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By Bruce D. Hanson

The Bureau of Mines conducted a series of experiments using four different coal types to determine the effect of attack angle and symmetric bit wear on airborne respirable dust (ARD) generated by point-attack bits and in energy consumption. Neither had a significant effect on ARD at the 95-pct confidence level, but bit wear had a significant effect (95 pct confidence) on specific energy (energy per gram of cut coal) for three coal types, Depth of cut was the most significant factor affecting ARD and specific energy.

Jan 1, 1979

By Bernard Porter

The rate of the heterogeneous reaction between reactor-grade yttrium and lithium fluoride in lithium fluoride-yttrium fluoride mixtures was measured using a quartz spring balance. At 950° C the magnitude of the rate of reaction is 10-5 grams of yttrium/cm2-sec. The heat of activation for the reaction is 38.3 kilocalories per mole of LiF. A surface-controlled mechanism is proposed in which LiF is adsorbed on the yttrium metal surface. An activated complex is formed when additional LiF reacts with the adsorbed LiF-metal site. The activated complex then decomposes to the products) which are lithium metal and YF3. The importance of the reaction in the electrowinning of yttrium metal from fluoride electrolytes is discussed.

Jan 1, 1967

By Arthur J. Hudson, Lawrence W. Scott

The performance of RETIMET metal foam as a flame arrester on explosion-proof enclosures was investigated by the U.S. Bureau of Mines both in laboratory tests and at the U.S. Mine Safety and Health Administration's (MSHA's) Approval and Certification Center, Triadelphia, WV. The objective of this research was to develop a permissible pressure vent for use on lightweight, vented, explosion- proof enclosures. In laboratory tests, four grades of RETIMET, a stainless steel foam material, were evaluated: (1) 45 NC-7, (2) 45 NC-13, (3) 80 NC-7, and (4) 80 NC-13. Explosive gas mixtures were prepared by a dynamic flow system. Ignition was by a low-voltage arc. Each grade of RETIMET metal foam successfully arrested the flame front in all methane-air tests. To evaluate RETIMET metal foam on large, commercial size enclosures, a multicompartmented enclosure was designed and tested in MSHA's explosion gallery in Triadelphia, WV. Extensive explosion testing revealed that a minimum vent-area-to-enclosure-volume ratio of 11.33 in2/ft3 is required to keep internal pressure rises below 3 psig. The RETIMET metal foam functioned satisfactorily in all tests as evidenced by the absence of external ignitions.

Jan 1, 1992

By C. W. Smith

The U.S. Bureau of Mines; Tuscaloosa Research Center, in cooperation with the U.S. Army Corps of Engineers under interagency Agreement No. 14-09-0078-1510, conducted a comprehensive sampling program of 10 upland disposal sites along the Alabama, Black Warrior, and Tombigbee River systems in Alabama. Samples from each site were characterized according to particle size, chemical analysis, mineralogical content, and potential end use. Additionally, samples were subjected to the Toxic Characteristic Leachate Procedure to determine the presence of potentially harmful heavy metals. Based on the results of these studies, each sample was determined to have properties amenable for use as aggregate in general-purpose portland cement concretes and certain asphalt concrete applications.

Jan 1, 2010

By E. S. Shedd

Misch metal was electrowon from a treated bastnasite concentrate in a REF3-LiF-BaF2 electrolyte at 950° C. The metal was prepared and tapped from a 1,000-ampere cell, and nearly 100-percent utilization of the rare-earth oxide was achieved. Prolonged operation in a smaller cell (40 amperes) indicated that the composition of the misch metal product was reasonably constant, and no significant increase of impurities, with the exception of carbon, was noted.

Jan 1, 1970

By Albert W. Deurbrouck

Twelve samples from six Barbour County coal beds were analyzed for this report. The samples collected were generally high sulfur content coals, frequently exceeding 3 percent in the raw-coal sample. Many of them could not be upgraded to acceptable metallurgical standards even by rigorous preparation procedures. The production of coal in the county in 1963 amounted to almost 3 million tons of which 44 percent was mechanically cleaned.

Jan 1, 1965

By D. J. Stoops, H. Kato, M. D. Carver

The effects of impurity elements silicon , aluminum, copper , nitrogen , and manganese , at 50 to 300 ppm, on properties of the zirconium alloy Zircaloy 2 were investigated . Variations in microstructure , mechanical properties , and corrosion behavior in some inorganic acid and salt solutions were observed with variations in level of impurity element . Corrodents were solutions of sulfuric acid , phosphoric acid , copper chloride , and iron chloride . Silicon was found to modify annealed microstructures by spheroidizing and dispersion of secondphase material throughout grains . Silicon or manganese improved ultimate and yield strength of the alloy without loss in ductility . All five elements affected corrosion rates of the alloy , the effect being generally different for each element .

Jan 1, 1964

By H .. B. HUMPHREY, F. E. Cash

Sixty-one fatal accidents were reported in the mines of Alabama during 1930. This number is a decrease of 15 per cent as compared with 1929; however, production was 13 per cent and the man-hours worked were 16 per cent less than in the previous year. There were 21,731 men employed inside and 3,386 outside. Table 1 gives the comparative rates per million tons and per million man-hours for the United States and for Alabama for 1929 and 1930. These rates are based on figures published by the State and by the United States Bureau of Mines, with preliminary figures for 1930. (These sources of data are used throughout this paper.)

Oct 1, 1931

By Vincent Castranova, Jane Y. C. Ma, Joseph K. H. Ma, Chang-geng Mo, Carl J. Malanga

"A group of bisbenzylisoouinoline alkaloids has been shown to exhibit various degrees of effectiveness in preventing silica-induced fibrosis in animal models [1, 2]. The objective the present study was to characterize the binding of several of these alkaloids to phosphatidylcholine vesicles and rat alveolar macrophages using fluorometric and equilibrium dialysis methods, respectively. The lipid binding affinity of these alkaloids was found to depend upon several structural factors including hydrophobic substitutions, chiral configurations, and double oxygen bridge-restricted conformation of the benzylisoquinoline moieties. Tetrandrine, which is a highly effective agent in preventing fibrosis, showed strong binding to both lipid vesicles and alveolar macrophages. In contrast, certain analogues of tetrandrine such as curine and tubocurine, which have little or no effect on silicosis, exhibited only weak binding to lipid vesicles and almost no binding to cells. The moderate binding affinity of fangchinoline to vesicles and cells corresponded to a moderate effectiveness of the compound as an antifibrogenic agent. Methoxyadiantifoline, an alkaloid of unknown antifibrogenic potential, also exhibited high binding affinities for lipid and cells. In conclusion, the results of these studies indicate that alveolar macrophages exhibit large binding capacities for certain members of this class of bisbenzylisoquinoline alkaloids. A positive correlation was observed between binding affinity to alveolar macrophages and the reported antifibrotic potency of these compounds. These data also suggest that the ability of these drugs to interact with alveolar macrophages may be a key step in inhibition of the progression of silica-induced pulmonary disease.INTRODUCTIONInhalation of crystalline silica is associated with the development of silicosis. This fibrotic disease is characterized by the appearance of concentric hyalinized nodular lesions in the lungs with the progressive development of pulmonary dysfunction [3, 4]. Many theories concerning the etiology of silicosis involve silica-induced activation of alveolar macrophages. Evidence indicates that in vitro silica exposures result in the generation of chemiluminescence, and the release of superoxide and hydrogen peroxide from alveolar macrophages [5]. Activation of alveolar macrophages has also been demonstrated after intratracheal instillation or inhalation of silica [5, 6]. Such excess release of reactive products from pulmonary phagocytes has been associated with damage to the lung parenchyma [7, 8]. In addition, silica exposure results in the release of mediators from alveolar macrophages, which enhance proliferation of fibroblasts and collagen synthesis by these pneumocytes [9-12]."

Mar 1, 1992

By John W. Buch

Safety and cost in mining coal beds under the extreme pressures found at depth, full extraction to conserve resources, and even surface subsidence to minimize damage of improved areas have directed much well-deserved attention, in the United Kingdom; to roof-control methods. Because the effects of pressure will be felt intensely as our Pennsylvania anthracite mines grow deeper, the senior author took advantage of an opportunity afforded by a mission to Europe3/ to observe, to a limited extent, the effects of pressures found in deep mines and the manner in which they are con trolled. Organized research relating to strata control has been carried on in Great Britain for nearly 25 years. These activities have been ably outlined by Dr. D. W. Phillips.4/ Physical properties of coal-measure rocks, movements of roof and floor, and types of face and roadway supports have been investigated. Same of the forces induced by the extraction of coal have been measured. The results of this research have been publicized and openly discussed, and much progress has been made in establishing a better factual understanding of roof-control problems and their solution.

Jan 1, 1951

By Eric R. Bauer

This U.S. Bureau of Mines study was conducted to gain a basis for recommending methods to predict and prevent the occurrence of cutter roof failure, a common ground control problem in mines of the Northern Appalachian Coal Basin. This was accomplished by determining the geologic and engineering factors responsible for cutter development at six mines affected by cutter roof failure. Three distinct factors were found to be initiators of cutter roof failure: (1) high horizontal roof stress, (2) surface topographic variations, and (3) geologic anomalies. Effective control of cutter roof was obtained through improved bolting techniques, entry and mine reorientation, and entry and pillar size modifications, but only when selected based on the actual cause of failure.

Jan 1, 1990

By Louis C. Brichta

The Capital Mine is one of, the more important zinc mines in Lawrence County, Mo. Owing to the urgent need for additional zinc during the war and the available facilities for the treatment of zinc-lead ores at the property, the Bureau of Mines examined the mine during July and August 1942 and selected it for further investigation by churn drilling, which was accomplished in the fall of 1943 and spring of 1944. At the conclusion of the drilling on the Capital holdings, the Greenland property, immediately south, was investigated by drilling two additional holes. Results of the investigation are presented in this report.

Jan 1, 1948

By Thomas Fraser

About 24 per cent of our total production of bituminous coal is used in industrial power plants. As regards fuel conservation, therefore, the recovery of unburned fuel from furnace refuse presents interesting possibilities. Considerable attention has been given to this problem in the past, but because of the comparatively low initial cost of power plant fuel in the pre-war period little progress, has been made in this direction in the United States. Because of the higher price of coal in Europe more attention has there been given to the problem. In Germany a process has been developed for separating unburned coal in refuse by using an electromagnetic separator In the United States the use of mechanical stokers enabled low-priced screenings of high ash content to be used, so that even with relatively high percentages of combustible material remaining in the refuse, the loss in money is not excessive. If the price of screenings returns to the pre-war level around $1.00 per ton the process proposed here will probably not be especially interesting, except where the freight charges are very high. However, if the price of delivered coal continues high, such a process should result in considerable saving. The cost of continuous operation of such a refuse treating plant should not exceed 75 cents per ton of fuel recovered.

Jan 1, 1921

By J. M. Stuve

Provisional values for the heat of formation of europium trichloride and europium sesquioxide were determined by solution calorimetry utilizing europium metal of more than 99-percent purity. The resulting values for the heats of formation of Eu203 (cubic) and EuCls (hexagonal) were -386,970 ±l,200 cal/mole and -218,740 ±650 cal/mole, respectively, measured at 298.15° K.

Jan 1, 1965

By M. B. Cooke, A. D. Bauer, E. W. Dean

The Bureau of Mines is collecting and analyzing representative samples of crude petroleum from all the producing fields in the United States , and the results are being published in a series of reports that are preliminary to the issue of a bulletin covering the entire survey . The bureau has recently completed a survey of crude oils from the Kansas district . In all 27 samples were collected and analyzed , under the direction of A. W. Ambrose , chief petroleum technologist of the Bureau. Valuable assistance was received through the cooperation of oil companies operating in the State , especially the Prairie Pipe Line Co. , and the Empire Pipe Line Co. The present report issued as Serial 2322 , on the Kansas crudes , forms the fifth of the series . Of the four previous papers , the first ( No. 2202 ) deals with crudes from the Eastern fields of the United States , the second ( No. 2235 ) with crudes from the Rocky Mountain district , the third ( No. 2290) gives additional data , cn viscosities and pour tests , for the crudes from these two fields , and the fourth ( No. 2293 ) covers the fields of northern Texas , northern Louisiana , and Arkansas . The details of the methods of collecting samples , making laboratory tests and interpreting results , have been discussed in these earlier reports . It has also been pointed out that the only adequate method of interpreting analyses of crude oils is to compare the individual reports with the analysis of some crude oil that is familiar to the operator . For this reason , no comprehensive discussion of the results of the Kansas survey is attempted, although some general statements may be made .

Feb 1, 1922

By W. E. Miller, W. P. Yant, G. W. Jones, R. E. Kennedy

"The determinations of the limits of inflamability of diethyl ether and ethylene in air described in this report were made primarily for comparison with similar determination of other compounds in the same apparatus and by the same laboratory technic. The experimental procedure and the results obtained differ somewhat from those of other investigations. The work also included determinations of the limits of inflamability of these combustibles in oxygen The investigation,was conducted at the Pittsburgh Experiment Station of the United States Bureau of Mines in cooperation with Merck & Co., Inc. LIMITS OF IMFLAMIABILITY OF DIETHYL ETHER-AIR MIXTURESThe limits of inflamability if diethyl ether in air were determined for upward propagation of flame in an upright, closed 8-liter, cylindrical iron bomb 10.2 cm in inside diameter and 96.5 cm in length. This bomb been described in a previous publication. 6Two brands of diethyl ether were used, one a C. P. sulphuric ether manufactured by Baker & Adamson, and,the other Merck & Co. product manufactured for anaesthesia and containing about 3.5 percent of ether alcohol."

Jul 1, 1935

By R. H. Jefferson

An electrochemical method to selectively determine sulfur dioxide in the presence of sulfur trioxide was investigated. A hydrophobic gas-permeable membrane separates the gas sample solution from an internal filling solution containing a fixed quantity of chloride ion and a sufficiently large excess of sodium bisulfite so that its concentration may be considered constant. Sulfur dioxide diffuses through the membrane to dissolve in the internal filling solution and liberates an equivalent quantity of hydrogen ions. The electromotive force between a precision-ground, flat-ended pH electrode, which acts as the sensing element, and a chloride sensing electrode, which acts as the reference element, gives a direct measure of S02 in the gas sample solution. Calibration curves in water, tetrachloromercurate (TCM) , and citrate buffer absorption solutions were closely parallel with slopes in their linear segments, ranging from 57 to 52 mv/decade of S02 concentration. The slopes compare reasonably well with the theoretically expected slope of 58 millivolts at 21° C. The water standard curve was linear with respect to the logarithm of S02 concentration from 1 to 1,000 ppm S02; the TCM standard curve was linear from 10 to 2,000 ppm S02; and the citrate standard curve was linear from 30 to 5,000 ppm S02' The high efficiency and nontoxicity of citrate favor it as a substitute for the conventionally used TCM in the absorption solution.

Jan 1, 1976

By B. K. Shibler

As a part of the Bureau of Mines' intensive; 'investigation of domestic manganese deposits, ore-dressing studies were conducted on three samples of oxide and silicate manganese ores from various Wyoming properties. The samples wore as follows: 1. A 2-ton sample of ore was obtained by a Bureau engineer during examination of the Caulkins-McGuckin property in the center of Crook County, 10 miles north of Sundance, Wyo. The ore body was described as a vein deposit in rhyolite porphyry. 2. The J. B. C. Mining Co. submitted a 1-ton sample of oxide manganese ore from a property located 44 miles northeast of Rock River in Albany County, Wyoming. 3. A 1-ton sample of oxide-silicate-ore was obtained by a Bureau examining engineer from the Gheen property in the northeast corner of Washakie County, Wyo. The ore body was described as a replacement deposit in a country rock of silicified limestone. As the samples differed widely in physical and chemical characteristics and also in their response to methods of concentration, ore from each property was considered a separate ore-dressing problem.

Jan 1, 1949

By Marvin L. Whisman

Several parameters controlling the reproducibility of tritium determina¬tion in organic compounds by liquid scintillation counting were evaluated by the Federal Bureau of Mines. These included optimum volume of scintillator solution for maximum counting efficiency, reproducibility of counting a sealed commercial standard and comparison with duplicate counts on laboratory-prepared samples. The error introduced by using microliter pipets, optical differences in counting vials, reproducibility of counting organic samples where quenching is a factor, reproducibility of counting laboratory-prepared samples with an added internal standard, optimum ratio of internal standard activity to sample activity, effect of sample volume upon counting efficiency, count rate at which coincidence losses become apparent, and reproducibility of organic compound radioassay by the standard addition technique are outlined. From the evaluation of these parameters, a technique that can be applied routinely to organic compounds containing tritium has been established, and details are included in this report.

Jan 1, 1961

By J. A. Lamonica

The Bureau of Mines studied a pulsation damping device designed to smooth pulsating flow in personal respirable dust samplers. The effect on the pulsation dampener efficiency of six parameters was investigated, as follows: Volume, diaphragm elasticity, diaphragm area, center orifice area, inlet-outlet orifice area, and geometry (LID ratio). The results indicate that volume pre-dominates in determining snubber efficiency, while the other parameters become important at small volumes. Geometry has no effect on snubber efficiency. Criteria for an efficient pulsation dampener construction were obtained.

Jan 1, 1971