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By Manuel Gomez

This report presents low-temperature tar data from studies by the Bureau of Mines of tars produced in an externally heated (entrained state) pilot-plant-scale retort. Analytical data covering 20 low-temperature tars, derived from the. carbonization of various ranks of foreign and domestic coals, are tabulated. The character of the tar is discussed in relationship to carbonizing conditions and the rank of coal. It is seen that in carbonization techniques that employ entrainment or fluidization of the coal particle, carbonization conditions are secondary to coal rank with respect to tar-oil yields and composition. The influence of distillation conditions on recoverable yields of tar products is presented. The probable yield of commercially important chemical products, based on a ton of pure (moisture- and ash-free) coal, are predicted. INTRODUCTION Low-temperature tars produced by entrainment or fluidized carbonization techniques that employ internally heated reactors represent the most nearly primary tart produced by industrial processes. In brief, such a process involves the application of a heat gradient to the coal particle "boiling" or suspended in a turbulent state in the reactor chamber. Conditions are observed so that the coal particle remains suspended within the reaction zone by a gas stream for a time interval commensurate with maximum tar-oil yield. The heat necessary for the carbonization reaction may be obtained entirely from the hot (preheated) gas stream, or it may be derived partly from the combustion of the volatile products and char by the transport gases, usually air. The volatile material moves out of the carbonizing zone at a rate that approaches the velocity of the transport gas. Carbonizing conditions are ideal when a minimum particle residence time is obtained within the reactor at a given temperature and a maximum yield of condensable volatile matter is released. In industrial practice this objective is a compromise.

Jan 1, 1957

By W. W. Adams

With greater production of coal per man-hour of work than ever before achieved, the coal-mining industry of the United States established a better safety record in 1941 than in any year since 1930, the earliest for which complete reports of nonfatal as well as fatal injuries were collected by the Bureau of Mines, United States Department of the Interior. In only one year (1933) of the 12-year period 1930-41 was the fatal-accident rate better than in 1941, whereas the rate for nonfatal accidents was better in 1941 than in any previous year. Accident and employment reports received from mine operators, together with fatal-accident reports received monthly from State mining departments and inspectors, showed that 546,692 men were employed in and about the coal mines of the United States during the calendar year 1941. This number does not include office employees or coke-oven workers. The increase of 1.3,426 over the number of employees in 1940 was accompanied by a gain in man-hours of work performed at the mines and an increase in average number of hours worked per man during the year.

Jan 1, 1944

By D. Randolph Berry

This report describes a study to develop a detailed set of guidelines and equipment recommendations to be used as a guide for mine operators, mine inspectors, and equipment manufacturers in implementing the emergency escapeway standards for metal and nonmetal underground mines. It was sponsored by the United States Bureau of Mines. The first part of this report reviews the historical background of metal and nonmetal mine fires and the development of present and proposed mandatory standards. This is followed by a discussion of the survey of representative mines and how the proposed standard effects these mines. The remainder of the report covers technical discussions of each escapeway component including a comprehensive computer simulation of mine evacuation. Following the technical discussion of each group of escapeway components is a list of the pertinent guidelines. The major escapeway components discussed are the following: Escaperoutes Refuge Chambers Hoisting System. Escapeway Signs Ventilation Fuel Storage Fire Retardants Warning Systems Auxiliary Transportation

Jan 1, 1976

By Donald F. Reed

Deposits of gray hematite occur in two districts in Talladega County, Ala., the Emauhee-Tallasechatch and Weewoka, both in the; vicinity of Wintorboro, 50 miles east of Birmingham. The deposits were investigated by the Bureau of Mines in 1945 and 1944. Approximately 15,000 feet of diamond drilling was done and 6,000 linear feet of trenches excavated and sampled.

Jan 1, 1949

By R. J. Fantel

The Bureau of Mines investigated the resource potential of 201 mines and deposits in 28 market economy countries and 17 mines and deposits in the U.S.S.R. and China. The 201 mines and deposits evaluated from market economy countries contain an estimated 34.2 billion metric tons of recoverable phosphate rock (at the demonstrated resource level), with Morocco and Western Sahara accounting for 61% (21 billion tons), followed by the United States with 19% (6.4 billion tons). The 17 mines and deposits evaluated in the U.S.S.R. and China contain approximately 1.5 billion tons of potentially recoverable phosphate rock. Potential annual capacity from low-cost, high-grade producing mines in the United States is estimated to decline significantly during the latter half of the next decade, and the United States will have to develop new, higher cost, lower grade mines in order to satisfy demand into the next century. Of the world's new production capacity which could likely be developed over the next decade, slightly over one-third could be produced at an estimated 1981 cost of $40 per ton or less, and about two-thirds would cost in the $40 to $50 range (including a 15% rate of return). In comparison, moot of the competing phosphate rock from producing mines in Morocco could be produced for under $40 per ton. The United States has sufficient demonstrated resources of phosphate rock (plus huge quantities at the identified and hypothetical resource levels) to satisfy domestic consumption for many years to come, but its future ability to compete in the major export markets against low-cost competitors is much more uncertain.

Jan 1, 1984

By J. P. Powell

The importance of recovering more oil from known petroleum reserves has placed increasing emphasis on the application of secondary producing methods. One of the most successful of these has been the injection of water into depleted oil reservoirs. Water flooding is now recognized as a valuable conservation measure that not only prevents the premature abandonment of stripper leases but also is credited with reviving operations in many oil-producing areas previously abandoned. The injection of water into an oil-producing zone as a method of stimulating oil production was legalized in Kansas in 1935. Although water flooding had been attempted previously in other parts of the State, 1935 marked its introduction into the shallow stripper area of eastern Kansas. Two years later flooding was begun in the five-county area that is described in this report. Figure 1 is a map showing the water-flood areas in Allen, Bourbon, Crawford, Labette, and Neosho Counties, Kans. To July 1, 1955, the 77 projects in the oil fields of these 5 counties are credited with recovering an estimated 12.3 million barrels of oil that would not have been produced by methods used previously. These projects are expected ultimately to cover 10,700 acres, of which only 5,400 has been flooded to date.

Jan 1, 1957

This publication contains four papers presented at a seminar on mine subsidence control held in Pittsburgh, PA, on September 19, 1985. The seminar was designed to keep the mineral industry informed of new technology developed by the Bureau of Mines that permits reliable and accurate prediction of mine subsidence. The papers describe actual field studies undertaken by the Bureau to monitor surface subsidence over longwall panels. Topics discussed include the efects of subsidence on water table levels, the development of subsidence pre calculation methodology suitable for use with the specific lithological conditions of the Pittsburgh coalbed, an engineering comparison of technologies used in surveying for longwall mine subsidence, and a comparison of the process of subsidence over two different longwall panels.

Jan 1, 1985

By John H. Hild

"INTRODUCTION Alunite occurs within a radius of 10 miles of Marysvale, Piute County, Utah, in veins and as replacements of igneous rocks. A number of each type of deposit was explored by the Bureau of Mines, in cooperation with the Geological Survey, under the Strategic Minerals program during 1942. The exploratory work comprised geologic and topographic mapping, diamond drilling,,bulldozer and hand trenching, sinking test pits, rehabilitation of old workings, sampling alunite exposures, and constructing and repairing roads.ACKNOWLEDGNENTSIn its program of exploration of mineral deposits; the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches-are under the supervision of Dr. R. S. Dean, assistant director.With particular reference to this publication, acknowledgment is given to Richard E. Mieritz and William E. Young, who assisted on the project at various times; P. T. Allsman, chief. Salt Lake Division, Mining Branch, who advised on exploratory problems and gave valuable assistance in preparing the report and illustrations; A. P. T. Schumann, for preparing the illustrations; and to Gordon L. Bell, Max Willard, and Eugene Callaghan, of the Geological Survey, who cooperated as representatives of that agency."

Nov 1, 1946

By Alton B. Cook

In the Scurry Reef field, Scurry County, Tex., a study was made to determine the physical properties of the oil in all parts of the reservoir by a new method developed for this study. The method involved correlation of data from a survey 1 of the gravity of the produced oil, from measurements of gas-oil ratios on key wells selected to give representative data for the entire reservoir, and from laboratory analyses of reservoir oil samples. A field survey was made of the API gravities of the produced oil by testing oil samples from 107 key wells. Precise gas-oil-ratio tests were made on 45 key wells that were producing under comparable separator-operating conditions. Subsurface-oil samples were obtained from seven wells, selected to provide reservoir oils ranging approximately from a minimum to a maximum in saturation pressure. The physical properties of the subsurface-oil samples were determined, and correlations were made of these laboratory data with the field gas-oil-ratio test data. These correlations were then used to estimate physical properties of the oil throughout the reservoir. A logical procedure of determining the variations in physical properties of reservoir oils in most fields is to obtain and analyze subsurface-oil samples from enough key wells to provide an ample coverage of the field. Under this procedure, data from a large number of samples would be needed to provide the desired information on the Scurry Reef field, as it is one of the largest known in the United States.

Jan 1, 1955

By Lyman C. Hitchcock

The objective of this program was to determine the minimum luminance requirements for underground coal mining work from the working face to the first transfer point. The resulting data encompasses 114 visual tasks from conventional continuous and longwall mining methods representing the salient visual tasks found in the jobs listed. Cutter Operator Roof Bolter Face Drill Operator Airdox Operator Longwall Jackman Shuttle Car Operator Loader Operator Shot Fireman Continuous Miner Operator Longwall Head Conveyor Operator Longwall Tail Conveyor Operator

Jan 1, 1973

By Cecil Q. Cupps

Results are presented of a comprehensive study of the characteristics of the original oil in the Weber sandstone reservoir, Rangely oil field, Colorado. Through the medium of subsurface sampling, adequately representative samples of the original reservoir oil were obtained from many parts of the reservoir over a period of 5 years concurrent with active development of the reservoir. Data of differential gas liberation, pressure-viscosity, and. pressure-volume-temperature relationships are shown for 12 subsurface oil samples. Data also are given of reservoir pressure and. temperature, composition of liberated or solution Gas, composition of 22 produced-gas samples, and Hempel analyses of crude-oil samples from 18 wells. The characteristics or physical properties of the 12 subsurface oil samples, as determined by laboratory analyses, were correlated with elevation of the top of the Weber sandstone. These relationships of oil characteristics to elevation in the reservoir show that only the oil in contact with the initial gas cap was gas-saturated at the existing pressure and temperature. The characteristics of the original reservoir oil were marked by an appreciable decrease of saturation pressure and solution gas-oil ratio and increase of viscosity and density with depth below the gas-oil contact. The composition of solution gas and of' produced was also was found to vary with elevation of the oil in the reservoir.

Jan 1, 1951

By Warren E. Morrison

This study was prepared in response to the need for a series of data that reflect the basic flow pattern of energy resources in the United States. To effectively measure and analyze energy,2 it is necessary to prepare balances that reflect both production and consumption, and the various forms energy resources take at different stages of utilization. Before energy can be measured it must also be put into a common unit. In this study the common unit used is the British Thermal Unit (Btu). The ideal point to survey energy is at the stage of final ultimate use, representing the useful work derived from the interaction of energy inputs and the prime mover. Unfortunately this concept of efficient or useful work from energy output cannot readily be measured in the aggregate. With the present available official data, energy measurement can be carried to the point of calculation of net inputs of energy3 into the economy at various stages of utilization. However, preparation of energy balances, on a net basis is hampered by the fact that this can only be done for years when the censuses of Mineral Industries and Manufactures are taken, usually at 5-year interval.

Jan 1, 1964

By Warren E. Morrison

This study was prepared in response to the need for a series of data that reflect the basic flow pattern of energy resources in the United States. To effectively measure and analyze energy,2 it is necessary to prepare balances that reflect both production and consumption, and the various forms energy resources take at different stages of utilization. Before energy can be measured it must also be put into a common unit. In this study the common unit us d is the British Thermal Unit (Btu). The ideal point to survey energy is at the stage of final ultimate use, representing the useful work derived from the interaction of energy inputs and the prime mover. Unfortunately this concept of efficient or useful work from energy output cannot readily be measured in the aggregate. With the present available official data, energy measurement can be carried to the point of calculation of net inputs of energy3 into the economy at various stages of utilization. However, preparation of energy balances, on a net basis is hampered by the fact that this can only be done for years when the censuses of Mineral Industries and Manufactures are taken, usually at 5-year intervals.

Jan 1, 1964

Explosives identification tagging refers to the addition to explosives, during manufacture, of coded microparticles that can survive detonation, be recovered and decoded, and allow the explosives to be identified and traced to the last legal possessor as a result of distribution records kept of the coded tagged explosives. This study seeks to prepare the way for National implementation of identification tagging of all dynamites and cap-sensitive slurries (also known as water gels) by resolving technical issues and by developing a plan for pilot testing of the program. It is presented in two volumes: Volume I, National Implementation Model, and Volume II, Pilot Test Plan.

Jan 1, 1977

By John C. Machisak

Injury data and experience, with related employment statistics, at coal mines in the United States for 1959 are presented in this publication under the following general sections: (A) General injury experience: Tables 1 to 6: Current data on number of injuries degree of injury, frequency and severity rates, average severity, and related employment and production data by work location. (B) Selected injury experience: Tables 7 to 38: Current data on principal agencies of injuries, distribution of injuries by part of body injured, days of disability, extent of hand and machine loading, experience by employment and production groups, and various other operating factors and physical conditions related to the occurrence of injuries at the Nation's coal mines.

Jan 1, 1961

By E. D. Gardner

This is one of a series of papers describing mining and related subjects affecting mining in western mining districts and mineralized areas. The parts of this paper pertaining to current production, mining and milling methods and practices, and general conditions affecting mining were collected principally during a field survey made in May 1935. Some original data obtained on previous visits to the area are also included. The history, geological background, and past production of the mines and district are largely abstracted from previous publications, for which due credit is given later in the test. The principal districts in the Black Mountains are the Oatman or San Francisco and the Union Pass or Katherine. This range contains the principal producing mines of the State, in which gold is the only important metal. Although the total production of gold is relatively small as compared to other districts where the precious metals are obtained as a by-product in copper min¬ing, the area is one of considerable economic importance to the State.

Jan 1, 1936

By D. F. Hambley

This manual contains a step-by-step procedure for the design of ore passes for open pit mines. The manual is comprehensive and deals with all aspects including location, design, construction and operating considerations. In the construction section, all applicable raising and shaft sinking methods are considered and cost estimates and advance rates provided for each. The design process is divided into several sections - rock flow requirements, support design, dump point design and draw point design. Use of this manual provides open pit planning engineers with a means of designing and assessing the feasibility of ore passes for their operations.

Jan 1, 1983

By Forrest T. Moyer

Quarry accidents in 1963 caused 61 fatal and 3,468 nonfatal injuries which occurred at respective frequency rates of 0.31 and 17.91 per million man-hours of worktime. The fatality record in 1963 was better than in 1962 but was appreciably worse than in 1.961. For nonfatal injuries, the 1963 record was slightly worse than in 1962 but was better than in 1961. The injury--severity rate of 2,913 days lost or charged per million man-hours in 1963 was better than that of 3,046 in 1962, the first year for which such data became available. The average severity of all injuries in 1963 was 160 days lost or charged per injury, 15 less than in 1962. An average of 91,960 men were at work on active days in 1963 and these men had an aggregate worktime of 193.7 million man-hours during the year.

Jan 1, 1972

The contribution of minerals to the growth and development of the United States is best demonstrated by the uses which have evolved during the past two centures. During pre-Revolutionary days the colonies were essentially agricultural in character, producing cotton, tobacco, rice, indigo, grains and flour, fish, livestock, dairy products, and timber. Shipbuilding was the major manufacturing industry. In 1763, the total value of exports for Virginia, Maryland, New York, Pennsylvania, and Massachusetts was £2,722,000, of which £55,000, or 2 percent, was for "copper ore, and iron in pigs" (3)1 and £49,000 was for 21,000 barrels or hogsheads of "pot-ash." The value of 75 ships built for sale in 1763 by the colonies was £61,500.

Jan 1, 1976

By Jos. R. Guiteras

This paper has been written to describe briefly the mining and milling of gold and silver ores in the Black Canyon and neighboring mining districts in Yavapai County, Ariz. The description of present operations is the result of a 10-day visit to the region by the writer in March 1936. Acknowledgments The author is indebted to earlier writers on the geology and mining in this regions and to the mine managers and their staffs, whose courteous cooperation has made possible the assembling' of material for this paper. Individual acknowledgments are made in the text.

Jan 1, 1936