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By Daniel I. Carey

Current and potential dragline reclamation usage was evaluated for the U.S. coalfields based on data gathered and analyzed during field surveys, literature reviews and contacts with manufacturers. It was concluded that current wining plans have been adapted to federal and state strip mine and reclamation laws in ways which limit the potential for drag line reclamation systems at active mine sites. At abandoned conventional contour mine sites in steep-sloping areas such as central Appalachia, however, it was found that dragline reclamation systems have great potential application and may be the only practical solution to many reclamation problems. Alternative dragline systems were examined for restoring abandoned sites, and it was concluded that a tower excavator system offered superior characteristics and should be evaluated and developed under field conditions. A testing program was developed to provide a framework for the monitoring and analysis of cost, production and environmental data during a field demonstration of a tower excavator system.

Jan 1, 1981

By W. R. Gilliland, G. W. Jones

"One-phase of the accident prevention program of the Bureau of Mines is the determination of the explosion hazards of various combustible gases and vapors encountered,mining and allied industries and the development of means and methods of eliminating them.Gasoline is foremost among the combustible-liquid's as to quantity used and variety of applications in industry, It is a chief contributor to the causes of fires and explosions, taking an enormous yearly toll in property damage and considerable loss of lives.The results presented in this report evaluate the effect of various gaseous inert substances, which owing to their chemical composition, should be of considerable value in the prevention of gasoline fires and explosions. The substances investigated are as follows: Nitrogen (N2), automobile exhaust gas (85 percent N2 + 15 percent CO2), carbon dioxide(CO2), dichlorodifluoromethane (CCl2F2-Freon-12), trichloremenofluoromethane (CC13F-Freon-11), and dichloromonofluoromethane (CHCl2F-Freon-21).The general term ""gasoline"" designates a combustible liquid of such characteristics as to give satisfactory operation without preheating in spark-ignition-type internal-combustion engine. It comprises a complex hydrocarbon mixture having a limiting distillation range and produced commercially by distilling or ""cracking"" crude petroleum or other various petroleum stocks. Small proportions of other substances may be incorporated in the gasoline to enhance its antiknock properties or operating characteristics in internal-combustion engines and to increase its stability during storage, transportation, and use.It is thus seen that gasoline may have rather wide variations of chemical and physical properties, and it would: appear that the results of any investigation dealing with one particular gasoline might not be applicable to other types. However, as indicated by the results given in this report, the inflammable properties of different gasolines at normal atmospheric temperatures are influenced largely the mars volatile hydrocarbons containing 5, 6, 7 carbon atoms- in the molecule, and that the heavier constituent of higher molecular weight have a minor influence on the inflammable properties at ordinary temperatures."

Apr 1, 1946

By W. R. Hardwick

This Information Circular describes the development of block-caving methods and practices by the Miami Copper Co. at the Miami mine in Gila County, Arizona. It is one of a series published by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. This report gives a history of the district and outlines early prospecting and exploration including methods of sampling and estimation of ore tonnage and value at the Miami mine. Early mining methods are described, particularly those that influenced developments in the caving method. Mine exploration, development, and operating methods for block caving are described with particular attention to those factors, physical, economic, engineering, and managerial that have improved efficiency in the mining operations over a long productive period. Extraction, ventilation, wage system, safety, water supply, power plant, and shop facilities are discussed. The last section gives a brief summary of such costs as are available for publication.

Jan 1, 1965

By A. C. Smith

The U.S. Bureau of Mines evaluated the effectiveness of automatic water sprinkler systems on the suppression of incipient and propagating conveyor belt fires under ventilated conditions. Large-scale experiments were performed at airflows ranging from 1.1 to 4.6 m/s. In incipient fire experiments with 100°C, standard-response sprinklers installed above and between the belts, the sprinklers activated later, the peak heat release rates were larger, and more belting was consumed at the higher airflow. In similar experiments with 74 °C, fast-response sprinklers, the sprinklers activated at the same heat release rate for both high and low airflows, but the peak heat release rate and amount of belting consumed was slightly higher at the lower airflow. In incipient fire experiments with sprinklers located only above the top belt, the heat release rate and amount of belting consumed was larger at the higher airflow. The propagating fire experiments showed that sprinklers located above and between the belts were effective in stopping flame propagation. Peak heat release rates and amount of belting consumed were larger at the higher airflows for both the 74 °C, fast-response and 100 °C, standard-response sprinklers. The sprinklers were equally effective at each airflow.

Jan 1, 2010

By Charles H. Etheridge

A new filter cassette is described which can be used with Coal Mine Dust Personal Sampler Units (CFR, Title 30, Part 74). The sealed cassette design reduces the chances of sample loss due to reverse flushing, impact or cassette opening. The filter capsule weight is approximately 400 milligrams and is stable for at least one year in storage. The alpha quartz content of the filter element is less than 5 nanograms per square millimeter of surface. The cassette is designed to be used with a new sampling head. The manufacturing costs of the new cassette will require an increase of approximately 30% in the selling price.

Jan 1, 1978

By Merwin H. Howes

In constructing the NORAD Combat Operations Center, controlled blasting techniques were employed to achieve smooth walls and to avoid shattering the rock beyond excavation lines. Extraordinary measures were taken to stabilize the rock to permanently preserve the openings. Rock stabilization was accomplished by means of reinforced concrete and gunite linings, rock boltings, installation of chain-link fabric, and epoxy resin and cement grouting. A particular zone of weakness at a vital location was supported by exceptionally thick reinforced concrete lining, rock bolts, and cement grout.

Jan 1, 1966

By Oliver Bowles

The term" sandstone" is applied to a rock composed of mineral grains smaller than pebbles, cemented together more or less firmly. "Conglomerate" is the name given to a rock composed of pebbles, or pebbles and bowlders, of various sizes cemented together. If the pebbles are large and well rounded the rock is sometimes called " pudding stone." Although the term "sandstone" includes all varieties, certain specific terms are applied to types characterized by particular compositions, colors, or uses. "Quartzite" is a variety in which the individual grains are so firmly cemented together with quartz that the rock will fracture as easily through the grains as through the cement; "ferruginous sandstone" is one rich in iron as cementing material, or as grains, or both; "micaceous sandstone" is one in which mica is prominent; " arkose" is a feldspathic or granitic sandstone composed of angular grains; "calcareous sandstone" is one containing considerable calcium carbonate; and" argillaceous sandstone" is one containing considerable clay. The term "flagstone" is used for a rock that splits readily into sheets suitable for flagging; "freestone" for rock than can be cut or carved readily, and with equal ease in all directions; and" ganistel'," in the United States, for sandstone suitable for the manufacture of refractories. Others are named from their characteristic colors such as " bluestone," " redstone," or " brownstone."

Jan 1, 1917

By Jerry E. Olson

In 1986, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied part of the 20,071-acre South Fork Wilderness Study Area (OR-005-033) and part of the 8,791-acre Sand Hollow Wilderness Study Area (OR-005-034) in order to evaluate their identified mineral resources. The study areas are located in Crook County, OR, about 58 air miles east from Bend. The areas studied are underlain by Tertiary- and Quaternary-age volcanic and tuffaceous sedimentary rocks. No mineral resources were identified in or adjacent to the study area. Except for common opal and agate occurrences along the northern boundary of the study areas, no mines, prospects, or mineralized zones occur within the study areas. Bentonite is periodically mined less than 1 mi southwest of the Sand Hollow study area boundary. Neither of the study areas has geothermal leases, but both areas are under lease for oil and gas.

Jan 1, 1987

By S. M. Marshall

The investigations recorded in this bulletin were conducted by the Pacific Coke & Coal Co. in cooperation with the United States Bureau of Mines and the University of Washington. They cover one phase of a comprehensive investigation to determine whether coals from an extensive, undeveloped area of Pierce County, Wash., can be used in the manufacture of coke for the iron blast furnace. The completed investigation had three parts: (1) A geological survey of the coal property, (2) washing and crushing tests of the coals, and (3) coking and by-product tests. The geological survey, which was not conducted in cooperation with the Bureau of Mines and the University of Washington, included systematic tracing of the coal beds by test holes throughout the property, except some portions covered by an impenetrable layer of glacial drift. By this means all of the beds were correlated, their thickness and general character were determined, and tonnage estimates were made. Only such parts of the survey results as are necessary to a full explanation of the investigations described herein are included in this bulletin.

Jan 1, 1931

By Bill Linville

Producing oil, gas, and coal in sufficient amounts to satisfy U.S. demands for fuels, electrical power, and chemicals promises to be one of the country's major challenges during the 1970's. Adding significantly to this challenge is the urgent task of satisfying soaring fuel and power demands without destroying the natural environment or jeopardizing long-range requirements for resources. The Bureau of Mines, U.S. Department of the Interior, is engaged in a comprehensive program of research to help industry meet this challenge. This report reviews the aims of the research program and accomplishments in 1970; the first 11 sections cover coal programs, nine sect ions are then devoted to petroleum, and the concluding five sections deal with oil shale research. Figure 1 shows the nationwide distribution of Bureau of Mines energy research installations; Full addresses are given in appendix A. Many of the publications resulting from the Bureau?s energy research efforts are discussed throughout the report; others are listed in appendix B.

Jan 1, 1971

The Bureau of Mines has sponsored a comprehensive research program to enhance the safe, effective, and efficient use of blasting technology by the mining industry. Recent research results of the surface mine blasting program were presented at a seminar on April 25, 1987, in Chicago, IL. Many of the topics discussed at the seminar are presented in this proceedings. The new research described in these papers includes computer monitoring of rock motion, the influence of blast delay times on rock fragmentation, blasting effects on Appalachian water wells, blast vibration measurement near structures, and the reduction of accidents through improved blasting safety.

Jan 1, 1987

By D. J. Stoops, H. Kato, M. D. Carver

The effects of impurity elements silicon , aluminum, copper , nitrogen , and manganese , at 50 to 300 ppm, on properties of the zirconium alloy Zircaloy 2 were investigated . Variations in microstructure , mechanical properties , and corrosion behavior in some inorganic acid and salt solutions were observed with variations in level of impurity element . Corrodents were solutions of sulfuric acid , phosphoric acid , copper chloride , and iron chloride . Silicon was found to modify annealed microstructures by spheroidizing and dispersion of secondphase material throughout grains . Silicon or manganese improved ultimate and yield strength of the alloy without loss in ductility . All five elements affected corrosion rates of the alloy , the effect being generally different for each element .

Jan 1, 1964

Papers presented at a U.S. Bureau of Mines (USBM) technology transfer seminar describe the causes of violent material failure in U.S. mines, measurement techniques for monitoring events that result in violent failure, and mitigation techniques for controlling failure. Specific factors contributing to violent failure are identified on the basis of geotechnical monitoring in 16 U.S. hard-rock and coal mines and on statistical analyses of 172 coal bump events. New monitoring and analysis techniques developed as tools for assessing violent failure; geotomographic methods that provide new capabilities for the study of material failure and stress changes over large areas; and seismic methods for determining source locations, calculating energy release, and determining source mechanisms are described. Fair correlations have been established among seismic parameters, elastic stresses, face support load, and violent events. USBM studies have identified the advantages using both yielding and stable pillars for coal bump control. A computer program has been developed as an aid for selecting room-and-pillar layouts. The practical aspects of implementing a destressing program is outlined for coal mines, while the importance of mine orientation and timely support installation in controlling buckling-type failure is identified for hard-rock mines.

Jan 1, 1995

By D. E. Kirby

The electrochemical reduction of AlC13 was investigated as a process for the production of aluminum. An externally heated, single-compartment cell with a rammed refractory lining was used with molten KCl-NaCl-AlC13 electrolyte. Aluminum was deposited qt 700° to 760° C with a current of 100 to 200 amperes on a molten aluminum cathode. Chlorine was evolved at a graphite anode and collected and measured to provide a quantitative evaluation of the AlC13 reduction. Aluminum was removed from the cell by siphoning or ladling. Granular AlC13 was added periodically to replenish that depleted from the electrolyte. Concentrations of 7.5 to 17.5 percent AlC13 in the electrolyte were optimum for operation. Anode current efficiencies of 83 to 85 percent were attained, using anode current densities of 5.9 amperes per square inch and an anode-cathode distance of 4 inches. The chemically bonded, alumina liner was resistant to attack by aluminum and chlorine but susceptible to erosion at the surface of the electrolyte. Titanium diboride proved suitable for the electrical connection to the molten aluminum cathode. Aluminum of a purity equal to or better than 1100 series metal was electrowon continuously from commercial AlC13 for a period of 4-1/2 months.

Jan 1, 1970

By Robert H. Peters

This U.S. Bureau of Mines report identifies the types of serious accidents that occur most frequently at small underground coal mines and describes the strategies that could help prevent these accidents. A wide variety of methods for improving safety are suggested, including improvements in the design of equipment, work procedures, work schedules, safety programs, and emergency response plans, as well as techniques for diagnosing the potential hazards associated with new technologies and work procedures. Some of the papers in this volume focus on preventing specific types of mining accidents--ones associated with materials handling (primarily back injuries), equipment maintenance, improper machine guarding, and ground failure during retreat mining. Although the recommendations in this volume are heavily influenced by research performed at underground coal mines in the Appalachian coalfields, most of the papers contain advice that is equally pertinent to almost any type of mine.

Jan 1, 1994

By Thomas P. Mucho, Thomas M. Barczak, Dennis R. Dolinar

Maintaining ground stability in the gate roads, particularly the tailgate, has always been critical to the success of longwall mining, both in terms of safety and productivity. Several new support technologies have been developed in recent years to replace conventional wood and concrete cribbing for secondary roof support. Since their performance characteristics are unique, the best practices that have been developed with conventional wood cribbing may not be applicable for these alternative support technologies. Therefore, with so many options to consider and the importance of achieving adequate ground control at minimal cost, the trial-and-error approach to longwall gate road support is no longer prudent. This paper discusses a design methodology for standing secondary tailgate supports. This design technique requires in-mine measurements of tailgate support loading and convergence to establish a tailgate ground reaction behavior based on support and strata interaction. The methodology uses the performance characteristics generated in the National Institute of Occupational Safety and Health's (NIOSH) Mine Roof Simulator (MRS) to match the stiffness and load characteristics of various supports to the measured ground reaction behavior. It can be used to determine the appropriate application of alternative roof support systems or to design in-mine trials so that a fair and equitable comparison of different support systems can be made. A case study of the methodology at a western Pennsylvania mine site is presented in the paper, including a comparison of four alternative support technologies to the conventional wood and concrete cribbing historically used at this particular mine.

Jan 10, 2000

The Bureau of Mines conducted large-scale laboratory copper ore leaching tests to enable improving copper recovery from large dump-leaching operations. This was done by comparing leaching progress when copper was recovered from recycled leach liquor either by cementation or by solvent extraction. Copper was leached from 7-ton ore samples at room temperature using pH 2 ferric sulfate solutions. With are samples containing 11 percent minus 0.5-inch fines, no marked advantage in using either of the copper recovery methods was evident after 416 days of leaching. With ore containing 32 percent minus 0.5-inch fines, solvent extraction of copper was advantageous in that 60 percent of the copper was extracted after 568 days, whereas only 48 percent of the copper was extracted when cementation was used. Less acid was consumed during leaching when solvent extraction, rather than cementation, was used for copper recovery. Iron, contributed by cementation with scrap iron, plugged the ore bed containing 32 percent fines.

Jan 1, 1981

By Frank B. Fulkerson

A study was made of scrap iron and steel in the South Central States in order to determine trends in processing, shipment, and consumption if this important commodity. These data were derived in part from statistical sources and in part by visits to scrap yards and steel mills. Trends in the industry were reviewed. Dealers in 1963 supplied 1.8 million tons of iron and steel scrap to steel mills and foundries in the south-central area, compared with 2.1 mill ion tons in 1955. Most of the scrap was processed and shipped within 200 to 300 miles of consuming centers. Exports provide a principal outlet for dealers along the gulf coast. Most of the scrap that fills these orders is loaded onto freight cars at yards in Texas and Louisiana and is shipped to ports for direct transfer from railroad car to ship. The tonnage exported varies greatly from year to year. The largest scrap operations are in or near large cities which are heavy scrap generating areas, steel mill sites, or port cities for export of scrap. A tentative analysis indicates that the short-run supply of prepared scrap is inelastic to price changes; therefore, buyers probably are in a strong bargaining position at times of declining demand. One technological development in the iron and steel scrap industry is the use of large presses which can take complete automobiles with frames, wheels, springs, and other heavy parts still intact and reduce them to bundles. At Houston, Tex., and Kansas City, Mo., shredding plants are in operation that reduce car bodies and other light scrap into flat pieces 4 to 6 inches in size.

Jan 1, 1966

By P. M. Gruzensky

Several experiments have been carried out in efforts to evaluate qualitatively a variety of electrolytes for refining bismuth. Most extensive work was done with the basic tartrate, hydrochloric acid, and hydrofluosilicic acid electrolytes. Deposits that are smooth and adherent can be obtained from these three electrolytes if low cathode current densities are employed. All three electrolytes were effective in purifying crude bismuth considerably, with additional purification indicated in each instance by a reelectrolysis step. With the basic tartrate electrolyte best results were obtained when the electrolyte was at 40° C, and contained at least 100 grams of bismuth per liter, An apparent disadvantage was depletion of bismuth from this electrolyte, causing the deposits to become spongy and nonadherent.

Jan 1, 1956

By G. M. Kintz, Charles B. Carpenter, G. W. Jones

"INTRODUCTION At 9:12 a. m. on April 16, 1947, the ammonium nitrate cargo in hold 4 of the S. S. Grandcamp, a 7,176 gross-ton Liberty ship owned by the French Government, detonated at pier 0 of the Texas City Terminal Railway Co., Texas City, Galveston County, Tex.This detonation was the first of a series of explosions and fires that took the lives of approximately 600 persons, injured 3,000 other persons, and caused a property damage and business loss that will exceed $58,800,000. It has been estimated that the life, accident, and workmen's compensation insurance loss will be $8,200,000.At 1:10 a. m. on April 17, 1947, the ammonium nitrate cargo in hold 5 of the S.S. High Flyer, a 6,214-gross-ton Liberty ship owned and operated by the Lykes Bros. Steamship Co., Inc., detonated at pier L. This explosion materially increased the property damage caused by the first explosion, in between 50 and 100 persons, and is believed to have taken the life of only one person.The exact number of casualties resulting from the Texas City disaster may never be known. On June 22, 1947, 65 days after the explosions, the red Cross and the Texas Department of Public safety repoted:,""Identified dead, 405; unidentified dead, 63; believed missing, 100; injured, 3,000; hospital¬ized, 600; still in hospitals, 37."""

Feb 1, 1948