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By M. A. Lucas

The Bureau of Mines has developed a computerized mathematical model to predict the distribution of accessory elements throughout a metallurgical process. The model can be used to determine process conditions that effect better accessory element control consistent with continued high primary metal recovery. The model presented is specific for determining the bismuth distribution in lead smelting but can be adapted to most extractive metallurgical processes. Thermodynamic, kinetic, and process parameters form the base for the model. Its logic and structure are described in detail.

Jan 1, 1983

The latest Active List of Permissible Explosives and Blasting Devices was published in July, 1929, as Bureau of Mines Report of Investigations 2947, 2 under the title or "Active List of Permissible Explosives and Blasting Devices Approved Prior to June 30, 1929.' Subsequent Reports of Investigations 2253, 2958, 2962, 2972, 2988, 2992 and 3000, were issued to record the official actions taken during July, August, September, October, 1929, and January, February, and March, 1930. No changes were made during November and December, 1929, and April, 1930. The following additional changes in the list recording the actions taken during May, 1930, are now authorized. [ ]

Jan 1, 1930

By Anthony T. Lannacchione, Donald G. Puglio

The Bureau of Mines developed data on the methane content of the Hartshorne coalbed, Haskell and Le Flore Counties, Okla. The methane content is calculated to be between 1.1 and 1.5 trillion cubic feet, based on an estimate of total coal in place of 2.4 to 3.2 billion short tons. Methane increases with depth, but the rate of increase decreases with greater depths. Degasification in advance of mining is recommended for all mines operating at depths greater than 500 feet to reduce hazards and methane explosions, decrease mine ventilation costs, and conserve the natural gas that would be otherwise wasted.

Jan 1, 1979

By J. Schlocker

The present emergency has greatly stimulated interest in the light metals - aluminum and magnesium - owing to their extensive use in airplane construction. The $63,000,000 plant being erected in the Las Vegas Valley by Basic Magnesium, Inc., under the auspices of the Defense Plant Corporation,

Jan 1, 1942

By Sathit Tandanand

Massive roof overlying the working seam in longwall operations can cause hazards if it does not cave readily behind the face supports. The overhang thus formed can overload the supports and endanger personnel when it collapses suddenly as a large rock mass. This Bureau of Mines report proposes the use of a concentrated load, either strip or point loading, applied onto the roof with the help of the upward thrust of the face supports. An experiment was conducted in the laboratory to obtain information about break characteristics and the values of significant parameters of three sedimentary rocks. The results were used to determine the breaking load requirement for a strong roof possibly encountered in typical longwall operations. The results show that the roof slab of moderate thickness can be fractured within the load capacity of off-the-shelf powered supports.

Jan 1, 1979

By Larry G. Stolarczyk

1.0 FRAMEWORK FOR COMPARISON This document describes the decision factors that bear on the selection of the modulation process for the wireless underground medium frequency (MF) communication system. The selected modulation process must satisfy the Bureau of Mines stated objective of improving general communications within an underground mine. The improvement being sought includes the development of a wireless communication technology of measurable benefit to both mine safety and mine productivity. The improvement will allow wireless communications paths to exist between roving miners. The wireless communication paths will also be made compatible with the existing underground telephone system to extend paging and voice communication throughout the underground mine. The new wireless equipment will include man-pack, vehicular, repeater, and base station transceivers. Repeaters and base stations will feature coupling networks for interfacing with the existing telephone circuits. Frequency modulation (FM) and single sideband (SSB) modulation processes are analyzed in view of the special conditions associated with underground mining. Of primary importance is the tremendous electrical noise generated in an operating mine that could adversely affect communications quality. High noise coupled with high attenuation rate of near field signals forces the communication system to be inherently short range. Fortunately, near field signals can propagate over great distances on underground wires and cables. The framework for comparison is generated by presenting all factors that

By Sean Gallagher

The vast majority of ergonomics research has addressed the demands of work in standing or sitting postures, and understandably so. However, many workers (for example, underground miners, aircraft baggage handlers, plumbers, agricultural workers, mechanics, and others) are often required to adopt postures such as kneeling, stooping, squatting, or lying down for significant periods of the work day.

Jan 1, 2005

By C. W. Dwiggins

This report describes the development, theory, and application of techniques and instruments for quantitatively determining nickel, vanadium, and iron in oils, using direct, X-ray emission spectrographic methods (5, 6).3 The methods developed apply to petroleum and other oils as well as some specific fractions of oils. The quantities of nickel, vanadium, and iron in various petroleums are of practical and theoretical interest. Even traces of nickel and vanadium may poison cracking catalysts, and X-ray methods have been used for determining nickel in such catalysts (7). At least parts of the nickel and vanadium occur as metal-porphyrin complexes, a fact which may have considerable bearing on knowledge of the origin of petroleum.

Jan 1, 1962

By W. S. Anderson

The use of flexible liners for support of underground openings has been investigated by the Bureau of Mines. This report presents installation procedures and instrumentation results of a full-scale flexible liner field installation in the Burgin mine. The flexible liner is a part of the mine support system and has provided maintenance-free support for 22 months

Jan 1, 1975

By David C. Oyler, Paul B. Stubbs

The Bureau of Mines and United States Steel Corp. are conducting a joint project to monitor formation pressures at a large (23-well) coal- bed gas drainage field near Oak Grove, AL. Three monitor holes were drilled in late 1981, and pressure monitoring began in December 1981. The Bureau of Mines direct method was used to obtain gas content data from cores taken in the monitor holes. Comparison of the 1981 gas con- tent data from the monitor holes with initial gas content values obtain- ed from the production wells in 1977 indicates a 50-pct reduction in ad- sorbed gas content inside the pattern and a 29-pct reduction at one point 500 ft outside the pattern. The combination of pressure and gas content data has also allowed an in situ isotherm curve, relating the formation pressure to adsorbed gas content, to be developed for the area of the production wells. From the current rate of pressure decline (1 lbf/inz per month), the observed changes in gas content, and the isotherm curve, it appears that most of the early gas production came from within the pattern, but since 1981 (and possibly earlier) most of the gas produced has been migrating to the wells from outside the pattern area.

Jan 1, 1985

By Noel N. Moebs

The Bureau of Mines conducted five reconnaissance magnetometer traverses across a small abandoned chromite mine in the State Line district of Pennsylvania and Maryland to determine the geophysical response of the area. The results indicate that more extensive geophysical surveys of the region might establish some worthwhile guidelines for chromite exploration. While chromite only rarely can be detected directly by magnetic methods, there is a possibility that geophysical signatures in the adjacent host rock could provide some guidelines for further exploration. Prior to 1875, all the chromite produced in the United States came from the State Line district, and the potential for discovering additional podiform deposits could be significant. Virtually no state-of-the-art geuphysical or geochemical studies have been conducted in this district since World War II and sizable areas remain undeveloped and suitable for exploration. While the results reported in this paper are not supported by drilling, it may encourage others to investigate the area more fully for improved methods of detecting subsurface podiform chromite deposits. New theories on the emplacement of ophiolites also could contribute to an assessment of the chromite potential of the serpentinite belt.

Jan 1, 1991

By B. W. Gandrud

In the summer of 1950, Bureau of Mines engineers visited a number of coal-preparation plants in western Europe and Great Britain to obtain information on European and British coal-cleaning and froth-flotation practices. In view of the growing importance of froth flotation as a process for cleaning fine sizes of coal, it was felt that such data and information would be of value in this country, for, although froth flotation has been adopted for use in a few of our plants, it has not as yet been employed as extensively as in British and European preparation plants. Many of the important coal beds in western Europe, especially in the Ruhr Valley of Germany and in the Dutch coal-mining region of Limburg, Netherlands, are very friable, with the result that the run-of-mine product contains a large proportion of the sizes too fine to be treated successfully by any other method than froth flotation. Furthermore, the relatively high cost of producing coal from these beds has for many years made it economically feasible and desirable to treat the fines by froth flotation, especially in the coking-coal fields.

Jan 1, 1951

By R. B. Stroud

Bureau of Mines studies of copper-bearing Permian red beds, which extend from north-central Texas through western Oklahoma to southwestern Kansas, indicate heretofore undefined commercial possibilities for low-grade, medium-volume, strip-mining operations. Potential ore bodies are indicated containing 0.5 to 1.5 percent copper in zones 6 to 12 inches thick. Cost analysis studies indicate a commercial operation is feasible for a hypothecated 1,000-ton-per-day ore mining and milling complex where a maximum of 60 feet of overburden can be stripped in mining a seam of shale 12 inches thick containing 1.2 percent copper

Jan 1, 1970

By Robert D. Schmidt

This Bureau of Mines report describes the development and application of a computer model for simulating the hydrological activity associated with in situ leaching. The model is intended to provide uranium resource developers with a description of the flow behavior of leachants and ground water during the development, production, and restoration phases of a leaching operation involving an arbitrary pattern of injection and recovery wells. Different aquifer environments are modeled, using a closed-form solution to the partial differential equation that describes three-dimensional changes in piezometric head as a result of pumping from leachant injection and recovery wells. The computer program can model a maximum of, 50 arbitarily located wells. Numerical techniques involving difference quotients and Taylor expansions about time points are used to derive time, velocity, areal sweep, and fluid volume parameters associated with leaching hydraulics. These parameters are output by the program in graphic and tabular formats. Other numeric methods insure that the program running time is minimized without significantly affect-ing the accuracy of results.

Jan 1, 1980

By T. G. Carnahan

The Bureau of Mines conducted research to simulate in situ leaching of a porphyry copper sulfide ore. The purpose was to determine the effects on copper leaching of additions of NaCI to a conventional sulfate leach system and to analyze the oxidant requirements and the oxidation products that resulted from leaching of the sulfide minerals in the ore. Baseline sulfate and sulfate plus 2-pct-NaCl-leach-solution experiments employing 167-kg (367-lb) and 152-kg (333-lb) charges, respectively, were conducted. The minus 25.4-cm (10-inch) ore was leached at 90° C under flooded conditions with 2.8 MPa (400 psig) of oxygen bubbling through the system. Sixty-seven pct of the copper was extracted in 1,236 days of leaching in the NaCI experiment, whereas 47 pct of the copper was extracted in 913 days of leaching in the baseline experiment. Diffusion into and out of the ore fragments controlled the rate of leaching, which precluded enhancement of the leach rate by the chloride ions. The calculated oxygen consumption was 3.17 kg/kg of copper extracted in the baseline experiment and 3.46 kg/kg of copper extracted in the experiment to determine the effect of chloride ions.

Jan 1, 1982

By C. E. Hennig

On January 1, 1960 there were 310 petroleum refineries in the United States, with a crude-oil capacity of 9,901,424 barrels daily, according to the Bureau of Mines' annual survey. Compared with a year ago, this represents a net decrease of three in the number of refineries and an increase of 81,578, barrels per day in crude-oil throughput capacity. Continuing the trend to fewer units with greater individual throughput, the capacity of the average refinery in the United states increased during 1959 from 31,373 barrels per day to 31,740 barrels per day. Compared with the previous year, total crude-oil capacity of refineries on January 1, 1960 was lower in the Appalachian No. 1, Other Rocky Mountain, and Texas Gulf refinery districts. All other districts showed slight increases in capacity. At the beginning of 1960 the industry had under construction facilities that would increase the crude-oil capacity in the United States by 70,947 barrels per day. This was the smallest capacity increase under construction at the beginning of the year since 19460 Included in this construction of additional capacity were two new refineries, one in Michigan and another in Hawaii. In addition, the industry was constructing facilities to replace 50,250 barrels per day of existing crude-oil capacity.

Jan 1, 1960

By Donald Koch

The project investigated regional impacts of mining on the ground water system of the Powder River Basin by: 1) establishment of a regional ground water monitoring network. and 2)development at a set pit digital computer models to simulate ground water flow and quality, ground water contributions to surface water flow and quality (i.e., baseflow), and watershed run-off and recharge. Over 100 wells were monitored for physical and chemical parameters. Data were used as input to the models and for the development of a comprehensive data base. The basin was modeled on a regional and subregional scale using a finite -difference model employing an alternating difference technique. Two water-shed models were evaluated fur their ability to provide runoff and recharge inputs to the basic ground water model. Application of the regional and subregional models using conservative mining scenarios showed that drawdowns may extend west from the mines as far as ten miles but that impacts would be insignificant on a regional scale. The watershed model could be effectively applied to small watersheds only.

Jan 1, 1982

By Philip C. Tully

The Bureau of Mines, in a continuing effort to improve processes and methods of helium purification, has developed a differential distillation method for removing helium-3 from helium-4. Differential distillation at 4.2 to 1.6 K was used to reduce the helium-3 in helium-4 from about 200 to less than 1 part per billion. The results from four stills ranging in size from 1 to 25 liters are reported. The method has the potential to be adapted to commercial-scale separations.

Jan 1, 1975

By T. L. Joseph

The purpose of this article is to describe briefly the operation of a 6-ton blast furnace on a charge of bauxite, limestone, iron ore, and cast-iron turnings and to point out the bearing which smelting such a charge has upon the production of alumina cement. One object of the experiment, conducted by the Bureau of Mines in cooperation with the Aluminum Co. of America, was to determine whether tae so-called Pedersen process3 can be applied to the blast furnace. This process consists of smelting a charge of bauxite, iron ore, and. limestone, and results in to products. One is a slag containing about 50 per cent of A1203 and is intended for use in manufacturing aluminum, and the other is iron low in sulphur. Complete details of the test are published in other reports4. Blast-furnace slag is now recognized as a satisfactory and economical raw material for making Portland cement, Wm. A. Forbes5 has recently reported that in 1926 an important steel interest used well over 1 million tons of slag in producing about 24 million long, tons of cement. This is equivalent to about ½ ton of slag for each ton of cement. Alumina cement can be made direct in the blast furnace. Its physical character would have to be changed by grinding, but no change in its chemical composition would be necessary.

Jan 1, 1928

By J. G. Kirby

According to the annual Bureau of Mines survey of refinery capacity, there were 343 petroleum refineries in the United States as of January 1, 1953, with a total daily crude-oil throughput capacity of 7,638,661 barrels. Compared with the previous year, this represents a decline of 7 in the total number of refineries, but a gain of 305,776 barrels in daily crude-oil throughput capacity. The capacity of the average refinery to process crude oil increased to 22,270 barrels, a gain of 1,319 barrels during 1952. All refining districts reported increases in installed capacity for the year, with Texas Gulf Coast accounting for 28 percent of the increase; California, 21 percent; and the Indiana-Illinois-Kentucky district, 18 percent. Additional crude-oil capacity under construction January 1, 1953, was 60 percent greater than at the beginning of 1952. The total reported, 509,721 barrels daily, is a record high for refinery expansion. In addition to the new facilities under way, facilities for 127,755 barrels daily are being installed to replace those that are obsolete. Four new refineries were under construction at the beginning of the year, and three of these are now in operation. Plans for five' new refineries have been announced, but actual construction has not been started.

Jan 1, 1953