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By Richard F. Hewlett

Computing average grade and tonnage either for an entire ore deposit or for individual blocks of ore is a continuing problem in mining. As part of a research program, investigating application of statistical techniques to mine sampling, Bureau of Mines engineers at the Denver Mining Research Center have made extensive use of an electronic digital computer for developing mine sampling theory, simulation of ore deposits, and analysis of mine sample and assay data. This report is one of a series describing use of the digital computer for rapid solution of computing problems in the mining industry.3 4 Development of a computer program to compute ore reserves by the commonly used triangular method was necessary so that results could be made available for analysis within hours.

Jan 1, 1963

By George H. Holmes

This report describes the results of a reconnaissance survey of areas in California and Nevada considered favorable to beryllium mineralization. Pegmatite dikes, veins, intrusive sills, contact metamorphic, and disseminated deposits as well as tactite deposits in the former major tungsten-producing districts were investigated. A general geographic pattern of beryllium mineralization was found to be concentrated along a wide belt in eastern Nevada extending from the Ruby Mountains, Elko County, south through the Fish Creek Range, Eureka County, the Snake Range, White Pine County to the Virgin Mountains in Clark County, Nev., and Mohave County, Ariz. Sporadic occurrences of beryllium are in central and southern Nevada, and in the pegmatite dikes of San Bernardino, Riverside, and San Diego Counties, Calif., and the granite masses of the southern Inyo Mountains, Inyo County, Calif. Principal company activities are centered in the Snake Range, Fish Creek Range, and the Virgin Mountains, Nev., and the Inyo Mountains, Calif. Other areas in California and Nevada have been superficially explored with results indicating either limited or widespread, but submarginal, mineralization. Although beryllium was found to occur, to some extent, in many of the deposits, mining has been hindered by the lack of a market for beryllium ores and concentrates other than standard-grade beryl and also by the erratic pattern of mineralization and the high exploration and beneficiation costs required to produce a marketable product.

Jan 1, 1963

By George H. Holmes

This report describes the results of a reconnaissance survey of areas in California and Nevada considered favorable to beryllium mineralization. Pegmatite dikes, veins, intrusive sills, contact. metamorphic, and disseminated deposits as well as tactite deposits in the former major tungsten-producing districts were investigated. A general geographic pattern of beryllium mineralization was found to be concentrated along a wide belt in eastern Nevada extending from the Ruby Mountains, Elko County, south through the Fish Creek Range, Eureka County, the Snake Range, White Pine County to the Virgin Mountains in Clark County, Nev., and Mohave County, Ariz. Sporadic occurrences of beryllium are in central and southern Nevada, and in the pegmatite dikes of San Bernardino, Riverside, and San Diego Counties, Calif., and the granite masses of the southern Inyo Mountains, Inyo County, Calif. Principal company activities are centered in the Snake Range, Fish Creek Range, and the Virgin Mountains, Nev., and the Inyo Mountains, Calif. Other areas in California and Nevada have been superficially explored with results indicating either limited or widespread, but submarginal, mineralization. Although beryllium was found to occur, to some extent, in many of the deposits, mining has been hindered by the lack of a market for beryllium ores and concentrates other than standard-grade beryl and also by the erratic pattern of mineralization and the high exploration and beneficiation costs required to produce a marketable product.

Jan 1, 1963

By Potter G. M.

Ore-dressing tests were conducted on a sample of ore submitted by the Richmond Hill Mining Co. of Lead, S. Dak. as a part of the Bureau of Mines program for investigating potential domestic sources of manganese. Half of the sample was taken from the 300-foot level and half from surface cuts. The problems involved were liberation and rejection of silica and iron and removal of lead, Silver, and gold from the manganese concentrates. Although a portion of the silica and iron oxides was too intimately associated with manganese minerals for rejection by ore-dressing methods, thus limiting recovery of high-grade concentrates, the Richmond Hill ore was found amenable to simple gravity methods of concentration for producing intermediate-grade products. By jigging and tabling, 73.8 percent of the total manganese was recovered in a product that, when sintered, assayed plus 40 percent Mn. Lead, silver, and gold were successfully removed from gravity concentrates by a chloridizing roasting treatment.

Jan 1, 1948

By A. C. Watts, C. A. Allen

In the No. 3 Sunnyside mine of the Utah Fuel Co. a disastrous fire started on the afternoon of August 17 , 1920 , the effects of which are still present in the mine . On account of the extent of the fire , the expense involved in reopening the mine and the opportunities afforded for determining the effects of depleted air , a description of it is worthy of record . This paper is a summary of a more complete report , prepared by the writers , which will be published by the U. S. Bureau of Mines .

Feb 1, 1922

By D. H. Baker

This report, one of a series prepared by the Federal Bureau of Mines on the technology of titanium, describes the development of an electrorefining cell from which cathode deposits up to 30 inches long can be produced. Data show individual deposits to be homogeneous, comparable from top to bottom, and not varied in quantity or quality of metal over the entire length of the deposit. Investigations concerned with various diameter cathodes showed that cathode current efficiencies were materially reduced with cathodes less than 2 inches in diameter. Deposits produced on 1/2-inch-diameter cathodes showed cathode current efficiencies of 19 percent and on 1-inch cathodes, just over 22 percent, whereas deposits produced on 2- and 4-inch-diameter cathodes showed about 70-percent current efficiencies. A series of 20 deposits on 4-inch-diameter cathodes was produced under simulated production operation. The average current efficiency, based upon a divalent ion, was 72 percent with 11 1/2 pounds of metal produced per cycle of operation - 98.8 percent of which had a Brinell hardness number (B.h.n.) of 80 or less.

Jan 1, 1959

By J. Croeni

The search for new alloys for application in the atomic energy field had prompted investigation of zirconium-rare earth metal alloys by the Federal Bureau of Mines. In this instance the zirconium-dysprosium system was investigated by melting point, thermal analysis, resistivity, X-ray and metallographic methods. Results indicate a single eutectic system with a peritectoid reaction occurring at 890° C. The eutectic isotherm extends from 30 to 95-percent dysprosium at 1,280° C. Eutectic composition is located at approximately 70 percent dysprosium. Solid solubility of dysprosium in both alpha and beta zirconium is extensive. The extent of solid solubility of zirconium in dysprosium has not been determined. Although zirconium rich alloys exhibit a significant increase in hardness, they can be cold worked extensively. These alloys also appear adaptable to solution heat treatment. Additional investigations concerning corrosion resistance and other mechanical properties are necessary for satisfactory evaluation of these alloys. The superior corrosion resistance of zirconium and the nuclear cross-section characteristics of the rare earth metals have stimulated alloy investigations using zirconium as a base metal. Alloys combining these characteristics present a possible substitute for hafnium as a control rod material. In this particular study dysprosium was chosen as the alloying element, and several series of alloys were used to establish the equilibrium diagram.

Jan 1, 1960

By M. H. Kline

The Chestatee mine is one of several well known pyrite deposits in Georgia that are reputed to carry appreciable quantities of copper with the ore. The deposit is? in Lumpkin County on the Chestatee River, 6 miles northeast of Dahlonega (fig. 1). Old records and reports indicated the probable existence of an extensive unmined ore body, but the mine is inaccessible at present. The Bureau of Mines, after studying old maps and records, decided to cor8-drill along the strike of the lense beyond the limits of the indicated old workings in an attempt to extend the possible reserves. The advantageous location of the property indicates that it could become an economic source of pyrite to be used for the manufacture of sulfuric acid. Iron sinter resulting from the roasting of the ores could be sold at a premium in the Birmingham, Ala., area, and the copper content could be extracted to help replace the nation's depleted resources of this metal.

Jan 1, 1949

By H. J. Lechtenberg

This Bureau of Mines report investigates solvent injection as a means of increasing oil production from low-gravity oilfields; thus, wells in two California oilfields that produce from reservoirs having low-gravity oil were injected with highly aromatic solvents to increase their oil recovery. The wells were either allowed to soak or the solvent was circulated for a period of time. In some of the wells, the solvent was followed by a slug of water. The post-stimulation production rate was considerably higher than the prestimulation rate of the wells. Wells in which the solvent was not followed by water showed an immediate increase in oil production, and essentially all of the solvent was recovered. The wells in which solvent was followed by water essentially showed a delay in the increase in oil production, thus indicating a temporary water block. The results show that the production rate is usually increased by the injection of solvent, and the method may prevent early abandonment of marginal producers. Cumulative post-stimulation oil production indicates that cyclic solvent injection treatment can be an economic success.

Jan 1, 1974

By Maria I. De Rosa

The Bureau of Mines performed experiments to determine concentrations of toxic gases and liquids, and smoke-particle diameters and diameter-concentrations evolved during degradation of PVC-derived brattice with and without nylon-woven fabrics, fiberglass, cotton, and jute brattices, and other mine materials. The samples were exposed in a 20-L chamber at temperatures of 1500 to 4500 C, with a chamber airflow of 10 L/min; 27.3 cm3/s of which was directed into a submicrometer-particle detector-analyzer. During the degradation of PVC-derived brattice, large concentrations of hydrogen chloride (TLV, 5 ppm; STEL, 100 ppm) evolved at a temperature as low as 2000 C. The minimum toxic load of 3.1 mg or 40 ppm in 50 L of dilution air, with O.l~g weight loss, may be reached at a mine face with 314,000 L of dilution air, at the 5th min, during which less than 1 kg of brattice undergoes combustion. Fiberglass, cotton, and jute brattices, pine wood dust, and coal dust showed small concentrations of carbon monoxide evolving during early stages of combustion. Hydrogen cyanide gas evolved from the PVC-derived, nylon-reinforced brattice; at a later stage of combustion, large concentrations pf carbon monoxide and dense smoke evolved from all PVC-derived brattices. Experiments to characterize smoke particles showed that marked differences exist in particle diameter-concentrations among the materials.

Jan 1, 1986

By Geo. H. Williamson

This paper describing the dredging operation of J. K. Davison & Bro. on the Allegheny River near Pittsburgh, Pa., is one of a series being prepared for and published by the United States Bureau of Mines on methods and costs of dredging sand and gravel in the United States. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total costs. It is recognized that publication of total costs might in many instances cause embarrassment to individual operators as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue. ACKNOWLEDGMENTS The author wishes to acknowledge the assistance of H. R. Hissrich, chief engineer of the Goodman Engine and Machine Co., in compiling details of the dredge construction; of H. H. Stewart, auditor of J. K. Davison & Bro., in preparing cost and performance tables; and of J. R. Thoenen, mining engineer of the United States Bureau of Mines.

Jan 1, 1932

By John R. Reeves

The principal oil aha.le in Indiana ie known as the New Al'baZ\Y shale. It 11 ot Devonian age, and ia usually correlated with, although not certainly of the 1ame age a,, the Antrim shale of northern Michiga.. the Ohio shale of Ohio, and the Chattanooga shale ot Kentucky. Termescae • a."ld Georgia. The nqtmal thickneaa of the formation 1n Indiana 1e a.bout 100 faet, ltbough 1n the region of its out­ cro;l the tall th!::kne,111 io rarely exposed because cf the general d:.p of the strata, which is 11 about 30 feet per mile to the west. With the exception ot thin local pha1e1, the entire thickness is oil shale,

Aug 1, 1922

By S. J. Page, P. Bolsaitls, W. E. Wallace, C. A. Hill, M. J. Keane

"Boiling respirable quartz dust in water for 10 to 40 minutes decreases the cytotoxicity for both erythrocyte hemolytic potential and pulmonary macrophage release of lactate dehydrogenase in vitro. The potential is reduced to near zero in the boiling concentration range of 1 to 10 mg quartz per ml water in boiling times of 20 to 40 minutes. Below this range the detoxification occurs over a longer boiling time. Above this range the hemolytic potential remaining after 40 minutes of boiling approaches native quartz potential with increasing concentration up to 30 mg quartz per ml water. Replacing the media with fresh at the midpoint of boiling results in full detoxification through 20 mg per ml. Pre—boiling the medium with quartz or silica gel reduces the effect of subsequently boiling test samples. Detoxification persists after mild drying at 110 C for 8 hours, and persists after three days of resuspension in water at room temperature. Additional data on persistence of the effect, on the use of acidic and basic media treatment, and on surface analyses are presented, with a discussion of a working hypothesis and research needs.IntroductionResearch underway to determine interactions of quarts and other mineral dust surfaces with pulmonary fluids and alveolar macrophages in culture led to the observation that when dusts were autoclaved in aqueous suspension, their cytotoxic effects on macrophages wore suppressed, in some cases fully and even after several days incubation with the cells. This finding was in direct contradiction to earlier results from both short term macrophage lysosaal enzyme release assays, as well as longer term cytotoxicity assays from macrophages in culture; in those studies, dusts were steam autoclaved at 121 121 ºC with no liquid water but with steam present. (1,2) However detoxification under boiling conditions has been reported in other research.(3). It was decided to use the hemolysis assay to further investigate these findings, because of its sensitivity, simplicity and cost."

Jan 1, 1988

By Ad. Breyre

For more than 20 years, Belgium, leading all the coal-mining countries, has made increasing use of sheathed explosives, which wore first suggested by the late E. Lemaire, predecessor of the author gas Director of the Institut National des Mines. It appears to the author that it will be valuable to show how the use of sheathed explosives has developed in Belgium, how the various difficulties encountered in their manufacture have been overcome gradually, and the tyros of sheathing that have survived and the reasons for their survival.

Jan 1, 1940

By Cecil E. Lester

Since the advent of coal mining, the minimal lighting in the under¬ground working place has been an obstacle to the safe and efficient performance of the miner's many tasks. Compounding this problem is the fact that the machines being operated in the working place are so large that the vertical and horizontal clearances around the machinery are severely limited. Consequently, in these poorly lighted and congested working places, the machine operator is unable to utilize his peripheral vision. He cannot see hazards as they develop and, too often, cannot react in time to avoid serious injury or death to himself or his fellow miners. The greatest hazard to miners inby the last open crosscut is from falls of roof which are often preceded by warning signs such as falling rock fragments, roof supports taking weight, or a sudden reduction in the height of the working place. These warning signs often go undectected because the machine operator's attention is focused on the small circle of light emitted from his cap lamp. Congress recognized the illumination deficiencies, and, in the Federal Coal Mine Health and Safety Act of 1969, charged the Secretary of the Interior with the authority and responsibility for development and promulgation of minimum standards for illuminating working places in coal mines. These standards have been developed and, as stated in the April 1, 1976 Notice, Federal Register, Volume 41, No. 64, will be promulgated on October 1, 1976, as mandatory regulations under Section 75.1719, Title 30, Code of Federal Regulations. The regulations require that the designated surfaces within the miner's normal field of vision be illuminated to 0.06 foot-lamberts while self¬propelled mining equipment is being operated in the working places. The term "working place" is defined in the Act as "the area of a coal mine inby the last open crosscut".

Jan 1, 1976

By J. T. McCartney

In an effort to correlate the size of pyrite particles in coal and coal-particle association with the removal of pyrite before burning, the Bureau of Mines conducted a study of 61 coals presently being used for electric power production. The results were obtained by visual microscopic studies of polished briquets of minus l4-mesh samples. Mean pyrite particle sizes ranged from 20 to 400 microns and proportions of pyrite contained in coal particles to an extent greater than 50 percent by volume (estimated) ranged from 20 to 95 percent. These parameters were correlated with reductions in pyrite accomplished by float-sink tests at 1.60 sp gr on 14-mesh, 3/8-inch, and 1-1/2-inch samples. The correlation coefficients between pyrite removal and mean pyrite particle size were 0.89, 0.84, and 0.79, respectively, for these samples. Correlation coefficients between pyrite removal and coal-pyrite association parameter were 0.92, 0090, and 0.85, respectively. It is apparent that extent of pyrite removal can be fairly well predicted from microscopic analysis.

Jan 1, 1969

Develop a 22-ton capacity temporary mine roof support light enough to be easily lifted and transported manually from one place to another. Approach Several potential approaches were investigated in developing a new temporary support. An all-hydraulic, high-strength aluminum design was chosen as the best. The support was designed, fabricated, and tested in several mines. The first units, built for 6- to 8-foot seam heights, have a load- bearing capacity of 22 tons, and weigh only 55 pounds. How It Works The lightweight hydraulic support is designed for use in any temporary support situation in place of wood posts or steel mechanical or hydraulic supports. This includes use prior to roof bolting in room and pillar mining and in longwall development sections, use as head and tailgate supports for a longwall, and use as turn posts and breaker posts in retreat mining operations. The supports feature a release valve for quick manual extension to roof level, a lanyard

Jan 1, 1983

By Travis Q. Lyday

The Other South Pacific Island states extend from Palau, also called Belau, near the Philippines in the west, to French Polynesia in the east. However, a number of countries and territories have been omitted, from this chapter because their mineral production was insignificant to the local economy. These include the French over-seas territories of French Polynesia and Wallis and Futuna Islands; independent states, including Kiribati, Marshall Islands, Micronesia, Palau, Tonga, Tuvalu, and Vanuatu; the New Zealand freely associated state of the Cook Islands, and the New Zealand dependency of Niue. What mineral production existed in these islands was limited to construction materials such as coral reef limestone, crushed stone, and sand and gravel in minor quantities solely for domestic consumption. FIJI The mineral industry of Fiji continued to be dominated by gold, although this sector contributed less than 1 % to the gross domestic product (GDP) of the country. Gold and silver together ranked second in value among the country's exports. Fiji's economy contracted 11% during the 8-month period following the first, on May 14, of two military coups. Although the island nation had been a member of the British Commonwealth of Nations since its independence on October 10, 1970, Fiji's membership terminated with the emergence of the Republic or Fiji on October 15.

Jan 1, 1989

By Walter K. Utt

The vibration levels of the heavy machines used in surface mining are much greater than for vehicles used on highways. In order to assure the proper functioning of electronic equipment placed on the surface mining vehicles, the U.S. Bureau of Mines has conducted a program of field measurements to define their vibration environment. The information in this report is for a class of vehicle that has a blade for scraping and wheels with rubber tires. The statistical information derived from these measurements can be used as a basis for laboratory testing to qualify equipment for a surface mining vehicle of this class. The envelope that would encompass 99 pct of the vibrations encountered in normal operations is presented for each location on the vehicle. The five locations for which data were recorded are the floor of the cab, the engine, the frame, the drive train (gear, differential, and torque converter), and the axle. Tabulated data are provided for those who wish to use a different probability level. The appropriate test profile for the laboratory testing can be determined from the information presented in this report.

Jan 1, 1993

By S. H. Katz, J. J. Bloomfield

Fires in zinc dust have sometimes given particular trouble owing to their resistance to extinguishers and the liability of explosions . Similar problems , notably with aluminum dust* , have previously been subjects of investigation by the Bureau of Mines .

Mar 1, 1922