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By W. G. Pariseau

The U.S. Bureau of Mines has been conducting a series of rock mechanics investigations at the Lucky Friday Mine in the Coeur d'Alene Mining District of northern Idaho. The present study uses rock deformation measurements to validate and calibrate a geomechanical model of the experimental Lucky Friday underhand longwall (LFUL) stope on the 5,100-ft level of the Lucky Friday Mine, Mullan, ID. The calibrated three-dimensional, finite-element model and measurements of rock mass displacement show a correlation of 0.795. The calibration reduces rock mass modulus to 14 to 17 pet of laboratory values and rock mass strength (with an energy rule) to 37 to 41 pet of laboratory values. This model suggested that stress-related ground control problems would be encountered west of the stope where the vein makes a right-angle turn and then splits. Rock burst activity was concentrated in this area during mining of the LFUL stope.

Jan 1, 2010

By M. H. Kline

The Scarlet mine, in Randolph County, N. C., was operated on a small scale at intervals from 1899 to 1915, but no records of the quantity of ore produced are available. J. I. Moore unwatered the mine in March 1948, and Bureau of Mines' engineers examined the underground workings. Several assays checked previous sampling of the mine and indicated a small but comparatively high-grade copper-zinc deposit. The high metal content of the veins and the possibility of developing additional reserves prompted the Bureau of-Mines to drill three holes, totaling 530 feet, at the deposit during March and April 1948. Drilling disclosed that the mineralized vein did not extend over 300 feet along the strike and is probably limited in depth to the contact with the granite mylonite.

Jan 1, 1949

By C. W. Davis

There are four parts to this circular and, respectively, they list firms in the Eastern (pp. 5-8), Southern (pp. 9-10), Central (pp. 11-15) and Western (pp. 16-22) United States and Provinces of Canada. Before listing the laboratories and the work performed there, it is proper to make clear what is done and what is not done by Federal bureaus, States, and Territories, as well as by Canada and Mexico. FEDERAL Bureau of Mines. - The Bureau of Mines does not make assays, analyses, or tests for individuals or firms unless they be incidental to investiga¬tions that are of possible benefit to the entire mineral industry. All significant results obtained in this way are made public through published reports. Any mineral sample sent to this Bureau for simple identification will be subjected to a cursory examination.

Jan 1, 1938

By S. W. Zoldok

[The Bull Valley iron-ore district lie,; in the northern part of Washington County, Utah, approximately 30 airline miles southwest of the highly productive Iron Springs area (fig. 1). Iron-ore occurrences in the district have been known for many years, but they have not been mined, largely because of the inaccessibility of the area. The Bureau of Mines established a development project in the Bull Valley district in September 1941. Two separate areas, the Pilot and the Cove Mountain, were investigated. The work was planned to increase iron-ore reserves for steel production in the Western United States. During the project period three diamond-drill holes aggregating 1, 000 feet were completed (fig. 2). The program also included 6 408 linear feet of surface trenching and 171 feet of underground work (figs. 2 to 8, inclusive). Analyses were made of 460 samples from the diamond-drill holes and surface and underground excavations. The results of the analyses are given in tables 1, 2, 4, and 5, and the logs of the diamond-drill holes are shown in table 3. Field. work was completed in September 1942.]

Jan 1, 1953

By A. L. Engel

A representative sample of gold-silver ore from the Keystone Mine, Manhattan, Nye County, Nev., was submitted for these tests. The ore was an altered diorite rock with very small amounts of sulfide minerals of copper, lead, zinc, antimony, and arsenic disseminated in fine grains throughout. As indicated by test results, much of the silver content of the ore apparently was associated with these sulfide minerals. The gold probably occurred with iron oxides in the ore. Assays showed 0.16 ounce of gold and 2.8 ounces of silver per ton of ore. This investigation was made to study application of activated carbon in the cyanidation treatment of the ore. The treatment proposed for u.se at the mill is as follows: The ore is crushed to minus-10-mesh size and separated into plus -and minus-65-mesh portions. The minus-10, plus 65-mesh sands are cyanided by leaching and the minus -65-mesh slimes by agitating. After 48 hours of agitation the slime pulp is thickened to about 1:1 water:solid ratio, and part of the pregnant solution is recovered. The pulp is then diluted to a 2:1 ratio, and the remaining dissolved values are extracted with the activated carbon. The barren pulp then can be discarded. This procedure eliminates the necessity for further washing the slime pulp and also recovers most of the excess sodium cyanide required for extracting the optimum amount of silver from this portion of the ore.

Jan 1, 1951

By John S. Berber

Olefin and paraffin mixtures (C10-C16 and C10-C22) were separated from low-temperature lignite tar by urea adduction and sulfated to yield secondary alkyl sulfate detergents. The C10 ?C16 secondary alkyl sulfate showed a 99.3 percent biodegradability, and the C10-C22 fraction showed a 96.8 percent biodegradability, exceeding the required standard of 80 percent for the biodegradability of anionic detergents in washing and cleaning compounds. Chlorination of paraffins yielded a detergent of 93.2 to 93.4 percent biodegradability.

Jan 1, 1968

By Suresh K. Bhatt

A mathematically simulated modeling technique is used in this U.S. Bureau of Mines report to represent a hypothetical mining operation with existing mining technology and prevalent mining costs. Mining scenarios were prepared and evaluated for potential benefits and costs available through computer-assisted mining. Base criteria, parameters, and methodology are described.

Jan 1, 1993

By Dorsey A. Lyon

"The ceramic industry of the United States has a total yearly manufactured product of nearly half a billion dollars, despite large foreign importation.After careful investigation of the industry by the Bureau of Mines, it is the belief of those in charge that the usefulness of the industry can be greatly enlarged and the importations greatly lessened through the development of processes that will lead to a greater and better development of the ceramic resources of the United States. This will result in a greater industry with more men employed than ever before, and perhaps a world's supremacy in ceramic trade matters.Investigations in behalf of the ceramic industry are being made at the Bureau of Mines experiment ceramic station at Columbus, Ohio, under the supervision of R. T. Stall, superintendent, who reports a number of instances of practical, beneficial cooperation between the industry and the station during the last fiscal year.Graphite to Crucibles:Prior to 1914, practically all graphite crucibles manufactured in the United States were made from Ceylon graphite bonded with German Klingenberg clay. It was the general belief among graphite crucible manufacturers and users that good crucibles could not be made from American bond clays and graphites.Graphite crucibles were essential for melting certain alloys and special steels urgently needed for the manufacture of war materials. The demand for such metals was so great that it created an unprecedented demand for graphite crucibles.After the European war began no Klingenberg clay could be shipped out of Germany. However, it was fortunate for the cyucibly makers that they had large stocks of Klingenberg clay on hand. When the stock of Klingenberg clay became exhausted, it was necessary for the credible makers to turn their attention to American clays. There were no data or other information available to guide the crucible makers in the selection of good bond clays for their crucibles. It was necessary for them to select their clays more or less by ""guess"", which resulted in the period of service or life of graphite crucibles being shortened 15 to as much as 60 per cent."

Feb 1, 1921

By M. H. Rinkenbach, C. A. Taylor

The detonating compound cyanuric triazide was discovered*** and patented**** by Erwin Ott, and on account of his claims, the Bureau of Ordnance, U. S. Navy, desired more complete data, so an investigation was made. The results obtained were such that the Bureau of Crdnance recommended publication thereof for the benefit of the explosives industry. Some of the patent claims regarding cyanuric triazide are as follows: 1. It is not poisonous in contradistinction to fulminating mercury and lead azide. 2. In contradistinction to the hitherto employed priming agents it is fusible, and its fusion point (94°C) is so low that the product melted by a single heating in water or steam bath, can be poured without danger in the capsule shell. It solidifies therein after cooling, and shows the density of 1.5. 3. It has been determined that the cyanuric triazide, in spite of its very much higher priming actions, is much less brisent then ful- minating mercury and lead nitride. 4. The chemically pure cyanuric triazide (C3M2) constitutes colorless crystals melting at 94°0., and is not volatile. It is not affected by cold water, and only slowly saponified by hot water. It is relatively insensitive to friction and not too strong concussion, but explodes by impact or when hea ted to 170°C., or when heated suddenly. It is not more sensitive to friction and shocks then fulminating mercury. 5. The preparation of the triazide is preferably carried out by acting with an excess of sodium azide in an aqueous solution; in the cold, on cyamric chloride gradually suspended in the said solution.

Aug 1, 1923

By R. V. Ramani, R. Stefanko, G. W. Luxbacher

1 9 THIS IS A DIGITAL COMPUTER SIMULATION OF THE VENTILATION SYSTEM OF A MINE LOCATED IN WASHINGTON COUNTY; PENNSYLVANIA. THE VENTILATION SURVEY ON WHICH THIS SIMULATION IS BASED WAS RUN FROM OCT. 27-30 AND ON NOV. 2;1976 IN THE ACTIVE PORTION OF THE MINE INBY COMBS SHAFT AND THE INACTIVE PORTION AROUND AND INBY DONAHOO SHAFT. FOLLOW-UP SURVEYS WERE THEN RUN ON FEB. 18 AND FROM MARCH 7-11;1977 TO INCLUDE THE MAIN HAULAGE SYSTEM OUTBY THE ACTIVE AREAS 0F THE MINE. ALL SURVEY DATA WAS NORMALIZED TO A STANDARD DENSITY OF 0.075 POUNDS/CU.FT. PRIOR TO THE CALCULATION OF INPUT PARAMETERS FOR THIS SIMULATION.

Jan 1, 1977

By Stephen D. Cramer

A nondestructive procedure for measuring electrodeposit porosity has been developed which records the location and number of deposit defects including pores, pits, and voids. The procedure involves the passage of an X-ray beam through the deposit-substrate system onto suitable film. The defects are recorded as images on the film. Variables studied included intensity and spectra of the X-ray beam, composition and thickness of deposit and substrate, film type and developing procedure, and limits for detecting defects. At an X-ray tube voltage of 40 kv, pores several mils thick were easily detected in copper-nickel specimens more than 20 mils thick. To illustrate the utility of the procedure, the effect of substrate oxidation and of current density on electrodeposit porosity was briefly studied.

Jan 1, 1970

By E. Morrice

High-purity neodymium, praseodymium, and didymium (a cerium-free mixture of light rare-earth elements) were prepared by electrolysis of the oxides in a medium consisting of the respective rare-earth fluorides and lithium fluoride. The metals were electrodeposited in the liquid state and collected as nodules on a skull of frozen electrolyte. Cells were operated from 1,000° to 1,100° C. The requisite temperature was maintained by passing alternating and direct currents through the bath. Graphite was used for the anodes and tungsten for the cathode. The metal products contained <0.02 percent each carbon and oxygen and <0.025 percent tungsten as major impurities. Analysis of typical didymium metal nodules showed an approximately twofold enrichment in neodymium and praseodymium over their respective concentrations in the cell feed. The lanthanum content of the metal was about one-half its content in the oxide.

Jan 1, 1967

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 D. A. Reynolds

The Bureau of Mines-American Gas Association survey of the carbonizing properties of American coals was begun in 1929, and has been continued almost without interruption since that time. Upwards of 100 coals have been carbonized at low, medium, and high temperatures in this survey, and about 200 additional coals have been carbonized at high temperatures only. All survey coals were blended with coal of different rank for carbonization at one high temperature (900° C,). During the past few years, 12-high-volatile A coals were blended with Pocahontas No 3 coal from Kimball, McDowell County, W. Va., and in this report the physical properties of the cokes from these high-volatile coals and their blends are compared.

Jan 1, 1949

By L. M. Demers, D. C. Kuhn, N. El-Ayouby, C. F. Stanley

"Oxygenated metabolites of arachidonic acid (MJ are produced by the alveolar macrophage (AM) and have been shown to mediate inflammatory reactions. We therefore assessed the production of eicosanoids by AM harvested from the lungs of rats ex· posed to a bituminous coal dust for 2 wk in an inhalation chamber in order to determine if AA metabolism was altered in a manner that may promote an inflammatory response in the lung. Exposure to coal dust resulted in a 66% increase in the number of AM harvested, an increase in thromboxane A2 (TxA;i) and leukotriene 84 (LTB,j) production to 222% and 181% of control values, respectively, and a decrease in prostaglandin E2 (PGE:i) production to '62% of control values. In AM harvested from rats allowed to breath clean air for 2 wk following coal dust exposure, PGE2 production returned to control levels but TxA2 and LTB4 production remained elevated. The TxA2 synthesis inhibitor UK 38,485 reduced TxA2 production in dust-exposed AM both immediately and 2 wk following exposure. Thus, exposure of rats to coal dust significantly alters the metabolism of AA in AM, with potentially important aspects of AA metabolism remaining altered even after a 2-wk recovery period. Based on the established role of eicosanoids in inflammatory and fibrotic processes, these results suggest that the alteration of AM eicosanoid production as a result of the inhalation of coal mine dust may be an important factor in the pathophysiology of coal workers' pneumoconiosis.The authors are grateful to Joan Greenwood and Barbara Scheetz for their excellent technical assistance and to Brenda Pavone for the preparation of the manuscript. This research was supported by the U.S. Department of The Interior's Mineral Institute Program administered through the Generic Mineral Technology Center for Respirable Dust under grant 1135142.Request for reprints should be sent to Douglas C. Kuhn, Ph.D., Department of Pathology, The M.S. Hershey Medical Center, Hershey, PA 17033.INTRODUCTIONPulmonary alveolar macrophages (AM) are activated by foreign particles and microorganisms that enter the small airways (Kass et al., 1966; Herscowitz, 1985). This defensive reaction involves phagocytosis, lysosomal enzyme release, and the generation of reactive oxygen species by the AM (Snella, 1986; Rich et al., 1987). A number of agents, including phorbol esters, zymosan, adenosine diphosphate, organic hydroperoxides, and calcium ionophore, have been shown to activate the AM in vitro (Badger, 1986; Marshall and Lands, 1986; Snella, 1986). The AM response to these activators appears to be mediated in part by the oxygenated metabolites of arachidonic acid (AA) (Bertram et al., 1988; Demers et al., 1987; Mcleish et al., 1987).The AM may metabolize AA through cyclooxygenase- and lipoxygenase- catalyzed pathways to produce a variety of eicosanoids including prostaglandin (PG) E2, thromboxane (Tx) A2, leukotriene (LT) B4, LTC4, LTD4, and several hydroxyeicosatetraenoic acid derivatives (HETEs) (Willis, 1970; Camp et al., 1983; Poubelle et al., 1986). The production of these eicosanoids may enhance the. defensive ability of the challenged lung since they stimulate chemotactic cell recruitment to the site of invasion, enhance extravasation of circulating immune cells, and promote local vasodilatation. However, continued stimulation of the AM population, with the consequent production of proinflammatory eicosanoids, may ultimately enhance the disease process by contributing to chronic bronchoconstriction, fibrosis, and the persistent release of toxic oxygen species."

Jan 1, 1990

By R. W. Huber

While conducting an investigation on electrolytic reduction of magnesium oxide in 1943, it became necessary to obtain accurate data on the conductivity and density of various mixtures of fused chlorides. AZ the required information was not available in the technical literature, or there were inconsistencies in the data from several investigators, an independent study was made at the Bureau of. Mines laboratory at Salt Lake City on the conductivity and density of the molten chlorides MgCl2, CaCl2, BaCl2, KCl, and NaCl and the binary mixtures of MgCl2 with the other four chlorides. Studies were also made on the binary system KCl-CaCl2 and on certain portions of several ternary systems. Measurements covered a temperature range from the melting point to 1,000° C. The results of this study were reported in an intra-Bureau report prepared early in 1944. Since then the Bureau of Mines has received several requests for data on fused chlorides; the results of the previous study, therefore, are being published to make the data available.

Jan 1, 1952

By Wallace W. Roepke

The Bureau of Mines has a well-established health and safety research effort directed to fundamental studies of the mine cutting system. This report describes the ignition danger of using cutting bits with flat wear area on still-intact carbide inserts.

Jan 1, 1983

By Joanne L. Johnston

Researchers at the U.S. Bureau of Mines have developed a new technique for bonding strain gauges to rock bolts. These instrumented bolts are used to determine load at intervals along the length of the bolt so that reliable, consistent measurements for the design of support systems can be obtained. In this Information Circular, this technique is described in detail and should result in improved miner safety in underground mines.

Jan 1, 1993

By Thomas A. Phillips

This publication is an economic evaluation of the Bureau of Mines electrolytic process for recovering lead from scrap lead-acid batteries. In this process, scrap batteries are crushed and separated into metal and sludge fractions. The metal fraction is cast as anodes and electro- refined. Lead in the sludge fraction is converted to lead carbonate by reaction with an ammonium carbonate-ammonium bisulfite solution. The lead carbonate is then dissolved in a fluosilicic acid electrolyte from which pure lead metal is electrowon. A cost estimate is presented for a plant capable of processing 10,000 scrap batteries per day. The fixed capital cost for this plant is estimated to he $14 million on a fourth quarter 1984 basis. Operating costs are estimated to be $0.15/lb Pb recovered. Assuming a lead selling price of $0.17/lb, the interest rate of return on investment after taxes is 11 pct. A lead selling price of about $0.21/lb is needed to obtain a 20-pct-interest rate of return.

Jan 1, 1986

By Synthia N. McIntosh

The U.S. Bureau of Mines investigated the feasibility of using ammonium carbamate (NH2CO2NH4) leaching to recover manganese from steel plant slag. This investigation showed that treatment of the slag in hydrogen prior to leaching enhanced manganese extraction. Up to 80 pct of the manganese and 50 pct of the iron could be extracted from a silicon steel slag that had been pretreated in hydrogen at 700° C. Two 4-h leaching stages conducted at ambient temperature with a solution containing ammonia and carbon dioxide dissolved manganese and iron as their carbamate complexes. Heating the pregnant solution to 65° to 85° C decomposed the complexes and precipitated the metals as insoluble carbonate salts. Ammonium carbamate leaching of other slags from several steelmaking plants produced lower manganese extractions, which suggests that the method cannot be applied satisfactorily to all steelmaking slags

Jan 1, 2010