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By George W. Huseman, W. D. Mcmillan

"INTRODUCTION Feldspars represent one of the most abundant groups of minerals and constitute nearly Go percent of the material contained in the igneous rocks. They are grouped in a series of related aluminum silicates with varying amounts of potash, soda, and lime. .Approximately 85 percent of the feldspar produced in the United States is used as a flux in the production of glass, pottery, enamel and sanitary ware, brick, and tile. Notwithstanding the abundance of feldspar in the earth's crust, the only deposits that are worked to any extent are the pegmatites or coarsely crystalline dikes where natural segregation of the constituents facilitates recovery of the feldspar with a minimum of free quartz, mica, tourmaline, garnet, and other iron-bearing minerals that are detrimental in most ceramic industries.Although there are three glassplants and numerous other ceramic industries in Texas, all of the feldspar used in these plants is from other States. In the Llano region of central Texas, however, there are numerous coarse pegmatite dikes consisting primarily of feldspar and quartz in ratios up to 3 to 1. One of the more important of these dikes is the Badu Hill deposit in Llano County, Tex., which was first described by Carl Chelf 4/ in 1942. Following an examination of the deposit by W. D. McMillan, engineer in charge of the Texas field office of the Bureau of Mines, in January 1946, a proposal was made to investigate the deposit by core drilling in cooperation with the Department of Ceramic Engineering, University of Texas. This report presents the results of the cooperative investigation, which was begun April 24, 1946, and completed May 17, 1946."

Jul 1, 1947

By Donna D. Harbuck

The Bureau of Mines has investigated a process to produce titanium powder directly from titanium salts. If successful, such a process could lower the cost and increase the use of titanium. In this study, K2TiF6, K2TiF3, and TiF3 were reduced with potassium in the temperature range of 650° to 750° C. Under certain conditions, titanium powder 1.6 to 3.3 microns in size was produced. After leaching the product with a 0.1M HCl solution, powder impurities as low as 0.04 pct potassium and 0.28 pct fluorine were obtained. However, oxygen levels of over 1 pct and the frequent formation of insoluble byproducts demonstrate the need for further research to make the powder suitable for powder metallurgy applications.

Jan 1, 2011

By H. Dolezal

An investigation was made on the use of magnesium for the direct reduction of rutile to make low-cost, offgrade titanium which could be upgraded to an acceptable grade of metal by electrorefining. Reductions made with charges containing magnesium chloride under hydrogen yielded products with oxygen con-tests close to the theoretical equilibrium composition. Two reduction products were made from rutile for use in electrorefining amenability tests: (1) a product from reduction in an inert atmosphere which contained 88.9 percent titanium and 4.42 percent oxygen, and (2) a product from reduction in a hydro-gen atmosphere which contained 92.5 percent titanium and 2.40 percent oxygen. Reduction products obtained under both of these conditions were amenable to electrorefining.

Jan 1, 1965

By E. J. Gleim

The construction of explosion-proof electric mine equipment for operation in gassy coal mines of the United States was begun as early as 1903. In 1.906, similar equipment with special protective devices was built for export. An investigation of explosion-proof motors was conducted by the United States Bureau of Mines during 1910 and 1911. In other words, this was among the first efforts of the Bureau directed toward the saving of life and property subsequent to its establishment by act of Congress in 1910. In these early motors, those with special devices for relief of explosion pressures predominated. At that time it was generally considered that, by providing for pressure relief, the enclosures could be made lighter in weight because of the lower explosion pressures developed within.

Jan 1, 1954

By John S. Berber

To improve the economics of low-temperature carbonization of coal, the Bureau of Mines is conducting research on the upgrading of the product tar to marketable chemicals. This report describes experiments on the catalytic hydrodealkylation, followed by catalytic vapor-phase oxidation of the dealkylate to phthalic and maleic anhydrides, of mixed residues from the urea adduction of lignite-neutral oil fraction and on the catalytic thermal dealkylation of high-boiling tar acids. The hydrodealkylation experiments were conducted at pressures from 1,000 to 1,750 psig and at temperatures from 600° to 1,000° F. The oxidation was, in all cases, at atmospheric pressure and 9500 F. Maximum yield of maleic anhydride, based on the liquid feed to the hydrodealky1ation unit, was 12.2 percent at 750° F and 1,500 psig; that of phthalic anhydirde was 6.9 percent at 650° F and 1,500 psig. Maximum yield of combined anhydrides was 18.8 percent at 650° F and 1,500 psig. The non-dealkylated feed material, upon oxidation, yielded 8.9 percent and 3.8 percent maleic anhydride and phthalic anhydride, respectively.

Jan 1, 1967

By L. M. Demers, D. C. Kuhn

"Kuhn, Douglas C., and Laurence M. Demers. Effect of surfactant on basal and silica-induced eicosanoid production by the alveolar macrophage. Am. J . Physiol. 269 (Lung Cell. Mol. Physiol. 13): L165-Ll 70, 1995.-Infiammation and fibrosis subsequent to the inhalation of certain mineral dust particles has been suggested to result from the activation of eicosanoid synthesis by the alveolar macrophage (AM). To determine if surfactant modifies dust-induced generation of eicosanoids by the AM, we evaluated the effect of the surfactant lipid dipalmitoyl lecithin (DPL) on the production of eicosanoids by rat AM exposed to respirable silica dust in vitro. During the first 24-h exposure period, DPL alone significantly increased basal production of eicosanoids but completely inhibited silica-induced thromboxane A2 synthesis. In contrast, leukotriene B4 (LTB4 ) production was only partially reduced by DPL. During a second 24-h exposure period, LTB4 production in response to the highest dose of silica remained significantly elevated in the presence of DPL. Similar results were obtained when the surfactant preparation Survanta was evaluated. These results suggest that 1 ) DPL and Survanta independently activate AM eicosanoid production, 2) DPL and Survanta modulate the response of the AM to silica dust, and 3) L TB4 may be the most important eicosanoid mediator of the long-term effects of silica dust exposure on lung pathophysiology. THE OXYGENATED METABOLITES of arachidonic acid (AA) (here collectively termed eicosanoids) have been implicated as important regulators of lung physiology and are thought to be involved in pathophysiological sequelae such as acute respiratory distress syndrome, asthma, and the pulmonary complications of sepsis (20). This role is manifested through both direct effects on lung physiology as well as through an indirect modulatory effect on the release of other mediators of lung injury, in particular profibrotic cytokines such as the interleukins and tumor necrosis factor (15). Recently, exaggerated eicosanoid production by both the alveolar macrophage (AM) and the type II epithelial cell has been demonstrated to result from the exposure of these cells to several particulates, including crystalline silica (quartz) dust (5, 9, 17). These observations have led to the suggestion that eicosanoids play a major role in the etiology of pneumoconioses.Another secretory component of the pulmonary environment, surfactant, has been shown to modulate crucial AM functions, such as bactericidal activity and the recruitment of circulating immune cells (25). Indeed, an important feature of the lung's reaction to inhaled mineral dust is an increase in surfactant production, perhaps as a compensatory or protective response (1, 16). In addition, the alteration of the surface properties of mineral dust by surfactant or its components has been shown to influence the biochemical response of the AM to the dust, perhaps by altering the surface charge of the dust particle (11, 29, 32). And recently, Wallace et al. (28) have shown that the coating of mineral dust with surfactant, and its subsequent removal by lysosomal phospholipase, unmasks differences in dust cytotoxicity that are not apparent when AM are exposed to uncoated dust. Thus it appears that the inclusion of surfactant in in vitro exposure studies may be important in evaluating both the absolute levels of eicosanoid production by the normal and dust-exposed AM and the temporal relationship between dust exposure and the production of inflammatory mediators by the AM. Therefore, we characterized the effects of the surfactants dipalmitoyl lecithin (DPL; the primary lipid component of natural surfactant) and Survanta (a commercially available surfactant derived from bovine lung) on basal and silica-induced AM eicosanoid production during two 24-h periods after exposure to dust particles to both allow the enzymatic removal of surfactant from the particle surface and evaluate the k"

Dec 1, 1996

By J. A. Eisele

The Bureau of Mines is investigating the recovery of alumina from domestic nonbauxitic resources, including anorthosite. The United States has large reserves of anorthosite, but its aluminum content is less than 50 pct soluble in acid, unless a source of fluoride is added to the acid. A flowsheet that includes leaching with HCl and fluoride followed by crystallization of AlC13.6H20 from the pregnant liquor by HCl gas injection was designed. Approximately 90 pct of the aluminum values were recovered from the anorthosite when a ratio of 0.14 mole of fluorine per mole of aluminum was used. Sodium chloride is cocrystallized with the A1C13.6H20 but is removed by water washing of the Al203 product. A material balance is given based on results of laboratory studies of the unit operations.

Jan 1, 1983

By D. N. Tallman

The electrokinetic properties of MgO have been utilized to simultaneously filter suspended solids and remove trace amounts of dissolved heavy metals from synthetic mine water. Greater than 95 pct removal of metals from influent at neutral pH containing 1 to 6 mg/L of dissolved Cd, Cu, Mn, Ni, and Zn can be routinely achieved by filtering through a granular bed of MgO at flow rates typical of rapid sand filtration (0.3 cm/s). Filtrate concentrations of most metals can be maintained below 0.1 mg/L for 160 bed volumes or more loading. The more mobile metals (those with larger solubility products) are more difficult to remove, and are strongly bonded to the MgO granules so that chemical stripping with chelating agent is required to clean the bed. Less mobile ions are easily removed by the filter and are effectively stripped by conventional filter backwashing. The fraction of metals recovered by chemically stripping the loaded MgO filters correlates to the zero points of charge of the metals. This process may be applicable to removal and recovery of trace amounts of heavy metals in mine drainage that is partly neutralized by liming. Also, since many of these metals are critical and strategic, the technique can be adapted not only to recycle process water from mineral and milling waste streams, but also to reclaim their metal values.

Jan 1, 1986

By R. A. Beall

Consumable-electrode arc melting is now accepted throughout the industry as the best method for producing ingots of zirconium, titanium, molybdenum, and their alloys. In addition, the technique is widely used in laboratories for fusing samples of such metals as hafnium, chromium, tantalum, columbium, and thorium. The production of consumable electrodes from these metals presents some rather difficult problems, the accepted industrial solution being the use of heavy powder-metallurgy-type presses. This paper summarizes information on fabrication of consumable electrodes by this and alternative means, such as sintering, nippling, and welding lightly pressed compacts of scrap metal. A possible saving of considerable capital investment is shown in the case of sintered compacts. The electrical circuit components of a pilot sintering unit are analyzed. INTRODUCTION The consumable-electrode arc-melting process has been accepted by most of the industry as the best method at present for producing high-quality pure or alloy in-got from sponge titanium or zirconium. This technique is not particularly new, having been patented by Von Bolton (l)3/ in 1909 for melting tantalum. However, it has been applied to industrial-scale operation only in the last few years. Among the important contributions to this technique are the work of Kroll (2) and Parke and Ham (3) and the work reported by the Office of Naval Research (4). The Bureau of Mines-has added considerably to the knowledge of this process (5-9).

Jan 1, 1956

By Thomas J. Peters

In 1987, at the request of the U.S. Bureau of Land Management, the Bureau of Mines studied the 350-acre Henry?s Lake Wilderness Study Area (ID-035-077) in order to evaluate its identified mineral resources. The Wilderness Study Area is located in northern Fremont County, ID, approximately 140 air miles north-northeast of Pocatello and 3 miles south of the Montana border. The Wilderness Study Area is near the north shore of Henry's Lake at the foot of the southwest-facing slope of Black Mountain. Archean hornblende gneiss, the main rock type present, crops out northeast of the Madison Range Fault, which trends northwest across the southwest corner of the Wilderness Study Area.

Jan 1, 1988

By James E. Mauser

This report deals with the investigation of a continuous process for producing pure zirconium. It covers the construction, operation, and maintenance of the semicontinuous reactor. The report covers a study of test variables, such as reactor temperature and reluctant charge weights, and evaluates the results, such as billet metal hardness, residual billet salt content, and suitability of a purified billet as a consumable electrode for arc melting. The purpose of this project was to develop an inexpensive and continuous process for producing pure zirconium. The process developed, termed the semicontinuous reactor process, produced billets of compacted zirconium sponge. The metal was produced by reducing zirconium tetrachloride with sodium and magnesium beneath molten byproduct salt. Hydraulic rams at each end of a vertical reaction tube compacted the sponge and ejected it as a billet. These billets were purified by heat under vacuum to remove entrapped salt. The goal was to utilize the purified billet directly as a consumable electrode for arc melting.

Jan 1, 1961

By R. V. Ramani, S. Shankar

"Available literature on the effect of re-entrainment on overall airborne dust concentration in mine airways or the fundamental mechanisms of coal dust re-entrainment in mine atmosphere is scant (Shankar and Ramani, 1991 ). Therefore, as part of the Respirable Dust Center's ongoing research, the following three-part study was undertaken:• a study of the re-entrainment phenomena of anthracite and bituminous coal dust particles in a wind tunnel under the influence of varying air velocities;• a study of the same in the Lake Lynn Laboratory Mine of the USBM with both air flow and walking by personnel causing re-entrainment; and• the mathematical modeling and computer simulation of the re-entrainment phenomenon.In this paper, results from the re-entrainment studies in the wind tunnel and the Lake Lynn Laboratory mine are presented. Comparing the results from the two studies,it was observed that increasing the air velocity increased the rate of re-entrainment ( Shankar and Ramani, I 994a) and the rate of re-entrainment decreased with the time of exposure of the source dust to the flowing air. In addition, when the source dust was composed of particles of different sizes, the airborne dust concentrations due to re-entrainment were higher than when the source dust was composed of particles of the same size. The contribution of airborne dust concentration due to air flow was negligible compared to the contribution due to walking. IntroductionIn underground coal mines, dust is produced primarily during the process of mining and during such activities as pillar spall, loading, belt transfer and roof fall. The generated dust is entrained and then collects on surfaces through dispersion, diffusion and eventual deposition. Removal forces, such as flowing ventilation air or turbulence caused by walking and moving vehicles, can re-entrain the deposited dust (Hall, 1955). A portion of the re-entrained dust remains airborne and increases the concentration of airborne dust in mine airways.The presence of airborne coal dust in mine airways in large concentrations can be hazardous. Health effects include coal workers' pneumoconiosis (CWP) and silicosis, and it can be a nuisance affecting visibility. In addition, as is common during methane explosions, if the concentration of airborne coal dust becomes significant, there could be a coal-dust explosion (Singer, Cook and Grumer, 1972; Singer, Harris and Grumer, 1974; Edwards and Ford, 1988). Through concerned research efforts over the last decade, significantprogress has been made in reducing the airborne dust concentration in mine atmospheres. However, secondary sources, such as re-entrainment, have not been studied in-depth. It is important to understand the phenomenon of re-entrainment and its potential contribution to the airborne dust concentration in mine airways for further decreasing airborne dust hazards in mines."

Dec 1, 1996

By Dennis A. Long

Slip and fall accidents are a major cause of lost-time injuries associated with large mobile equipment in surface mines. An evaluation of the safety hazards associated with getting on and off large surface mining vehicles showed that most of the accidents occur at the point where personnel attempt to mount or dismount the machine at ground level. The major hazardous design conditions were identified as excessively flexible supports for lower steps or rungs, inappropriate ground-level-to-first-step distances, poor step designs, access designs that use vehicle components as steps or walkways, and inadequate hand- rail and guardrail designs, Additional hazards are introduced by the lack of proper maintenance of ladder hardware and the work practices of operators in carrying articles while mounting and dismounting the vehicle. This Bureau of Mines report describes the design and in-mine testing of improved access system for large mobile mining equipment.

Jan 1, 1984

By C. H. Schack

Although viscosity is known to be important in processing and handling finely ground urea, its effect has never been fully quantified. This report describes the methods used and the results obtained in the initial phases of a broad investigation of the influence of viscosity of water suspensions of minerals in flotation, thickening, filtering, and other mineral-dressing unit operations. Several types of vis-cosimeters were tested before reliable and reproducible results could be obtained on mineral suspensions. After the viscosimeter used in the research was calibrated and standardized, tests were made on six pure minerals to study the relationship of pulp density, particle size, crystallinity, and cleavage on viscosity. An orifice-type viscosimeter equipped with a mechanical stirrer gave as good results as other types and was more flexible, faster, and simpler to operate. The orifice-type viscosimeter, when calibrated and standardized with glycerin and water mixtures, proved satisfactory over a wide range of viscosities. The accuracy and reproducibility were reasonably constant between 1 centipoise and 200 centipoises, the anticipated range in common mineral-dressing unit operations.

Jan 1, 1957

By D. G. Lee

Diesel particulate matter (DPM) often contains small amounts of metal as a minor component but this metal may contribute to adverse health effects. Knowledge of the mechanism for particle formation as well as the size preference of the trace metals is critical to understanding the potential for health concerns. To achieve this, the size and the composition of each particle should be optimally measured at the same time. Single particle mass spectrometer (SPMS) would be the best tool for this objective. In this paper, we therefore will introduce new findings about the mechanism and distribution of the trace metals in DPM, derived from a study where an SPMS was used to analyze freshly emitted DPM. KEY WORDS : Single particle mass spectroscopy, Diesel particulate matter, Characterization, Metal contents

Jan 1, 2006

By Charles W. Huggins

To determine the nahcolite and dawsonite content in oil shales, the Bureau of Mines compared X-ray diffraction, infrared spectroscopy, thermal methods, and a previously published method by Smith and Young based on the selective solubility of sodium compounds. The Smith and Young method and a new method based on the weight of carbon dioxide produced by thermal decomposition are recommended for determining nahcolite. X-ray diffraction and the Smith and Young method are recommended for determining dawsonite. X-ray diffraction, infrared spectroscopy, and differential thermal analysis were useful for identifying other minerals in the samples.

Jan 1, 1973

By David P. Lindroth

The objective of this research by the Bureau of Mines was to determine the technical feasibility and associated pilot data for drying minus 1/4-in coal with microwave energy at a frequency of 2.45 GHz. The drying data were obtained experimentally on three coal types: bituminous, subbituminous, and lignite. The experiments were performed with a custom-designed conveyorized microwave oven having a continuous power capability of 12 kW. Drying efficiencies near the theoretical maximum of 1.54 kg of water per kilowatt hour of energy input were achieved for two coals and two sizes; overall drying efficiencies averaged 77 pct.

Jan 1, 1986

By J. T. McCartney

The Bureau of Mines has developed an automated reflectance scanning microscope system, primarily for determination of volume proportions, size distribution, and mode of association of the physical (petrographic) components of coals. The process, which is potentially more rapid and objective and less tedious than a visual microscopic procedure, involves magnetic tape recording of several millions of reflectance readings on micro-meter sized areas of polished coal surface and computer analysis and interpretation of some characteristics of the coal components. The system was tested in a study of pyrite distribution in steam coals. The application was essentially successful, but defects in polished pyrite surface characteristics and problems in adequate sampling prevented completely satisfactory results. Pyrite con-tent and coal-pyrite particle association could be determined nearly as well as by visual microscopy, but size distribution data were less acceptable.

Jan 1, 1969

By John C. Holtz

"INTRODUCTION Information on the gaseous products from the detonation of explosives has been obtained in two ways. In the first, the atmosphere in mines is analyzed after blasting, and in the second, the gases found after detonating an explosive in a testing apparatus are analyzed. The Bureau of Mines, in a cooperative research 3/ that compared data obtained in the field with those obtained in the testing station, showed that the results were not in entire agreement. The production of carbon monoxide was found to be governed chiefly by the oxygen balance of the explosive, but the production of oxides of nitrogen did not change in so simple a manner. Because of the increasing interest in correlations between the composition of the explosive and the production of toxic gases, it seemed desirable to continue the investigation.PURPOSE OF INVESTIGATIONAs field tests are both time consuming and expensive and as field results are affected by factors that are not always under control of or clearly evaluated by the operator, the purpose of this investigation is to develop a testing-station procedure that will reproduce the gaseous products quantitatively under known conditions analogous to those that may be expected in the field. In addition, the factors affecting the formation of toxic gases, particularly oxides of nitrogen, will be studied,"

Apr 1, 1940

By R. Duncan Gardner

This paper describing the mining practice at the Harmony mine, Baker, daho, is one of a series being prepared by the Bureau of Mines on mining practices, methods, and costs in the various mining districts in the United States. About 150 tons of copper ore containing 4 per cent copper, 0.001 ounce gold, and 0.1 ounce silver, is being produced daily from the Harmony mine by the shrinkage method of mining. The ore is taken by an aerial tramway 1/3 mile long to the mill, where it is concentrated. The concentrate is shipped 8 miles by truck to the railroad and thence by rail to Utah for smelting.

Jan 1, 1930