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By Lester J. Crow

A preliminary survey was performed to investigate the impregnation of relatively weak, porous volcanic tuff and a relatively strong, dense sandstone with five different monomers. Increases in compressive strengths by factors of 2 to 5, and elastic moduli by factors of 2 to 3.5, are reported for natural rocks (tuff., sandstone, dacite), which were impregnated with five monomers (methyl methacrylate; chlorostyrene; 40 percent TMPTMA-60 percent styrene; 40 percent TMPTMA-60 percent chlorostyrene; 60 percent polyester-40 percent styrene); polymerization took place after monomers were forced into the rock. Impregnation was performed (1) by pressurizing rock specimens from one end, or (2) by a vacuum-soak operation. Polymerization was accomplished by either radiation or chemical initiation techniques. Strength improvement is dependent on (1) the type of monomer used, (2) the amount of polymer incorporated into the rock, and (3) the degree of water saturation of the rock. Water saturation strongly reduced the effectiveness of the method for the polymer systems tested. The more viscous monomers (for example, 60 percent polyester-40 percent styrene) were more effective in displacing the water from the rock, and compressive strengths of wet rock were doubled with these systems. Water saturations ranging from 25 to 100 percent of maximum saturation gave essentially identical results. Further tests on other types of mine rock; including shale and coal, are planned. Water-compatible polymer systems should be developed, or present systems should be suitably modified. For application to tunnel stabilization, design studies evaluating the improvement in rock strength and its influence on the support system are also recommended.

Jan 1, 1971

By John J. Henn

As part of the U.S. Department of the Interior programs on rutile, authorized by the Office of Emergency Preparedness in June 1967 under provisions of the Defense Production Act, the Bureau of Mines reviewed available literature on major proposed processes for producing rutile substitutes. The processes are grouped according to the major processing step, and important operating features are described. Sixty-one references are cited.

Jan 1, 1970

By H. D. Jacobs

The Federal Bureau of Mines, as part of a program to insure future raw material needs for the iron and steel industry, undertook research to beneficiate the oxidized taconites from the western Mesabi range in Minnesota. The data presented were obtained by applying the Bureau-developed selective-flocculation/cationic-flotation process to the second of three oxidized taconite samples. These three samples are representative of an estimated 10 billion tons of ore analyzing 30 to 40 pct iron. The experimental work was performed in a 900-lb/hr pilot plant. Treating the ore sample (36.1 pct Fe) with the Bureau's process produced commercially acceptable concentrates averaging 63.5 pct Fe and 4.3 pct SiO2, with an average iron recovery of 84.6 pct.

Jan 1, 1980

By A. L. Murray, C. A. Allen

"The Industrial Commission of Utah from a study of the accidents (especially the fatalities) occurring in connection with mining in the State was struck by the large number arising from lack of due care on the part of the employee injured or carelessness on the part of some fellow employee. Figures show that approximately 40% of the deaths are due to carelessness as against only ) 10% or 12% that can be laid to faulty conditions in the mines. With a view to reducing the number of these accidents an intensive campaign of education was inaugurated, conducted jointly by the Industrial Commission of Utah and the United States Bureau of Mines.Through the cooperation of the U. S. Bureau of Mines, Mine Rescue Car No. 11 operating in Utah has been utilized as the means of carrying on the campaign. In making the regular training visits to the mining camps of Utah the crew of car 11 was authorized to include with the courses of instruction in Mine Rescue and First Aid, safety and health rallies, foremen's safety meetings, and appeals carried on through the public schools to stimulate an awaking of personal responsibility of miners and their familiar' in safety and health endeavor. The work was placed under the direct charge of Dr. Murray who has had previous experience in similar work and brought to the campaign helpful enthusiasm. He was assisted by Bruce Johnson, fore¬man miner of Car 11, who had been safety engineer for the U. S. Smelting Company, and R. W. Clark, first aid miner of Car 11. The expense of providing posters, literature, pledge cars, buttons, rental of special educational films and incidental expenses of foremens' meetings has been born by the Industrial Commission.Plan of the Campaign.In planning the campaign the main object was to revive as much as possible, among the workers, a spirit of responsibility for safety. Any considerable reduction of preventable accidents can be accomplished only through the workers themselves who are responsible for such accidents, therefore, the more personal the application could be made to all the workers the greater the accruing results would be."

May 1, 1921

The U.S. Bureau of Mines (USBM) has developed a test procedure to compare the initiating strength of detonators by using adjustable-sensitivity liquid explosives. Various tests of detonator strength are currently used by the industry, but many of them do not quantify the ability of detonators to initiate detonation reactions in an explosive charge. The USBM used mixtures of nitromethane and ethylene diamine, the sensitivity being "fine-tuned" by 2-nitropropane. Military standard J-2, commercial No.6, and commercial No.8 detonators were evaluated using three test configurations: (1) axially immersed in the test explosive, (2) tip just touching surface of the explosive, and (3) immersed transversely in the explosive. Markedly different results were obtained for these three configurations, indicating that the directional effects are important. This explains why different detonator strength tests do not correlate well with each other. Some tests, such as the sand bomb and underwater, measure the total energy out-put, while other tests, such as the plate dent, test measure the energy in the axial direction. The USBM's test data indicate the importance of conducting the experimentation in the manner in which the detonator is actually intended to function.

Jan 1, 2010

By R. G. Warncke, Stanley M. Walker

The United States Bureau of Mines was created by an act of Congress in 1910 as a governmental agency to work , on a national scale , toward reducing the huge annual loss of life in the production and processing of the Nation's minerals . From 1906 to 1910 , inclusive , nearly 2,500 miners lost their lives in 84 major explosion disasters , and more than 13,000 suffered fatal injuries from all causes in the coal mines of the United States . Also , conditions in the metal and nonmetal mines were proportionately hazardous during this period , and the total loss of life in all mines and quarries exceeded 3,000 annually and approximately 250,000 workers suffered serious injuries . Under these conditions it is readily understandable why Congress took notice of this " high cost of mining" , and from the investigations and hearings of the day emerged the Bureau of Mines charged with the prevention of accidents and the preservation of the health of all those engaged in the mineral industry; this has continued to be a most important part of the work of the Bureau . Throughout its existence the Bureau of Mines has had no legal authority of enforcement , except during war years , when enforcement necessary to the national security was given to it . The Bureau believes that persuasion , with factual evidence , is the proper and best way to obtain compliance with the safety suggestions made by its engineers and scientists . There is no panacea for accidents , nor will any single " approach " , instill safety consciousness in all workers , and without it accidents will occur --and occur again . To persuade men to work safely, numerous forms of appeal are required to reach the various temperaments of workers in many types of mines operating under diverse conditions .

Nov 1, 1949

By Michael Sokaski

A dense-medium cyclone pilot plant was built to clean 112-inch to 0 size coal. This pilot plant does not require the removal of the extremely fine material (usually minus 1/2-mm) from the feed, which is necessary in conventional dense-medium cyclone plants. The essential difference between conventional cyclone plants and the pilot plant is in the medium-recovery system. The latter uses a combination of sieve bend screens, classifying cones, and magnetic separators for medium recovery. Eight tests were run in the pilot plant at a feed rate of 5 tons per hour with four different raw coals and one crushed jig middling product. Sharp separations were obtained as indicated by an average error area of 27 and probable error of 0.047 for the 112-inch to 200-mesh size range. Magnetite loss averaged about 2.5 pounds per ton of feed. The influence of several factors on cleaning performance of the cyclone was investigated. The diameters of both the overflow and underflow orifices were found to be important for optimum cleaning performance, but these diameters could vary over a wide range without serious effect; however, if this range was exceeded, cleaning performance deteriorated. Better cleaning performance was obtained when the cyclone inlet pressure was increased from 9 psig to 13 psig. The size of the magnetite particles in the medium was found to have a substantial effect, and the best cleaning results were obtained with grade B magnetite. Demagnetizing the magnetite in an effort to decrease the effective particle size did not improve cyclone performance.

Jan 1, 1963

By C. O. Ruud, R. E. Siemens, D. Chandra

The mineralogical constitution of a lateritic ore dictates the type of metallurgical process that can be used to extract valuable metals such as nickel and cobalt . To provide needed mineralogical information on the interrelationships of the metals contained in domestic laterites , the Bureau of Mines awarded a grant to Denver Research Institute to study the transition - type , low - grade laterites found in northern California and southern Oregon . For comparison , limonitic - type laterites from New Caledonia and the Philippines were also studied . X-ray diffraction , electron microscopy , electron beam analysis , and conventional petrography were used to determine the mineralogical associations of nickel and cobalt in the laterites . Results showed that for both laterite types studied most of the nickel and minor amounts of cobalt are associated with the mineral geothite ( FeO ( OH ) ) . Most of the cobalt and minor amounts of nickel are associated with a mixed manganese oxide (wad ) mineral .

Jan 1, 1983

By R. G. Dressler

The Federal Bureau of Mines designed, constructed, and operated a demonstration plant at Louisiana, Mo., to produce gasoline, liquid fuels, and organic compounds from coal by a modified Fischer-Tropsch gas-synthesis process. Satisfactory equipment was developed to produce and purify synthesis gas and convert it into the desired products. Coal or coke was gasified with oxygen and steam to make a gas consisting essentially of carbon monoxide, hydrogen, and carbon dioxide. Dust in the raw gas was removed by cyclone separation, water scrubbing, and electrostatic precipitation. Carbon dioxide, hydrogen sulfide, and organic sulfur were removed with diethanolamine, iron oxide, and activated carbon. The gas was passed over iron catalyst and was converted into synthetic liquids, which were then separated and fractionated into gasoline, diesel oil, other liquid fuels, and oxygenated organic compounds. A 39-day continuous run demonstrated the feasibility of the process. Addition of 3 milliliters of tetraethylead per gallon of upgraded (or finished) gasoline gave a product with an octane rating up to 90 by the research method. After a caustic wash, the diesel oil was of a superior quality; its cetane number was 60 or above.

Jan 1, 1961

By V. T. Dow

In April 1957 the Bureau of Mines instituted a reconnaissance of titanium-and zirconium-bearing heavy sandstone deposits in the Four-State area of Utah, Wyoming, New Mexico, and Colorado. This report summarizes the study. Eighty-two deposits or groups of deposits, containing an estimated 27,920,000 tons of titaniferous sandstone, were examined in the Four-State area; 16 in southern Utah, 19 in Wyoming, 33 in New Mexico, and 14 in southwestern Colorado. The 16 deposits examined in Utah contain an estimated 1,043,000 tons with an average grade of 17.98 percent TiO2, 5.67 percent ZrO2, 20.98 percent Fe, and 0.09 percent equivalent Th02. The 19 deposits investigated in Wyoming are estimated to contain 21,873,000 tons of titaniferous sandstone having a weighted grade of 5.22 percent 702, 0.55 percent ZrO2, 24.8 percent Fe, and 0.01 percent equivalent Th02.

Jan 1, 1961

By James M. Stuckey

In a search for improved methods of upgrading tar obtained by low-temperature carbonization of coal, monoethanolamine (MEA) was found to be effective in extracting tar acids from coal tar distillates derived from a subbitunwous and a lignite coal. Patch extractions showed that both yield and purity of the extracted acids improved with increasing volume ratios of monoethanolamine to tar acid, varied from 1:4 to 8:1. Yield improved, but purity decreased as the concentration of monoethanolamine was changed from 30 to 70 volume-percent, and as the concentration of tar acid in distillate was increased ad from 14 to 45 percent. In a continuous countercurrent extraction employing a double solvent (monoethanolamine and hexane) approximately 80 percent of the tar acids was extracted from 170° to 350° C. tar distillate when using 1.6:1 volume ratios of amine:tar acids. Tar acids isolated from his extract, although of improved purity, contained appreciable quantities of neutral oils and some tar bases. Aqueous monoethanolamine was not effective for extracting the last 10 to 15 percent of tar acids in 170° to 350° C. distillate oil from lignite coal. The highest yield of isolated tar acids and the best recovery of monoethanolamine were obtained by diluting the extract with water and saturating with C02. Some losses of solvent were encountered when aqueous monoethanolamine solutions were heated through decomposition of the amine with the liberation of ammonia.

Jan 1, 1960

By M. M. Wong

Salt mixtures consisting of KC1, BaC12, and HfCl4 with RbCl or CsCl were investigated as electrolytes for refining hafnium. The presence of RbCI or CsCl in the electrolyte appeared to suppress the volatility of. Best electrorefining was obtained with an electrolyte containing 50.7 percent KCl, 27.l percent BaCl2, 15.7 percent CsCl, and 6.5 percent HfCl4. In this electrolyte, hafnium metal with an average oxygen content of 470 ppm was produced from an anode feed containing l,600 ppm oxygen. All metallic impurities were lowered, except titanium, manganese, and tin.

Jan 1, 1966

By Raghoottma S. Pandurangi, Mohindar S. Seehra

"The interaction of amorphous 1ilica particles with several hydrogen bonding agents (H2O, C2H5OH, C7H2NO) was investigated by monitoring the changes in the bulk and surface IR vibrational modes of silica using photoacoustic spectroscopy. It is argued that the intensity of the silanol band at 3747 cm-1 provides (an inverse) quantitative measure of the interaction or surface groups, along with the shift in the broad hydroxyl band, the interaction following the order C7H2NO > C2H5OH > H2O. Index Headings: Silica; Surface vibrational modes; Photoacoustic spectroscopy; Hydrogen bonding agents.INTRODUCTIONThe use of m spectroscopy to study the adsorption on solid surfaces is well documented in the literature.1 2 For example, hydroxylation of a clean silica surface results in the formation of the free silanol group Si-OH, with a sharp IR band near 3747 cm-1• Further hydroxylation produces a broad band near 3500 cm-1, which is believed to result from various hydrogen-bonded silanol bands leading to a multilayered surface structure of few nm.3-5 Earlier studies had indicated a relationship between the surface silanol band and various chemical activities of silica such as cytotoxicity, 7- 9 catalysis, 10-12 and others.13 Recent studies from our group14-in which the intensity of the silanol band and cytotoxicity of silica, heat-treated at various temperatures up to 1095°C, were investigated have provided a strong correlation between cytotoxicity and intensity of the silanol band.Coating of silica by PVPNO (polyvinyl-2-pyridine N-oxide with the empirical formula C7H8NO), a strong hydrogen bonding agent, is known to reduce the cytotoxicity of silica, presumably by chemically blocking the silanol groups from phospholipids.15 This interaction of the hydrogen bonding agents with the silica can be studied by m spectroscopy, and Knozinger16 and Rouxlet and Semples11 have used transmission m spectroscopy to study the effect of various chemicals on the surface IR modes of silica. However, one of the major disadvantages of transmission IR spectroscopy is that the sample preparation (grinding and mixing with KBr and pelletizing) usually distorts the surface modes (see, e.g., Ref. 14) and there is always a doubt about the effect of the sample preparation on the measured properties. In recent years, photoacoustic (PA) spectroscopy has become the technique of choice for studying the IR spectra of samples in their natural state, since no sample preparation is necessary.18•19 Moreover, according to a recent paper, 20 the relative intensity of the surface modes in PA spectroscopy of silica particles is much higher than that in transmission FT-IR spectroscopy. Consequently PA spectroscopy is ideal for studying the surface chemistry. In this work, we have used PA spectroscopy to investigate the interaction of three hydrogen bonding agents (C7H8NO, C2H50H, and H20) with the silica surface by monitoring changes in the surface m modes. Our results show that the surface IR modes get perturbed to a larger extent than the bulk IR modes in interaction with the hydrogen bonding agents. Moreover, whereas in the earlier studies, the shift of the broad silanol band near 3500 cm-1 was used as a measure of the interaction with hydrogen bonding agents,16•17 here we show that the relative decrease in the intensity of the sharp silanol band near 3747 cm-1 also serves as a quantitative parameter for the relative surface coverage and surface modification. Details of this work are given below."

Jan 1, 1990

By N. A. Eilertsen, Rolf S. Paine

The Bureau of Mines studied the presplitting technique used for controlling overbreakage in the walls of a vertical shaft at the U.S. Army Corps of Engineers Littleville Dam project near Huntington, Mass. The periphery of the shaft, the dimensions of which were 16-1/2 feet wide by 21 feet long and 52 feet deep, was presplit (cracked) in the solid to a depth of 48 feet prior to full-depth sinking. Presplitting prevented overbreak in a fairly soft schist and provided sound self-supporting walls which required very little scaling.

Jan 1, 1965

By D. H. Hileman

Economic investigations indicate that bituminous coal can be mined underground in the Uinta region and marketed at a cost competitive with that of other energy sources in the West. A selling price of $3.90 per ton of coal was calculated from a cost analysis of a projected coal mine in the Emery coal- field of Utah. Although mines in some of the coalfields have extremely difficult mining conditions and cannot compete in the energy market at this price level, at least two other coalfields in the Uinta region contain coal reserves that could be mined and sold at a price of approximately $3.90 per ton. Projections by power companies and other coal-consuming industries indicate a strong future market for the large coal reserves in the Uinta region.

Jan 1, 1970

By Foster Fraas

This report describes the application of pulsed magnetic fields derived from alternating and intermittent magnetizing currents. Application of such pulsed magnetic fields to the matrix-type separator permits (1) the complete discharge of the magnetic fraction with wet feeds and (2) the dry separation at particle sizes down to 325 mesh. At smaller particle s indications are that frequencies above 60 hertz will be required. Applications of intermittent magnetizing current to the cross-belt separator give the cross-belt-separator an advantage over the conventional constant-field cross-belt and induced roll separators; the intermittent current enables the cross-belt separator to separate matted fibrous and magnetically coagulating feeds, a type of feed that occasionally occurs with mineral, industrial, and secondary materials.

Jan 1, 1973

By R. W. Van Dolah

The Bureau of Mines t.ced its investigations into sympathetic detonation of ammonium nitrate (AN) and ammonium nitrate-fuel oil (AN-FO) to define the scaling law for safe separation from detonating AN-FO. Both missile- and non-missile-producing AN-FO donors, weighing up to 5,400 pounds, were employed with acceptors of the same size. The usual cube-root scaling law was not confirmed; exponents for the relationship S = f(Wx) for AN were 0.51 with non¬missile-producing donors and 0.61 for missile-producing donors. For AN-FO an exponent of 0.80 was indicated in the missile-producing case. AN-F0 in polyethylene bags appeared somewhat more easily initiated than bulk AN-FO. The efficacy of barricades in protecting AN charges was investigated. detonation distances were reduced from one-third to one-seventh when filled barricades were employed. The investigation was extended to dynamite with both types of donors. With 1,600-pound missile-producing donors and an equivalent weight of dynamite, initiation would be expected in 50 percent of the trials at 167 feet. The corresponding value in the non-missile case was 67 feet. The data developed in this program of sympathetic detonation will allow the development of a rational set of safe separation distances for AN, AN-FO, and explosives.

Jan 1, 1966

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

By J. F. Barkley

Two major problems in the operation of air preheaters for boilers are corrosion and the accumulation of deposits on the heating surfaces. Corrosion or loss of metal necessitates replacement of parts; the accumulation of deposits decreases the size of the gas and air passages, resulting in increased pressure drop for the same gas flow, and also affects the heat transfer. These items, either singly or together, limit the capacity and efficiency at which the equipment can be operated and affect its availability, even causing undesirable shutdowns under extreme conditions The field and laboratory work on regenerative air preheaters described in this report covers research on the relative corrosion resistance of different materials, such as various metals, special metal coverings, and fired clays, and studies on deposits, their nature, analyses, and corrosive effects. This is the first report on cooperative work of The Air Preheater Corp., of New York City, and the Federal Bureau of Mines.

Jan 1, 1953

By James A. Wasson

This report analyzes the petroleum-production potential of the basal Greenbrier dolomite zone, Sycamore-Millstone field, Sherman District, Calhoun County, W. Va., through the application of certain secondary-recovery methods. The well logs obtained and the core recovered from a well in this formation permitted an evaluation of the productive capability of the reservoir, Approximately 120,000 stb of oil may be produced from a 20-acre five-spot unit at breakthrough if the property is waterflooded. At an assumed limiting producing gas-oil ratio of 20)000 sef/stb, approximately 69,000 stb of oil should be recovered by low-pressure gas drive.

Jan 1, 1967