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By Mah Alla D.

Previously existing heat-of-formation values for the oxides of vanadium were rudimentary. They were subject to uncertainties of 1 to 5 kilocalories per gram-atom of contained oxygen. This fact has been the only adverse influence on the accuracy of thermodynamic calculations involving these substances, as the requisite entropy and high-temperature heat-content data are known with reasonable accuracy. This report presents new heat-of-formation data for four oxides of vanadium (VO, V203, V02, and V205), obtained by combustion calorimetry. It is believed that the uncertainties have been reduced to 0.1 to 0.3 kilocalorie per gram-atom of contained oxygen. The new heat-of-formation data were combined with existing entropy and high-temperature heat-content values to obtain free energies of formation of the four oxides at temperatures up to 2,000° K.

Jan 1, 1961

By D. E. Wolfson

This report presents 900° C BM-AGA carbonization and related data for coals from the principal beds of Nicholas, Randolph, and Webster Counties, W. Va. Thirty-three samples from nine coal beds in three counties were car-bonized at 900° C in the l8-inch-diameter BM-AGA retort, data from which have been correlated with industrial production. Host of the samples were chemically suitable for metallurgical use, and their coking properties were satisfactory. Except for four of the Lower Kit-tanning samples, the ranges of constituents in the coal seams were 1.8 to 9.0 percent ash and 0.4 to 1.1 percent sulfur, values within the range of accept-ability for metallurgical coals. Coke strength indexes were normal for Appalachian coals of similar rank, and the tumbler stability indexes of the coke ranged from 35 to 57.

Jan 1, 1969

The results of a Feasibility and Design Study of Surface Impregnation Equipment to be used for Chemical Stabilization of Coal Mine Structures are described in this report. The study was sponsored by the United States Department of the Interior, Bureau of Mines, under Contract H0210055. This program was undertaken as an essential part of the Bureau of Mines Chemical Ground Stabilization Program. The responsible prime contractor was The Eimco Tunneling and Mining Machinery Division of the Envirotech Corporation. The Rocketdyne Division of the North American Rockwell Corporation performed part of the feasibility study and design and testing of the metering and feed system as a subcontractor to Eimco.

Jan 1, 1972

By Russell R. Trengove

The Strawberry tungsten mine is in the Jackass Mining District, in an isolated portion of eastern Madera County, near the southeast corner of the Yosemite National Park. The deposit was discovered in 1941, and production started in 1943 when the mill was completed. With the exception of 1946 and 1947, production has been continuous. The area in the vicinity of the mine is granite containing islands of sedimentary beds highly altered by metamorphism that resulted from the intrusion of acid igneous rock. Schoelite occurs in almost vertical lenses of tactite between the limestone and the granite.

Jan 1, 1949

By A. B. Clayton

The Bumpus Cove area is in Unicoi County, Tenn., about 9 miles south of Jonesboro and 5 miles northwest of Erwin. Iron and lead ores were mined in the Bumpus Cove area before the American Revolution. The production of those metals continued intermittently until 1916. In 1850 this area was the most important producer of iron in the South. In 1911 several carloads of zinc ore was recovered from old dumps and shipped to Missouri smelters. In 1913 systematic mining of zinc ores was begun and continued until 1916. After that year, mining again became sporadic and continued so until discontinued in 1943.

Jan 1, 1949

By J. E. Pahlman

Spontaneous oxidation and combustion of sulfides and resultant fires are serious problems in underground mines. The Bureau of Mines has con-ducted fundamental thermal gravimetric analysis (TGA) research to deter-mine the mechanisms and factors governing the rate of low-temperature pyrite oxidation, and to identify possible inhibitors to spontaneous oxidation and combustion. The mechanism of low-temperature pyrite oxidation was found to be topochemical, meaning that the oxidation process is controlled by the chemical reaction at the interface between pyrite (FeS2) and iron sulfate (FeS04)' An activation energy of 8.9 kcal/mol FeS2 was obtained for oxidation of minus 500-mesh pyrite in an atmosphere of 60 vol pct water vapor and 40 vol pct . Water-vapor content of the atmosphere was found to be the critical factor in the rate of spontaneous oxidation of pyrite, with a water-vapor content greater than 20 vol pct needed for accelerated oxidation. An atmosphere of pure oxygen resulted in negligible oxidation. The rate of pyrite oxidation is also greatly affected by the particle size of pyrite. Pyrite-oxidation rate increased drastically for particles less than 40 ~m. Room-temperature pyrophoric behavior was observed for freshly ground unoxidized pyrite (55 pct minus 5 ~m) upon exposure to air. Addition of water-adsorbing materials such as activated alumina (Alz03) decreased the rate of pyrite oxidation.

Jan 1, 1986

By Richard W. Lewis, Lloyd Carpenter

The objective of the investigation was to determine spectrochemically 19 elements in the general range of 0.5 to 1,000 ppm in high - purity hafnium and its compounds . Samples were converted thermally to hafnium dioxide , mixed with buffer - carrier - internal standards , and excited by a dc arc . Spectra were recorded on photographic plates . Transmittance values were recorded densitometrically and converted to relative - intensity ratios . Four groups of standards were used to establish analytical curves from which the concentrations of impurities were obtained . Average precision of the method was 14.2 percent relative standard deviation , and relative error was 4.2 percent .

Jan 1, 1964

By G. St John Perrott

"The United States Bureau of Mines is cooperating with the State of Utah and the City of Salt Lake in an investigation of methods of abating the smoke nuisance in Salt Lake City. In the course of this work samples of the atmosphere have been collected and analyzed in an attempt to determine the part played by sulphur dioxide or smelter gases in polluting the air at Salt Lake City.A fairly wide-spread opinion exists in Salt Lake City that the smelters contribute appreciably to the smoke nuisance. The gases discharged from the smelter stacks are believed (1) to float over the city in a heavy blanket which prevents the smoke from rising, and (2) to unite with the water vapor in the air to form corrosive fogs injurious to health and property.The first of these theories seems untenable. If the gas did not mix with air it would sink, owing to its heavier specific gravity, and form a blanket an the earth. Actually, the gas diffuses rapidly in air and any part reaching Salt Take must he thoroughly diluted. Perhaps sulphur dioxide in sufficient concentration might aid in fog formation. The more obvious nuisance, however, would be the injury to health and vegetation.The Garfield smelter is 16 miles west of the city, The Murray smelter 8 miles south, and the Midvale smelter 12 miles south. Under normal operating conditions, a relatively small amount of solid matter is discharged from these stacks. The toxic gaseous constituent of the discharge is sulphur dioxide, it is being discharged from the smelters the year round. If they are a factor in the city's smoke problem, the concentration of this gas in the air of the city should be appreciable and should increase toward the smelters, the con centration being highest with a south or a west wind."

May 1, 1920

By Martin J. Gavin

The oil- shale studies of the Bureau of Mines , conducted in cooperation with the State of Colorado and the University of Utah , have for their primary purpose the determination of retorting and refining conditions most favorable for obtaining the highest yields of most satisfactory products . Oil shales , typical of the deposits in several States , are retorted in carefully controlled retorts of differe types , the conditions being varied in successive runs as the results indicate that improvement in the yield and quality of the products most desired may be expected . Each shale presents a somewhat different problem , for it has been found that different shales treated under similar conditions yield products of different natures , and also that the same shale will yield products of different natures when retorted under different conditions . Some shales apparently can not be made to yield , under any set of conditions , products of so high an order as are yielded by other shales . This indicates that the oil -yielding materials of certain shales differ in constitution and in their manner of breaking down when undergoing destructive distillation . Other shales appear to contain oil - yielding materials that resemble each other closely as regards chemical constitution , yet they require some. what different conditions of treatment , if products of similar nature are to be produced from each . In such cases the controlling factors seem to be the richness of the shale that is , its content of oil -yielding material and the physical and chemical nature of its mineral parts .

Mar 1, 1922

By N. S. Dalal, X. Shi, V. Vallyathan

"Electron spin resonance (ESR) and cytotoxicity measurements were made on newly fractured silica to examine specifically the role of the fractured-induced, siliconbased radicals (Si· and SiO·), and silica-generated hydroxyl (·OH) radicals in the mechanism of the cell membrane damage by silica. The concentration of the Si· and SiO· radicals was controlled through decay processes, thermal annealing, and boiling, while that of the ·OH radicals was varied by using catalase, superoxide dismutase, KMnO4, Ha2seO3, ascorbic acid, and metal ions, and monitored via ESR spectroscopy. The dust's cytotozicity potential was evaluated by measuring the silica-induced hemolysis and also by determining lipid peroxidation (using linoleic acid). Prom the comparison of hemolysis and ESR results it is deduced that the radicals play little· or no role in the silica-induced hemolysis. However, the lipid peroxidation data indicate that the radicals might be involved in the initiation of an oxidative chain reaction leading to the macrophage membrane damage through lipid peroxidation. INTRODUCTIONThe biochemical mechanism of Quartz-related pneumoconiosis is still not fully understood. It is believed, nevertheless, that one event of primary importance is the perturbation of cell membranes by the dust particles (Allison et al., 1966; Allison and Harrow, 1971; Bateman et al., 1982; Parazzi, et al., 1968; Reiser and Last, 1979; Shi et al., 1989; Summerton et al., 1977). The ensuing cell-membrane damage unleashes certain lytic enzymes resulting in additional cell injury and eventual fibrosis (Nolan et al., 1981; Summerton et al., 1977). Thus considerable effort is currently being made towards the understanding of the processes by which quartz particles disrupt the membrane of a red blood cell (RBC) or a pulmonary alveolar macrophage (PAM). A simple but important method of evaluating the membrane damage potential of a dust is the hemolysis test (Harington et al., 1971). Even though this test is used routinely for screening dusts for their cytotoxicity potential, the biochemical mechanism underlying the cell lysis by many dusts, including quartz, is still controversial (Kilroe-Smith, 1974; Singh and Rahman, 1987), and this provided us the impetus for the present undertaking."

Jan 1, 1989

By F. D. DeVaney

The supply of manganese is a subject of much interest. The idea of obtaining it from rhodochrosite-MnC03 is attractive because the carbonate is supposed not to be so contaminated with impurities as the commonly utilized oxides. Large bodies of rhodochrosite-bearing rock have been known for a long while to exist at Butte, Mont. Hence samples were obtained from that place. In the two samples examined quartz was the chief diluting substance. The leaner sample was about one half quartz; some copper, lead, zinc, and iron sulphides were also present. The rhodochrosite amounted to about 40 per cent, so that the sample had a tenor of about 20 per cent manganese. This sample was the subject of the examination reported herein.

Jan 1, 1928

USBM Contract H0133045 consists of the design, build and test of 50 waveform generators. The waveform generator is a small ULF transmitter operating in the 1 to 3 KHz frequency range for the purpose of locating trapped miners during a mine disaster. This contract provided for the design, test, and building of 50 waveform generators using a discrete component construction with an option of using hybrid construction techniques within 105 days after the effective date of the contract. Because of large quantity economic considerations, this option was not initiated. Two engineering models were designed, constructed and tested and 50 final production units were fabricated using discrete construction. Complete documentation is supplied under a separate package which includes final schematics, parts list, layout information, equipment specification, production test procedures and qualification test procedures. Ten units have been delivered to the USBM. The remaining 40 units are being retained for packaging under contract H0242010 Transmitter Package and Receivers. A great deal of experience has been gained as a result of this contract. A final discrete potted printed circuit configuration has been arrived at that is now ready for field testing. After field testing, any desired changes should be incorporated into a final design. However, as a result of the current experience gained building and testing the production units, this printed circuit package together with potting procedure could be improved to reduce future costs. For example, the printed circuit board could be increased in size by 0.125 to 0.2 inches and all components could be mounted directly to the board eliminating costly hand stacking of components. The new printed

By L. R. Burdick

This paper presents a review of published investigation dealing with the importance of sulfur compounds in the deterioration of materials or providing some basis for estimating the extent of loss shareable to such air pollution. Materials included are cement, stone, metals, paint, leather, paper, sand cloth. The investigations may be divided into two classes, one of the laboratory type in which the sulfur content and the humidity of the air were controlled and the other dealing with the exposure of materials to atmospheres not under control. The first type of work has shown that cement is subject to deterioration by the action of sulfur dioxide gas. The experiments with stone indicate that although limestone takes up sulfur dioxide, from the air, moist sulfur dioxide-air mixtures alone cannot be used for establishing- the comparative weathering- qualities of the different types of stone by accelerated test methods. Laboratory tests indicate that sulfur compounds in the air accelerate the corrosion of iron, steel, zinc, copper, and nickel at normal air temperatures and at certain relative humidities. It has also been indicated that certain types of paint are, affected by high sulfur dioxide concentrations, and that paper is attacked by sulfur dioxide in the atmosphere. The investigations of the second type show the amount or variation of corrosion in different localities and under different types of exposure. The investigations (10) (18)4/ during which sulfur determinations were made indicate that sulfur dioxide is a main controlling factor in the corrosion of iron and steel but according to Quick (18) may not be for some nonferrous metals. In general, the laboratory tests do not Jive definite data on the loss due to sulfur compounds at the concentrations normally found in the air. The data from atmospheric exposures are not complete from the standpoint of the exact effect of the sulfur compounds. Damage to materials so exposed is affected by factors such as other chemical contaminants, humidity, rainfall, solid deposits, and sunlight. A simple scheme has been devised in Great Britain which is considered to provide a measure of the attack of sulfur compound, on building materials (1). Small cylinders coated

Jan 1, 1939

By J. E. Matta

The Bureau of Mines made laboratory absorption measurements on oil shale samples, which showed that the amount of methane absorbed is proportional to pressure and oil yield, and can be much larger than would be predicted based solely on porosity. Oil shale cores collected in the field were also measured for their gas content using the Bureau of Mines direct method. Cores taken from deep locations and far from outcrops yielded more gas than cores from shallower locations or at outcrops, when taking into account variations in oil yield, and all data indicate that oil shale mines that are both deep and far from an out-crop will emit low levels of methane gas.

Jan 1, 1977

By Paul M. Tyler

Hafnium appears to be among the more abundant of the newly discovered elements . Though quite widely distributed in nature , its compounds chemically so resembled those of zirconium , its sister element , that it escaped detection until 1923 , when Coster and Hevesy announced the discovery of the element , to which they gave the name of " hafnium " , from Hafniae , the Latin name for Copenhagen , where their research work was performed . Hafnium has so far been found only as a minor constituent of zirconium minerals . Zirconium as an element was discovered more than 140 years ago , but only a few unimportant uses were found for the metal or its compounds until some 18 years ago ; it is still classed among the rarer commercial metals . It is not surprising , therefore , that hafnium has not yet found a definite place for itself in industry . Nevertheless it has commanded a considerable interest among scientists ; and in 1930 some 70 grams of perfectly pure oxide of hafnium were prepared in Europe . A commercial future for hafnium is already glimpsed in the radio industry , and its high melting point and electronic emissivity have already led to the taking out of patents for its use in radio tubes and incandescent electric lamp filaments and for the cathode surfaces of devices such as X- ray tubes and rectifiers .

Apr 1, 1931

By L. C. IlsLey

The United States Bureau of clines has been conducting Investigations of electrical equipment during a period of more than 25 years in an endeavor to encourage the development of safer electrical equipment for coal mines. In order to conduct these investigations in an orderly manner they are carried out under a published schedule of tests known as Schedule 2C, which specifies detailed requirements for motors, controllers, etc., and fees covering the various inspections and tests made as part of a routine investigation.

Jan 1, 1937

By Frank G. Horino

The Bureau of Mines studied the uniaxial compressive strength of model rock pillars as a function of the angle and spacing of noncohesive planes of weakness. The model pillars were prepared from NX 2-l/8-inch diameter drill core of limestone, sandstone, and granite, and the planes of weakness were diamond saw cuts ground flat and smooth. The angle of the planes of weakness, measured from the horizontal, varied from zero to 57° in approximately 15° increments. When two planes of weakness were used, the thickness-to-diameter ratio of the wafer was 1/4, 1/2, and 1, Approximately 400 model pillars were tested in uniaxial compression. The results indicate that the uniaxial compressive strength of model pillars decreases rapidly as the angle of the plane of weakness increases from 30° to 57°, and that the spacing of these planes of weakness has only a minor effect on the strength. The effect of the number of horizontal planes of weakness, with a spacing of 1/4 and 1/2 of the diameter, upon the compressive strength of model pillars was also investigated. These results indicate that as the number of planes of weakness increases the compressive strength of the pillar decreases. Normalizing the data provides useful estimates of model pillar strengths for any rock type.

Jan 1, 1968

By Milford L. Skow

Utilization of domestic ores in the winning of metallurgical alumina requires a convenj.ent method of treating siliceous bauxites and other aluminous materials. In the United states there are only small reserves of high-grade bauxite but considerably larger tonnages of low-grade material. In addition, there are large deposits of high-alumina clays. If these high-silica bauxites or high-alumina clays could be beneficiated, either by are dressing or by chemical dissolution to remove a large proportion of the silica, then the potential reserves of aluminum ores would be increased materially. Faced with a similar situation, the German industry, chiefly dependent on high-grade French bauxites prior to World War II, was compelled during the war to Use lower-grade ores. For desilicating the lower-grade bauxites before the Bayer treatment, a method was developed in which the bauxite was calcined and then given a dilute caustic leach preliminary to the pressure digestion. It was planned to regenerate the caustic by treatment of the desilication liquor with lime. As European bauxites are mineralogically different from those found in this country, preliminary work was undertaken to determine whether this process might be applied to domestic materials. The results of this work, along with a review of the German process, are presented in this report.

Jan 1, 1950

By Ronald H. Church

As part of the Bureau of Mines health and safety research program in strata control, a ground-penetrating radar (GPR) system capable of pene-trating approximately 10 ft into the mine roof has been devised to identify anomalistic conditions. The GPR system consists of a transmitter with carrier frequencies of 250, 500, and 1,000 MHz, utilizing a dipole antenna, and a receiver, consisting of a dipole antenna fed into a sampler with a time base housed in a storage oscilloscope. A computer was utilized for data acquisition and data processing. Data analysis by computer enhancement revealed recognizable return ra-dar signatures from the middle man rock and main roof of the test site. These stratigraphic anomalies can be cataloged for recognizable fea-tures, which from the past history of the mine may have been shown to create strata control problems. Early recognition of such features could lead to immediate corrective actions and result in the saving of lives.

Jan 1, 1985

By L. C. IlsLey

The United States Bureau of Mines has been conducting investigations of electrical equipment curing a period of more than 25 years in an endeavor to encourage the development of safer electrical equipment for coal mines. In order to conduct these investigations in an orderly manner they are carried out under a published schedule of tests known as Schedule 20, which specifies detailed requirements for motors, controllers, etc., and fees covering the various inspections and tests made as part of a routine investigation.

Jan 1, 1937