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By Edward F. Redente

Several research projects have been conducted in the western United States to determine the optimum soil replacement thickness for reconstruction of rangeland and cropland. However, the information gained from these studies tends to be site-specific and not broadly applicable. Moreover, the possible interaction between soil thickness and mechanical and fertilizer manipulation of the overburden has not been adequately studied. To meet these information needs, research was initiated at Trapper Mine in northwestern Colorado in 1980 to study vegetation response to soil thicknesses of 15,30,45, and 60 cm and five manipulations that included disking, ripping, and fertilizing. All crops were harvested at peak standing crop and then weighed in the laboratory. Wheat grain yields were highest when soil thickness was 45 cm and the soil and overburden were ripped. Alfalfa yields appeared to be highest when overburden was disked and fertilized and soil was replaced to a thickness of 60 cm. For range vegetation, standing crop biomass was highest when overburden was ripped and soil was replaced to 60 cm thick. However, optimum performance was obtained from the maximum number of species and life forms by disking overburden and replacing 15 cm of soil. The performance of most range plant species has improved over the three years of the study. When the results of this study are compared to the results of other soil thickness studies, we can conclude that selection of management practices should be influenced by local climate, local soil and overburden conditions, type of crop or vegetation to be grown, and specific management goals for that crop or vegetation.

Jan 1, 1984

By F. Garcia, J. Cervik

Recent advances in the commercial separation of gases using membranes have renewed interest in the possibility of applying this technology to the recovery of methane ( CH4 ) from mining operations . This Bureau of Mines report briefly reviews the history of the development of membranes for gas separation , the theory of how they work , and their application to the separation of methane from air and associated problems . However , methane -air mixtures are difficult to separate with membranes because the pertinent gas couples , 02 - N2 , 02 - CH4 , and N2 -CH4 , have poor separation characteristics , as indicated by their separation factors of about 3 or less . Even if these separation factors were substantially higher , there is doubt that methane could be recovered economically from the low concentrations in mine ventilation exhaust ( 2 vol pct or less ) . The exhaust pressures are not sufficient for adequate separation . The power cost of compressing the methane recovered . these mixtures would far exceed the value of New discoveries could make separation of gob hole methane - air mixtures practical . These mixtures have much higher concentrations of methane (from 30 to 100 vol pct ) ; however , for safety reasons , be limited to gob gas with 60 vol pct CH4 or more .

Jan 1, 1988

By L. C. George, J. W. Jensen

A new system for precisely counterbalancing and measuring vapor pressure operates by servomechanical principles . It was developed with the objective of determining the vapor - pressure equations of metal halides . The system is isolated from the vapor - pressure bulb by a diaphragm transducer that signals a pressure regulator to null any pressure difference that is detected . Pressure measurement and readout are continuously performed by a servomanometer , accurate to ±0.003 cm Hg for the range of 0.1 to 200 cm Hg . High response rate and sensitivity are obtained . Methods of use are described , and results for CdC1 and PbC1 , in agreement with data of other investigators , are given as examples .

Jan 1, 1964

By H. E. Powell, T. E. Hill, W. A. Calhoun

The object of this investigation was to determine the effectiveness of certain cationic flotation collectors , Ethomeens , in recovering fine particles of lead minerals from mill tailings at a grade equal , at least , to that of the mill feed ( 1.7 percent lead ) . The Ethomeens , derived from tertiary amines having one fatty alkyl group and two polyoxyethylene groups attached to the nitrogen , were evaluated by bench- scale flotation tests . The 14 Ethomeens tested consisted of four groups : Coco amine , soybean amine , tallow amine , and stearyl amine . The best results were obtained with coco amine C / 12 , soybean amine S/ 15 , tallow amine T / 12 , and stearyl amine 18/20 . From a feed containing 0.23 percent lead , rougher concentrate grades of 2.12 to 3.89 percent lead were obtained , with recoveries of 17.3 to 27.5 percent of the total lead . Some of the lead mineral particles recovered had diameters of less than 1 micron . In comparative tests , the Ethomeens , or polyethoxylated amine types of cationic surface active agents , were more selective than conventional xanthate collectors for flotation of slimed lead minerals .

Jan 1, 1964

By O. C. Blade

This report on the properties of motor fuels sold through service stations in the United States was made in accordance with a cooperative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Department of the Interior. By agreement with the American Petroleum Institute, identification of the items is confidential. It presents analytical data for 4,421 samples, representing the products of 131 companies. The samples were collected during June, July, and August, 1953. As in previous surveys, the gasolines covered by this survey include those from both large and small suppliers. The data were obtained by laboratories of various refiners, motor manufacturers, and chemical companies and submitted to the Bureau of Mines for compilation. A list of the National Motor-Gasoline Survey reports published during the past 10 years is given on page 5.

Jan 1, 1954

By J. W. Town

As part of the Federal Bureau of Mines titanium resources examination program, samples from seven deposits in the Pacific Northwest were tested for amenability to various beneficiation techniques. The samples obtained by the Bureau's Office of Mineral Resources at Spokane, Washington represent a large potential source of titanium. This report summarizes the results of tests at the Bureau's Metallurgy Research Center, Albany, Oregon. Recoveries from tabling placer samples were about 50 percent at grades of 30 percent titanium dioxide. Flotation was the most effective method for concentrating the fine ilmenite in clay samples; recoveries of approximately 50 30 percent titanium dioxide. Flotation was the most effective method for concentrating the fine ilmenite in clay samples; recoveries of approximately 50

Jan 1, 1961

By O. C. Blade

This report on the properties of motor fuels sold through service stations in the United States was made in accordance with a cooperative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Department of the Interior. By agreement with the American Petroleum Institute, identification of the items is confidential. It presents analytical data for 4,857 samples, representing the products of 103 companies. The samples were collected during June, July, and August 1955. As in previous surveys, the gasolines covered by this survey include those from both large and small suppliers. The data were obtained by laboratories of various refiners, motor manufacturers, and chemical companies and submitted to the Bureau of Mines for compilation. A list of the National Motor Gasoline Survey reports published during the past 10 years is given on page 5.

Jan 1, 1956

By Fun-Den Wang

This report presents the results of two large scale field coal pillar strength tests (80 ft by 80 ft), the results of a series of laboratory small core sample tests, and the correlation between those field and laboratory tests. The concept of applying laboratory coal sample strength data to predict the in situ coal pillar strength appears to be feasible. The deformation property of large pillars can be obtained successfully by testing the coal sample in the laboratory within acceptable accuracy. There are prevailing directional strength and deformation properties in coal pillars along the butt and face cleat system.

Jan 1, 1976

By S. J. Aresco

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions5/ issued by the Bureau of Mines; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor and, if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1961

By Foster Fraas

Almost all minerals show irreversible changes in electrical conductivity after heating in the temperature range 100° to 800° C. This effect can be detected with only a limited number of minerals with the standard ionizing-electrode-type separator, which differentiates between nonconductors and conductors in the single-particle resistivity range of 1011 to 1013 ohms. Tests outside this range with other type separators, such as the static field type, increase the number of minerals with which the effect can be detected to almost all that were tested. Irreversibility may be the result of an alteration of adsorption layers, volatilization of surface cations or anions, or an oxidation or reduction. One example is limonite, which decomposes to hematite and passes through two minima and two maxima in conductivity in the temperature range 100° to 900° C.

Jan 1, 1959

By William O. Vanderburg

Some mines after passing through the prospecting stage and becoming sizable enterprises still adhere to the development program of the prospect, extending their workings without definite plans. In mining operations where definite structural conditions do not exist, a prearranged layout of mine development is not feasible; but where exploration and preliminary development have indicated the extent and probable limits within which the ore is expected, careful planning of development will result in a lowering of mining costs and a consequent increase is profits. A lack of definite plane for laying out mine workings is one of the contributory factors to unnecessarily high costs. Although this paper deals primarily with the influence of level spacing on mining costs, still other phases of mine development, such as the proper spacing of ore chutes and raises, can be analyzed on a cost basis in a similar manner, as shown herein. LEVEL SPACING The problem of establishing a new level or levels in order to exploit steeply dioping ore deposits and prospect the ground at depth recurs at intervals during the active life of mines. Driving levels is largely "dead work" and therefore costly. By the judicious selection of the proper level interval after balancing the opposing factors involved in the problem, a considerable saving in mining costs can be effected. Although much has been written in regard to the various methods employed in ore extraction, mining literature is still incomplete in regard to the factors-influencing level spacing at various mines. Level spacing involves procedures not lending themselves readily to description, and, moreover, it is a phase of mining operations that is apt to escape criticism, because only those in close contact with the operations are equipped with the necessary familiarity with the conditions to pass judgment.

Jan 1, 1932

By T. F. Tomb

Past experience has shown that the penetration characteristics of the 10-mm nylon cyclone used on approved personal sampling equipment are significantly different from those determined in the laboratory using a nonpulsating flow source. The Bureau of Mines has developed and recommended a modification to presently approved equipment that will alleviate this difference. However, as a result of this modification, a new relationship for converting respirable dust concentrations measured with approved personal sampling equipment to equivalent concentrations as measured with an MRE instrument will have to be established. This Bureau of Mines report describes the underground sampling program conducted to establish a new factor for converting respirable dust concentrations measured with personal sampling equipment, modified with a recommended pulsation damping device, to an equivalent concentration as measured with an MRE gravimetric dust sampler.

Jan 1, 1973

By R. L. Crosby

The Bureau of Mines investigated alloys of copper with 2, 3, and 4 vol pct alumina and with 2 vol pct yttria. Alloys were prepared by a coprecipitation process and were fabricated by pressing and sintering of powders, extrusion, and swaging. Tensile properties at room and elevated temperatures, stress-rupture strength, electrical conductivity, and density were measured. The superiority in elevated temperature strength of dispersion-strengthened copper to OFHC copper was confirmed. Increasing the oxide content from 2 to 4 vol pct produced only a small improvement in strength properties and decreased the electrical conductivity. The 3 vol pet alumina alloy had the best overall combination of properties.

Jan 1, 1969

By W. L. Crentz

San Juan County, which occupies the extreme northwest corner of New Mexico, contains large reserves of coal in the Fruitland formation and in the Menefee formation of the Mesaverde group. The coals have bright luster, are brittle, and break easily in handling. All mines sampled are in the La Plata-Fruitland and Rio Chaco districts of the Durango-Gallup coal field. This large area, all within San Juan County, contains numerous coal beds 5 to 15 feet thick. Ellis2/ mentions the Carbonero (Fruitland in this report) bed in the La Plata-Fruitland district attaining a thickness of 36 feet. This bed has been correlated with the Carbonero bed, formerly mined at Carbon Junction, near Durango, Colo. During the field investigation covered by this report, no operating mine in the Fruitland bed was working a bed thickness of more than 15 feet.

Jan 1, 1957

By John B. Knaebel

This paper, describing the milling operations of the St. Joseph Lead Co. at Balmat, N. Y., is one of a series of similar papers being prepared by the United States Bureau of Mines on practice at various mills in the United States, Canada, and Mexico. The company also operates a mine end mill at Edwards, 12 miles northeast of Balmat. Mining practice in the district, as exemplified at the Edwards mine, is described in another information circular of the Bureau of Mines.3 The writer gratefully acknowledges the generous cooperation of the company officials which made this investigation possible, and wishes to thank R. J. Mechin, manager, P. W. Wolf, mill superintendent, and F. G. Kuehl, assistant mill superintendent, for their helpful assistance. Especial thanks are due J. S. Brown, geologist, for supplying information on the characteristics of the ore, and to C. F. Jackson, principal mining engineer, U. S. Bureau of Mines, for helpful suggestions.

Jan 1, 1932

By A. T. Coumbe, I. F. Avery

The Bureau of Mines has completed a survey of petroleum pipe - lines by direct correspondence with the oil companies and the use of the records of the Interstate Commerce Commission in order to cover both interstate and intrastate systems . The review shows that crude petroleum and product pipe -lines in the United States had a total length of 152,814 miles on January 1 , 1950 , an increase of 25,463 miles since May 1 , 1941 , the time of the last previous survey . The expansion in pipe -line systems was due largely to new trunk-line construction , as the mileage built to carry refined products increased by 11,880 miles , and those intended for crude -oil transportation gained 6,193 miles . Trunk lines represented 60 percent of all pipe -line mileage on January 1 , 1950 , compared with 58 percent in 1941 . The average diameter of trunk -lines for crude oil , as calculated on the various sizes and weighted according to their respective lengths , increased to 9.8 inches on January 1 , 1950 , compared with 8.4 inches on May 1 , 1941. The mileage for lines up to 8 inches used in crude trunklines has decreased since the 1941 survey , while those of larger sizes have increased . The extensive use of large- diameter oil pipe -lines has developed since the construction of two major lines from Texas to the East Coast at government expense as a World War II emergency measure . The successful operation of these lines proved their economic advantages over smallerdiameter lines as well as their effectiveness in moving unprecedented volumes of oil during the period when tanker movements were restricted by submarine action in the Atlantic Ocean . The 24-inch diameter " Big Inch " line carries over 300,000 barrels daily of crude oil , and the 20 -inch " Little Big Inch " carried over 230,000 barrels daily of gasoline and light fuel oils to destinations where they were urgently needed . Hence , Although these lines were sold and converted to natural -gas service in December 1946 , after fulfilling their wartime mission , their record proved to the industry that significantly lower operating and investment costs per barrel -mile of oil moved could be achieved than were possible with the comparatively small lines in general use up to that time . the several major oil pipe -line projects that have been constructed since the late war are of large diameter pipe . To assure supplies and market outlets of sufficient magnitude to support such lines and provide adequate flexibility , ownership is often shared by several large companies whose transport needs are served in common . The principal recent expansion in facilities has been from supply points in Southwestern States toward markets in the North and East and to Gulf tidewater .

Dec 1, 1950

By Robert A. Speirer, Richard G. Burdick

Methods of detecting geologic faults and other linear features by means of processed LANDSAT satellite images have gained prominence during the past several years . There have been numerous programs written to pick these " lineaments , " but they have been almost universally tailored to large computers . This Bureau of Mines report describes a detection method developed for use with a minicomputer . The method comprises a suite of programs that scans an image for all " potential " lineaments . From this partially analyzed data , the final lineaments are picked by another routine . The method was field tested in an area of south- central Wyoming , and results indicated good agreement between computer- picked lineaments and ground features . Most of the known geologic faults in the area were picked by the method . Such features as roads and trails were also picked but were easily distinguished from faults during field inspection . The method is relatively new but promises to be a viable reconnaissance technique for the mining industry in geologic structural analysis .

Jan 1, 1965

By W. P. Haynes, J. W. Mulvihill, G. B. Taylor, S. Katell

Capital and operating costs have been estimated for separating methane and hydrogen in gas - separating plants designed to produce 90 million scf per day of product gas containing a minimum of 90 percent methane . After a preliminary literature review of various separation techniques , three different processes --moving - bed adsorption using active carbon , oil absorption , and liquefaction -- were chosen for the cost estimates . Three different methane feed gas concentrations , 5 , 20 , and 50 percent ( cases 1 , 2 , and 3 , respectively ) , were chosen as representative methane concentrations for the separation estimates . Capital and operating costs were lowest for the moving - bed adsorption process in all three cases investigated . Operating costs declined from $ 0.24 to $ 0.06 per 1,000 cu ft of product gas , and capital costs declined from $47,490,800 to $7,411,200 as the percentage of methane in the feed gas increased from 5 to 50 percent .

Jan 1, 1964

By Raymond L. Lowrie

Coal deposits in the Boulder-Weld County coalfield in Colorado are analyzed in relation to economic factors governing the growth, stability, and competitive potential of the coal industry. Recoverable reserves, estimated to be 571 million tons, are discussed in detail, particularly those in the Erie and Frederick Quadrangles. Geology of the coal measures, quantity and quality of water resources, and chemical and physical properties of the coal are described. Coal production factors, including mining techniques and equipment, labor requirements, transportation facilities and rates, and markets, are considered for coal's position in competition with alternate fuels. Growth of the fuels market, through increasing thermal-electric power generation in the Denver Metropolitan Area, will stimulate coal production in Colorado. Reserves of the contiguous Boulder-Weld coalfield, if mined in a sustained, year-round, high-tonnage operation, could be used to supply much of that fuel demand.

Jan 1, 1966

By J. Grumer

The Bureau of Mines, under the sponsorship of the Space Nuclear Propulsion Office, conducted a laboratory-scale hydrogen safety study which determined several combustion characteristics of hydrogen diffusion flames. Experiments show that ambient air may enter the top of a hydrogen flare stack when the hydrogen flow is low. A new concept, supported by photographic evidence, predicts that diffusion flames burning in air on a wide, upright pipe (stack) and fed with slow, upward flows of buoyant gas will induce a downward flow of air along the walls of the pipe that can support combustion within the pipe. Predicted flamedip limits agree roughly with experimental values determined on 6-, 12-, and 18-inch-diameter stacks and increase with increasing stack diameter. Measurements were made of the limiting flow at which a hydrogen diffusion flame blows out in still air. By means of an empirical application of the critical boundary 8 velocity gradient concept, these data lead to a blowout limit of about 10 reciprocal seconds for a hydrogen diffusion flame. Burning rates of large hydrogen diffusion flames ranging from about 0.03 to 1 ft/sec were used to predict approximate flame heights on flare stacks. Temperatures of larger hydrogen diffusion flames up to about 3,600° F were observed, but the most representative value appears to be about 2,600° F. It was found that crosswinds do not strip significant amounts of unburned hydrogen from its diffusion flame and that water-cooled flare stacks are not likely to be damaged when flame is blown back into them by opposing winds.

Jan 1, 1970