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By Jeffrey H. Welsh

The Bureau of Mines studied the use of computerized, continuous, remote monitoring systems for safety from power system faults in underground coal mines. In this report the need to improve protection against power system faults is documented, and types of faults are identified. The relationship between mine safety regulations and computerized, continuous, remote monitoring is analyzed.

Jan 1, 1983

By H. S. Caldwell

A magnesium-base incendiary alloy, containing about 20 percent cadmium, 4 percent aluminum, and 0.5 percent zinc, was investigated in a series of vacuum-distillation experiments to determine the feasibility of recovering magnesium and cadmium as refined metals. Alloys prepared in the laboratory and actual bomb-casing alloy were studied at temperatures of 550° to 750° C. and pressures of 100 to 150 microns. Simple distillation and fractional distillation methods were only partly effective in separating the cadmium and magnesium. They were separated satisfactorily, however, with a special vapor baffle designed to condense the metals selectively. Magnesium and cadmium products were 99 percent pure and together comprised 82 percent of the total condensate. About 17 percent of the condensate was intermediate-grade alloy that could be recycled with new charge and contained about 70 percent magnesium and 30 percent cadmium.

Jan 1, 1959

By K. A. Fowler, L. W. Higley

Steels with an alloying addition of depleted uranium were studied to develop successful melting , casting , and fabricating methods ; to obtain data on mechanical properties ; and to determine the effects of this alloying element . Uranium in amounts up to 1.5 percent was added to steel - base compositions containing approximately 0.5 percent carbon , 2 percent nickel , 0.25 to 2.0 percent silicon , and 0.75 percent manganese in both vacuum- melted and air -melted heats . Radiation levels were monitored for all operations . Bureau of Mines research at the Rolla Metallurgy Research Center showed that uranium additions did not increase tensile strength ; that hot - shortness occurred during forging above 1,090 ° C because of the presence of a low melting point constituent of a eutectic type ; and although a measurable amount of radioactive contamination resulted from processing , the quantity was never large enough to require the work area to be identified as a radiation area .

Jan 1, 1964

By G. Asai

The Bureau of Mines has been engaged in a program to increase the utilization of chromium by providing samples to individuals and institutions requesting chromium for research investigations. This report consists of a tabulation of the disposition of chromium samples distributed from July 1953 through June 1961; 109 requests for chromium were answered by providing chromium as electrolytic plate, powder, or wrought forms. The demand for samples reached a peak in fiscal year 1959 and declined to a relatively low level in fiscal year 1961. The largest number of requests came from individuals engaged in mechanical property studies; there were also many requests from those concerned with vaporized metal and physical properties studies. Most noteworthy application for chromium was the experimental use of the radioactive form, Cr61 in radiotherapy of cancer.

Jan 1, 1964

By G. Asai

The Bureau of Mines has been engaged in a program to increase the utilization of chromium by providing samples to individuals and institutions requesting chromium for research investigations. This report consists of a tabulation of the disposition of chromium samples distributed from July 1953 through June 1961; 109 requests for chromium were answered by providing chromium as electrolytic plate, powder, or wrought forms. The demand for samples reached a peak in fiscal year 1959 and declined to a relatively low level in fiscal year 1961. The largest number of requests came from individuals engaged in mechanical property studies; there were also many requests from those concerned with vaporized metal and physical properties studies. Most noteworthy application for chromium was the experimental use of the radioactive form, Cr[51], in radiotherapy of cancer.

Jan 1, 1964

By R. W. Smith, S. H. Ash

Marked progress in safety has characterized the operation of coal mines in general in the State of Washington during the 5- year period 1928-1932 , particularly during the years 1931 and 1932. Physical conditions such as steep pitches , inherently bad roof and floor , prevalence of gas , and explosibility of the dust of Washington coals present certain definite hazards . Although advances have been made in accident reduction in Washington , the State still has far to go in that direction . The State has endeavored to reduce its coal -mine accidents by the usual method of making certain definite safety requirements mandatory . The value of education has not been underrated , but the educational method used has not altogether achieved the res lts desired by the industry itself , particularly within certain imdividual organizations . The past 2 years have witnessed a growth , in certain instances , of the essential ideas that the observance of safety precautions on the part of all is demanded if accidents are to be reduced , and that the initiating and carrying out of any program to promote and obtain desired results in accident elimination must begin and function from the top downward . Mining operations of Washington mines have been described in various publications of the United States Bureau of Mines .

Jun 1, 1933

By Fremont F. Clarke

"INTRODUCTION Clay beds of southwestern North Dakota were investigated to determine (1) the average alumina content of the clays in four principal areas of occurrence, (2.) which, if any, would be the most feasible method of extracting alumina from the clays, and (3) whether the clays had any other commercial uses.During the investigation exposed sedimentary beds were examined for clay and the thickness and areal extent of outcropping clay beds in the more promising areas were measured. Four-principal areas of bentonitic clays, comprising 6,967 acres in Stark, Slope; and Billings Counties, N. Dak., were mapped and sampled.ACKNOWLEDGMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our natural resources to the end that they make the greatest possible contribution to national security and economy. The Mining Division, Lowell B. Moon, chief, conducts preliminary examinations, does the actual investigative work, and prepares the final report. The Metallurgical Division, Oliver C. Ralston, chiefs analyzes samples and makes beneficiation tests.Acknowledgment is duo John P. Gries, professor of geology, South Dakota School of Mines and Technology, for his studies of and advice on geological phases of the work. His data were drawn on freely in preparing this report; also E. D. Gardner, regional engineer, Rolla, Mo., and E. Y. Dougherty, district engineer, Rapid City, S. Dak., for assistance and advice in supervising the program."

Mar 1, 1948

By Ned H. Snyder

In recent years the Government and other large consumers of coal have appreciated more and more the desirability of definitely determining by chemical analysis and test the character and quality of the coal they purchase. Higher prices for coal point forcibly to the need of giving more study to engine room and boiler room efficiencies and economies; this implies an intimate knowledge of the character and quality of the fuel used. Analyses and tests of delivered coal furnish data whereby power plant results can be comprehensively studied and a continuous check maintained on the coal and on the conditions of plant operation. Under authority of acts of Congress making appropriations for technologic investigation of fuels and the analyzing and testing of fuels belonging to or for the use of the United States Government, a laboratory is maintained at the Pittsburgh station of the Bureau of Mines, where samples representing deliveries of coal purchased for Government use are analyzed and tested.

Jan 1, 1923

By J. D. Zetterstrom

This report supplements an earlier publication on lightweight aggregates of North and South Dakota.3/ The purpose of the investigation was (1) to study the expansion characteristics of large samples of Dakota clays and shales in a 12-inch by 15-foot rotary kiln; and (2) to improve the laboratory bloating test as a tool for predicting the suitability of samples for the rotary-kiln process. This was done by comparing results of the laboratory and kiln tests.

Jan 1, 1956

By E. C. Perkins

The purpose of the research described in this report was to develop techniques for using ilmenite from domestic deposits for the production of titanium tetrachloride. The research was done by the Federal Bureau of Mines in cooperation with the General Services Administration under contract DMP-116, Utilization of Domestic Ilmenite. Bench-scale continuous chlorination of an Idaho ilmenite containing 27.9 percent titanium and 35.6 percent iron yielded a crude titanium tetrachloride suitable for purification and for the production of titanium metal and pigment. A summary of the results of 380 hours of operation showed that 82.4 percent of the titanium was chlorinated, with 92.5 percent utilization of chlorine. The construction- of a. quartz tube chlorinator 4-inches in diameter and 24 inches long is described with the necessary details of operation.

Jan 1, 1961

By D. Harrington

Misuse of explosives and heedless disregard of well-known safety rules covering the use of commercial explosives cause many avoidable accidents resulting in the death or maiming of men who can ill be spared by already undermanned industry at present, and who cannot be spared by their families at any tire. Blasting accidents, when not fatal, are usually serious; the past and present needless loss of life and maiming of men from this cause are appalling and types of waste that can and should be virtually eliminated. Dead, crippled, and maimed men are distinct losses to society as well as to industry, and compensation payments for such accidents represent only a portion of the financial loss, because the value of their lost potential production can only be surmised. By their very nature, explosives are dangerous to handle, otherwise they would not perform the services for which they are used; all men on a blasting crew are subjected to the results of the carelessness of any one member, and in many instances the misuse of explosives by one person has killed scores of fellow workers. Inexperienced men should be assigned to blasting operations only under the close supervision of men well-experienced in the work and familiar with its inherent hazards. Men should be selected for blasting crews that are known to be careful, willing to follow instructions, cool-headed, and unlikely to become excited in an emergency; they should be instructed in the safe handling of explosives in accordance with the safety rules established by the explosives -manufacturing companies or the safety codes of the various industrial organizations. Unfortunately, American industry has never adopted a uniform code for the safe handling of explosives; however, many mining companies have made rules that will eliminate most unsafe practices if established safe procedure is followed carefully. The Bureau of Mines has issued numerous pamphlets giving information on the causes of accidents due to explosives in the mining industry and indicating the ways in which a good proportion of those accidents can be avoided.

Jan 1, 1943

By William C. Cooley

A review was made of two Russian books and a chapter from a third book dealing with pipeline transport of coal. Emphasis was placed on hydrotransport of coarse coal in underground mines or surface pipelines. The books reviewed were: "Means of Increasing the Effectiveness of Hydrotransport," by V. N. Pokrovskaya (1972), "Parameters and Modes of Hydraulic Transport of Coal" by V. V. Traynis (1970), and the chapter "Calculations of Hydrotransport of Useful Minerals and Waste Rock" from the book "Hydromechanization of Opencast Workings" by G. A. Nurok (1970). All three are unique and useful additions to the world literature on hydrotransport. The Traynis book reveals the development and results of circular wheel stand tests to simulate hydrotransport in horizontal pipes, which is a potentially outstanding contribution to slurry pipeline technology. Graphical data and equations are presented which suggest that headlosses for coarse coal can be predicted with good accuracy for pipe sizes up to 14 inches in diameter. Wheel stands permit tests for pipe wear and lump degradation without recycling coal through pumps. Recommendations are made for wheel stand tests and for correlation of existing data.

Jan 1, 1976

By A. A. Berk

In the course of a study of the formation of external deposits on tubes in water-tube boilers it became desirable to determine the sulfur dioxide (SO2) and sulfur trioxide (SO3) in the Due gases. Determinations made by the A.S.M.E. method for SO2 and SO3 in gaseous products of combustion did not give accurate results. It was found that minute quantities of copper, present in the flue gases from the coal in use, caused oxidation of sulfite in the absorption bottle and that the carbon dioxide (CO2) in the flue gases caused high values for SO2. The A.S.M.E. test procedure was revised to prevent oxidation of sulfite in the absorption bottle and to allow for the effect of CO2; subsequent analyses of flue gases produced reliable results. The revised procedure is described.

Jan 1, 1950

By Berk. A. A.

"INTRODUCTION Corrosion of sections of piping used in steam-heating systems is frequently regarded as unavoidable, and periodic replacement is provided. Surfaces exposed to newly condensed steam appear to be especially vulnerable to attack. As an added nuisance, solid products of the corrosion tend to accumulate, plugging return lines.The trouble is ascribed in the main to carbon dioxide and oxygen 3/ 4 / 5/ 6/ dissolved in the condensate. When oxygen is the principal factor, the corrosion usually is characterized by pitting. Carbon dioxide tend3 to cause an acidic condensate which dissolves the metal more uniformly and produces the familiar failure at threaded areas where the piping is relatively thin, and where high stress may tend to acceletate the attack. Carbon dioxide enters the system with the feedwater, generally in a combined form such as carbonates and bicarbonates. Oxygen enters both with the raw feedwater-and as air leaking into lines under partial vacuum. The larger central-heating plants have sought to reduce corrosion by eliminating these gases as much as possible. A smaller plant ordinarily lacks the equipment and technical supervision required for this purpose."

Jun 1, 1944

By Jack L. Henry

The ternary system A14C3-AIN-Al203 has been examined to determine compositions which may display desirable high-temperature refractory properties. Powder methods were employed in the synthesis of all test compositions. Forming and sintering behavior was examined and hot-pressing parameters were measured. Several properties were studied for each composition of interest in the system. The properties included hydrolysis rate in moist air, elevated temperature oxidation rate, density, softening point, tensile strength, and rupture strength. In most cases equilibrium was not achieved, and the data are representative of a nonequilibrium system. Approximately 16 separate phases have been observed in the system. Forming behavior and selected properties of five compositions of interest were compared with those of aluminum oxide and aluminum nitride. None of the compositions compared favorably. Oxidation and vaporization appear to be serious drawbacks to the use of these compositions at elevated temperatures.

Jan 1, 1969

By Doyle A. Ellerbruch

An FM-CW microwave system was investigated for measuring coal layer thickness. Measurements were made in three different mines near Pittsburgh, Pennsylvania, near Fairview, West Virginia, and near Coffeen, Illinois. Microwave frequencies in the range 1-2 GHz were used to measure samples up to 55 cm thick. All samples were backed with a naturally occurring shale. Measurements were also made on coal and shale samples compounded in the laboratory at the Bureau of Mines Pittsburgh Mining and Safety Research Center near Bruceton, Pennsylvania. The results indicate that layer thickness can be determined in most cases, although large anomalies may, in some cases, produce misleading results. Many anomalies that were detected with the FM-CW system were verified visually by drilling into the coal layer. The dielectric constant of coal apparently varies significantly within a coal seam. The form of the output signals from the FM-CW system seem to simplify the data interpretation and analysis process as compared to the manually swept microwave system used previously. It appears that this technique has the potential of measuring changes in the dielectric constant of a coal seam and providing an output that can be used for real-time corrections in layer thickness; measurement.

Jan 1, 1976

By F. B. Petermann

The Bureau of Mines conducted electric furnace smelting tests on sintered flotation concentrate and siliceous log-washed are. The flotation concentrate was derived from the Maggie Canyon deposit of the Artillery Mountains area, Mohave County, Ariz., and contained, before sintering, 35.6 percent Mil and 19.4 percent Si02 + A1203. The log-washed ore was from the McGregor deposit of the Artillery Mountains area, Mohave County, Ariz., and contained 31.2 to 33.6 percent Mil, 19.5 to 27.6 percent Si02 + A1203, and 2.5 percent Pb. This work was undertaken to determine the most effective smelting technique for producing standard products from such nonspecification ore and concentrates. The objective was to collect data, using a small furnace, which would be reasonably accurate and permit extrapolation to large-scale practice for comparing with results on specification-grade are.

Jan 1, 1962

By R. Karl Zipf, Z. T. Bieniawski

"Researchers at The Pennsylvania State University are engaged in a project to understand the mechanics of respirable size fragment formation in coal. The project is based on the premise that a thorough understanding of the fundamental mechanics of fine fragment formation may lead to techniques for reduction and better control of coal dust problems in mines. Presently, it is believed that the mode of fracture propagation which can range from pure tensile to pure shear or any mixed mode in between and the loading or displacement rate can influence the amount of respirable size fragments that are generated on new fracture surfaces during the fracture propagation process The essence of any coal cutting process is one of mixed mode fracture propagation. To study the crack propagation process, a unique mixed mode testing rig was designed and fabricated. This rig is capable of applying loads to a prenotched test specimen that range from pure Mode I (tensile mode) to nearly pure Mode II (shear mode) or many mixed mode loading combinations. It is also possible to apply different loading or displacement rates to the test specimen. With this rig, it is possible to create new fracture surfaces via the different fracture modes and under various loading conditions.These new fracture surfaces are examined with a scanning electron microscope (SEM) to characterize the amount of structural damage and respirable size fragment formation that occurs during the fracture process. Initial observations suggest that the amount of fine fragment formation and the new fracture surface appearance is related to the fracture initiation conditions, particularly the fracture mode and the loading rate. Mode II loading and higher loading rates seem to generate more structural damage and respirable size fragment formation that Mode 1 loading at slower rates.With the mixed mode test rig, the mechanics of fracture initiation for a single crack can be controlled to better understand its influence on respirable size fragment formation. Such understanding may lead to methods which characterize the tendency of specific coal seams to produce undesirable fine fragments during the fracture process, or it may lead to rational recommendations and design guidelines or coal mining machines which inherently produce less dust.IntroductionAs part of a larger effort to reduce the incidence of coal workers pneumoconiosis (black lung) in coal miners, researchers at The Pennsylvania State University are engaged in a project to understand the fundamental mechanics of fine fragment formation in coal. This project is part of a com¬prehensive research effort within the Generic Mineral Technology Center for Respirable Dust which is jointly administered by The Pennsylvania State University and West Virginia University.The principal source of the coal dust in underground mining is the cutting operation. The U.S. Bureau of Mines (USBM) and various European research organizations have conducted investigations into the mechanics of coal cutting for many years. These studies of airborne respirable dust (ARD) formation have concentrated on empirical studies of the various cutting parameters and their effect on ARD for¬mation. The parameters study include depth of cut, cutting speed and bit spacing.(1,2) Other studies investigated the effect of symmetric and asymmetric bit wear and various bit geometries and designs (3-5) Roepke(6) summarized the principals of proper coal cutting to minimize dust formation by recommending to ""cut at maximum depth (maximum advance rate) at all times, at minimum RPM, with the fewest possible bits, having the lowest possible included tip angle."" Most coal in the U.S. is mined with the continuous mining machine which inherently cannot meet these design recommendations.(3)It is recognized that respirable size dust particles are formed and/or liberated by a fracture process. One extremely interesting and useful study performed very early in the USBM dust re"

Mar 1, 1989

By Edmund S. Leaver

[In previous reports 5/ of ore-testing studies standard methods of conduction tests with precious-metal ores selected as representative of certain mining districts were discussed in considerable detail.]

Jan 1, 1941

By S. J. Aresco

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions5/ issued by the Bureau of Mines; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor and, if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1961