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By C. J. Chindgren

A refractory-lined, garage-type automobile incinerator with a natural gas afterburner for air pollution control was cooperatively constructed and tested by the Bureau of Mines and the Wasatch Metal & Salvage Co. in Salt Lake City, Utah. The incinerator is capable of relatively smokeless burning of 32 to 60 cars per day, dependent on the degree to which the cars are stripped prior to incineration. Preliminary burning campaigns indicate the cost of incineration to be approximately $2.75 per car.

Jan 1, 1970

By J. B. Gayle

A 1/2-ton experimental coke oven was installed ac the Bureau of Mines Southern Experiment Station, Tuscaloosa, Ala., in 1948. Designated as the Tuscaloosa oven, this unit features a 17-inch carbonizing chamber, globar heating elements, and silica-brick walls designed to simulate as closely as possible the carbonizing conditions for commercial slot-type ovens. Because of the small force exerted on the oven walls in most tests conducted to date (probably owing to the practice of charging coals and blends at a moisture content approximating that normal to commercial plants operating in this district), little information has been obtained about expansion properties. Two sole-heated ovens have therefore been constructed and used as supplementary equipment for determining the expansion properties of coals tested in the Tuscaloosa oven. The reasons for constructing the Tuscaloosa oven, the details of design, the operating, characteristics of the oven and the reproducibility of results have been discussed in previous publications. 3 4 5/ The present report deals with the effects of substituting various high- and low-volatile coals for components of a selected base blend carbonized under conditions similar to those normally used for producing foundry coke. Results of tests of 11 coals and 14 blends indicate that several blends tested rave cokes having physical properties very similar to those produced from the reference blend.

Jan 1, 1957

By E. D. Eastman

"The factors that determine the efficiency of reduction of iron oxides by gaseous reducing agents may be considered in two classes; those which effect the equilibrium between the reacting substances end their products, and those which affect the rete of reaction. Both sets are of prectical importance, the former as influencing the maximum possible efficiency and the latter as determining what fraction of the maximum yield may be readily or profitably obtained. In addition, the thermal changes attending the reduction greatly affect the chance of successful industrial application of any such process, and knowledge of them is necessary for the intelligent design of apparatus and control of the reaction. Some aspects of each of these three divisions of the problem are discussed below.I. The Maximum Reducing Power of Fuel Gases on the Oxides of IronsThe gases that heve been considered specifically in this work are coal gas, water gas and producer gas, typical analyses” of which are given in Table 1 Of the various hydrocarbons represented in Table 1, (several being grouped or averaged as C2R4), methane is the only gas assumed to be capable of existence at appreciable pressures under the conditions of interest here. The equilibria in the several systems which may ensue when one of the above gases is allowed to react with the iron oxides, may therefore be represented in the most general case by equations of the type of the following arbitrarily chosen ones:"

Jun 1, 1923

By John J. Sammarco

Mining has one of the highest annual average fatality rates among major US industries. Health and safety dangers have been inherent to mining since the early days of picks and shovels. Even though miners' health and safety has improved over the years, mining is still one of the most dangerous occupations. Mining was traditionally a low tech industry. It is now driven by competitive pressures to go high-tech by using programmable electronics (PE) for machine control, atmospheric monitoring and material processing. The industry's experience with the functional safety of PE is limited compared with other industries. Thus, PE is an emerging technology for mining that can potentially create or worsen hazards. The US National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory in Pittsburgh, PA is addressing the safety of this new technology. NIOSH has a proactive project to generate recommendations for addressing the functional safety of PE-based mining systems before the technology proliferates. The recommendations take the form of a safety framework encompassing the entire life cycle for a PE-based mining system.

By J. D. Marchant

The Bureau of Mines studied solid-state electromigration to determine the value of the technique as a method of purifying cerium metal. Cerium metal in bars 6 inches long and 1/2 inch in diameter was refined at 600° C by solid-state electrolysis to remove iron, copper, and manganese. Iron and manganese were electrotransported to the anode and copper was electrotransported to the cathode. The concentration of iron at the anode of a cerium bar was 800 times greater than the concentration at the cathode. The concentration of manganese at the anode was twice the value at the cathode. The concentration of copper was 170 times greater at the cathode than at the anode. A radiotracer technique was used to follow the iron migration in the cerium metal. Molybdenum, silicon, and aluminum impurities were not electrotransported.

Jan 1, 1967

By Miles B. Royer

The experimental blast furnace has attracted increasing interest during the past decade as a practical means for investigating a broad range of blast-furnace smelting problems. Under experimental-furnace conditions, information can be obtained with less expenditure of time and raw materials and, therefore, at lower cost than comparable information could be obtained under industrial operating conditions. Furthermore, the experimental furnace may be operated beyond the range of smooth operation, even to failure, to delineate the limits of operability. Such deviation from normal operating practice would be economically intolerable in industrial operations where production and operating stability might be disrupted. The Federal Bureau of Mines experimental blast furnace at Bruceton, Pa., near Pittsburgh, has been operated and under development since 1951. However, the usefulness of this experimental data to industrial practice was somewhat nebulous in early experiments, and the correlation of the experimental blast furnace with the industrial blast furnace was not known.

Jan 1, 1961

By F. P. Haver

The Federal Bureau of Mines investigated aqueous electrolysis as a means for reducing lead chloride prepared by ferric chloride leaching of galena concentrate: NaC1 PbS + 2FeC13 ? PbC12 + 2FeC12 + S°. During electrolysis, metal was produced from solid lead chloride in contact with the cathode rather than from lead in solution. Relatively high current densities--up to 300 amp/ft2--were possible when operating in this way. A very simple cell, having a horizontal lead cathode at the bottom and a vertical graphite anode at the top, was employed. Lead chloride crystals, covering the cathode, were converted to metal powder during electrolysis, and chlorine gas or FeCls was produced at the anode, depending on the electrolyte composition. Electrolytes tried included aqueous solutions of HCI, NaCl, NH4Cl, and FeC12-NaC1. Optimum results (96-pct current efficiency, 0.23 kwhr/lb Pb) were obtained with 20 pct HC1 at 25° C, using a current density of 15 amp/ft2 and an electrode spacing of 1 inch. When the current density was increased, the energy requirement increased also but only to 0.41 kwhr/lb at 150 amp/fr3 and 0.58 kwhr/lb at 300 amp/ft2.

Jan 1, 1978

By R. L. Grayson, W. E. Wallace, T. Simonyi, J. C. Harrison

"Application of an SEM-based methodology suggests a reason for past contradictory results on the relationship between quartz and coal workers' pneumoconiosis (CWP). Results indicate that coal seams with the same bulk analysis of quartz may have different amounts of surface-availablequartz. Our research shows that the amounts of pure and surface-available quartz in a respirable dust vary directly with the rank of a coal seam, except in the case where rock materials are mined. The estimated amount of surface-available quartz therefore provides a measure of the quartz-related fibrogenic potential of a respirable dust.INTRODUCTIONFrom our previous work (Grayson, 1991), we have shown that the amount of pure quartz in a respirable coal mine dust sample appears to vary directly with the rank of the seam (using fixed carbon as the basis for comparison), except when a substantial rock parting, roof or floor are mined. Our other work (Wallace et al., 1989) showed that high-silica particles in a clay mine may generally be coated with clay, rendering the quartz core non-available for surface reaction in the lung. The combination of these findings led us to hypothesize that the coating phenomenon may indeed be present in coal mines as well, and that a rank relationship may be present regarding this phenomenon. Thus higher rank coal seams may have more surface-available quartz as well as more pure quartz particles in their respirable dusts. The scientific protocol for testing this hypothesis and the results obtained to date are discussed in this paper. Thus far, there is no reason to doubt that the relationship holds."

Mar 1, 1992

By A. W. Fahrenwald

[In studying coarse sand flotation3/ the question of the relation between fineness of grinding and mill capacity logically arose. Everyone familiar with present fine-grinding practice knows that the capacity of a ball mill or similar mill is determined, among other things, by the fineness of the finished product. Undoubtedly a great many mining companies must have a good deal of data directly bearing on this point, yet no quantitative relationship between ball-will capacity and fineness of finished product has been established. The experimental study presented here is an effort to establish this relationship in a semiquantitative way. The subject is a tremendously large one and grows in complexity as the study becomes more searching. In this work the power consumed by the mill in the various experiments was not determined end neither vas the steel consumption measured; mill capacity only was considered.]

Jan 1, 1930

By Carl F. Wingquist

Electrical resistance heating to effect thermal fragmentation of semiconductive rock was examined by the Bureau of Mines. Tests were carried out on copper-bearing ores of the Nonesuch Shale Formation in the laboratory and in the the field at White Pine, Mich. Fieldwork included primary and secondary breakage tests. Heating tests on in situ rock failed to produce thermal dam-age to an extent considered useful; however, boulders up to 30 ft3 were effectively broken by the method. Power input to the test rock was taken from a 50-kV, 5-amp dc power supply.

Jan 1, 1976

By T. A. Henrie, E. K. Kleespies

Electrolytic studies were conducted to determine the transfer rates of the alloying constituents from molten titanium anodes to solid titanium cathodes in molten salt systems . The metals , nickel , tin , copper , bismuth , and manganese , were selected on the basis of thermodynamic data and the melting point of the alloy system . The transfer of nickel , tin , and bismuth was very low . The content of these elements in the cathode was in the range of less than 0.01 to 0.001 percent . The copper transfer was 0.6 to 0.8 weight - percent in electrolytes containing titanium chlorides and 0.12 weight - percent in titanium fluoride salt systems . The manganese transferred at rates comparable to that of titanium . Highpurity titanium and titanium- manganese alloys of uniform composition were produced by electrorefining molten titanium alloys in chloride electrolytes . Comparisons are made between the calculated and the actual quantities of metal transfer .

Jan 1, 1964

By John W. Frey

This paper presents one of a series of digests of foreign mining legis- lation and court decisions which is being prepared in advance of a general re- port relative to the rights of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the laws of Portugal, prepared from the best available information in Washington, has been slightly amplified in accordance with suggestions trans- mitted through the courtesy of the Department of State by Fred Morris Dearing, American Minister at Lisbon.

Nov 1, 1929

By Russell C. Frith, David C. Oyler, Dolinar Dennis R., Christopher Mark

Unusual circumstances may require that a longwall retreat into or through a previously driven room. The operation can be completed successfully, but there have been a number of spectacular failures. To help determine what factors contribute to such failures, a comprehensive international database of 131 case histories has been compiled. The cases include six failures where major rock falls occurred in front of the shields, and seven even more serious failures involving major overburden weighting. The case studies suggest two types of room failure mechanism. The first is a roof fall type failure caused by loading of the immediate roof at the face as the fender or remnant longwall panel narrows. The second is an overburden weighting type failure caused by the inability of the roof to bridge the recovery room and face area, and affecting rockwell above the immediate roof. The data indicate that the roof fall type of failure is less likely when intensive roof reinforcement (bolts, cables and trusses) is employed together with higher-capacity shields. The overburden weighting failures, in contrast, occurred when the roof was weak and little standing support was used. Weighting failures were not greatly affected by the density of roof reinforcement. In one of the overburden weighting cases, in a Pittsburgh coal bed mine, stress cell, convergence, bolt load and extensometer data have been used to analyze the failure in detail. Key words: coal mining, ground control, longwall, recovery room.

By S. J. Pearce

The need for a simple, very sensitive, and accurate method for the determination of benzene in blood and urine vas evident throughout a recent study of chronic benzene (C6H6) poisoning conducted cooperatively by the United States Bureau of Mines, The Barrett Company, and the producers of benzene. A combustion method which will be described in a later publication, and a previously described/ adaptation of Smyth's method were developed and used during that investigation. The adaptation of Smyth's method gave satisfactory results when dealing with exposure conditions that produced chronic poisoning in a comparatively few days, but it was time-consuming; and lacked the accuracy necessary for a study of the absorption, distribution, and fate of benzene in the body during exposure to threshold concentrations of benzene vapor in air. The combustion procedure was satisfactory from the standpoint of sensitivity but was cumbersome, intricate, time-consuming, and required the use of special and somewhat expensive Physical and chemical apparatus. Following the termination of this study of chronic poisoning, possibilities ides for developing better methods occurred, and these have been investigated by the Bureau of Mines with the aid of Relief Works Division personnel microcolorimetric method for the determination of benzene in air has been described recently.6/ The present report deals rich the adaptation of this new colorimetric method to the determination

Jan 1, 1936

By Martin S. Oudenhoven

This Bureau of Mines report presents the results of a microseismic study conducted in the Climax block cave mine at Climax, Colo. Rock noises created by caving were monitored and their sources located during a 3-month period. A planar array of seven accelerometers, located above the block of ore being caved, detected the rock noise. A computer was used to calculate the location of the microseismic activity, using a traveltime difference method. The accuracy of these locations was estimated to be ±20 feet. An analysis of the data taken during the recording period showed a concentration of microseismic events located in the wall of the cave panel. This concentration of events was found to occur in a "high-silica" geologic forma-tion that cut across the caving panel approximately 200 feet behind the undercut.

Jan 1, 1973

By Nan C. Jensen

Silica, the world's most abundant mineral compound, is composed of the two commonest elements - oxygen and silicon. In addition to being the life-giving constituent of the atmosphere and the major element in the waters of the earth, oxygen comprises almost half of all known terrestrial matter and occurs combined with most of the other ninety-odd elements in the solid crust of the earth; however, a large proportion of the oxygen is combined with silicon. Silicon is second only to oxygen in abundance in nature and constitutes more than one-fourth of all known terrestrial matter. The compound of oxygen and silicon, called silicon dioxide or silica, forms 59.08 percent of the earth's outer 10-mile crust. Some of the silicon dioxide exists as

Jan 1, 1942

By D. H. Baker

THIS REPORT presents the technique and equipment used in determining the hardness of titanium sponge. Detailed descriptions are given of the methods used in preparing test samples for chemical analysis and hardness testing, the method of melting and surfacing test ingots, and the technique of reading Brinell-hardness impressions. The arc-melting furnace described, for which engineering drawings are included, will produce from 70 to 90 double-melted buttons each 8 hours of operation. Experimental data are also presented depicting the effect on hardness of the methods of surfacing specimens, temperature of test specimens, and the effect of time at test load. These data show that surfacing of the specimen involves no critical machining operations but that the test surface must be paralleled by a relatively flat surface for contact with the anvil of the Brinell tester. The heating of a specimen to 150° C. during surfacing does not materially affect the results if the ingot is cooled to room temperature before the hardness impressions are made. The optimum time at load appears to be approximately 30 seconds, but load times of as much as 1/ ½ minutes will not cause major errors.

Jan 1, 1959

By S. R. Borrowman

Mill tailings from conventional uranium extraction processes contain nearly all of the radium originally in the ore. Such tailings require controlled storage in perpetuity to safeguard the surrounding environment from radioactive contamination. Alternatives to controlled storage of the tailings are (1) removal of the radium from the tailings for separate storage or use or (2) removal of the radium when processing the uranium ore. In laboratory tests conducted by the Federal Bureau of Mines, radium was leached from tailings using either hydrochloric acid or ethylenediamine tetraacetic acid. A hydrochloric acid leaching method was used to extract both radium and uranium from the ore to yield tailings containing less radium than those produced by either conventional sulfuric acid or alkaline leaching processes. From 77 to 94 percent of the radium in mill tailings was concentrated by sedimentation in slime fractions representing nearly 25 weight-percent of the original sample.

Jan 1, 1975

By William Hustrulid

The National Institute for Occupational Safety and Health (NIOSH), as part of a comprehensive program to improve mine safety through the widespread acceptance of careful excavation principles in drifting, have revisited standard drift round design concepts. Although the initial emphasis was on contour row design and providing improved design tools for blasting with de-coupled charges, the focus has broadened into the development of a general gas pressure-based drift round design approach. The concept of a damage radius (Rd) for a given explosive-hole-rock mass combination is introduced. With the damage radius as the basic building block, the blast holes are positioned on the face, beginning with the buffer row, to achieve the desired excavation size, shape and smoothness. The design of the contour row of holes is also performed using a pressure-based approach. The paper presents in some detail the overall approach and the required gas pressure-based design equations.

Jan 1, 2007

By R. C. Butman

The Lincoln Terminal System (LTS) is a stand-alone computerized training device that presents high quality visual displays, and audio messages to a student. A keyboard is provided for student input. A variety of student-machine interactive programs arc provided. These programs allow the author/instructor to evaluate numerical entries and responses to simple and compound multiple-choice questions (where a compound choice is defined to be more than one choice, ordered or unordered from one or more list(s) of choices. Descriptions of LTS applications, lesson development procedures, hardware provided and support facilities required are given. A contract history summary, and a bibliography of reports published under three successive BoM contracts supporting LTS development, is provided.

Jan 1, 1979