft3 of methane per ton of coal mined, and the Bureau estimates that methane emission in a deep, extensively developed mine in this area may exceed 3,000 ft3 per day per ton of coal mined. Average face cleat and butt cleat trends in the Beckley coalbed measured underground are N 33° W and N 53° E, respectively. Close cleat spacing con- tributes to the friable nature of the Beckley and provides easy movement for methane and water. Because rider coals, splits, and carbonaceous shales may contribute methane to mine emissions, predictions of methane emission based on gas content of the Beckley coalbed alone may be conservative. Beckley coalbed reserves in the study area are 234 million tons. The gas content of the Beckley coalbed averages 407 ft3/ton, and the coalbed gas reserves are 108 billion ft3.

Jan 1, 1976

By E. M. Kawenski, J. K. Richmond, M. J. Sapko, G. C. Price

This Bureau of Mines publication presents investigators' reports of all major coal mine explosion disasters that occurred in the United States from 1959 through November 1981, along with a brief analysis of common factors in these disasters, The report reviews the Federal mine health and safety acts of 1969 and 1977, and discusses how implementation of these acts has reduced the number of both fatalities and disasters, Current Bureau health and safety research is summarized, and an appendix lists most of the ignitions and explosions in the period of record,

Jan 1, 1983

By D. R. Tesarik, R. W. McKibbin

Material properties affecting slope stability were measured in a large 50-year-old, partially consolidated rockdump located in an active open-pit mine. Field tests included single-ring infiltration and density. In addition, a nuclear depth-moisture gauge was used to measure water content in six stainless-steel-cased drill holes on the crest and an upper bench of the rock dump. Precipitation, evaporation, wind speed and direction, and temperature data were collected at a weather station installed on the dump’s crest. Laboratory tests included particle-size distribution, specific gravity, Atterberg limits, and water content. By measuring material properties of a rock dump presumed to be stable, the safety of miners working on or at the toe of old rock dumps constructed of similar material and located in a similar climate can be assessed.

Jan 1, 1999

By R. E. Thill

The ultrasonic pulse measurement system described measures velocities of longitudinal (compressional) and shear waves in rock to give values that can be used with density values to determine the dynamic elastic constants of rock. A special feature of this pulse measurement system is its unique acoustical bench that minimizes errors in pulse transit times that are commonly associated with coupling, sample alinement, and sample orientation. Some special features of the acoustical bench are its highly versatile transducer cartridges, a pneumatic ram coupling device, an orientation mechanism, and a vacuum chuck sample holder. The lathe-bed-like construction of the acoustical bench assures automatic alinement of samples and versatility in accommodating samples of various shapes and sizes.

Jan 1, 1968

By Noel N. Moebs

Coal mine roof failure is categorized according to character, trend, or pattern of occurrence. Two principal categories of failure are proposed--geology related and stress related. Geology-related failure includes both lithology and structure. Each of several subcategories reflects the probable cause of failure and thereby provides a basis for the selection of appropriate techniques for reducing the incidence of failure. These control techniques, depending on local conditions, may include supplementary support, destressing, reduction of mine air humidity, or a change in the customary support methods.

Jan 1, 1986

By Donald J. Barnes

Gold was found in samples collected from Pleistocene and Holocene stream and terrace deposits. Approximately 15,000 cu yd (11,400 cu m) of small and discontinuous terrace and stream gravel deposits in the study area are composed of material derived from sedimentary and granitic rocks. The detritus is subangular to subrounded, and poorly sorted, ranging from boulder to sand size. Gold values in samples collected averaged 8.2 cents per cu yd (gold value of $500 per oz). Pan concentrates and rock chip samples collected from reported mineralized zones showed an absence of economic minerals. Stream placer deposits are uneconomic. No potential was observed for metallic or nonmetallic minerals in the La Panza study area. No potential exists for gas, oil, or coal resources.

Jan 1, 1981