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By W. F. M. GOSS

The locomotives in service on the railroads of this country consume more than one-fifth of the total coal production of the United States. The amount is so large that any small saving that can be made effective in locomotive practice at once becomes an important factor in conserving the fuel supply of the nation. For this reason the United States Geological Survey gave attEmtion to the special problems of combustion in locomotive boilers. It approached this task from several different directions. The facts presented herewith constitute one series of results. In the fall of 1906 the locomotive-testing laboratory of Purdue University, at Lafayette, Ind., entered on a series of tests, one purpose of which was to determine in precise terms the degree of efficiency with which a modern high-class American locomotive utilizes the heat energy of the fuel supplied to it. The general interest in the subject, the elaborate plans which had been formulated for conducting the work, and the substantial character of the support which had been pledged to maintain it justified the Geological Survey in aiding the investigation. a The cooperation of the Survey consisted in detailing experts to assist the regular staff of the laboratory in the chemical and calorific work of the tests. These experts, working under the general supervision of the director of the Purdue laboratory, became responsible for the sampling of smoke-box gases, of the fuel used, of the cinders caught in the front end, of the sparks discharged by the stack, and of the refuse caught in the ash pan. The gas analyses were made by them at the university laboratory. The analyses of all solid samples and the calorific tests of the fuels were made at the government fuel-testing plant at St. Louis. The representatives of the Survey were not concerned with other phases of the work.

Jan 1, 1911

By A. B. Hooker, L. C. IlsLey

"The last previous Bureau of Mines publication relative to details of permissible electric mine lamps is Bulletin 332, which describes 16 lamps approved prior to May 1930. Some of the lamps have become obsolete through the development of improved models which, with several new types, make it desirable to supplement the Bureau's published data relative to permissible electric mine lamps.In the following descriptions, lamps approved since May 1930 and prior to July 1, 1935, are placed in the three following groups: (1) Electric cap lamps, (2) electric hand lamps, and (3) lamps for miscellaneous applications,ELECTRIC CAP LAMPS APPROVED UNDER SCHEDULE 6B1. Edison model J lamp, approval no. 24. - The features that distinguish this lamp from earlier models of Edison electric cap lamps are:(a) The battery consists of two F-2 cells of square cross section and about 1-1/4 inches higher than M-14 cells in the model H lamp, making the battery narrower and higher than any of the earlier models of Edison cap lamps.(b) The cells are insulated from each other and the Monel-metal casing by enclosure in vulcanized-rubber baglike enclosures. Both cell terminals are insulated from the cell jar.(c) The battery is equipped with rubber-tube Bunsen-valve-type gas vents.(d) The battery casing is secured by a new-type magnetic lock.(e.) The battery and cover terminal clips have been redesigned to give a wiping contact."

Jun 1, 1936

By Charles H. Parr

A testing program was conducted to determine the suitability and reliability of adhesives and polycarbonate lenses for extended use in luminaires in mine environments. Polycarbonates were exposed, for periods up to 36 months, to four environments including ultraviolet light, humidity, intermittent water spray, and heat of either 180°F or 407 in various combinations. Rod impact tests on the exposed lens material indicated, that polycarbonate functions well under all 180°F environments and could be used with confidence for periods exceeding the test period, for as long as ten years, with a suit) able safety factor employed in design. The specimens exposed at 240°F showed decreased toughness after 24 months' exposure. Extrapolation of these data was deemed to be risky. A 462-day compatibility test between polycarbonate and six hydraulic fluids was run on stressed PC beams. One fluid caused beam breakage in less than one day, while three caused breakage at intermediate times. Two fluids exhibited essentially no effect on the PC when compared to a control. Epoxy and silicone adhesives were tested as lens adhesives and sealants. Three epoxy combinations tested showed low and erratic failure stresses. A room-temperature-cure silicone adhesive functioned extremely well for time periods up to 36 months and temperatures u2 to 240°F.

Jan 1, 1985

By J. B. Gayle

The Bureau of Mines studied the effects of air oxidation on the recovery of float coal. Both batch-and continuous-type tests were made on six bituminous coals, representing the range in rank of coals now commercially used for carbonization, and on one anthracite coal. The effects on flotation recovery of oxidation at 1000 C for periods up to 50 days were investigated using an alcohol-type frother and a kerosine-pine oil reagent. Two series of release analysis tests were made, using one medium-volatile bituminous coal. Float coal recovery was adversely affected by oxidation in all tests where the alcohol-type frother was used. Conversely, a small degree of oxidation improved recovery with kerosine-pine oil frother for some of the coals in continuous tests. Prolonged oxidation (beyond about 14 days) adversely affected float coal recovery for all coals, the effect being more pronounced for batch-type tests and for tests using alcohol-type frother. Reagent selectivity for the rejection of both ash forming and sulfur bearing minerals was reduced by oxidation. Severe reduction of reagent selectivity required only about 3 days' oxidation for alcohol-type frother but more than 10 days' oxidation when the kerosene-pine oil reagent was used.

Jan 1, 1965

To reduce operator exposure to drilling noise from roof bolting machines. Background Noise-induced hearing loss (NIHL) is a prevalent occupational illness in the United States. Studies indicate that 70%?90% of miners have NIHL significant enough to be classified as a hearing disability. Mine Safety and Health Administration studies indicated that roof bolting machine operators are among those overexposed to noise. Field studies support the premise that, on average, drilling is the loudest noise source to which a roof bolting machine operator is typically exposed and contributes greatly to the operator?s noise exposure. The National Institute for Occupational Safety and Health (NIOSH) has further determined that the drill steel and chuck radiate a significant amount of noise during drilling. To address this noise hazard, NIOSH developed a collapsible drill steel enclosure (CDSE) to encapsulate the drill steel during the drilling portion of the roof bolting machine duty cycle. In addition, NIOSH is collaborating with J. H. Fletcher & Co. in the continued development of a CDSE.

Sep 1, 2008

By B. L. Razzaboni, P. Bolsaitis

"The formation of reactive oxygen species resulting from the interaction of silica dust particles with red blood cell membranes was investigated; particularly, the effect of surface hydroxyl (silanol) group concentration on the rate of formation of such reactive oxygen species was investigated. The rate of formation was measured indirectly through the effect of catalase, a hemoprotein peroxidase, on silica-induced hemolysis. It was found that the addition of exogenous catalase to erythrocytes markedly reduces the hemolysis caused by silica particles. Furthermore, the amount of catalase required for deactivation of silica per unit area of particle surface is lower for fumed silica particles and calcined crystalline particles than for uncalcined, crystalline silica, suggesting a correlation between the concentration of OH groups at the silica particle surface and its potential for generation of H2O 2• The addition of albumin, a copper chelator, also decreases hemolysis. These results suggest that the hemolysis caused by silica particles is at least partly related to the formation of H2O2 at the particle surface and its subsequent reaction with Cu+ ions. The relationship between the concentration of surface silanol groups on the silica surface and the amount of catalase required to decrease hemolysis may also provide a method for testing potential fibrogenicity of respirable dusts. IntroductionReactive hydroxyl groups on silica surfaces are known to be cytotoxic and are believed to play a major role in silicosis (1-9). It has been proposed that this cytotoxicity results from hydrogen bonding to cell membranes and a resulting increase in membrane fluidity and permeability (4). Surface hydroxyl groups on silica surfaces have also been shown to interact with carbonyl oxygens in cell membranes (1,5). An extensive study by Nolan et al. (6) of the relationship between the negative surface charge resulting from ionized silanol groups and the hemolytic activity of crystalline a-quartz (Min-U-Sil) has shown a positive correlation between hemolytic activity and the surface concentration of silanol groups. These authors demonstrated that the hydrogen bonding of polyvinyl-N-oxide (PVPNO) with silanol groups, as well as the bonding of metal cations to the ionized sm- groups, results in significant decreases in hemolytic activity. Furthermore, it has been found that the complete removal of surface hydroxyl groups from the surface of respirable silica particles nearly eliminates the hemolytic potential of silica (7), suggesting that hydroxyl groups might be involved in other cytotoxic processes associated with silica-induced lung injury. Reactive oxygen species have been .implicated in cellular damage caused by respirable silica particles. Evidence for the presence .of oxygen radical species (02, OH°, H2O2) generated by silica, especially on freshly formed surfaces, has been produced by various investigators. Kalbanev et al. (8) detected H2O 2 in aqueous suspensions of quartz. Electron spin resonance and spin trapping by Shi et al. (9) confirmed the presence of OH"" radicals in aqueous suspensions of quartz, and Gulumian and van Wyk (10) suggested that both glass and quartz produce hydroxyl radicals in the presence of H2O 2 • Gabor et al. (11) detected the presence of malondialdehydereactive lipid peroxides (i.e., lipid-0°) in cultures of macrophages and respirable silica particles using the thiobarbituric acid (TBA) reaction test. Will (12), however, reported that iron enhances the TBA value of peroxidized lipids, and Scheulen and Kappus (19) found that catalase augmented malondialdehyde formation, thereby increasing the TBA values."

Jan 1, 1990

By George A. Bell

This paper reviewing the leaching practice of the New Cornelia mines of the Calumet & Arizona Mining Co. at Ajo, Ariz., is the first of a series being prepared by the Bureau of Mines on leaching methods and costs in the various mining districts. ACKNOWLEDGMENTS The author acknowledges the assistance of T. G. Chapman, consulting engineer, and E. D. Gardner, supervising engineer of the Southwest Experiment Station, Bureau of Mines, Tucson, Ariz.

Jan 1, 1930

By M. D. Carver

This publication describes development by the Bureau of Mines of a quality evaluation procedure for certifying the adequacy of production lots of Kroll process zirconium sponge the Bureau had produced for reactor applications. After the procedure was devised, the next step was to apply it in controlling the quality of one-half million pounds of zirconium sponge com-prising 259 production lots, called blends, originating at the Metallurgy Research Center of the Bureau at Albany, Oreg. The Bureau concluded that the evaluation method developed was adequate and that by this method the zirconium blends having impurity levels or other property values outside specification limits were differentiated and thus were diverted from nuclear energy end uses. The research was performed under contract for the Bureau of Ships, Department of the Navy, and for the Atomic Energy Commission (AEC).

Jan 1, 1960

By Sabri Ergun

Previous studies of magnetic separation of pyrite from coals have been reviewed critically. Magnetic susceptibilities of United States coals of differing rank have been measured. The effects of crushing, magnetic mixing, drying, weathering, and heat treatment on the enhancement of the magnetism of pyrite have been analyzed. The importance of size distribution of pyrite in the coal and the necessity of crushing to liberate the pyrite has been discussed. It has been found that the inherent susceptibilities of the carbonaceous, mineral-free portions of coals (? -0.5 X 10-6 in cgs units) and of relatively pure pyrite isolated from coals (? -0.3 X 10-6) do not permit efficient separation of pyrite from coal; the average susceptibility of the magnetic fraction of coal must be raised to 3 X 10-6. Friction forces encountered in crushing sedimentary pyrite embedded in coal do not increase its susceptibility. Subsequent weathering or heat treatment below 400° C leads to the formation of iron sulfate and hence increases the effective paramagnetism of pyrite. Ferromagnetic compounds of iron are not formed in significant quantities at temperatures below 400° C. The degree of liberation and apparent susceptibility of pyrite are the most important parameters in its separation. It is concluded that effective beneficiation of coals can be achieved by magnetic separation. A sufficient increase in the susceptibility can be achieved by converting less than 0.1 percent of pyrite into ferromagnetic compounds of iron. Such conversions occur only at temperatures >500° C. An investigation of the dielectric properties of coals and pyrite in the frequency range 0.1 to 60 Mhz indicates that the imaginary dielectric constant of the pyrite is about 100 times larger than that of coal. Exploratory experiments indicate that pyrite can be selectively heated to temperatures above 500° C without appreciable rise in the temperature of coal. It appears that dielectric heating of coals in the Ghz frequency range is the most feasible method of enhancing the paramagnetism of pyrite.

Jan 1, 1968

USBM Contract H0133045 consists of the design, build and test of 50 waveform generators. The waveform generator is a small ULF transmitter operating in the 1 to 3 KHz frequency range for the purpose of locating trapped miners during a mine disaster. This contract provided for the design, test, and building of 50 waveform generators using a discrete component construction with an option of using hybrid construction techniques within 105 days after the effective date of the contract. Because of large quantity economic considerations, this option was not initiated. Two engineering models were designed, constructed and tested and 50 final production units were fabricated using discrete construction. Complete documentation is supplied under a separate package which includes final schematics, parts list, layout information, equipment specification, production test procedures and qualification test procedures. Ten units have been delivered to the USBM. The remaining 40 units are being retained for packaging under contract H0242010 Transmitter Package and Receivers.

Jan 1, 1974

By C. Fang, D. B. Kittleson, K. L. Rubow

"Under contract to the U.S. Bureau of Mines, a study was conducted to investigate the feasibility of using the microorifice. uniform deposit impactor (MOUOI) to measure the size distribution of aerosols containing various mixtures of coal dust and diesel exhaust particles. The project objective was to determine if the mass concentration of diesel exhaust particles, in an airborne mixture of coal dust and diesel exhaust particles, could be determined on the basis of the size distribution of the two aerosols. In general, the mass of diesel exhaust particles is in the submicrometer size range while that of the coal particles lie in the larger size ranges.The MOUDI is a cascade impactor with small diameter nozzles to obtain small cut sizes and rotating impaction plates to avoid particle overloading of the deposit. For this study, a 7 stage version was used. At the sample flow rate of 30 L/min, the cut sizes were 0.10, 0.23, 0.70, 1.0, 2.6, 4.9 and 10 pm.Size distributions of aerosols generated in the laboratory and in several underground coal mines were measured. The primary emphasize of the laboratory tests was to ascertain if the diesel exhaust particles could be separated from the coal dust, regardless of mass fraction of the diesel exhaust particles in the total aerosol mixture. Diesel exhaust, from a Caterpillar Type 3304 NA diesel engine, was mixed with coal dust generated with a· TSI Model 3400 fluidized bed dust generator. Experiments showed the size distributions of the mixed aerosols exhibited two definite modes with the minimum between the two modes in the 0.7 to 1.0 um size range. Distinct modal separation was obtained as the mixture fraction of the diesel exhaust aerosols was varied from 3% to 98%.The field study was conducted in three underground coal mines, two utilizing diesel-powered equipment and the third exclusively using electric equipment. Sampling sites were selected to obtain a wide variety in the diesel exhaust and dust aerosol concentrations. Size distribution data showed these aerosols are bimodal. The mass median aerodynamic diameters of the diesel particulate mode and the coal dust mode were approximately 0.15 µm and 3 to 10 un, respectively. The results, in all cases, clearly show a separation between the two modes in the 0.7 to 1.0 µm size range with the minimum in the vicinity of 0.8 pm. The separation was found to be independent of mass fraction of the diesel exhaust particles, total particle concentration and sampling site."

Jan 1, 1989

By E. Morrice, R. D. Smith

Thermal expansion and electrical resistance measurements were made on cerium metal from 4° to 300° K. The apparatus developed , including a specimen holder and a cryostat system , are described along with the experimental techniques used in obtaining the measurements . The total linear thermal expansion Data at of 99.83 weight - percent cerium metal between 4 ° K and room temperature was 4.24 percent . The resistivity at 4° K was 7.0 x 10-6 ohm- centimeter . 4° K indicate a fundamental relationship between residual resistivity and purity of cerium metal . The effects of annealing and repeated thermal cycling on resistivity were determined .

Jan 1, 1964

By P. A. Wasson

The investigation described in this publication was conducted by the Bureau of Mines to determine the effectiveness of the anionic silica flotation method on goethitic iron-bearing materials from the Cuyuna Range, Minn. Samples used in this investigation were a composite of drill core from 13 holes, and 3 samples from lean ore stockpiles. These samples are believed to be typical of the mineralization occurring in an area with a potential reserve of several million tans of submarginal iron ore. Results from batch tests showed that the iron-bearing minerals could be effectively concentrated by flotation removal of the siliceous gangue. The drill hole composite yielded laboratory flotation concentrates from locked tests containing 56.8 percent Fe and 6.1 percent silica, with an accompanying iron unit recovery of 94.2 percent. Concentrates containing 52.4 to 53.7 percent Fe also were produced from the lean ore stockpile materials; corresponging iron recoveries ranged from 71 to 79 percent in the batch tests, with the possibility remaining for additional recovery of iron from the middlings.

Jan 1, 1963

By C. C. Furnas

In the course of an investigation3 of the flow of gases through beds of broken solids the author obtained a number of data .on the specific volume of beds of broken solids of variously mixed sizes. A mathematical theory of the limiting conditions has been developed and some generalizations have been made for intermediate cases. A more definite knowledge of the relation between space occupied and size composition would be valuable to all those who are handling large quantities of broken materials. Such knowledge might be advantageously applied to the operation of a coke oven. For example, the output of the oven depends in general upon the number of pounds of coal which can be put in the oven at charging. It is known that the capacity of one battery of ovens was increased several per cent by slightly increasing the proportion of fine material in the charge.

Jan 1, 1928

By David R. Flinn

This Bureau of Mines report describes methods to electrodeposit erosion-resistant titanium diboride coatings from molten alkali metal borate baths at 900° C. These coatings have been shown to be highly resistant to material loss during impingement with high-velocity alumina and silicon carbide powders, and they show promise as protective coatings to reduce metal loss in erosive chemical environments, such as coal gasification systems. The most erosion-resistant coatings were prepared on nickel, Inconel, and molybdenum from an electrolyte containing LiBO2, NaBO2, Na2Ti03, and TiO2. The best coatings were deposited at current densities of [~]20 ma/cm2, using titanium or titanium diboride anodes. Erosion-resistant coatings were shown to exhibit (1) a high degree of crystallographic orientation along the (100) or (110) planes, (2) a chromium impurity level of less than 3 pct, and (3) a uniform, smooth, consolidated surface appearance when viewed under a microscope or by scanning electron microscopy. Optical spectroscopic studies of the molten electrolyte suggest that the lower valent (+3) titanium ion predominates in the baths.

Jan 1, 1979

By Israel Liebman

The Bureau of Mines developed three types of passive water barriers for suppressing slow-moving coal dust explosions. One type is a modification of a conventional tub barrier and depends on the dynamic pressure generated ahead of an explosion to tilt the tub to release its water and suppress the explosion. The other two barriers operate in response to an increase in static pressure developed ahead of the explosion. Tests indicate the first barrier begins to release its water at air speeds as low as 50 ft/sec, and the second and third barriers will operate at a rise in static pressure as little as 0.5 psi. All three barriers were found to be effective in suppressing coal dust explosions propagating at speeds as low as 100 ft/sec. A plan is described for installing a water barrier in a working mine on a trial basis.

Jan 1, 1976

By L. W. Kelly

The purpose of this paper is to indicate some of the benefits that have been derived in the Zeigler No. 3 mine by using roof bolts under extremely adverse roof conditions J with the thought that much better results could be obtained in other mines with more normal roof conditions by applying some of the practices that were developed in this mine. Some of the benefits that have been obtained in this mine, which will be shown in this paper, are: 1. Increased tonnage per man-shift at the face when roof bolts are used, as compared to the tonnage under similar conditions when conventional timbering methods were used. 2. Increased efficiency of roof bolting by giving the foremen a definite plan to follow. 3. Reduction in delays caused by failures of the trailing cables of loading, mining, and drilling machines. 4. Reduction in the number of accidents after roof bolting was adopted. Inasmuch as the success that followed roof bolting in this mine was obtained under one of the most treacherous roofs in the Middle West, it is reasonable to suppose that correspondingly better results could be obtained under more favorable roof conditions by using the same procedure.

Jan 1, 1952

During 1990-1999, a total of 458 fires occurred in all coal mining categories; 157 of those fires caused 164 injuries and 2 fatalities. The greatest number of fues and fire injuries occurred at surface mines, whch also had the highest risk rate values. A total of 66 fuefighting interventions were required. Of these, there were 25 mine rescue team interventions in underground mines, including 5 mobile equipment firefighting interventions, and 41 fire brigade and fire department interventions at all surface operations, including 19 mobile equipment interventions. In all, 50 fires destroyed or heavily damaged equipment (including 16 pieces of mobile equipment) because of failure of other firefighting methods, late fire detection, undetected fires, or fire size. A total of 1 14 fires were detected late by smoke, and 42 fires were not detected.

By Harold E. Marr

Energy dispersion X-ray analysis was evaluated for possible application in the secondary metals industries for the rapid analysis and identification of copper-base alloys. Laboratory investigations of standard brass and bronze samples indicate that X-ray methods are capable of separating standard alloys into 10 general classes with analytical times of less than 3 seconds per sample for clean, flat samples. A radioactive source of americium 241 with a secondary fluorescer was used as an excitation source, and a lithium-drifted silicon semiconductor detector was utilized for energy discrimination of X-rays.

Jan 1, 1974

By D. C. Crowell

This publication presents the results of a laboratory investigation of displacement of gas by injection or imbibition of water into sandstone models under essentially isobaric conditions. A brief discussion of scaling requirements is included. The influence on residual gas saturation of independently varying the parameters of dimensional ratios of the porous media, rates and methods of flooding, surface tension, initial water saturation, and permeability is shown. Of these variables, increased initial water saturation and decreased surface tension reduced residual gas saturation significantly, whereas variations in flooding rate and dimensional ratios had no apparent effect. No correlation was evident between absolute permeability and residual gas saturation.

Jan 1, 1966