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By Thomas Fraser

About 24 per cent of our total production of bituminous coal is used in industrial power plants. As regards fuel conservation, therefore, the recovery of unburned fuel from furnace refuse presents interesting possibilities. Considerable attention has been given to this problem in the past, but because of the comparatively low initial cost of power plant fuel in the pre-war period little progress, has been made in this direction in the United States. Because of the higher price of coal in Europe more attention has there been given to the problem. In Germany a process has been developed for separating unburned coal in refuse by using an electromagnetic separator In the United States the use of mechanical stokers enabled low-priced screenings of high ash content to be used, so that even with relatively high percentages of combustible material remaining in the refuse, the loss in money is not excessive. If the price of screenings returns to the pre-war level around $1.00 per ton the process proposed here will probably not be especially interesting, except where the freight charges are very high. However, if the price of delivered coal continues high, such a process should result in considerable saving. The cost of continuous operation of such a refuse treating plant should not exceed 75 cents per ton of fuel recovered.

Jan 1, 1921

By W. J. Wenger

Oil fields in the Powder River Basin of Wyoming have produced 731 million barrels of petroleum through 1959. Production in 1959 was 32 million barrels, the highest production since 1924. The record production was in 1923, when the Basin produced 38 million barrels of oil and the Salt Creek field, then at its peak, produced 35 million barrels. In this report, the characteristics of crude oils found in the Basin are used as a basis for determining the best re-fining uses for the oils and for predicting the characteristics of oils that may be discovered in the Basin in the future. Analyses of 108 oils sampled over a period of 30 years are presented Crude oils of two major types are produced from the Powder River Basin. One has a low sulfur content and occurs in younger formations, and the other has a high sulfur content and occurs in older formations. The oils with low sulfur contents are generally light colored and waxy, and may be either paraffinic or naphthenic. The oils with high sulfur contents are usually dark colored and asphaltic; only their low boiling fractions are paraffinic. Alteration appears to account for the anomalous properties of some oils found at shallow depths. Shapes and slopes of correlation index curves classify the oils into the same two groups as their sulfur contents, with gently sloping curves representing the low-sulfur oils and steep curves representing high-sulfur, asphaltic oils,

Jan 1, 1961

By Wm. W. Odell

For a number of years there has been a very appreciable annual,, increase in the production and recovery of natural gas and natural-gas gasoline2 in the United States the latter product being used largely for blending with gasoline from petroleum in the production of motor fuel. On account of the increased amount of oil cracking in the production of gasoline and the accompanying increased percentage of low-boiling constituents in the resulting product, the specifications for the natural gasoline suitable for blending have been altered, that is, the amounts of propane and butane which it can contain have been limited. The result has been that large quantities of the latter materials are wasted because there has been no ready market for thorn in large quantities. Because of this wasteage and because it is probable that large quantities of there and similar materials will be produced in the near future us a result of the more general use of oil cracking processes, a study was made by the Bureau of Mines, under a cooperative agreement with the assistance of the Phillips Petroleum Company, of the suitability of these materials alone or in mixtures for use as gas enricher in the carburetion of water gas for city distribution. This investigation included: (a) A study of the properties of the low boiling members of the paraffin series including pentane with particular reference to their utilization as gases.

Jan 1, 1927

By D. W. Frommer

Mineral dressing research was conducted by the Federal Bureau of Mines under a cooperative agreement with the St. Joseph Lead Co., on three samples of iron ore from the Pea Ridge deposit in central Missouri. The objective was to provide information on how to upgrade these submarginal ores and produce marketable concentrates. Samples were prepared from drill-hole cores of similar composition and character to produce (1) a medium-grade mixed hematite and magnetite, (2) a high-grade mixed hematite and magnetite, and (3) a high-grade magnetite. In all three ores phosphorus and sulfur constituted objectionable impurities; excessive amounts of silica were also present in the medium-grade ore.

Jan 1, 1960

By Robert Stefanko

The growing demand for energy during the post World War I and World War II periods has prompted underground coal production to increase rapidly. This has been met primarily by mine mechanization, resulting in the development and application of new mining machine types. Correspondingly, the total connected horsepower of each machine as well as the number employed has enlarged rapidly since 1950. (2,3,9,14,16,17) Electrical consumption for each mine has also grown. In the early years of mining electrical applications, only d-c power was utilized underground. Yet, d-c machine limitations were soon realized, and many a-c systems were substituted to permit economic and efficient utilization of a-c distribution and motors. Due to the attractive torque characteristics, ease of distribution and speed control, several traction applications have continued to be powered by d-c motors. The result has been the now prevalent use of mixed a-c/d-c mine power. However, augmented electrical power employment seems to have added to underground coal mining electrical accidents.

Jan 1, 1974

By Robert H. Dickson

This paper describing the mining practices at the Verde Central mine at Jerome, Ariz., is one of a series being prepared by the United States Bureau of Mines on mining practices, methods and costs in various mining districts of the United States. ACKNOWLEDMENTS The costs contained in this paper were prepared by R. J, Huddleston, chief clerk, Verde Central Mines, Inc.

Jan 1, 1931

By K. K. Kershner

Nickel having a purity of more than 99.99 percent with reference to metallic impurities was electrodeposited at the Rolla Metallurgy Research Center of the Federal Bureau of Mines. The production of high-purity nickel is in keeping with the current trend in technologies for producing metals with lower and lower percentages of impurities. To understand more fully the role to be played by nickel by itself and as a component in many alloys, the element must be in a state of high purity. Procedures are outlined for purifying nickel solutions by precipitating and filtering off impurities. Details are given for using the purified solutions as electrolytes in depositing high-purity nickel. The elecneleposited nickel contained 0.0005 to 0.002 percent each of cobalt, copper, aid iron together with spectrographically detectable traces of aluminum, magnesium, and silicon. The deposits were smooth and dense; the crystalline structure was typical of an electrodeposited metal. Some preliminary experiments for purifying nickel solutions by liquid-liquid extraction are also described in this report. Tests of this type were limited since more encouraging results were obtained by other methods of purification.

Jan 1, 1961

By George S. Rice, J. W. Paull, R. R. Sayers

"Standard rock dust for use in the rock dusting of coal mines might be defined tentatively as powdered mineral, light colored and free of carbonaceous matter and free silica, all of which will pass a 20-mesh screen while 50% of it will pass-through a 200-mesh screen.Such dust may be prepared from limestone, gypsum, anhydrite, or shale free of sand and flint. For the initial rock dusting of the average nongaseous bituminous mines enough standard rock dust should be applied so that the combustible content of the resulting mixture of rook dust with mine dust shall not exceed 45%, a range somewhere between 35% end 45% being the practical objective sought.All entries, slopes or passageways and room necks should be rock dusted.Additional safeguards are:a.,Rockdusting roomsb.,Scattering of dust in vicinity of shots before firing.c.,Placing of barriers in the mouths of panels, cross-entries and other key positions.Redusting becomes necessary whenever the combustible content of the mine dust exceeds the permissible maximum. This should be determined by regular, systematic sampling, followed by a simple analysis of the samples for combustible content. A Bureau of Mines volumeter for measuring the density can be used for the determination of combustible content."

May 1, 1924

By Todd M. Ruff

Researchers at the National Institute for Occupational Safety and Health are investigating technologies that could be used to detect objects, small vehicles, and pedestrian workers that may be in the blind areas of haulage equipment used in mining and construction. A detection system that warns the equipment operator that there is an obstacle nearby could prevent collisions and save many lives each year. One popular technology for collision warning systems is radar. Several different types of radar have been tested in the laboratory and on mining equipment. Early in the study, questions arose concerning the best way to test radar systems. Many factors affect the performance of radar, including the size, shape, and composition of the object that is to be detected; the height of the radar antenna(s); and the relative motion of the radar system and/or object. This report discusses several different test procedures and test targets and recommends methods to determine how effective a radar system will be in detecting a person near heavy equipment.

Jan 1, 2002

By Frederick C. Trutt

A guide to the utilization and development of extensions and modifications to the APL Mine-electrical-system Load-flow Program is presented. These modifications include the development of algorithms to minimize computational operations within the iterative-solution techniques, as well as minimization of the number of required iterations. Extensions to the load-flow program include the development of algorithms for the calculation of balanced faults, simplified specification of fault parameters, optional inclusion of pre-fault currents, and an alternate-solution technique.

Jan 1, 1978

By Joseph A. DeCarlo

Coal is one of our basic sources of energy (heat, power, light) and an essential raw material for most metallurgical processing. More than two-thirds of the electricity currently produced by thermal powerplants in the United States is generated by coal, and it is expected that coal will continue to be the major fuel used for this application at least through the 1970's. Coke produced from bituminous coking coal is the principal fuel of iron blast furnaces, and unless ironmaking methods change greatly, coal will continue to maintain a dominant role in iron-ore processing and steel manufacturing for many years. Export markets are expected to increase also, adding to the overall increased demand for coal. Accompanying the increased total requirement, however, will be an ever-increasing demand for higher quality coals, specifically, coals of low sulfur content. Except for special-purpose coals such as those used for the production if coke and ceramics where impurities in the fuel contaminate the end product, the amount of sulfur in coal has been only a minor consideration in the selection of a particular coal for fuel. Major considerations, particularly for the coals used to generate electric power, have been availability and cost. An increased national concern for control of air pollution, however, particularly that resulting from the emission of sulfur oxides in stack gases to the atmosphere, has led to more rigid specifications on coal quality, and the sulfur content of coals will become increasingly more important in the future.

Jan 1, 1966

By Joseph A. DeCarlo

Coal is one of our basic sources of energy (heat, power, light) and an essential raw material for most metallurgical processing. More than two-thirds of the electricity currently produced by thermal powerplants in the United States is generated by coal, and it is expected that coal will continue to be the major fuel used for this application at least through the 1970's. Coke produced from bituminous coking coal is the principal fuel of iron blast furnaces, and unless ironmaking methods change greatly, coal will continue to maintain a dominant role in iron-ore processing and steel manufacturing for many years. Export markets are expected to increase also, adding to the overall increased demand for coal. Accompanying the increased total requirement, however, will be an ever-increasing demand for higher quality coals, specifically, coals of low sulfur content. Except for special-purpose coals such as those used for the production if coke and ceramics where impurities in the fuel contaminate the end product, the amount of sulfur in coal has been only a minor consideration in the selection of a particular coal for fuel. Major considerations, particularly for the coals used to generate electric power, have been availability and cost. An increased national concern for control of air pollution, however, particularly that resulting from the emission of sulfur oxides in stack gases to the atmosphere, has led to more rigid specifications on coal quality, and the sulfur content of coals will become increasingly more important in the future.

Jan 1, 1966

Early in 1936 the Interstate Oil Compact Commission and other groups interested in forecasts of demand for petroleum requested the Bureau of Mines to make a physical inventory of crude-oil stocks in the United States. Accordingly, the 74th Congress -appropriated funds for conducting such a survey during the fiscal year ended June 30, 1937. In the discussions end hearings2/ relative to the need for the survey, the opinion was expressed that crude oil held is storage for long periods had lost so much of its gasoline content that the economic significance of total stocks should be discounted materially. Therefore, a primary objective of the survey was to

Jan 1, 1938

By Kenneth M. Smith

"The kaolin deposits of Aiken County, South Carolina (fig. 1), have been worked continuously since 1852. It has been long known that the deposits contain a high percentage of alumina and that large reserves exist. These facts led to the early selection of this area for examination in the search by the Bureau of Mines for high-alumina clays. An exploratory program was started by the Bureau, and drilling was carried on from June 27, 1942, to October 31, 1942.The kaolin-bearing district occupies an area approximately 25 miles long and 11 miles wide, running northeast, with its center at Aiken, S. C. (fig. 1). Within this district, a triangular area bounded by Horse Creek, Silver Bluff Road, and Hamburg Road was roughly prospected by boring 43 machine and 12 hand holes. As a result of the data obtained, a final smaller area was chosen for more systematic prospecting. This area is bounded by Pine Log, Tewkesbury, Silver Bluff, and Craig Sawmill Roads and covers about 4,000 acres.Mineral exploration agreements covering 11,272 acres were signed by 35 property owners, and 11,956 feet was drilled in 200 holes on these properties.The Bureau of Mines exploration work in the district has indicated 19,514,000 short tons of kaolin, of which approximately 10,000,000 tons would average over 35 percent alumina.The tonnages and grades of kaolin developed by this exploration are tabulated below.All grades of this kaolin average approximately 2 percent Fe203 and 1.5 percent Ti02.This project was under the general supervision of J. R. Thoenen, supervising engineer, Non-Metals Mining Section of the Mining Division, Bureau of Mines, until July 1942. The -project was then under the general supervision of E. J. Lintner and later Rowe McCrae, consecutively district engineers for Georgia, South Carolina, and Florida. The final report was prepared, under the general supervision of V..J. Lynch, chief, Raleigh Branch, Mining Division, by William A. Beck from the original report by the author.Acknowledgment is made for the wholehearted cooperation and assistance given to the Bureau of Mines by the various operating companies in the district. Particular thanks are due Theodore Henderson, general manager; North American Clay Co., Wilbur Driver, general manager, and Howard Driver, assistant general manager, The Huber Clay Co.; H. W. Smith, president, The South Carolina Clay Co.; and J. Richard Parker, president, J. R. Parker Clay Co., all of Bath S. C.; J. B. Howard, Jr., superintendent/ the Immaculate Kaolin Co., Langley, S. C.; Richard Jones, president, National Kaolin Co., and William Winans, president, The Southern Clay Co., both of Aiken, S. C.; and W. S. Burkalter, Warrensville, S. C.Acknowledgment is also due the Metallurgical Division for analytical determinations and to James J. Page of the Federal Geological Survey for his aid in mapping and logging the holes.The first known use of kaolin from this district was by the Bath Pottery Co., which began mining an outcrop in Horse Creek Valley, near Bath, in 1852.. In 1867, R. McNamee, of New York City, acquired this pit and continued mining. This first mine is still known as the McNamee, and from its operation grew the present kaolin industry of South Carolina."

Dec 1, 1949

By Martin J. Gavin

"Before discussing oil shales it may be well to consider briefly the conditions surrounding the petroleum industry in the United States, because these largely explain why so much interest is being manifested in oil shales. The United States is not only the greatest producer of petroleum in the world, its output amounting to about 65 per cent of the world's total production; but is also the world's greatest consumer, using more petroleum than it produces within its own borders. For the past four or five years it has been necessary to import oil at a continually increasing rate to make up the deficit between domestic production and domestic consumption. Experts who have made a close study of the future supply and demand for, crude petroleum are satisfied that under present production practice and with the development of possible undeveloped productive areas, the gap between domestic consumption and production will steadily .increase.As possible solutions for the impending domestic shortage of oil, various expedients are receiving attention. These may be grouped under three heads, as follows:(1) Temporary measures, such as curtailment of consumption, development of more efficient methods of production, and more efficient utilization of supplies of petroleum still available. It is unlikely that there will be any great curtailment in consumption of petroleum in the United States; rather, consumption will continue to increase unless a real shortage of oil actually forces curtailment of consumption. The other two possibilities mentioned deserve, and are resolving, serious thought. Much experimental work along these lines, some of which has already yielded excellent results, is being done. Obviously, however, any of these remedies are temporary ones only, so far as regards domestic production of petroleum."

Oct 1, 1920

By B. W. Naugle

The Bureau of Mines investigated the changes that occur in decomposition products when coal is carbonized in a fluidized bed with steam as the fluidizing medium and the vapors are subsequently cracked without condensation in a fluidized bed of high-temperature coke. The coal used was from the High Splint bed, High Splint mine, Harlan County, Ky. Since this coal is agglomerating, it was blended with char. The integrated unit used in this investigation consisted of a 3-inch-diameter fluidized coal carbonizer, a 3.5-inch-diameter cracker containing a bed of high-temperature coke fluidized by the tar vapors and steam from the carbonizer, and gas-cleaning and product-recovery systems. The carbonizer was operated at 485° C and the cracker at 600°, 700°, and 800° C. The process variables investigated were temperature, residence time, and concentration (pound of tar vapors per pound of steam to the cracker) of tar vapors in the cracker. The total tar yields decreased as the temperature of the cracker increased, and at a constant cracker temperature of 600° C the yield of paraffins, acids, aromatics, and olefins in the distillate increased directly with the tar vapor concentration in the cracker. At 700° and 800° C only the acids and aromatics increased with increased concentration. Bases remained essentially constant regardless of the temperature and concentration. Similar results were obtained when the tar from the carbonizer was condensed prior to feeding to the cracker.

Jan 1, 1965

By Marcia L. Harris

The National Institute for Occupational Safety and Health (NIOSH), as part of its continuing research program for evaluating coal dust explosion hazards, has investigated several areas in which current practices may need to be updated in order to adequately protect mines against coal dust propagated explosions. In the United States, current rock dusting requirements remained largely unchanged since 1969. US Title 30 Code of Federal Regulations Section 75.403 is based on a coal dust particle size survey performed in the 1920s and later was supplemented by full-scale testing of the rock dust ability to inert a coal dust explosion. NIOSH recently conducted a comprehensive survey of US underground coal mines to determine the range of coal particle sizes found in dust samples collected from the mine entries. Due to advancements in technology and modern coal mining techniques, the current coal dust particles in intake airways are significantly finer than those found in the mines in the 1920s. According to past full-scale dust explosion test results, the current rock dusting practices used in today?s mines to inert a coal dust explosion may not be adequate. Other closely related issues such as rock dust testing methods and sampling procedures are discussed.

Jan 1, 2009

By Ronald B. Stotelmeyer

This report summarizes studies of 55 Idaho national forest roadless areas completed by the U.S. Bureau of Mines (USBM) in the period 1966-1992. These roadless areas have been recommended for addition to the National Wilderness Preservation System, proposed as special management areas, or otherwise recommended for study by the U.S. Forest Service or the Idaho congressional delegation. The Bureau of Mines' studies indicate which parts of the roadless areas contain mineral resources. They also show where mining and prospecting are likely to occur in the future, where mineral production has occurred in the past, and where abandoned mine workings (possible hazards) would be encountered. The number of mine and prospect workings found are a measure not only of surface disturbance, but of areas not wilderness in character.

Jan 1, 1994

By Steven J. Page

Researchers have developed a model to describe airborne respirable dust (ARD) generation on surface coal mine drills. By measuring a few basic parameters and using a graph, a drill operator or engi­neer can estimate the relative severity of drill dust emissions as well as how much of a reduction in ARD can be obtained by changing any given parameter. Geometric parameters include: drill deck cross-sectional area, shroud leakage associated with the deck shroud as well as the operational parameters of bailing air­flow, and dust collector airflow. The rela­tionships yield predictive ARD values which fall in the range measured on oper­ating drills for collector/bailing air flow ratios greater than 2. Overexposure to airborne respirable crystalline silica dust can cause serious or fatal respiratory disease. Exposures of sur­face coal mine rock drillers to respirable crystalline silica are of particular concern. In a 1992 alert on silicosis in rock drillers, the National Institute for Occupational Safety and Health (NIOSH) reported on 23 cases of advanced silicosis (acute, acceler­ated, and chronic) ranging in ages from 25 to 60 with drilling tenures ranging between three and 20 years.1 Most of the cases involved drill operators in their 30?s and 40?s, indicating high silica exposure levels are associated with their occupation. A more recent lung x-ray surveillance study of a 664 volunteer population of surface coal miners showed that the prevalence of silicosis-like abnormalities was 9%.2 The two most significant factors associated with these abnormalities were increasing age and years of drilling experience.

Jan 1, 2008

By Eldon Keith Stanek

This annual report deals with four distinct tasks related to research on the safety and reliability of mine electrical power systems. Task one is to develop tests and the associated instrumentation to detect incipient faults on a mine or any low-voltage power system. Task two is a dual effort related to the digital prediction of electrical transients on mine power systems and laboratory testing of transient suppression devices. Task three is also a dual effort. This task consists of both theoretical and laboratory work to assess both the reliability and the fail-safe characteristics of several items of protective equipment used in mine power systems. Task four consists of an effort to use programmable calculators and/or computer terminals to check overcurrent protective device coordination.

Jan 1, 1976