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This study was conducted to determine the feasibility of using large tractor dozers in land reclamation of strip-mined areas. The procedures used are patterned after engineering models developed for evaluation of military ground vehicles in cross-country operations. Tractor dozer manufacturers furnished information on capabilities of existing equipment and ideas on the practicability of using dozers larger than those currently available Generally, they believe that current dozers in the 500? to 700-horsepower range are about as large as can be built and remain economically feasible. However, one manufacturer has a wheeled dozer rated at 1200 horsepower, and another is testing a tracked dozer of about the same horse-power.

Jan 1, 1975

By Kenneth L. Bickel

During an underground mine fire, the importance of controlling the spread of smoke and toxic gases with suitable ventilation structures has been proven. However, under certain conditions, control of the propagation of the fire itself may be even more critical in insuring a safe mine evacuation. Fire doors offer the means for accomplishing both objectives. In 1978, the Bureau of Mines initiated research to evaluate the state of fire-door technology and develop and test a fire door suitable for large openings (10 by 12 ft or larger) in noncoal underground mines. This report discusses current fire-door technology in the context of the underground mine environment and the design, fabrication, lab testing, and in-mine field testing of a mineworthy fire door. This door has a 1.5-h fire resistance rating and limits temperature rise across the door to 2500 F during the first 30 min of fire exposure.

Jan 1, 1987

By W. W. Adams, T. D. Lawrence

"A. larger enrollment and a greater number of man-hours of employment by the enrolled companies were the outstanding features of the National Safety Competition of 1942, an annual safety contest conducted by the Bureau of Mines, United States Department of the Interior, for the promotion of safety among workers in the mines and quarries of the United States. The accident-frequency and accident-severity rates were somewhat higher than in 1941, but the frequency of accidents in relation to the number of man-hours worked was strikingly lower than in the earlier years of the 18-year period during which the contests have been conducted.Companies that enroll in the National Safety Competition compete for a bronze trophy known as the ""Sentinels of Safety."" Six of these trophies are provided by THE EXPLOSIVES ENGINEER annually for award by the Bureau of Mines. The trophies for 1942 wore won by an anthracite mine in Pennsylvania, a lignite mine in North Dakota, an underground metal mine in Tennessee, a limestone mine in Ohio, an open-cut metal mine in Minnesota, and a lime-:tone quarry in Pennsylvania. The trophies are presented to the companies for 1 year and are then transferred to the winners of the succeeding year's contest.The contest rules state that a mine or quarry must have at least 25 men employed underground or in the pit for at least 100 days, and the plant must be in operation 30,000 or more man-hours to be eligible for a trophy. The rank of mines and quarries is determined by accident-severity rates, or, in the case of accident-free records, by the number of man-hours worked."

Oct 1, 1943

By Stephen R. Iverson

Manganese deposits exist in the Wonder Mountain RARE II area (fig. 1). The manganese mineral is primarily bementite, a silicate. It occurs with Jasper and manganese oxides in tabular or irregular lenses along the contact between red limestone and basalt. There are about 11,000 tons (10,000 t) of indicated sub-economic resources in the northeast part of the study area. Of this, 10,700 tons containing 27.1 percent manganese is at the Apex Prospect and 300 tons averaging 24.8 percent is at the Brown Mule Mine (fig. 1). Another 1,000 tons (900 t) containing 27.0 percent manganese is at the Steel Creek deposit 0.5 mi (0.8 km) west of the area (Wiebelt, 1942, p. 1, 2). Each of these deposits is subeconomic due to small tonnage and high estimated recovery costs. They are in a regional belt of manganese occurrences trending northwesterly through the area. Pardee (1921) reports that manganese ore was shipped from the Triple Trip (Brown Mule) Mine in 1916.

Jan 1, 1982

By H. J. Schroeder

Legislation and Government Programs.-The Occupational Safety and Health Administration (OSHA) accepted written comments until July 23, 1976, and held an informal hearing on August 24, 1976, to receive oral testimony regarding an economic and inflation impact statement prepared by OSHA on the proposed standard for occupational exposure to inorganic arsenic. These written and oral submissions were to be used in conjunction with information supplied at 1975 hearings to promulgate emission standards. An in-depth study for the Environmental Protection Agency (EPA) assembled and interpreted comprehensive information on arsenic and its compounds and the effects of these substances on people, animals, and plants.2 Another study for EPA assessed the role of arsenic and its compounds in the environment and in the economy of the United States and evaluated the need for and the projected effect of controlling its production, use, dissipation, and emission.3

Jan 1, 1978

This chapter summarizes data on crude nonfuel mineral production for the United States, its island possessions, and the Commonwealth of Puerto Rico. Also included are tables that show the principal nonfuel mineral commodities exported from and imported into the United States and that compare world and U.S. mineral production. The detailed data from which these tables were derived are contained in the individual commodity chapters of Volume I and in the State chapters of Volume II of this edition of the Minerals Yearbook. Although crude mineral production may be measured at any of several stages of extraction and processing, the stage of measurement used in this chapter is what is normally termed "mine output." It usually refers to minerals or ores in the form in which they are first extracted from the ground, but customarily includes the output from auxiliary processing at or near the mines.

Jan 1, 1988

By George H. Johnson

This report describes the procedures and summarizes the results of an investigation of surface subsidence above caving blocks at the San Manuel mine, San Manuel, Ariz., in order to obtain quantitative information on subsidence and ground movement caused by mining large volumes of ore. This investigation is one part of an overall study of rock mechanics being undertaken by the Bureau of Mines. Attention was given to the improvement of a rapid and precise method of surveying a large number of subsidence pins and cracks in the surface terrain. Photogrammetric methods were used as an adjunct to the triangulation subsidence surveying as well as in ordinary topographic work Maps of various kinds were prepared to show the results obtained. The computation of the survey notes was programed for an electronic digital computer at a saving of time and expense over the use of a desk calculator and trigonometric tables.

Jan 1, 1963

By A. J. Kraemer

For a number of years the Bureau of Mines has been conducting an investigation of crude petroleum from producing fields in the United States and the Western Hemisphere and has published a series of reports on these fields. Analyses of crude-oil samples tom some oil fields of Louisiana are given in Bulletin 291.4/ Analyses of 26 representative crude oils from various producing formations of southern Louisiana are given in is report. These.samples are from 14 field's in 10 parishes in the southern part of the State, usually designated as the "Louisiana Gulf Coast area." ACKNOWLEDGMENTS Thanks are due the representatives of the various companies from whom samples were obtained for their cooperation and assistance in helping to secure representative samples. The samples were analyzed under the direction of E. C. Lane at the Bartlesville station of the Bureau of Mines.

Jan 1, 1934

By Martin Smirlock

A novel instrumentation system has been developed which enables simple, quick, and accurate measurement of vehicular dynamics within low speed ranges. The system, consisting of a microwave transceiver and microprocessor data acquisition and reduction system, measures the deceleration dynamics of low-speed mining and construction equipment. It makes the basic measurement, calculates key parameters such as average deceleration, initial velocity, stopping distance, and brake system delay time, and produces autoscaled graphs of velocity, acceleration, and displacement versus time.

Jan 1, 1981

By E. J. Gleim

A study of the records on file in the Bureau of Mines reveals that moray fire in coal mines have been started by electrical equipment or circuits. There the fires were of undetermined origin, electricity often was Strongly suspected as the probable cause. While it is unfortunate that positive evidence as to the cause is so often lost in the general destruction resulting from fires, there are many lessons to be learned from fire s in which the origin was definitely established as electrical. For modern high-speed methods of producing coal, electrically operated machinery has become virtually indispensable underground. With increases in the amount of equipment it has not always been necessary to increase the number of circuits in the mine where direct current is mainly used, but it has been necessary to increase the carrying capacity of these circuits. For example, lends such as heavy-haulage units drawing 1,000 amperes or more have brought boat the introduction of 6/0 and "No. 9 section" trolley wires. This has not made the task of fire prevention any easier, for it has meant that circuit breakers s must be set so high that partial short circuits fail to open them, therefore an arc of considerable proportions can be maintained without causing the, beaker to open. Thus, if as fall of roof brought a trolley wire down against a loaded car of coal, an arc might be struck that would ignite they cowl without opening the circuit breaker.

Jan 1, 1937

By Allan E. Martin, George Glocker, C. E. Wood

"INTRODUCTION As part of a comprehensive investigation of the mechanism of defurization of iron and steel by slags, the Blast Furnace Studies Section, Metallurgical Division, Bureau of Mines, in cooperation with the Institute of Technology, University of Minnesota, has made a study of the forms in which sulfur occurs in blast-furnace slag. This report presents data on the three sulfides most important in iron smelting, namely, ferrous sulfide, manganous sulfide, and calcium sulfide. The tendency of these sulfides to form colloids in the molten slag was determined by an examination of quenched samples with an ultramicroscope.Vogt/ conducted experiments on sulfide silicate melts and examined synthetic blast-furnace slags in a partly crystallized condition. His conclusions were that FeS, CaS, and MnS, or isomorphous compounds, such as (FexCay)S and (MnxCaa)S, were precipitated from the melt, depending on the composition of the slag. In all specimens sulfides were visible and were spherical.Coloration of glass by sulfur also provides indirect information on the nature of sulfur in blast-furnace slags./ There seems to be a general agreement at present among the workers in the field of colored glasses that ferrous sulfide is a strong color producer. Colors that have been attributed to this compound include yellow, orange, brown, blue, and black. Apparently the ferrous sulfide is considered to be dissolved in these glasses. There is no indication that any of them have been examined for a colloidal phase.Lorenz 7/ investigated a single manganese slag in the glassy state and observed a Tyndall beam in an ultramicroscope. His conclusion was that either a manganese compound had precipitated in a finely divided condition or that metallic manganese had volatilized and penetrated into the slag as a vapor and thus formed colloidal particles."

Feb 1, 1941

By Jeffery L. Kohler

This final report on Bureau of Mines Contract J0338028 presents the results of a research effort to predict incipient failure in electric-power-system components. The development of continuous monitoring techniques to detect an incipient failure would represent a significant improvement in system maintainability, availability and safety, This report describes the analytical and experimental aspects of the project. Mathematical models have been developed to study the behavior of cables and motors which are undergoing a deterioration process. These models allow a detailed study of the effect of deterioration on the component's terminal characteristics and performance. The efficacy of using negative-sequence monitoring is a reliable indication of deterioration has been established. Techniques for assessing the sensitivity of the prediction algorithm to component deterioration have been presented. An approach for modelling electrically-excited vibrations, and including these in the algorithm, has been presented.

Jan 1, 1987

By Don] [Hinkle

Unable to Load

Jan 1, 1977

By W. K. Connor, O&apos

The U.S. Bureau of Mines investigated the Sheep Creek prospect in the north-central Alaska Range to evaluate the Pb, Zn, Ag, and Sn resources. The studies included field investigations, mineralogical characterization, and concentration tests. Mineralization at Sheep Creek consists of disseminated, banded, and massive pyrite, sphalerite, and galena. Tin occurs as grains of cassiterite (Sn02) in the quartz-mica matrix and within pyrite and sphalerite grains, and Ag occurs in solid solution within the galena. Three bulk surface samples and two sets of core samples were collected at the Sheep Creek prospect for this study. Gravity concentration yielded products with up to 30 pct Sn, and the best result was a product that recovered 52 pct of the Sn at a grade of 22 pct Sn. Bulk sulfide flotation yielded products that recovered up to 89 pct of the Zn, 73 pct of the Pb, and 75 pct of the Ag, but grades were relatively low; selective flotation would significantly increase the grades.

Jan 1, 1989

By H. W. Wainwright

.1. The purification pilot plant and the equipment, solution, and gas cycle used for removing hydrogen sulfide and carbon dioxide are described. 2. As sulfur recovery is necessary in any large Fischer-Tropsch plant, pilot-plant runs were made at 300 p.s.i.g. to study the efficiency of tri-ethanolamine solutions in removing selectively hydrogen sulfide from gases containing varying amounts of carbon dioxide. 3. Aqueous solutions of TEA of 20, 30; 35, and 50 percent were investi¬gated. Data indicate that 30 to 35 percent is the optimum concentration if both selectivity and economy are considered. Slightly better selectivity is obtained with the.20 percent solution, but steam consumption is greater owing to the higher solution rates. Results from our pilot plant runs indicate that a 50 percent solution not only produces an acid gas of lower hydrogen sulfide content but also requires high solution rates to effect hydrogen sulfide purification. 4. Data from 37 runs using TEA are presented in tabular form. In addition, the data are correlated and presented in three sets of curves. By using these curves, it is possible to calculate the compositions of the purified and acid gases for various raw gas mixtures. 5. In cooperation with the Southern Natural Gas Co., investigations were carried out at 300 p.s.i.g. on the simultaneous removal of hydrogen sulfide and carbon dioxide, from gases using various concentrations of diethanolamine. 6. Data from 17 runs employing 20, 30, and 40 percent DEA are reported in both tabular and graphic form. 7. A comparison of the data from one DEA run made at 200 p.s.i.g. with those from the runs operating at 30O p.s.i.g. shows float the absorption capacity of the solution, and, hence, the steam requirements per gallon are about the sage for both pressures. .The only real advantage of the higher pressure is the additional volume of gas that can be treated. 8. The quantity of steam needed to reactivate fouled TEA and DEA solutions increased as the reactivator pressure was increased about 1,0 to 1.1 pounds of steam was required for each gallon of circulating solution when the reactivator was operated at 5 p.s.i.g. 9. A curve is included that shows the effect of the hydrogen sulfide con-centration in a lean 35 percent TEA solution on the hydrogen sulfide content of the purified gas and on steam consumption for reactivation. 10. Both TEA and DEA reduced the organic sulfur content of the raw synthesis gas considerably. Analyses of the lean amine solutions showed a gradual build up of sulfur compounds, indicating that the compounds formed by the amines and organic sulfur do not break down under the ordinary operating conditions of the reactivator. 11. Considerable operating difficulty was encountered in the pilot plant owing to foaming of the amine solutions. Laboratory experiments in which the effectiveness of certain antifoam agents was studied showed Alkaterge C to be most promising for the particular conditions studied.

Jan 1, 1952

By L. W. Brandt

The Bureau of Mines, as part of its mission to effect pollution abatement, conducted research to study various means of dewatering Florida phosphatic clay wastes and reclaiming mined lands. The work was done in cooperation with 10 Florida phosphate companies. During this work, a novel technique to effectively dewater phosphatic clay wastes was developed. The solids contained in the clay waste slurry are slowly compressed by moving wire mesh screens through the system. In a typical application, the screens were moved downward, compressing solids ahead of the screens. The rate of movement of the screens is an important variable in the process. It is believed that the moving screens distort the gel structure of the phosphatic clay system and cause the release of water. Samples of 18 clay wastes, including a high-grade attapulgite from beneficiation plants of the Florida phosphate field, were studied using the method. Typical samples were concentrated from initial solids of 4.7 and 11.9 percent to 16.8 and 25.2 percent, respectively, in 3-1/2 days. The high-grade attapulgite sample was dewatered from 2.7 percent solids to 13 percent solids in the same period.

Jan 1, 1980

By Terry McMahon

This Bureau of Mines report describes the rock burst problem and measures being taken for its alleviation in the deep underground mines of the Coeur d?Alene Mining District in northern Idaho. The geologic features that contribute to rock bursting in that area are discussed and briefly compared with similar features in other burst-prone mining districts throughout the world. Early investigations to understand and control rock bursting are reviewed, and the mechanics of bursting are discussed in terms of the seismic events that produce them. Sources of strain energy, rock failure mechanisms, and the conditions necessary for the release of seismic energy are covered in detail. Rock burst research in the Coeur d'Alene District is described. Included are discussions of the microseismic method as both a research tool and as a rock burst monitoring system, rock destress blasting and preconditioning methods for rock burst control, and stoping methods currently being developed to reduce rock burst hazards.

Jan 1, 1988

By Kray Luxbacher, Mario Karfakis, Erik Westman, Peter Swanson

Three-dimensional velocity tomograms were generated to image the stress redistribution around an underground coal longwall panel to produce a better understanding of the mechanisms that lead to ground failure, especially rockbursts. Mining-induced microseismic events provided passive sources for the three-dimensional velocity tomography. Surface-mounted geophones monitored microseismic activity for 18 days. Eighteen tomograms were generated and high-velocity regions correlated with high abutment stresses predicted by numerical modeling. Additionally, the high-velocity regions were observed to redistribute as the longwall face retreated, indicating that velocity tomography may be an appropriate technology for monitoring stress redistribution in underground mines.

By Dipak Sengupta

This study analyzes the safety, technology, and economic impact of eliminating safety fuse from metal/nonmetal mines, based on operation and manufacturer experience over the past five to ten years. If safety fuse is eliminated, blasting accidents will decrease with no technical impact except for some limited, specific applications. The economic impact will be minor for large operations, but will be significant enough for small operations that some small operations will likely close rather than change. The majority of the mines would probably change over, with the extra cost absorbed by the market. Elimination of safety fuse would have obvious impact on the two manufacturers of safety fuse; one manufacturer already produces an alternative system, and will remain unaffected; the other will be affected if they do not change their production strategy. There will be a very minor effect on the mining industry as a whole due to abolishment of safety fuse from the standpoint of employment or production.

Jan 1, 1980

By Y. P. Chugh

This is the final report of a study done by IIT Research Institute for the Bureau of Mines to identify the problem areas and technological inadequacies in noncoal (metal, nonmetal, stone, and sand and gravel) mining and processing systems that are the primary causes of death, injury and occupational disease, and to make recommendations to improve safety and health in these operations. The findings and recommendations presented in the report are based on: (1) analyses of MESA injury and employment data for the period 1961-70, MESA fatality reports for underground noncoal mines (1968-72) and lost time accident data for 1970-72 obtained from mining and processing operation: (2) visits to a variety of noncoa1 mines and mills throughout the country to observe the operations and to study the safety organization and practices used in the industry and (3) interviews with industry and government representatives knowledgeable in the field of noncoa1 mining and processing safety and health. The report provides a comprehensive overview of safety and health problems.

Jan 1, 1974