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By Manuel Gomez

The Bureau of Mines used data from 31 core samples to develop prediction equations for evaluating chemical and carbonization properties of six seam units in a lignite deposit approximately 2 miles wide and 8 miles long in the Wilcox Formation of central Texas. Statistical response surfaces, based on core analyses, were computed for 14 parameters indicative of lignite quality. These computed surfaces, and their mathematical equations, can be used to predict values of the selected properties of the lignite seams at any desired surface coordinate position between core hole locations. The wide range of application shown by this study indicates that the methods of statistical regression analysis may be useful to evaluate large deposits of lignite or higher rank coal.

Jan 1, 1969

By K. K. Kershner, J. G. Donaldson

This investigation was conducted to obtain data on optimum conditions for chloridizing metal sulfides . Salt- roasting galena at 450° C for 8 hours chloridized 75 percent of the lead ; in an equal time of treatment at 750° C , the process chloridized 42 percent of the zinc in sphalerite . Hydrogen chloride at 500° C completely chloridized galena in 15 minutes , and at 600° C converted all of the zinc in sphalerite to the chloride in 4 hours .

Jan 1, 1963

By N. S. Dalal, Xiaoya Sun, Xianglin Shi

"The in vivo toxicity of vanadium(V) has been found to correlate with the depletion of cellular glutathione and related non-protein thiols. With a view to understanding the mechanism for this observation, we have investigated the oxidation of glutathione, cysteine N·acetylcystcinc and pcnicil· lamine by vanadium(V), using electron spin resonance (ESR) and ESR spin trapping methodology. The spin trap used was 5,5-dimethyl-l-pyrroline I-oxide (DMPO). It is found that the oxidation of these thiols by vanadium(V) generates the corresponding thiyl radicals and vanadilim- (IV) complexes. The results suggest that free radical reactions play a significant role in the depletion of cellular thiols by vanadium(V) and hence in vanadium(V) toxicity. 1. INTRODUCTIONThis communication reports on the identification of thiyl radicals formed as intermediates in the reaction of vanadium(V) with glutathione (GSH) and related nonprotein thiols. This study was undertaken because the biochemical mechanism of vanadium toxicity is still not fully understood,. despite being a topic of current research activity [1-20). As to possible clues, it is known that vanadium is most toxic when administered in its pentavaient state [21), and that vanadium(V) administration into laboratory mice reduces cellular levels of NAD(P)H and GSH [22). While the oxidation of NAD(P)H by vanadium has been studied extensively [16-20), that of glutathione and related non-protein thiols has been paid less attention. On the other hand, GSH and related thiols are important cellular antioxidants [23). Their functions include decomposing lipid peroxides and protecting cell membranes [23-25). Thus any reduction in the cellular contents of such nonprotein thiols after vanadium exposure may result in the accumulation of lipid peroxides which might ultimately lead to tissue injury. With a view of finding the mechanism for this thiol depletion process, we have investigated reactions of non-protein thiols with vanadium(V). Particular attention has been paid to the detection of thiyl radicals, since it has been postulated [l] (but not experimentally proven) that the glutathionyl radical (GS·) might be an intermediate in the reaction between vanadium(V), NADH and GSH. We have used electron spin resonance (ESR) and ESR spin trapping methodology for investigating the reactions of GSH, cysteine, N-acetylcysteine and penicillamine with vanadium(V). The results show that the corresponding thiyl radicals are indeed formed in the one-electron reduction of vanadium(V) by all of the above mentioned thiols."

Jan 1, 1990

By Robert W. Metcalf

The feldspars are a series of related aluminum silicates containing varying proportions of potash, soda, rind lime; smaller amounts of other minerals arc likely to be present as impurities. They comprise three principal types: Potash spars, microline and orthoclase (KA12Si208); soda feldspar or albite (NaA1Si308); and soda-lime e (plagioclase) fellspars. The last-named is an intermediate group ranging from albite through oligoclase, andesine, labradorite, and bytownite to anorthite or line feldspar (CnA12Si2O8), Minor varieties are barium feldspar or celsian and a potash-barium feldspar. Perthite is a mixture of orthoclase end albite in alternate layers. Graphic granite or "corduroy spar" is an intergrowth of feldspar and quartz characteristically in the ratio of 3:1. Cornwall stone is a natural mixture of feldspar, quartz, end kaolinite imported in former years in sizable quantity from Cornwall, England. (A similar synthetic mixture, including some fluorspar, has been blended and marketed in the United States as "Carolina stone".)

Jan 1, 1941

By R. V. Lundquist

A method was developed by the Federal Bureau of Mines for evaluating viscosity data from slurries obtained in leaching sinters from the lime soda sinter process for extracting alumina from aluminous silicates. The logarithm of the viscosity was observed to be a linear function with time. The slope of the plotted line provides a means for evaluating viscosity behavior in a lime soda sinter blurry and also a means for comparing gelation characteristics directly with other variables in the lime soda sinter process. This report presents one aspect of a continuing study by the Bureau of Mines on methods for treating siliceous aluminum ores. It is one of the many programs of the Bureau concerned with conservation, development, and use of our domestic minerals resources. Previous investigations of lime soda processes, both by the Bureau4-7/ and industrial concerns, have demonstrated that sintered materials containing CaO, Na2O, A1203, and S102 in various combinations exhibit a tendency to gel or set when mixed with water or other extraction solutions. Gelling prevents satisfactory recovery of alumina and in extreme cases prevents operation of an extraction plant.

Jan 1, 1960

By William Cochran

Data on the cost and quantity available were developed for rutile (TiO2), which is potentially recoverable as a byproduct at sand-washing plants in the Southeastern States of Alabama, Georgia, North Carolina, and South Carolina. Baaed on 1969 production data, an estimated 4,300 tons of rutile could be recovered annually from plants that process more than 25,000 tons of sand per year. Rutile prices at which this resource would be available ranged upward from $262 per ton, compared with the current market value of $185 per ton.

Jan 1, 1972

By R. Hogg, S. Chander

"INTRODUCTION The behavior of particulate systems in general is determined by the properties of the solid and fluid phases and of the interfaces between them. As particle size is reduced, the inter facial effects become increasingly important until, in colloidal systems, they become completely dominant. Interfacial phenomena are especially important in coal processing for a variety of reasons. Because coal is naturally hydrophobic and its density is low, surface forces begin to dominate over gravity at relatively coarse sizes. Coal is thermodynamically unstable in the presence of air, so that surface oxidation occurs readily leading to important variations in surface properties with time and environment. These effects are further compounded by the inherent heterogeneity of the material.Surface characteristics and properties play a significant role in most aspects of coal processing. Comminution, for example, is a process of creating new surface, while agglomeration involves the reduction of surface area and is usually controlled by surface forces. Both solid-solid and solid-liquid separations are influenced by interracial phenomena, Gravity separations are usually performed in a liquid phase and are affected by the wetting characteristics of the various solids present and by the need to ensure proper dispersion of the individual particles. Froth notation, of course, separates particles on the basis of differences in surface characteristics. Chemical processes such as leaching generally involve interfacial reactions whose rates depend on surface area and may be influenced by electrochemical effects in the electrical double layer at the solid-liquid interface, or by adsorption of reactant and/or product species from solution. Solid-liquid separations and associated processes such as flocculation are strongly dependent on the nature and properties of the solid-liquid interface.In characterizing solid surfaces, it is important to consider first the surface area, since this determines the relative importance of the interfacial effects. The structure and chemical composition of the surface may depend on the distribution of different petrographic constituents and impurities such as finely disseminated mineral matter, on the extent of surface oxidation, and on adsorption from the environment. These, in turn, will generally determine the surface properties which define particle behavior. Since the relationships between structure etc. , and properties are not generally known, it is usually necessary to measure properties such as wettability and electrical charge directly."

Jan 1, 1989

By Ronald P. Hollenbeck

Samples of clays, shales, and slates from 29 locations in the Appalachian Region of Alabama and Georgia were tested and evaluated to determine their suitability as raw material for the manufacture of lightweight aggregate by the rotary-kiln method. Samples from 11 locations in Alabama (one each in Etowah, Lawrence, and Morgan Counties and two each in Colbert, Cullman, Tuscaloosa, and Walker Counties) and one location in Walker County; Ga., produced satisfactory lightweight aggregate.

Jan 1, 1969

By D. D. Fischer

Recovery and separation of molybdenum and rhenium from a process solution was accomplished by a technique developed by the Federal Bureau of Mines involving a combined solvent extraction and activated carbon adsorption procedure. The processing sequence required treatment of the solution with S02 to reduce the chlorate ion and adjust the pR prior to solvent extraction of molybdenum and rhenium with a tertiary amine. Molybdenum and rhenium were stripped from the organic phase with an NH40H solution, and the strip solution was then passed through activated carbon to preferentially adsorb the rhenium. After washing entrained molybdenum from the column with a brine solution, rhenium was eluted with an MeOH-H20 mixture. The activated carbon was regenerated with water. Molybdenum was recovered as (NH4)6Mo7024 by evaporating the column effluent. Rhenium in the column eluate was reextracted with a tertiary amine, stripped from the organic phase with dilute NH40H, and recovered as NH4Re04 by evaporating the strip solution. The final (NR4)Re04 product contained < 80 ppm impurities. Sodium sulfate was crystallized from the first solvent-extraction raffinate by lowering the solution temperature to 0° C. Precious metals contained in the original process solution were adsorbed onto the activated carbon.

Jan 1, 1975

By E. P. Youngman

This paper is one of a series of digests of foreign mining legislation and court decisions that is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines" in various foreign countries. In the preparation of this interpretation of the laws of Norway, use has been made of William R. Orrmins' translations of various acts of the Norwegian Government, which were forwarded from the American consulate at Oslo^ and transmitted to the Bureau of Mines through the courtesy of the State Department. This digest is released subject to amplification and correction, if necessary, by the proper American foreignservice officers.

Nov 1, 1932

By Frank L. Hess

In the first cart of that little space of time that we have designated as the nineteenth century, chemistry had reached a wonderful stride. Viewed from the present heights attained by the efforts of innumerable chemists with perfected apparatus, mire reagents, air under pressure, water, gas, and electricity conducted to the desk, and. numberless other helps, it seems marvelous that chemists of that day obtained such results. In 1820, about half of the elements had. been discovered; of these discoveries, Swedes had made 15 or more, about once-third of the elements then known and nearly half of those discovered after 1700.

Jan 1, 1939

By H. B. Humphrey

The solvents used most widely in industry may be divided into groups according to their chemical and toxicological properties. These groups, with representative members, follow: Petroleum distillates (aliphatic hydrocarbons) Examples: Gasoline, benzine, Stoddard&apos;s specification solvents. Alcohols, esters, ketones, ethers, and ether alcohols Examples: Denatured alcohol (ethyl alcohol to which various denaturants may be added), methanol (methyl alcohol), ethyl acetate, amyl acetate (banana oil), acetone.

Jan 1, 1956

Information Circular (IC) 9453 Roof falls continue to be the greatest single safety hazard faced by underground coal miners. During1996-99, 44 coal miners lost their lives in rock falls and nearly 2,400 were injured. In addition, nearly 6,000 non injury roof collapses were reported. Roof supports are installed to protect the miners, but support system failures contributed to most of these incidents. Reducing the terrible toll taken by ground falls continues to be a major goal of research by the National Institute for Occupational Safety and Health (NIOSH).During 2000-01, NIOSH conducted a series of open industry briefings on New Technology for Coal Mine Roof Support in Norton, VA, Charleston, WV, Evansville, IN, Tuscaloosa, AL, Price, UT, Glenwood Springs, CO, and Washington, PA. Drawing on many years of research undertaken by the NIOSH Pittsburgh and Spokane Research Laboratories, the proceedings describe what types of coal mine roof support are available, how they work, and when they should be used. The major subjects covered include roof bolts, standing roof supports, cable supports, and longwall shields. Some special topics are also addressed, including an analysis of roof fall accident statistics, techniques for better skin control, and material handling considerations. The proceedings volume also contains information on several important new technologies, which are described for the first time, e.g., guidelines for selecting roof bolt

Aug 1, 2001

By H. C. Carpenter

Data are presented comparing results obtained with 17 different catalysts in hydrogenating crude shale oil to gasoline in single-pass operation. A method is described for predicting the maximum yield of gasoline obtainable at constant pressure for each catalyst from results of a limited number of experiments at different temperatures. Operating variables have considerable influence on yields and properties of products. With most of the catalysts, at operating temperatures below 890° F. liquid yield exceeded 100 volume-percent. Above this temperature the volume of liquid product decreased rapidly. Maximum gasoline production in most instances was achieved at a temperature higher than that at which the maximum volume of liquid product was produced.

Jan 1, 1959

By O. C. Blade

A summary of the characteristics of motor gasoline for the winter 1951-52 is presented in table I, and for comparison, a similar summary for the winter 1950-51 is shown in table 2. Trends of some of the more important characteristics over a period of years are shown in figures 1 and 2. The results of this survey show that octane numbers have risen slightly since the summer of 1951 but are below the record levels of the winter of 1950-51. The fractions of a unit change since the summer preceding have resulted in the research and motor-method octane values being virtually the same as the figures for the survey of summer 1950. In volatility characteristics the winter gasolines have changed very little. Average Reid vapor pressures are 10.5 pounds for both grades of fuel compared to 10.4 and 10.5 pounds for premium and regular-price gasolines, respectively, of the winter of 1950-51.

Jan 1, 1952

By Michael Rieber

Rail cars are referred to as "yellow-balled" when they are sufficiently old or damaged to preclude their efficient operation on long-haul or main line routes. For most coal carrying railroads, their alternative value is salvage. This, however, does not necessarily preclude their effective use, on a limited basis, by small mines located near existing trackage. Because of age, the sizes of these hopper and gondola cars ace currently 50 and 70 tons rather than the 100 tons commonly built at the present time. As a gathering system, yellow-ball rail could provide an alternative, particularly in Kentucky, western Pennsylvania and west Virginia, to coal trucks, conveyor belts and pneumatic pipelines [4, p.17], belts and pneumatic pipelines. Rail service of this type provides a limited alternative to track abondonment, a possible financial return to a railbank [3], a direct contribution to service demand on main lines, and a means by which many small eastern coal mines could retain or regain competitive viability [4]. In terms of energy efficiency, compared to trucking coal, the total direct energy impact (fuel) of yellow-ball rail can be expected to range from 280-990 Btu/ton-mile while that for trucks ranges from 1850-3120 Btu/ton-mile [2].

Jan 1, 1977

By Fay B. Dillard

This Bureau of Mines report reviews the disposition of natural gas as delivered to industrial consumers via main line sales. Salient information on main line, or direct, natural gas sales to industrial users is presented by State) standard industrial classification code (SIC) revenue, and type of sales for the years 1968 through 1973.

Jan 1, 1975

By G. F. Friel

A series of experiments in the U.S. Bureau of Mines Safety Research Coal Mine at the Pittsburgh Research Center evaluated the effects of crosscuts on the travel time of carbon monoxide (CO) along an entry to improve the accuracy of a mine-fire locator program. Three entries, ten single crosscuts, and three double crosscuts were instrumented with CO sensors. One-percent CO in nitrogen was released and monitored as it traveled the entries. In addition to dispersion of CO at the front of the CO wave, CO was entrained from the entry into the crosscuts. It was determined for an entry and single-crosscut configuration that the measured travel time for a concentration change of 5 ppm was 27% greater than the predicted time based upon entry volume only, but 13% less than the predicted time based upon entry and crosscut volumes. For an entry and double-crosscut configuration, the measured travel time for the same concentration change was 25% greater than the predicted time based upon entry volume only, but 10% less than the predicted time based upon entry and crosscut volumes. An effective dispersion coefficient for CO dispersion along one of the entries was estimated to be 1.5 m2/ s.

Jan 1, 2010

By L. B. Pankratz, R. Barany, W. W. Weller

Experimental determinations were made of the heats of formation at 298.15 ° K of cuprous ferrite and cupric ferrite ; the heat capacity of cuprous ferrite was measured over the temperature range from 50 ° to 298 ° K and the entropy at 298.15 ° K was evaluated ; the heat contents of cuprous ferrite and cupric ferrite above 298.15 ° K were measured to 1,500 ° K and 1,100 ° K , respectively . These thermodynamic values were combined with other pertinent data to obtain heat and free energy of formation values at high temperatures . The stability of the two ferrites with respect to their constituent oxides is discussed . Thermodynamic values are included for the decomposition of cupric ferrite to form cuprous ferrite , magnetite , and oxygen .

Jan 1, 1964

By Hamid N. Maleki

Cooperative efforts by the Bureau of Mines and Agapito & Associates, Inc., Grand Junction, CO, achieved the research objective of showing that data from measurements of the rate and change in rate of mine roof movement can be effective in detecting roof instability. Several instruments and techniques have been used to monitor roof movement and to detect imminent roof caves during pillar robbing. Early detection of unstable conditions can provide time either to withdraw personnel and equipment or to allocate supplemental support to prevent injury or down-time. Critical convergence rates were determined both manually and electronically. The detection of critical rate of movement has been shown to be an effective tool in ground control efforts.

Jan 1, 1988