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By Arthur Matzick

The oil shale from the Mahogany zone of the Green River formation in northwestern Colorado has the greatest potential in the United States for early utilization. A large reserve of adequately rich shale is available to support a sizable industry, and crushing of tremendous tonnages will be required if conventional processing methods are used. This report presents Bureau of Mines data on crushing experiments, physical properties, and related information for Colorado oil shale. Among the properties important to crushing are slab-forming tendency, resilience, slippery character of the richer grades, and heterogeneous nature of an average charge of Colorado oil shale.

Jan 1, 1960

By D. A. Paice

A power supply to operate fluorescent or mercury vapor lamps from 300 volt dc coal mine trolley wires has been developed for the Bureau of Mines. A high frequency regulated inverter unit incorporates ballasts for a mix of lamp loads up to 650 watts. For 600 volt trolley systems an additional power converter unit was developed to step down the dc voltage to 300 volts for the inverter unit. Both units have operated in a working coal mine for over 12 months without need for servicing. The lamp load in these tests included two 100 watt mercury vapor head lamps and six 75 watt fluorescent lamps.

Jan 1, 1979

By Allen D. Look, Alan A. Sharp

"INTRODUCTION The bottoming of the United Verde sulfide pipe has shortened the expected life of the United Verde mine to a matter of a few years. First located in 1876, this Arizona mine has had a long period of activity, having reached a peak production in 1929 of over 71,000 trans of copper. Through these many years of successful operation, a safety program has evolved in keeping with the proficiency developed in mining the ore body. It is the purpose of this paper to record the safety practices in effect at this mine so that others may have the benefit of lessons ,learned through experience 'and years of work toward an improved accident record.ACKNOWLEDGEMENTSAcknowledgment 'is 'made to ,the Phelps Dodge Corp. for its cooperation in making available data contained in this paper, and to C. E. Mills, general superintendent; W. W. Little, mine superintendent; John Riordan, employment agent; and G. S. Leisk, safety engineer, for their helpful suggestions and information furnished.GENERAL INFORMATIONThe United Verde copper mine is situated just west of Jerome, Ariz., at an altitude of approximately 5,500 feet. Purchased by the Phelps Dodge Corp. in 1935, the mine employs approximately 500 men - 385 underground and 115 on the surface."

May 1, 1949

By James P. McGee

Use of nuclear reactors to furnish high-temperature heat is a field that has not received as much attention as propulsion and electric power production. Investigations are being conducted under a joint Atomic Energy Commission (AEC)--Bureau of Mines research program to determine the feasibility of using nuclear heat for chemical processing. A part of this process-heat-reactor program is the study of a system in [hich] helium transfers heat from 8 nuclear reactor to a chemical processing [essel]. This requires construction of (1) a nuclear reactor to operate with helium exit temperature of 2,500° F. and with pressures in the range of 250 to 500 p.s.i.g. and (2) a processing vessel (heat exchanger) to convert the enthalpy of the helium into chemical process reaction heat. Neither component exists at present, and development of each promises to be a formidable task. To aid in the study of such a system, the Bureau of Mines has designed and constructed a vessel heated by electrical induction to simulate a source of nuclear fission heat. This vessel is undergoing preliminary testing. Gasification of coal and reforming of hydrocarbons are promising uses for nuclear heat. It appears that a higher price per unit of nuclear heat can be tolerated for chemical processing than that allowable for power generation.

Jan 1, 1960

By August J. Kwitowski

This report presents the results of a joint Bureau of Mines-U.S. Department of Energy project that evaluated a newly developed low-coal mining system: the 4M miniminer system. The evaluation took place from April through October 1981 and determined potential health, safety, and productivity factors for the mining system using the surface test facilities at Bruceton, PA. The planning, testing, results of testing, and a summary evaluation of the 4M miniminer system are included in the report. The miniminer system was found to be a very good concept with future potential for safe, healthful, and economic production in thin-seam mining. The mining system was also judged to have considerable potential for use in some coal seams that are presently considered unminable by other existing mining equipment. The preproduction, prototype version of the miniminer system that was tested suffered from several safety and production problems. These problems are also described, along with suggested remedies.

Jan 1, 1989

By W. H. Young

PRODUCTION of bituminous coal and lignite increased substantially in 1964. There were upward trends also in consumption, average value, exports, mechanization, and productivity. However, a significant decline in employment continued. Production.-The output of bituminous coal and lignite in the United States in 1964-487 million tons-was 6 percent greater than the 459 million tons produced in 1963. The gain was attributed largely to expanded consumption by the electric utilities, greater use at coke ovens, and an increase in exports.

Jan 1, 1965

By Richard Lusignea

A single boom roof bolting machine was outfitted with measurement and recording systems for detecting changes in machine parameters while drilling. The purpose of this instrumented bolter or "smart drill" is to detect changes in roof conditions from the machine parameters of penetration rate, thrust, rotation rate, torque, rejected light from rock cuttings, and vibration of the roof during drilling. The system was demonstrated underground in coal mine conditions and showed correlation between rock type and drilling parameters.

Jan 1, 1982

By Ernest E. Berger

"INTRODUCTIONOne of the outstanding problems in the normetallic industries, and one which involves two of the greatest of these industries, cement and gypsum, is the reaction of Portland cement with calcium sulphate. To all Portland cement clinker there is added in the manufacturing process, a small amount of retarder, as a necessary ingredient of the finished product. This retards the initial set, increases the strength, and adds to the plasticity of the cement so it will have the desired working and setting qualities. The retarder commonly used is gypsum, (CaSOA.2HO), which is the hydrous form calcium sulphate. Calcium sulphate is also available as plaster of Paris (CaSO4 1/2 HC) and anhydrite (CaSO4). The purpose of this inquiry was to determine the form or mixture of forms best adapted for retarder. The problem is complicated by the fact that cement clinker is a complex mixture of calcium silicates and aluminates, and that clinker from different mills, making cement of approximately equal quality, differs considerably in chemical constitution. Thus the same retarder may give very different results with different types of clinker, especially in the percentage of retarder required for the same degree of retardation.It has been known for some time that a small percentage of plaster of Paris will greatly retard the time of set of Portland cement as well as increase its strength and plasticity, but whether gypsum and anhydrite will have a similar effect is as such disputed question. The offects of gypsum have received little consideration in laboratory research because, even though it will not retard a clinker when the two are mixed in the laboratory, as has been noted in some instances, the cement will have a normal set when the two arc mixed in the large tube mill at the plant, so that practically, gypsum seems to be equally as goou as plaster of Paris, and because of the great saving in cost it has been used almost exclusively."

Sep 1, 1925

By J. Robert Wells

The Bureau of Mines has developed a spectrochemical procedure for determining 19 impurity elements in high-purity titanium metal, titanium oxides, and titanium halides in which all samples are converted to titanium dioxide. Determination of these impurities was studied in the general concentration range of 0 to 1,000 p.p.m., but different determination limits were found for the various elements. The procedure is quantitative for 18 elements but semi-quantitative3 for beryllium and has an overall relative standard deviation of 15.8 percent. Two mixtures were used, one composed of graphite and lithium carbonate plus gallium oxide and the other of graphite and lithium carbonate plus germanium dioxide. Each mixture was blended mechanically with an equal weight of titanium dioxide. Lithium carbonate served as buffer-diluent. Gallium was the internal standard for 1 impurity element, germanium for 7, and titanium for the remaining 11.

Jan 1, 1962

By W. J. Wenger

Colorado has been producing petroleum since 1863 but only recently has become a major oil State. The first well was drilled on Oil Creek near Florence, but out-put was relatively small until discovery and development of the Weber sandstone reservoir at Rangely. Oil was discovered in the Weber sandstone in 1933, and the reservoir was developed after 1940, bringing Colorado, in 1949, to 11th place among the 48 States as an oil producer. Colorado's output increased further because of the discovery and development of many fields in the Julesburg Basin since 1949 By 1954 Colorado was in ninth place and maintained that position through 1955.4/ Between 1946 and 1951, Colorado's oil production more than doubled, while the total United States production increased only 25 percent. It seems probable that production will continue to expand in Colorado for many years. This report presents analyses of 92 crude oils from 73 fields representing 90 percent of the production in 1955. Abridged analyses are listed for easy comparision, and complete analyses arc given in the appendix. Oil samples were collected for study from many different sources. Although many of the newer fields were not sampled, their oils probably are very similar to those from corresponding formations that were studied and tabulated.

Jan 1, 1957

By Nancy Estrada, Jane Nowell, Cathy Jennings, Debra Yniguez, Carol Lavery, Kristin Harrer

Pilots of the MH-60S helicopter are exposed to continuous whole body vibration (WBV). Pilot fatigue is a growing operational concern due to the increased frequency of extended durations of missions (6-8+hours) in support of Operations Iraqi Freedom and Enduring Freedom. Endurance aspects of the currently used rotary wing seating systems were not optimized for the longer missions and wide range of pilot anthropometric measurements, which is now typical of naval aviation. The current seating systems were designed primarily to meet crashworthiness requirements, not for the wide range of pilot anthropometry or to mitigate WBV. Albeit, an issue, pilot fatigue and reduced mission effectiveness are also critical concerns. Current Hazard Reports indicated that pain in pilots’ legs and backs begin two to four hours into the flight and increase with time. Mission readiness also decreases with an increase in flight duration due to the constant distraction of pilots shifting in their seats while trying to get comfortable. Froom, et al [2] reported a dose-response relationship between the length of military helicopter flights and back discomfort. He also concluded that this pain is typically dull, over the lower back, and its prevalence and intensity are dependent on the total flight hours of exposure. Methods This study evaluated WBV produced in the pilot seating systems onboard the MH-60S. The purpose of the study was to test and compare the effectiveness of two different seat cushions, the current seat cushion versus an anti-vibration seat cushion. Both seat cushions were measured for acceleration levels averaged over five-minute intervals using a triaxial seat pad accelerometer. The recordings were completed for a 3-hour straight and level flight. A frequency analysis from 0-80 hertz (Hz) was conducted on all acceleration measurements to determine the dominant axis and frequency of the pilots’ vibration exposure. The results were then compared to the applicable Threshold Limit Values (TLVs) established by the American Conference of Governmental Industrial Hygienists (ACGIH) [1] and the International Organization for Standardization (ISO) 2631.1 [3] to determine the MH-60S pilots’ permissible exposure time for both seat cushions. Results The results of the study showed that for both seat cushions the vibration levels of the z-axis at 16 Hz had the shortest allowable exposure duration, according to the ACGIH TLVs. In the z-axis at 16 Hz, the MH-60S’s current seat cushion’s acceleration levels indicated an exposure time limit of approximately 6 hours, while the anti-vibration seat cushion’s acceleration levels pierced the 8-hour exposure time limit curve. This is shown in the graph below.

Jan 6, 2006

By J. M. Stuve

Low-temperature heat capacities and the enthalpy of formation were deter-mined calorimetrically by the Bureau of Mines for CuO?CuS04. The derived standard entropy (S°298.15) was 40.36±0.04 cal/deg-mole, and the enthalpy of formation (?H°f) was -219.l±0.3 kcal/g-mole. A large thermal anomaly was observed in the heat capacity of CuO?CuS04 at 20±0.1 K. Gibbs energy of formation data are tabulated up to 1,200 K. Construction details of a precision low-temperature adiabatic calorimeter capable of determining heat capacities of solids in the temperature range 5 to 320 K are given. A calibrated miniature germanium resistance thermometer was incorporated into the calorimeter to extend the range of accurate measurements below 15 K. High-resistance dc heater windings were used throughout the cryostat to reduce heat conduction of inner connecting wires.

Jan 1, 1975

By Richard L. Sanford

This report summarizes the results of the development of a Directory of Computer Programs Applicable to U.S. Mining Practices and Problems. The Directory includes a sampling of computer usage in operating and manufacturing companies, consulting firms, computer companies, research organizations, universities, and various U.S. government agencies. References to computer applications throughout the mining industry are presented as well as comments on the availability of programs to interested organizations or individuals.

Jan 1, 1977

Approximately half of all the fuel energy used in the United States is now pro-vided by oil and natural gas. A persistent and rapid growth in energy demand during the last 3 decades has been absorbed largely by the liquid and gaseous rather than solid fuels. In 1948 the energy provided by coal was substantially the same as in 1920. Meanwhile, the use of oil and natural gas each had increased fivefold. On a per capita basis, the change is more significant. Coal consumption has dropped from about 6 tons per person to 4-1/2 tons, while oil has increased from 4-1/3 barrels to 14-1/3, and natural gas from 7,500 cubic feet to about 35,000. These facts would have only academic interest if the United States had unlimited supplies of all fuels. However, while the Nation's reserves of coal are adequate to meet our needs for centuries, those of oil and natural gas appear limited. It is obvious, therefore, that the security of our liquid-fuel position would be greatly enhanced if the supply could be based in an increasing degree on solid fuels, such as coal/and oil shale, which make up more than 95 percent of our fuel reserves, instead of natural oil and gas. In addition, this would create new employment and help to stabilize the market for coal, which may be facing comparatively bleak prospects in the near future unless its position with respect to other fuels is improved.

Jan 1, 1950

By O. M. Bishop

"SUMMARYAs a result of the increased demand for fluorspar during the war, the Bureau of Mines investigated numerous fluorspar properties in the southern Illinois field, which is centered in Rosiclare. Among these the J. J. Shelby 40-acre tract on the western edge of the district presented favorable factors that caused it to be chosen /or exploration.H. G. Spiller, formen lessee of the property, had explored the Shelby vein by means of an adit level and winze, and showed it to contain goad values in zinc and fluorspar at the depth explored. A diamond-drill hole with which Spiller explored the vein 78 feet southwest of the winze, however, failed to cut ore. After studying the field evidence, the Bureau concluded that the vein merited further exploration, particularly at a depth of about 440 feet, where the Fredonia limestone would form the foot-wall of the vein and the hanging wall would be the competent Cypress sandstone.Between October 17, 1944, and March 26, 1945, three diamond-drill holes were bored for a total inclined depth of 1,592 feet. Holes 1 and spaced approximately 500 feet apart, explored the vein at 440 feet 4 below the surface. The economic mineralization existed in the vein where cut. Hole 3 cut the fault at approximately 300 feet below the outcrop but failed to find any vein matter except stringers of calcite with small amounts of pyrite."

Apr 1, 1947

By John M. Devine

The severe corrosion of equipment that is caused by the presence of hydrogen sulphide in oil and gas has been described in detail by several authors. Such corrosion, termed "low-temperature hydrogen sulphide corrosion", presents a somewhat different problem from the "high-temperature hydrogen sulphide corrosion" that is encountered in refinery operation and which has been described by various-investigators of refinery corrosion.

Jan 1, 1932

By R. V. Ramani

The overall objective of this study is to contribute to the reduction of the quartz dust hazard in underground coal mines through a better under-standing of the sources and generation of airborne quartz dust. This research project has included extensive experiments in operating mines for (1) documenting the amount of respirable dust generated, (2) measuring the quartz levels in host materials and airborne dust, (3) analyzing the size consist of the mined product, and (4) establishing the relationship between these various parameters. The results of the study indicate that the amount of dust airborne is a very small fraction of the total (<15 µm) and respirable (<7 µm) dust generated. The quartz contents in the total and respirable airborne dust are generally higher than those in the host material. Quartz content increases with decreasing size of airborne dust. Also, it appears that rock breaks into a different size distribution than coal. The source of quartz for the airborne dust appears to be the roof and the floor material rather than the coal seam itself. No general relationship is found between the Hardgrove Grindability Index and either the quartz content in the airborne dust or the amount of respirable dust. Extended descriptions of the experimental design, the experiments, data analyses and results are presented in this volume. The raw data, the data management computer program and the sampling and safety plan are presented in Volume 2.

Jan 1, 1987

By Michael T. Nigbor

This Bureau of Mines publication identifies the significant environmental issues associated with the potential development of strategic and critical minerals in the Stillwater Complex, MT. The Stillwater Complex contains deposits of Cr, platinum-group metals (PGM), and Ni. Issues that must be addressed prior to minerals development include the effects mining, milling, and smelting will have on the land, water, and air, and methods of minimizing the environmental impacts.

Jan 1, 1985

By Mark L. Chatman

This report presents an economic mineral assessment and Inventory of mines and prospects In the approximately 176,000-acre Patagonia Mountains-Canelo Hills Unit of Coronado National Forest. Deposits or areas most likely to experience future development are characterized in terms of their economics, based on data acquired by the author from a variety of sources, and supplemented by USBM field data collected by other workers in 1990 and 1991. Numerous mine maps, rock-chip sample assays, and detailed descriptions of mine and prospect sites are in this report and appendixes. Heavy but sporadic mining, mainly between the 1850&apos;s and 1950&apos;s was nearly all confined to the Patagonia Mountains. High-grade sulfide veins, replacements, and skarn deposits accounted for most of the production, which included large quantities of zinc, lead, copper, and silver, and considerable quantities of gold. Small Quantities of molybdenum, manganese, tungsten, and placer gold have been mined. Most of the traditionally mined metalliferous sites will not see future activity due to the low tonnages present and removal of most high-grade rock. Possible future development areas include copper porphyries and breccia pipes; most are too deeply buried for current development. Localities where similar deposits may be concealed are identified.

Jan 1, 1994

This list is part of the long-range conservation program of the Bureau of Mines and is intended for use by those interested in the Bureau&apos;s publications dealing with oil shale and shale oil. The items included represent 51 years of research by Bureau of Mines employees on oil shale and shale oil and are available at any U.S. depository library. DISTRIBUTION U.S. Bureau of Mines report series contain both free and sales publications. An asterisk (*) designates publications for sale. Such publications can be obtained from Superintendent of Documents U.S. Government Printing Office Washington, D.C. 20402

Jan 1, 1969