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By H. R. Appell

The Bureau of Mines studied the conversion of a variety of cellulosic wastes, for example, sawdust, bovine manure, sewage sludge, urban refuse (free of metal and ceramics), etc., to heavy oils. The objective of the investigation was to determine the scope of the reaction and elucidate the chemistry involved. The reactions took place in the presence of synthesis gas and water or carbon monoxide and water under conditions of elevated temperatures and pressures. Waste conversions above 90 pct, often near 99 pct, with oil yields in the range of 40 to 60 pct, were obtained in the temperature range of 250° to 425° C and pressure range of 1,500 to 4,000 psig. Because mild conditions were sought, most of the experiments were conducted at temperatures of 250° to 350° C and pressures of 1,500 to 3,000 psig. In general, lower viscosity products were obtained at higher reaction temperatures. Conversions and oil yields were significantly increased by operating in the presence of a high-boiling oil; either anthracene oil or oil recycled from the process was satisfactory. Synthesis gas containing 50 pct carbon monoxide gave satisfactory results as a replacement for carbon monoxide. Cobalt molybdate on alumina catalyst, used with sodium carbonate, gave a product of lower viscosity and lower oxygen content than sodium carbonate used as the sole catalyst. The waste-to-oil process has been successfully investigated in continuous flow equipment as well as in batch autoclaves.

Jan 1, 1975

By Harry W. Campbell

In 1984 and 1985, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied part of the Meadow Valley Range Wilderness Study Area (NV-050-156) in order to evaluate its identified mineral resources. The study area is located in Clark and Lincoln Counties, NV, about 50 miles northeast of Las Vegas, NV. The Johnston and Fitchett prospect, in the northern part of the study area, has more than 3 million tons of marginal perlite reserves suitable for many commercial uses. A preliminary mining feasibility estimate suggests perlite could be profitably mined from the study area; however, it is unlikely these perlite deposits will be developed in the foreseeable future because of unfavorable market conditions. Zeolite minerals occur in alteration zones adjacent to perlite deposits at the Johnston and Fitchett prospect, but high quality material is closer to potential markets. A metalliferous black shale unit containing 800,000 tons of subeconomic resources may extend into the study area at the Bradshaw vanadium prospect on the northwest boundary. Limestone, stone, sand, and gravel occurrences are wide-spread, but other suitable deposits in the region are more accessible to potential markets. Seven prospects in and near the study area were examined. The entire study area is leased for oil and gas exploration. A group of perlite placer claims covering more than 480 acres was located in the 1940's in the northern part of the study area. A small group of lode claims was located in the mid 1950's in the southwest part of the study area. No mining claims are currently (1985) held inside the study area. No mineral production is known from within the study area.

Jan 1, 1987

By Mark P. Meyer

A mineral investigation of the Chugach National Forest, Alaska was conducted jointly by the U.S. Geological Survey and the U.S. Bureau of Mines from 1979 to 1983 as part of the RARE II program. The U. S. Geological Survey remapped the geology and distribution of mineral resources. The Bureau investigated mines, prospects, and mineral occurrences. Previously unreported mineralization in three areas, Long Bay, Wells Bay, and Miners River were discovered in the western portion of the SOUND study area. Copper, lead, zinc, gold, silver, nickel, cobalt, fluorite, and arsenic were found in north-northeast to north-northwest trending shear zones, veins, felsic dikes, and granitic intrusives in Tertiary Orca Group metasedimentary rocks.

Jan 1, 2011

By F. E. Armstrong

This Bureau of Mines publication reviews 237 papery on radiometric prospecting, which is the measurement of naturally occurring radioactivity in the earth's surface and its application to petroleum and natural gas exploration. Many theories and documented surveys are listed in both support and refutation of this reported phenomenon, and the Bureau of Mines is conducting research to obtain direct field information in order to determine the statistical credibility of a radiometric method of predicting petroleum accumulation.

Jan 1, 1973

By Richard A. Allwes

This U.S. Bureau of Mines report presents the results of structural analyses and full-scale physical tests conducted on a steel-set arch and tri-set. The purpose of the analyses and tests was to evaluate the suitability of these structures for use in roof-fall prone areas. The arch canopy test and design procedures previously developed by the Bureau were utilized in this evaluation. Theoretical resistance functions were established for the steel-set arch and tri-set and were representative of the experimental behavior of the structures. The resistance functions were used to determine the energy absorption capacity of the structures and to predict their dynamic response to impact loading. The dynamic tests demonstrated that the arch canopy design procedure is appropriate for tri-sets and yields conservative designs for both steel-set arches and tri-sets. As a result of this work, it is recommended that these two structures may be considered for use in roof-fall prone areas and for rehabilitation work, provided the arch canopy design procedure is utilized for each application and the principles underlying the design procedure are understood.

Jan 1, 2010

By Edward A. Barrett, Kathleen M. Kowalski-Trakofler

This paper discusses the application of a training intervention that uses degraded images for improving the hazard recognition skills of miners. Method: NIOSH researchers, in an extensive literature review, identified fundamental psychological principles on perception that may be employed to enhance the ability of miners to recognize and respond to hazards in their dangerous work environment. Three studies were conducted to evaluate the effectiveness of the degraded image training intervention. A model of hazard recognition was developed to guide the study. Results: In the first study, miners from Pennsylvania, West Virginia and Alabama, who were taught with the aid of degraded images, scored significantly better on follow—up hazard recognition performance measures than those trained using traditional instructional methodologies. The second and third studies investigated the effectiveness of the training intervention at two mining companies. Data collected over a3—year period showed that lost—time injuries at mines in Alabama and Illinois declined soon after the training intervention was instituted. Impact on Industry: Further exploration of the hazard recognition model and the development of other interventions based on the model could support the validity of the steps in the hazard recognition model.

By L. D. Schmidt

Now that the war is over, there is a great revival in popular demand to decrease pollution of the atmosphere in our cities. Great cities, such as Pittsburgh, are starting to enforce laws against violators of smoke ordinances. The substitution of low-temperature coke for bituminous coal in household heating is a most promising field for helping to eliminate the smoke nuisance. This Information Circular is written to assist in the very worth-while effort to reduce atmospheric pollution. Herein are de- scribed recent German developments in the production of low-temperature coke. Operating and cost data are given on German commercial-scale low- temperature carbonization plants.

Feb 1, 1947

By Dale William Avery

Thirty mines and prospects were studied; 22 are within the Dolus Lakes RARE II area. Three properties within the area and one adjacent to it were determined to have indicated or inferred gold, silver, or molybdenum resources (fig. 1 and table 1) associated with quartz veins and shear zones or quartz-pyrite stockworks in granodiorite. Five other properties in the area and three just outside have potential for the discovery of gold and silver resources. Minor amounts of very fine-grained placer gold are in glacial outwash in and near the area. The John G. Carlisle Mine (fig. 1, no. 9) produced 120 oz (3.7 kg) of gold between 1897-1899. The Independence Mine produced 481 oz (15 kg) gold, 197 oz (6.1 kg) silver, and 189 lb (86 kg) of copper between 1926 and 1935. These mines are adjacent to the study area's northern boundary.

Jan 1, 1983

By J. P. Bennett

Based on previous Bureau of Mines research indicating that improved high-temperature properties could be achieved for periclase refractories through chemical additions, the Bureau investigated the properties of full-size bricks produced from chemically modified periclase refractory grains and the suitability of making such chemical additions to Mg(OH)2 slurries prior to production of the periclase grains. In full-size brick testing, strength values, both hot and cold, for the optimized bricks were superior to those for a commercial 98-wt-pct-MgO refractory. The best results were obtained for a natural magnesite with an adjusted CaO:Si02 (C:S) ratio of 3.0 and a 1.0-wt-pct addition of Zr02 and for a seawater periclase with an adjusted C:S ratio of 2.5 and a 0.5-wt-pct addition of Mn02. For samples produced from chemically modified Mg(OH)2 slurries, additions of both Mn02 and Zr02 and an increase in C:S ratios produced significant increases in hot flexural strength, similar to those resulting from chemical additions made to periclase grains. The most effective modifications were additions of Mn02 to brine-derived periclases having a C:S ratio adjusted to 3.0. These results on chemically modified magnesia refractories indicate that such material could potentially substitute for magnesiachrome refractories containing imported chromite.

Jan 1, 1984

By H. B. Carroll

The performance of commercially available portable instrumentation for detecting nitrogen dioxide, sulfur dioxide, and hydrogen sulfide was evaluated. Length-of-stain detector tubes from several manufacturers were included in the study. The instruments were evaluated in atmospheres with 50-and 80-percent relative humidities at 75° F and containing test gas concentrations of 0.1, 0.25, 0.50, 1.0, 1.5, and 2.0 times the threshold limit values. The results from the gas analyzers were correlated with the known contaminant concentration by calculating and plotting an estimated line of regression, confidence limits, and correlation coefficient for each detector system. An increase in the relative humidity from 50 to 80 percent at /5° F changed the instrument response to the contaminants. The uncertainties in detection precision reported are for the observer-instrument system. The main difference or inconsistency in toxic gas concentrations determined with length-of-stain tubes resulted from the observer's interpretation of the results rather than from a predominant difference in the tubes.

Jan 1, 1975

By Robert P. Apa

Energy Incorporated has prepared this final report presenting the results obtained from the program for extracting alumina from anthracite culm along with the recovery of energy. This work has been accomplished under the auspices of the U.S. Bureau of Mines with technical coordination through the bureau's Reno, Nevada facility. The objective of this program was to develop a process to recover alumina and energy from Northeastern Pennsylvania anthracite mining waste. The program included Identification of sufficient resources to support a commercial facility, identification of the operating parameters which maximize alumina and energy recovery, the development of a conceptual process design, preparation of material and energy balance(s), and the performance of a system economical analysis. The program was conducted in three major phases. In the first phase the program concentrated on selecting several anthracite culm banks capable of supporting a commercial alumina producing facility. The chosen banks were then sampled and analyzed leading to the selection of two banks which were chosen far testing. The Harry E. and Eckley culm banks were the ones selected. Material from these banks was tested in Energy Incorporated?s Idaho Falls, Idaho testing facility. Parametric testing was accomplished in an eight-inch-diameter fluidized bed test facility. The test program consisted of twelve separate tests. After critical operating parameters were determined, the second phase started: process development in EI's 18-inch fluidized bed test facility. Three material and energy balance tests were completed in this facility. Following these tests a 72-hour demonstration test was performed. The data acquired from these tests were used in the last phase: the process conceptual design and economic analysis. The design basis was a commercial scale facility capable of producing 500,000 tons of alumina per year for 15 years. Based on the test program, It is technically feasible to build and operate such a plant today. The facility would produce, along with the alumina, 81.5 MWe of electricity for outside consumption. A preliminary rate of return indicates that the plant is not feasible with today's economic conditions. An increase in the market price of either the alumina or the electricity is required to provide an attractive rate of return for the facility.

Jan 1, 1982

By William H. Lesser

A recent survey of pumping plants in the anthracite region of Pennsyl¬vania showed that more than 90 percent of the pumps in use are the horizontal centrifugal types (1).2/ This report on the design and operation of centrifugal pumps should be helpful to engineers of the region who must select pumps that are best suited to particular pumping conditions in anthracite mines. Before a centrifugal mine pumping plant is designed, the special features of the pumps that may be used should be considered, especially when low repair costs and continuous operation during flood periods are prerequisites, and when acid mine water is to be pumped. Two important advantages of a centrifugal pump are that the flow is continuous and that it can be throttled without developing excessive pressure or overloading its driving unit.

Jan 1, 1950

By L. C. IlsLey

[In 1922 a conference of representative coal-mine operators, cable manufacturers, mining-machine manufacturers, and representatives of the United States Bur eau of Mines vas held at the Pittsburgh Experiment Station, regarding suitable cables for use with permissible raining machines. This conference recommended that the Bureau investigate rubber-sheathed trailing cables in order to obtain specifications for tests leading to approval for rise with mining machines. Effective until such time as an investigation could be made, the bureau asked the several manufacturers of approved mining machines to recommend cables for wise with their machines. In general the Cables recommended tentatively approved. Arrangements for the tests were completed in 1927. Concentric-type cables were investigated first, and Reports of Investigations, Serial No. 2909, covering the tests, was issued in January, 1929.]

Jan 1, 1929

By G. Andrews

This case study details the process that was used for project planning and permitting for the Greens Creek Mine, located near Juneau Alaska, as seen through the eyes of one of the primary environmental consultants. This case shows how a Company could involve the public and the agencies in the early 1980's and develop a project sensitive to concerns expressed with a high level of environmental protection. Comparisons are made to the current environmental permitting situation. Initial baseline studies performed during the exploration phase provided helpful information for more detailed environmental work in 1980-1981 as planning and permitting formally got underway. Since the mine was in a National Monument and abuts up to a designated wilderness, the Monument Manager administered the project for the lead agency, the USDA Forest Service. Planning and permitting progressed smoothly to a Final Environmental Impact Statement (FEIS) in 1983. Metal prices were depressed when the FEIS was completed and the project permitting proceeded slowly. Ownership changed several times in the mid-1980's. New owners re-evaluated the project and suggested five changes that required a supplemental EA prior to development. The project was fully permitted and started construction in 1988. Operation began in 1989. Today the environmental process in southeast Alaska is now much more complex, detailed, expensive, and time consuming than in the early 1980's. Significant issues discussed that may impede development and operation include overlapping agency jurisdictions, personal agendas of agency staff, conflicts between agencies that impede project progress, changing regulations, and a well organized environmental opposition.

Jan 1, 1993

By C. A. Rhoades

The spillage that accumulates under conveyor belt lines presents a possible fire and explosion hazard fomiinqjetsoruiel, especially to those who must clean up the spillage. The U.S. Bureau of Mines conducted research to reduce this hazard by identifying and investigating the parameters affecting the efficiency of conveyor belt cleaning. The amount of material carried back under the conveyor and the wear rates of metal cleaning blades decreased with increasing blade-to-belt pressure to a limiting value, after which the carryback and wear rates remained essentially constant. The optimum blade-to-belt pressure was found to be 11 to 14 psi for the research conveyor system. Greater pressures increased the blade-belt friction without improving either cleaning or blade life. The modes of blade wear were three-body abrasion and slurry erosion caused by the sand-lime test mixture. Wear rates were reduced by increasing the metal hardness, opti-mizing the pressure, and removing conveyor belt imperfections. Corrosion was not observed to affect the wear of various steels in tests of less than 34 h. The results of this study should allow mine operators to run their conveyors under conditions that will maximize cleaning and minimize equipment wear.

Jan 1, 1989

By R. J. Leary

Oxidation testing of copper-clad steel strip was performed in a muffle furnace to determine whether copper in contact with steel scrap could be removed by oxidation in an airstream at high temperatures. Substantially all of the copper was oxidized before any significant iron oxidation occurred. The rate of copper oxidation was not affected by contact with iron. Copper oxide scale separated spontaneously from the underlying metal during cooling. Results indicate the possibility of removing light-gage copper coatings and components from ferrous scrap by oxidation in an incineration process.

Jan 1, 1965

By Mark K. Larson

A constitutive model for rock interfaces based on the principles of static fatigue is proposed. The model is applicable to weak rock or joints with cohesion. Friction and dilation are decreased as plastic work increases. At equilibrium, the creep time increases by one time-step interval, and interface cohesion at each node decreases according to a power function. A constant-load, direct-shear simulation showed that the model is cap- able of mimicking constant-rate and tertiary creep and predicting failure. Tests on core from a coal mine showed constant-rate and, sometimes, tertiary creep, but also weak transitory creep. The cohesion deterioration function may need modification to simulate primary-phase creep. If model parameters are known for a site, the model can predict the onset of tertiary creep and failure. Such predictions can help engineers make better entry design and support decisions, which will reduce the likelihood of roof falls and increase safety for underground miners.

By H. D. Kline

This paper describes the methods of mining and washing brown iron are in 1957 at the Sawyer mine, leased by Wayne County Mining Co., and the Fore mine, leased by Four Mining Co., both in southern Missouri; it is one of a series prepared by the Federal Bureau of Mines on mining and milling methods and costs in various districts of the United States. The Sawyer mine is in Wayne County, about 10 miles north-northeast of Williamsville (fig. 1); the Fore mine is in Howell County, about 20 miles southwest of West Plains (fig. 2). Both are open-pit mines from which the crude are was upgraded by washing and hand-sorting to produce are of grade and quality suitable for sale to operators of iron and steel furnaces. The operations described are typical of many others that produce or have produced marketable brown iron are from small sedimentary deposits, several hundred of which outcrop on the crests or hill sides of southern Missouri (fig. 3). The 1957 production of marketable brown iron are by 40 separate operations in the southern part of the State was 281,427 wet long tons, valued at $1,637,243. Production from the Sawyer mine that year was 17,000 dry long tons of washed are, and from the Fore mine, 20,816 dry long tons.

Jan 1, 1960

By K. K. Kershner

The purpose of this investigation was to develop methods, on a laboratory scale, for recovering tin from Bolivian metallurgical slimes. Petrographic and chemical analyses were made of slime ore fractions from several well-known tin operations. High percentages of the total tin were volatilized as chlorides at temperatures below 600° C. Under optimum conditions reaction rates were relatively rapid, and the chloridizing reaction approached completion. Owing to the low temperatures involved and the high yields of tin, the process was considered to have possibilities for treating Bolivian slimes on a commercial basis. ACKNOWLEDGMENTS Appreciation is hereby extended to the Patino Mines and Enterprises, Inc., of Bolivia, for supplying slimed tin ores that were used in the experimental work. This company has since been nationalized.

Jan 1, 1959

By J. C. Dumbrille

The following account of wining practices of the Kirkland Late Gold twining Co., (Ltd.), at Kirkland Lake, Ontario, is one of 4 series of papers being prepared by the United States Bureau of Mines on mining practices, methods, sad costs in various districts. The author has prepared this paper with the help and permission of J. B. Tyrrell and W. M. Sixt, the managing director and the mine manager, respectively. This mine is operating at a daily rate of about 150 tons.

Jan 1, 1931