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By J. Cseff

A variety of shaft and hoist equipment exists in the United States. Nearly all hoist systems are electrically driven. Machine elements which comprise the hoists and ancilliary equipment include bearings, shafting, drums, gear reducers, couplings, brakes, clutches, sheaves and electrical motors. Volume I, Systems Description, describes the various components encountered in most mine hoist and shaft installations, and brief descriptions of functions and constructions. Hoist ropes and balance ropes are specifically excluded from this report. Associated with the hoisting system is the headgear, shaft and equipment, loading/dumping facilities and the actual conveyances and their rope attachments. Volume II, Inspection and Maintenance Procedures, discusses scheduled Inspection and preventative maintenance in general terms. Preventive scheduled inspection and maintenance procedures assist in the smooth operation of mine hoisting plant, by the prevention of unscheduled or catastrophic equipment failure and its attendant downtime. Schedules and overall maintenance planning is required at the management level. Records and equipment logs must record inspection and maintenance, and unusual operations or incidents. A cross reference between MSHA regulations and various equipment components is included as part of the report. A discussion of the various non-destructive testing methods which may be applied to hoisting equipment is also included.

Jan 1, 1981

By Arthur V. Petty

The Bureau of Mines has investigated the effect of refractory oxide additions, introduced in soluble form, on the refractory properties of 42-, 58-, and 70-pct-A1203 brick. Brick having porosities ranging from 12 to 16 pct were impregnated with solutions containing chrome, chrome-iron, zirconium, calcium, magnesium, cobalt, nickel, tin, and manganese ions. Additions of some of these ions provided dramatic improvements to such properties as hot modulus of rupture, hot load, and particularly slag resistance. These improvements can be related to reduction of porosity, amorphous grain boundary phases, formation of more refractory bond phases, and reduction of the wettability of Al203-containing refractories by metallurgical slags. Fifty-eight-percent-AI203 brick, impregnated with chrome, showed hot modulus of rupture, hot load, and slag resistance two to five times better than those of untreated 70-pct-AI203 brick. This could result in reducing the Nation's dependence on imported refractory-grade bauxite generally required for high-A1203 brick, as domestic alumina resouces could be used to produce the improved refractories.

Jan 1, 1984

By Raghoottma S. Pandurangi, Mohindar S. Seehra, Pedro Bolsait, Bronwyn L. Razzaboni

"Surface IR (infrared) modes of crystalline and fumed (amorphous) silica particles, calcined at temperatures up to 1095°C, have been studied by Fourier transform infrared spectroscopy. The ability of these same particles to lyse cells has been measured by a hemolysis protocol. The untreated crystalline and amorphous materials differ by a factor of 40 in specific surface area, and the intensity per unit mass of the sharp surface silanol band near 3745 cm-1 in the amorphous material is an order of magnitude larger than in the crystalline material. A similar difference is observed in the lysing potential of the two materials. The intensity of the silanol band increases after calcination for both materials, reaching peak values near 500°C, followed by a dramatic drop at higher calcination temperatures, and reaching negligible values for materials calcined near 1100°C. The lysing potential data follow essentially the same pattern for both crystalline and fumed silica. These results are consistent with the hypothesis that the surface silanol groups are involved in cell lysis. Further experiments are suggested to evaluate the relationship between the surface structure of ailica particles and their potential cytotoxicity. IntroductionThe characterization of the surface structure of various allotropic forms of silica is of interest because the cytotoxicity of silica particles of respirable size has been commonly related to the chemical interaction of functional groups on the surface of such particles with the lipoproteins contained in cell membranes (1-3). It has been found that the cytotoxic potential of silica particles varies greatly with their crystalline structure (4,5), particle size (6-8), surface composition (9), and molecular surface configuration (1,10). Studies of the infrared (IR) modes of various forms of silica have been reported by a number of researchers (3 ,11-19). Several books and reviews (20-24) have dealt with the identification of functional groups on silica surfaces and the effect of heat treatment on the surface structure. The nature of the surface is said to be critical in determining the biological activity of silica dusts (3).Fourier transform infrared (FTIR) spectroscopy is a highly sensitive ·technique for identifying IR surface modes of tine particulates, and it was deemed of interest to examine the surface structure and its relation to lysing potential of two widely different types of respirable silica dust. The lysing potential of respirable dust particles has been considered a first-level test for potential cytotoxicity."

Jan 1, 1990

By H. Kenworthy

The objective of this investigation was to evaluate the technical feasibility of smelting certain low-grade domestic iron ores in an electric furnace. Laboratory-scale experiments showed that a high recovery of iron in the form of pig iron can be obtained from east Texas ores containing less than 25 percent iron. The pig iron was amenable to standard-or electric-furnace-refining methods for producing steel. Car-bon, silicon, and phosphorus were the primary impurities removed in refining. Overall recoveries of iron as pig iron exceeded 95 percent, in contrast with commercial mineral-dressing recoveries on these particular ores of 50 percent of the iron as a 45-to 50-percent iron concentrate.

Jan 1, 1958

By E. S. Shedd

The Bureau of Mines investigated electrowinning and tapping lanthanum metal from lanthanum oxide in a fluoride bath. The electrolyte was composed of LaF3, BaF2, and LiF. Metal containing 0.2 percent impurities was produced at a rate of over 2 pounds per hour. Principal impurities were carbon, aluminum, and silicon. Low-carbon metal was produced by continually discharging the carbon oxide gases and maintaining 0.1-atmosphere pressure. Anode reactions and cell design were found to be important factors in cell operation. Both frozen electrolyte skulls and tungsten metal crucibles proved satisfactory for collecting the metal and did not react with the molten lanthanum.

Jan 1, 1966

By Sidney Katell

The reaction of coal, oil, or natural gas with air and oxygen and/or steam yields a gas containing varying amounts of impurities. Depending on the raw material and the end use of the product, these impurities include solids, such as dust or slag, and gases, such as hydrogen sulfide, carbon dioxide, and nitrogen. Considerable effort has been expended in developing and operating purification systems, and the literature is replete with equipment data and operating results. The research problems, the design, and the operation of the various systems have been the subjects of patent applications, journal articles, and textbooks.

Jan 1, 1959

By H. R. Appell

The Bureau of Mines studied the conversion of a variety of cellulosic wastes, for example, sawdust, bovine manure, sewage sludge, urban refuse (free of metal and ceramics), etc., to heavy oils. The objective of the investigation was to determine the scope of the reaction and elucidate the chemistry involved. The reactions took place in the presence of synthesis gas and water or carbon monoxide and water under conditions of elevated temperatures and pressures. Waste conversions above 90 pct, often near 99 pct, with oil yields in the range of 40 to 60 pct, were obtained in the temperature range of 250° to 425° C and pressure range of 1,500 to 4,000 psig. Because mild conditions were sought, most of the experiments were conducted at temperatures of 250° to 350° C and pressures of 1,500 to 3,000 psig. In general, lower viscosity products were obtained at higher reaction temperatures. Conversions and oil yields were significantly increased by operating in the presence of a high-boiling oil; either anthracene oil or oil recycled from the process was satisfactory. Synthesis gas containing 50 pct carbon monoxide gave satisfactory results as a replacement for carbon monoxide. Cobalt molybdate on alumina catalyst, used with sodium carbonate, gave a product of lower viscosity and lower oxygen content than sodium carbonate used as the sole catalyst. The waste-to-oil process has been successfully investigated in continuous flow equipment as well as in batch autoclaves.

Jan 1, 1975

By Laxman S. Sundae

Laboratory tests were conducted at the U.S. Bureau of Mines to determine the effects of roof-bolt drilling parameters on penetration rate in sandstone using tungsten carbide alloy (WC-Co) and polycrystalline diamond compact (PDC) drill bits. During the tests, water pressure of 552 kPa was found to be adequate for removing the cuttings from the tops of drill holes. Test results show that for both types of bits, penetration rate increased when thrust was raised from 227 to 1,588 kg. When water pressure rose from 554± 120 to 1,344±350 kPa, the effect on penetration rate was not significantly different. Conventional WC-Co bits became dull when one or two holes were drilled, after which the penetration rate dropped dramatically. Microscopic examination shows that the cutting edges of PDC bits also become somewhat dull, but at a much lesser rate than WC-Co tips. Microscopic examination also reveals that the wear mechanism of WC-Co and PDC bits is quite different, which may explain the longer life of the PDC bits.

Jan 1, 2010

By W. G. Pariseau

A U.S. Bureau of Mines case study of pillar recovery in high-grade ore near the Ross shaft at, the Homestake Mine, Lead, SD, has demonstrated the usefulness of the finite-clement method for the evaluation of shaft pillar mining plans and shaft stability. This report, one of three in a series describing the Ross shaft pillar case study, focuses on the premining stability analysis. The two-dimensional computer program UTAH2 was used in advance of pillar mining; results suggested that the shaft would remain stable. Subsequent reports describe parts 2 and 3 of the study. In part 2, borehole extensometers and other instruments were installed to provide data for model verification and shaft monitoring. Results of the recalibrated two-dimensional model confirmed the premining stability evaluation. However, after mining began, great concern developed because of the appearance of cracks and other signs of ground movement over considerable distances from the area of active pillar miping. In part 3, an intense three-dimensional modeling effort using UTAH3 was initiated. The results again showed that the shaft would remain safe. Three-dimensional analyses of alternative pillar mining scenarios indicated that more of the shaft pillar ore reserve could be recovered than previously thought.

Jan 1, 2010

By A. H. Roberson, F. S. Wartman

For many years , it has been the common practice at most copper mines to recover copper in solution in effluent mine water by precipitating the copper with scrap iron.4/ The technique employed varies from simply throwing scrap iron or tin cans into the waste ditches to passing the water through elaborate launder systems containing detinned scrap and baled cans . In general , a considerable amount of low - cost copper has been recovered that otherwise would have been lost . Iron consumption usually varies from 1 to 1-1/2 pounds of iron for each pound of copper recovered . The grade of the precipitate may be as much as 90 percent copper.4/ ,5/ Where the consumption of iron is materially greater , its cost is likely to be the determining factor of profit . In times of emergency, when the demand for scrap iron for remelting increases the cost of the iron sharply, and the supply of tin cans is not large enough to meet requirements , recovery of the copper might not be economical . The three principal reactions that take place when an acid mine water containing iron and copper salts in solution is brought into contact with metallic iron are : (1 ) Copper is precipitated and an equivalent amount of iron is dissolved , CuSO4 + Fe Cu + FeSO4 ; ( 2) ferric salts are reduced to ferrous salts , Fe2 (SO4 ) 3 + Fe = 3FeSO4 ; and (3) the free acid in the solution reacts. with metallic iron to produce ferrous sulfate , H2SO4 + Fe = H2 + FeSO4 . = Because of the reported high.consumption of iron (5 to 6 pounds per pound of copper precipitated ), when copper in water from the Hornet mine of the Mountain Copper Co. ( California ) was precipitated upon scrap iron , a series of tests was made to determine . the . optimum treatment, time , and consumption of iron .

Feb 1, 1944

By R. Havens, B. K. Shilber

"INTRODUCTION In the course of the investigation of the occurrence of manganese deposits in the western United States, ore-dressing tests were made on three samples procured by Bureau of Mines engineers from two properties in southeastern Juah County, Utah, each of which is known by the name Black Jack. To avoid confusion, the tests will be described under the names of the owners Kendall-Duvall and the Empire Mines.None of the samples were amenable to ore dressing for the production of high-grade manganese sinter.Ores from the Kendall-Duvall deposit represent an interesting metallurgical phase of low-grade manganese occurrence, as the occurrence of manganese as silicate (braunite) automatically governs the extent to which they can be beneficiated by mechanical methods of treatment. As less than 50 percent of the total manganese was recoverable by complex methods of treatment in a 40- percent-manganese sinter, attempts were made to recover most of the manganese in a low-calcite, intermediate-grade product that might be acceptable for subsequent metallurgical treatment. By selective flotation of calcite and manganese, up to 68 percent recoveries were obtained in plus 20-percent manganese products..No encouragement can be given for successful ore-dressing of Empire ores as represented by samples received for testing, as no products were obtained that would meet minimum marketing specifications. Empire ore contained only 1 percent lime and might be high enough in grade (19 percent manganese) for direct hydrometallurgical treatment."

Nov 1, 1947

By William O. Vanderburg

Tis paper describing the mining practices at the Cold Springs mine of the Wolf Tongue Lining Co. at Nederland, Colo., is one of a series of similar papers prepared by the Fureau of kines on mining practices, methods, and costs at various mines in the United States. The writer acknowledges the assistance of William Leach and William T. Todd, manager and mine superintendent of the Wolf Tongue Mining Co., respectively, in the preparation of this paper.

Dec 1, 1932

By H. E. Powell

Magnetic susceptibilities were determined by the Bureau of Mines fur 19 cobalt- and nickel-bearing minerals and for a suite for synthetic cobalt-nickel diarsenides analogous to the rammelsbergite and safflorite series. Relations between susceptibility and composition were found to be nonlinear for both impure natural minerals and pure synthetics.

Jan 1, 1967

By Ann G. Kim

The Bureau of Mines investigated factors that influence the formation of methane and other hydrocarbon gases in coal, which is an integral part of the coalification process. Coalification begins with a biogenetic stage in which plant debris decomposes and peat is formed; methane and CO2 are the predominant gases produced during this stage. During the diagenetic stage of coalification hydrogen and the hydrocarbon gases methane, ethane, ethylene, propane, propylene, butene, iso- and normal butane, and pentane are formed by dissociation of the organic material. Methane may also be produced by a secondary reaction of hydrogen with unsaturates or by the reduction of CO2. The gas contained in coalbeds is a mixture of methane, C2 through C5 alkanes, CO2, 02, N2, H2, and H2; its heating value is equivalent to that of natural gas. The gas content of coal depends on many variables, but an empirical relationship between adsorptive capacity, rank, and depth has been observed.

Jan 1, 1978

By William G. Pariseau

A small displacement-small strain finite element technique utilizing the constant strain triangle and incremental constitutive equations for elastic-plastic media that are nonhardening and obey a Coulomb yield condition has been applied to the analysis of gravity flow initiation in a V-shaped hopper containing a powder under lunar environmental conditions. Three methods of loading were examined. Of the three, the method of computing the initial state of stress in a filled hopper prior to drawdown by adding material to the hopper layer-by-layer is superior (as expected). Results of the analysis of a typical hopper problem show that the initial state of stress, the elastic moduli, and the strength parameters have an important influence on material response subsequent to the opening of the hopper outlet.

Jan 1, 1971

By Carl Rampacek

Recent research by the Bureau of Mines has demonstrated that the segregation process has merit for treating oxidized and mixed oxide-sulfide copper ores. The process comprises heating the crushed ore with salt and coke or other carbonaceous materials at about 700° C. to produce fine flake copper, which then is recovered by conventional copper-flotation methods. Bench-scale laboratory tests of a number of oxidized and mixed copper ores assaying 0.78 to 5 percent Cu gave copper recoveries of 73 to 96 percent. The flotation concentrates assayed 21 to 76 percent Cu, depending on the ore being treated.

Jan 1, 1959

By W. R. Huff

This report describes the development and operation by the Bureau of Mines of a pilot plant designed for using high-volatile A bituminous coal-in-water suspensions as a source of preheated coal and superheated steam in the pressure gasification of coal with oxygen. Figure 1 on page 2 is a block diagram of the integrated gasification process, in which a total of 70 tons of coal was fed from slurry and gasified. The present work included (1) development of equipment and methods both for mixing pulverized coal and water to produce slurry and for pumping and metering the slurry at gasification pressure; (2) development of equipment for heating the flowing slurry and, because slurry that can be pumped produces more steam than is necessary as a gasification reactant, developing equipment for removing and metering the excess steam; and (3) demonstration of the process under actual gasifier operating conditions, at a coal rate of about 800 pounds per hour and gasification pressures in the range 100 to 300 pounds per square inch gage. By using the forced-convection principle, a flow of slurry made from a caking, high-volatile A bituminous coal can be continuously heated to 600° F. in a coil-type heater. The flow rate and concentration of the slurry and the temperature gradient along the length of the heating coil must be closely controlled. In a radiant-type heater, involuntary reductions in flow rate, even momentary, can lead to coking and plugging of the heater coil.

Jan 1, 1961

By F. D. Stevenson

A metal diaphragm pressure relay system was constructed to measure vapor pressures of the metal halides, oxyhalides, and other substances at temperatures up to 700° or 800° C. The vapor pressure of arsenic (III) oxide (As2O3) was determined to verify the reliability of the apparatus for such measurements. The data for the liquid AS2 Os (2820 to 4830 C) are represented by the equation, log Pmm = 6.875 - 2,929/T, from which the normal boiling point was calculated to be 461° C. The heat of vaporization calculated from this equation was 13.40 ±0.09 kcal/g mole As4OS and is essentially constant over the interval studied. The melting point of the octahedral arsenic (III) oxide was determined to be 278° C from the inter-section of the solid and liquid vapor pressure curves, A thermal analysis apparatus is also described by which melting and transition temperatures could be checked by a method independent of vapor pressure data. The melting points of the monoclinic and octahedral forms were determined to be 314.4 ±1.4° C and 278 ±5° C, respectively.

Jan 1, 1963

This publication summarizes the research (in-house and contract projects) programmed by the Bureau of Mines for fiscal year 1984 (October 1, 1983-September 30, 1984) under its Health and Safety Technology Program. The objective of these projects is to provide an ordered and sequenced advance toward the Bureau's overall goal of providing the systems technology required to create a more healthful and safer working environment for the Nation's mining and minerals processing workers.

Jan 1, 1983

By R. W. Van Dolah, N. E. Hanna, F. C. Gibson

Measures that were taken to eliminate noise resulting from explosives work at the Bureau of Mines facility at Bruceton , Pa . , are described . A method for monitoring sound transmission characteristics of the atmosphere and control of the explosives testing is presented as a noise control measure that offered partial relief during the period in which the modifications were made . Design details of the replacement gallery , used for permissibility testing of explosives , and the modifications of four types of bombproofs are given . Operation of the closed facilities are completely satisfactory , and the noise problem has been entirely eliminated .

Jan 1, 1964