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By J. I. Paige

The effect of fluoride inclusions on the properties of titanium produced from the Bureau of Mines-developed induction slag melting process is of concern to the titanium industry. The objective of the research was to determine the effect of removing the nonconductive molten calcium fluoride (CaF2) slag used as an insulator between the titanium and the segmented copper crucible. The data were obtained from single-induction-melted ingots prepared with no CaF2 insulating slag and an ingot prepared with the normal addition of 4 pct CaP2 slag. The results showed that the mechanical properties of single-induction-slag-melted and annealed Ti-6AI-4V alloy exceed the minimum values specified in "Aerospace Materials Specification for Titanium Alloy Bars and Forgings AMS4928H." High-cycle, tension-tension fatigue testing yielded similar results. The data from 44 of the 45 specimens were contained within the typical scatter band for fatigue data on wrought Ti-6AI-4V alloy. Although the removal of the insulating slag is a desirable change, the data from the specimens with the previously standard 4 pct slag addition showed no detrimental effect from the slag inclusions.

Jan 1, 1988

By A. R. Taylor Jr.

The heat capacities of a-quartz form beryllium fluoride were measured at approximately 3° intervals from 8° to 300° K., using an adiabatic calorimeter. At 298.15° K the heat capacity and entropy were 12.39 cal/deg mole and 12.75 ±0.04 eu respectively. Enthalpy measurements were made with an ice calorimeter at approximately 30° intervals on the quartz and glassy forms of beryllium fluoride between 300° and 1,200° K. A melting point of 825° K and an 0,-8 type transition at 500° K with a heat effect of 75 ca1/mole were deter-mined from the enthalpy data for the quartz-type sample. Beryllium fluoride glass crystallized spontaneously into the quartz modification at 500° K. The heat of the reaction BeF2 (a-quartz) .... BeF2 (glass) was found to be 1,125 ±16 cal/mole at 298° K by solution calorimetry. This value, when corrected to 273° K, was used to correct for the heat absorbed by the formation of glassy BeF2 when the sample was dropped into the ice calorimeter from temperatures above the melting point. Using corrected enthalpy measurements, the heat of fusion was determined to be 1.13 kcal/mole at 825° K.

Jan 1, 1965

By J. R. Hauger, P. A. Romans, W. J. Niebuhr

With suitable instrumentation and techniques it is possible to determine the presence of tantalum in columbium to 20 ppm . This paper discusses the selection of X- ray spectrographic instrumentation and describes a technique for accomplishing the low level determination of tantalum . An ion- exchange method of separating tantalum from columbium is also described .

Jan 1, 1964

By H. R. Babitzke, H. Kato, R. E. Siemens

An investigation was made to provide further information for evaluating columbium- hafnium alloys for use as high - temperature structural materials . The columbium- hafnium system was investigated between 700 ° and 2,400 ° C by melting point , thermal analysis , X - ray diffraction , electrical resistivity , and metallographic techniques . The equilibrium diagram is the beta isomorphous type , with columbium tending to stabilize the beta phase . Addition of 60 atomic percent columbium stabilizes the beta phase at 700 ° C. The allotropic transformation temperature of hafnium is 1,750 ° ± 20 ° C. A minimum melting point occurs near 75 atomic percent hafnium .

Jan 1, 1964

By D. J. Judy, D. J. Rabovsky, W. H. Pailes, V. Castranova, K. Van Dyke, J. Rabovsky, N. A. Sapola, M. McPeek

"Platelet activating factor (PAF) can be released from pneumocytes following exposure to occupational dust (Am. Rev. Respir. Dis. 135:83, 1987). In addition, PAF has been shown to induce pulmonary inflammation, edema, and bronchoconstriction (Hosp. Prac. 19, 67, 1983). This investigation reports the effects of PAF on the properties of three types of cells found in the lung. PAF (1-100, K1/2 = 2.5 pH) caused depolarization of neutrophils as well as generation of chemiluminescence and secretion of hydrogen peroxide. These responses were dependent on the presence of extracellular sodium. However, PAF did not alter oxygen consumption of neutrophils. Although PAF (10 uM) caused depolarization of alveolar macrophages, no stimulation of chemiluminestence, superoxide secretion, or oxygen consumption was observed. However, PAF (10 uM). did potentiate chemiluminescence and superoxide secretion in response to zymosan (2 mg/ml) by 55% and 36%, respectively. In addition, PAF (10-90 uM) caused aggregation of alveolar macrophages. PAF (2-10 uM) also caused depolarization of type II cells, but did not affect membrane integrity or oxygen consumption. However, PAF (10-18 PM) enhanced the activities of two distinct forms of cytochrome P-450 in type II cells and caused aggregation of type II cells at PAF doses above 18 uM. These data indicate that PAF can affect the secretory activity of pulmonary phagocytes and the ability• of type II cells to detoxify foreign compounds (Bureau of Mines Grant - G1175142).INTRODUCTIONPlatelet activating factor (PAF) is a glycerophospholipid (1-0-alkyl-2-acetylsn-glycerol-3-phosphoryl choline) which has been shown to Mediate a broad range of biological activities (1-3). Its pulmonary actions include contraction of pulmonary tissue (4), secretion of leukotrienes from leukocytes (5), airway constriction (6), pulmonary edema (7), and enhanced migration of neutrophils into the airspaces of the lungs (8,9).PAF can be released from several different cell types, such as, basophils, neutrophils and alveolar macrophages, in response to a variety of particulates or membrane stimulants which include zymosan, calcium ionophore, phorbol esters, chemotactic agents, and endotoxin (10-13). Therefore, PAP may play an important role in the development of pneumoconioses by mediating pulmonary responses of lung cells to a variety of occupational dusts. To investigate this possibility, we determined the effects of PAF on several physiological parameters of neutrophils, alveolar macrophages, and alveolar type II epithelial cells."

Jan 1, 1988

By Rees D. Groves

The Bureau of Mines conducted research on reactions of copper sulfide minerals with chlorine in an aqueous system. Selected samples of covellite, chalcopyrite, chalcocite, bornite, and pyrite were leached with aqueous chlorine solutions. The mineral samples were sized on to minus 100- plus 325-mesh, individually mixed with precleaned sand and leached in an enclosed percolation column. Each mineral was leached in stages to achieve about 90 percent mineral dissolution. The chlorine leaching solutions were produced by reacting sodium hypochlorite with hydrochloric acid within the closed system. The study showed that when the mineral dissolution was complete, the reaction products (copper, iron, and sulfur) were in their highest oxidation states and a stoichiometric amount of chlorine was consumed. Although elemental sulfur formed as an intermediate product, it was oxidized to sulfate during the leach.

Jan 1, 1973

By B. J. Scheiner

The Federal Bureau of Mines has successfully demonstrated an electrooxidation-solvent extraction-carbon adsorption process for recovering molybdenum and rhenium from offgrade concentrates. The flow sequence consists of dissolution of metal values by electrooxidation, liquid-solid separation by thickening, acidification and chlorate ion removal by sulfur dioxide treatment, solvent extraction to concentrate the molybdenum and rhenium, separation of molybdenum and rhenium by carbon adsorption, and metal recovery by crystallization. Molybdenum and rhenium were recovered as ammonium paramolybdate and ammonium perrhenate. Electrolysis of brine-concentrate pulps to generate a hypochlorite oxidizing agent in situ resulted in the dissolution of 98.9 and 99.1 pct of the molybdenum and rhenium, respectively, at an energy consumption of 13.7 kwhr/lb of molybdenum extracted.

Jan 1, 1976

By John Nagy

Results of initial research by the Bureau of Mines are given on the dust explosion hazard of float coal and on the related factors of occurrence, rate of production, sampling techniques, transport, and deposition of float coal. Tentatively, it is suggested that where float coal deposits prevail, a mini-mum of 80 percent incombustible be maintained in the top 1/8-inch layer to neutralize the explosion hazard of the surficial coal deposit.

Jan 1, 1965

By Natalie A. Sapola, Knox Van Dyke, Jean Rabovsky, Vincent Castranova, William H. Pailes, Melanie McPeek, Deloris J. Judy

"INTRODCJCTJONPlatelet activating factor (PAF) is a glycerophospholipid (1-0-alkyl-2-acctyl-sn-glycerol-3-phosphoryl choline) which has been shown to mediate a broad range of biological activities. 1·3 Its pulmonary actions include contraction of pulmonary tissue,4 secretion of leukotrienes from leukocytcs,5 airway constriction,6 pulmonary edema,7 and enhanced migration of neutrophils into the airspaces of thelungs.8-9PAF can be released from several different cell types, such as, basophils, neutrophils and alveolar macrophages, in response to a variety of particulates or membrane stimulants which include zymosan, calcium ionophore, phorbol esters, chemotactic agents, and endotoxin. 1~1 3 Therefore, PAF may play an important role in the development of pneumoconioses by mediating pulmonary responses of lung cells to a variety of occupational dusts. To investigate this possibility, we determined the effects of P AF on several physiological parameters of neutrophils, alveolar macrophages, and alveolar type Il epithelial cells.METHODSIsolation of CellsNeutrophils were isolated from human blood by dextran settling and centrifugal elutriation.14 Isolated neutrophils (93% pure) were resuspended in HEPES-buffered medium (145 mM NaCl, 5 mM KCI, 10 mM HEPES, 5 mM glucose, and 1 mM CaC12; pH = 7.4). Cell number and volume were determined with an electronic cell counter equipped with a sizing attachment.Rat alveolar macrophages were obtained by pulmonary lavage with ea2+, Mg2+-free Hanks balanced salts solution. 15 Alveolar macrophages (94% pure) were resuspended in HEPES-buffered medium, counted, and sized electronically.Rat alveolar type Il cells were isolated by enzymatic digestion for 35 minutes at 37°C with 40 µ/ml type I elastasc and 0.1 % collagenase and purified by centrifugal elutriation. 16.17 Type Il cells (92 % pure) were resuspended in HEPES-buffered medium for measurement of membrane potential, oxygen consumption, and trypan blue exclusion. Type Il pneumocytcs were resuspended in 0.1 M NaCl plus 0.05 M HEPES (pH = 7.8) to measure cytochrome P450-dependent activities and aggregation. Cell size and number were determined electronically."

Jan 1, 1990

By George R. McCormick

Because several new and unusual synthetic minerals were found in the system MgO-MgF₂ - SiO2 with Li * , or Nat a similar system with Geo₂ replacing Sio , plus Lit was investigated . In addition to the expected compounds of germanium , Ge - fluor - hectorite and a Ge - fluor- chrysotile were synthesized . Protoamphibole was not observed . Data are given for 69 compositions prepared in the system MgO- MgF₂ - Ge02 at 6.94 percent LiF .

Jan 1, 1964

By L. Mark Irwin, R. A. Marsyla

The objective of this laboratory investigation was to develop a mattesmelting process for the recovery of copper from industrial smelter dusts . Experimentation was conducted on three samples of Cottrell precipitator dust from a northern Michigan smelter with variations in the following conditions : Temperature , charge composition , pelletization , and moisture content . Based on chemical analyses of the furnace slags , poorest recovery of copper was effected in smelting dry charges regardless of composition . Some improvement was noted with uniformly moistened charges and still more with pelletized (but dry) mixes , but best results were obtained from smelting moist , self - fluxing pellets . Under favorable conditions , experiments yielded furnace slags with an average copper content of only 0.15 percent , which is well below that of industrial copper reverberatory slags .

Jan 1, 1963

By I. AITKENS

The basic mining law of Cuba is contained in the basic Spanish mining decree having the effect of law December 29 , 1868. This legislation has remained substantially unchanged , with the exception of a few minor administrative changes made by the present Government . These changes provide for the register of mines , oil wells , and operations of such nature , and also provide for the keeping of records showing the value of minerals taken out . By Royal decree of April 17 , 1883 , the law of mines enacted for the Peninsula ( Spain ) on July 6 , 1859 , and the General Bases of December 29 , 1868 , were declared in force in Cuba . In order to encourage the mining of iron org , in 1883 the Crow of Spain issued a royal decree to the following effect.

Jul 1, 1931

By S. H. Ash

As part of the work done at the Washington coal mines during the year 1929 , a study was made of the safety practices in and about the mines . Inasmuch as electrical blasting has made considerable headway it is interesting to note the manner in which it is done and the reasons why it was discarded at some of the mines . Blasting is done at the mines in the State by means of capped fuse , electric blasting " caps , " and in some instances by electric delay detonators . Black blasting powder with fuse is used at most of the open- light mines . The use of squibs was discontinued several years ago because the coal operators , without exception , recognized the dangers incidental to their use . Permissible explosive and dynamite are also used at some of the open- light mines . With the exception of some rock work and the driving of level work in gangways and air courses the explosive is detonated by means of capped fuse .

Apr 1, 1930

By J. L. Stauffer, S. L. Lacey, L. J. Gaydos, L. M. Demers, D. C. Kuhn

"Tumor necrosis factor alpha (TNFa) and thromboxane A2 (TXA2) are major products of the activated alveolar macrophage and serve as key mediators of lung injury. In order to determine if the synthesis ofTXA2 and the release ofTNFa are associated, the production of these inflammatory agents by the human alveolar macrophage (AM), as a result of activation by lipopolysaccharide (LPS), was assessed in the absence and presence of the thromboxane synthase inhibitors UK 38,485 (Dazmegrel) and OKY 046. UK 38,485 and OKY 046 inhibited both LPS-stimulated TXA2 production and TNFa release in a dose-dependent manner. Prostaglandin E2 (PGE2) production was not increased by UK 38,485 or OKY 046. Neither LPS nor UK 38,485 had any effect on LT84 production by AM. Neither UK 38,485 or OKY 046 had any effect on LPS-stimulated interleukin-I beta release. However, the TXA2 mimetic, U46619, did not stimulate TNFa release by AM either in the absence or presence of UK 38,485. These findings suggest that 1) UK 38,485 and OKY 046 are inhibitors of both TXA2 production and TNFa release by activated human AM, 2) UK 38,485 probably does not exert its inhibitory action on TNFa release through effects on eicosanoid production and 3) the possibility that TNFa- and TXA2-induced lung injury may be subject to amelioration by imidazole-based compounds should be further evaluated.IntroductionTumor necrosis factor alpha (TNFa), produced by monocytes and macrophages, is a potent peptide mediator of lung injury (1,2). The exaggerated release of TNFa has been implicated in the etiology of acute lung reactions such as septic shock of bacterial or viral origin (3,4). The role of TNFa is expressed primarily through its ability to activate a variety of cell types within the lung environment including polymorphonuclear leukocytes (PMNs, ref. 5), type II epithelial cells (6) and fibroblasts (7). The role of lipid mediators in lung disease has also been extensively characterized (1). In particular, the relationship between pulmonary inflammation and fibrosis and the production of oxygenated derivatives of arachidonic acid (here termed ""eicosanoids"") appears to be a key factor in a variety of disease processes in the lung (8). The alveolar macrophage (AM) synthesizes primarily prostaglandin E2 (PGE2). thromboxane A2 (TXA2) and leukotriene 84 (LT84, ref. 9). These eicosanoids have been shown to produce a variety of effects in the lung including bronchial smooth muscle dilatation (PGE2, ref. 10), vascular smooth muscle contraction and platelet aggregation (TXA2, ref. 11) and oedema and immune cell extravasation (LT84, ref. 12)."

Nov 1, 1995

By R. P. Vinson

The Bureau of Mines examined the effects of high humidity and water droplets on the GCA Corp. real-time aerosol monitor (RAM--l). which uses a lO4mm cyclone preseparator. Tests were conducted both in a laboratory and in a full-scale model mine entry. The laboratory tests were conducted in a test chamber saturated with moisture and water droplets. Under these extreme conditions. the RAM-I responded by indicating dust concentrations of 1-1/2 to 2 mg/m3? although the air was dust free. Within the first 2 h of each test. water accumulated in the cyclone and affected the cyclone particle separation characteristics. resulting in readings of 3 to 4 mg/m3. In addition. condensation formed inside the RAM-I case and affected the liquid crystal display (LCD). However. the full-scale mine entry tests revealed that the RAM-I can function ac-ceptably in an atmosphere of water vapor and water droplets similar to the most severe conditions found in an underground mine.

Jan 1, 1984

By R. P. Jewett

The object of this investigation was to correlate the crushing strength of green pellets prepared from magnetite, specular and earthy hematite with the particle size of these respective raw materials. In this study no attempt was made to correlate the strength of fired pellets and particle size. The effect of particle size upon a number of fine ores and concentrates was studied. Much of the low-grade ore reserves in the Lake Superior Region must be finely ground before concentration and then agglomerated for iron and steelmaking processes. Fine natural ores also must be agglomerated. Pellets constitute an important type of agglomerate. Considerable handling occurs during screening to remove undersize and oversize pellets, and in transfering green unfired pellets from the balling machines to the heat-hardening equipment. As a result the strength of the green pellets is a factor of great importance.

Jan 1, 1961

By W. W. Simpson

During cyanidation of mercury-bearing gold-silver ores, significant amounts of mercury are extracted. The presence of mercury decreases. gold loading and increases mercury stripping time on activated carbon, complicates fire refining of the gold cathodes, and creates a potential health hazard. Addition of calcium sulfide (CaS) to the cyanide leach slurry precipitates the solubilized mercury but also some silver. The Bureau of Mines investigated silver loss during CaS precipitation of mercury. Addition of 0.1 lb CaS per short ton ore to a mercury-bearing gold-silver ore precipitated both mercury and silver. However, if copper was added with CaS, or if the ore contained copper, much of the sil-ver loss was prevented. Addition of 235 ppm Cu with 0.1 lb/st CaS, prior to carbon-in-pulp adsorption, resulted in 89-to 97-pct, 80-to 91-pct, and O-pct adsorption of the solubilized gold, silver, and mer-cury, respectively, on the activated carbon.

Jan 1, 1986

By R. Barany

Thermodynamic calculations pertaining to the minerals gibbsite, kaolinite, halloysite, and dickite have been hampered by the lack of adequate heat and free energy of formation data. Previous data for gibbsite were highly uncertain, and there were no data for the other three substances. By use of hydrofluoric acid solution calorimetry, the Bureau of Mines derived heat of formation values from the elements and from the oxides for the four substances, and the data were combined with known entropy values to obtain the corresponding free energies of formation. The results show that gibbsite and halloysite are thermodynamically unstable with respect to the oxides (a- alumina, a- quartz, and liquid water) at 298.15° K,, while kaolinite and dickite are only moderately stable (to about the same degree), The instability of halloysite, in comparison with kaolinite and dickite, results in a 60°-lower equilibrium decomposition temperature.

Jan 1, 1961

By Leroy Dockter

The grinding characteristics of lignite in a ball mill were investigated. The variables studied were initial lignite moisture content, degree of in-the-mill drying, and lignite source. The mill tested was a pilot-p1ant-size conical ball mill which had a maximum output of from 80 to 180 lb/hr pulverized product depending on the lignite and test conditions. The capacity of the test mill ranged from 82 to 103 lb/hr depending upon mine source, in pulverization of as-mined lignite with minimum drying, The capabilities of the ball mill could not be correlated to Hardgrove index of the individual lignites or other observed physical properties. Predrying lignite from its 35 to 40 percent raw moisture content to about 10 percent moisture before grinding improved the mill capacity 87 percent, compared to an increase in capacity of 74 percent with in-the-mi11 drying to the same product moisture.

Jan 1, 1967

By Martin H. Stanczyk

Acid leaching of selected copper sulfide minerals, impure copper sulfide flotation concentrates, and a cement copper precipitate at elevated temperatures and pressures was investigated. Copper extractions of 97 to 99 pct were obtained by leaching chalcopyrite and the flotation concentrates with water under oxidizing conditions at 200° C for 30 to 60 min. In tests with bornite, chalcocite,and cement copper, addition of sulfuric acid or pyrite to the autoclave was required to obtain similar copper extractions. The chemistry of leaching copper minerals was studied. It was determined that different copper sulfides altered to covellite as one step in their dissolution.

Jan 1, 1963