Search Documents

By N. Dixon

This report summarizes all work performed under U.S. Bureau of Mines Contract J0377014, "Development and Evaluation of Noise Control Techniques for Taconite Processing Equipment." Three areas of taconite processing equipment, grinding mills, fine screens, and crusher screens have been investigated. Extensive noise and vibration measurements have been made on grinding mills in which the process parameters that affect mill noise have been identified, and the level of shell impact noise around the mill defined. A multiplexing telemetry system was used to obtain shell vibration measurements from a rotating mill. Mill noise control methods were investigated and a partial mill barrier was built and tested on a semi-autogeneous mill. A noise reduction of approximately 3 to 6 dBA was achieved on the falling side of the mill. The use of rubber mill liners on autogenous mills has been evaluated. The noise sources on fine screens have been quantified, and noise control treatments developed. Noise reductions of 11 to 13 dBA were achieved at positions around the fine screen and some in-service testing has been done. Noise measurents of crusher screens were obtained and noise control through resilient screen decks appears to hold the most promise. Additional benefits might be lower life-cycle cost, since the service life of resilient decks is claimed to be longer than steel.

Jan 1, 1983

By M. E. Tyrrell

The Bureau of Mines produced building brick of good quality in an investigation designed to explore the possible utilization of high-glass fractions of municipal incinerator residues in the manufacture of building products. Common clays, lime, and sodium silicate were used as binders for the nonplastic residues Test bricks were formed by dry-pressing, soft-mud molding, and stiff-mud extrusion. A run of standard-size face brick dry-pressed and fired in the West Virginia University Coal Research Bureau pilot plant demonstrated that SW-grade glass-clay face brick can be produced on a commercial scale without difficulty. A cost evaluation made for production of the brick showed an estimated cost of $42.13 per thousand bricks for a shuttle kiln plant and $28.70 per thousand for a tunnel kiln plant.

Jan 1, 1972

By E. C. Perkins

Preliminary experiments are reported utilizing bacteria to leach manganese from a variety of domestic low grade manganiferous materials. In two large leaches manganese extraction ranged from 71.7 to 92.5 percent, and the products analyzed over 48 percent manganese. Nutrient requirements and leaching time experiments were made. The mechanism of leaching is not understood, but is different than the mechanism encountered in the microorganism accelerated leaching of copper in the presence of sulfide minerals.

Jan 1, 1962

By W. H. Blackburn

This paper describing the milling practice at the Tybo concentrator is one of a series of similar papers being prepared by the United States Bureau of Mines on milling methods and costs at the various mills in the United States. ACKNOWLEDGMENT A large part of this paper way prepared by H. M. Lewers, mill superintendent of the Tybo plant of the Treadwell Yukon Co., Ltd.

Jan 1, 1931

By B. D. Sartwell

The formation of alloyed regions near the surface of metals using ion implantation is being investigated by the Bureau of Mines as a means of providing corrosion resistance using much smaller amounts of the strategic alloying metals. Two ion implantation systems that can implant low-energy chromium, nickel, or aluminum ions into low-cost substrate materials such as iron or carbon steel have been designed and constructed. The development of the ion source, ion beam acceleration stage, mass analysis system, and target chamber are described in detail. The ion-implanted alloys have been characterized using proton-induced x-ray emission to give the total number of atoms implanted and to determine the extent of any surface contamination introduced by the ion implantation process. Research conducted at other laboratories on metallurgical applications of ion implantation is given.

Jan 1, 1980

By John E. Kelley

The Bureau of Mines conducted a study to determine the feasibility of joining refractory metal compounds to each other and to oxide ceramics by a vacuum hot press-diffusion bonding method. Very satisfactory joins were made of ZrC to ZrB2, ZrN to ZrB2, ZrC to ZrN, and of ZrC, ZrN, and ZrB2 to Al203. Each of these join assemblies contained a mixture layer comprising 50 weight-percent each of the two end compounds. The mixture layer, sandwiched between each end compound, enhanced bonding and smoothed out the thermal expansion gradient between the two end members. Strength and thermal shock tests showed that the join areas of the ZrC, ZrN, and ZrB2 joins were stronger and more shock resistant than the parent materials. Also included in the joining tests was one each of TiC to TiB2, TiC to TiN, TiB2 to TIN, and TiC to ZrB2 joins. Each of these was well bonded, showing that the vacuum-hot-press method can be used for a variety of systems.

Jan 1, 1969

By Paul M. Tyler

Graphite occurs in many places in the United States, but previous to 1914 the domestic production amounted to only 15 to 20 per cent of the natural graphite consumed in this country. Including artificial, graphite, the proportion was about 25 per cent. During the World War the production of both natural and artificial graphite increased until, in 1918 it, contributed more than one-half of the available supply, and since 1919 the proportion has not fallen below 40 per cent. Except during the war period, however, this apparently increasing independence has not been due to any large increase in production from domestic mines. It simply reflects a larger output of artificial graphite and reduced imports of Ceylon lung and chip, grades which have never been produced in substantial quantity in the United States. DOMESTIC DEPOSITS3 American graphite deposits, though numerous and often large, are characteristically low-grade. They constitute an abundant source of potential supply, but in normal times they have proved relatively costly to work, and even at the same price the various products have never been able wholly to displace certain imported qualities, notably crucible grades from Ceylon and pencil graphite from Mexico.

Jan 1, 1929

By E. J. Matson

This report covers the investigation of the MacArthur copper deposit and several adjacent claims in the Mason mining district; Lyon County, Nev. (fig. 1). As a part of the Bureau of Mines program of investigation and development of domestic mineral deposits, a project was begun first on the MacArthur claims. Work was done later on some adjacent claims in the immediate area, as shown by figure 2. Field work was begun by the Bureau of Mines on January 16, 1950, and completed on October 25, 1950. Eight diamond-drill holes were completed, for an aggregate of 3,414 linear feet, Analyses were made of' each drilling interval. The report includes a brief history of the district and a description of the deposits and of the work done by the Bureau of Mines.

Jan 1, 1952

By R. K. Franklin, S. T. Reese, J. J. Forbes

"INTRODUCTION It is a recognized fact that in the coal-mining industry coal dust must be allayed to promote the safety and health of underground workers. The Bureau of Mines has been cognizant of the hazards of coal dust for many years, and the necessity of controlling such dust was acknowledged when the Federal Mine Safety Code was formulated. Accumulations of coal dust increase the explosion hazard in a bituminous-coal mine and facilitate the propagation of an explosion. Some of the coal dust produced in mining is inhaled by the workers and contributes to respiratory infection. Impairment of vision and personal discomfort resulting from working in dense clouds of coal dust reflect unfavorably on the efficiency of workmen. Considerable coal dust, originating at the working face, is carried in the ventilating current and deposited elsewhere in the mine, thereby increasing the explosion hazard. It is apparent, therefore, that if coal dust could be allayed effectively at its points of origin, the dust-explosion hazard in bituminous-coal mines would be reduced greatly.Although dust control is practiced in many bituminous-coal and lignite mines, the extent and effectiveness of control for the, entire industry-is not generally known. The purpose of this circular is to present such information clearly, and to encourage coal-mine operators to install dust- allaying equipment.Factual data on dust-allaying practices at working faces in a large number of the bituminous-coal and lignite mines in the United States were .compiled from reports on recent Federal inspections of these mines, The information is presented in tabular form to permit review of the dust-allaying practices of a substantial part of the industry, by States, and also according to employment, and loading practice."

May 1, 1950

By Jeffrey H. Welsh

This report presents a study on the use of computerized, continuous remote monitoring systems for fire and explosive atmosphere safety in underground coal mines. The effects of these systems on the safety level in mines are investigated, and the relationship between mine safety regulations and computerized, continuous, remote monitoring is analyzed.

Jan 1, 1982

By V. R. Miller

The Bureau of Mines investigated methods for testing the tensile and sheer strength of cast specimens of bulk solder and of soldered joints in order to increase the strength and extend the useful temperature range of soft solders. A spread-area test for determining the wettability of solder on copper surfaces was developed. Mannitol was used as a flux in spread tests to control spreading and to avoid plating, etching, and other side effects of regular fluxes. Data on commercial and high-purity solders obtained by these methods show more consistency than those reported by others from similar tests.

Jan 1, 1967

By Harold Bailie

The purpose of this Bureau of Mines report is to furnish information on mining practices applied to flat-bedded fluorspar deposits in southern Illinois. It presents new and improved operating procedures and specialized techniques applicable to deposits of this type. All of the operating mines of the Ozark-Mahoning Co. in this area have been opened by vertical shafts which connect with levels consisting of haul-age ways, stopes, and loading stations. The stoping practice used locally called room and pillar, is open stoping with pillars left at different distances and diameters. To facilitate haulage and drainage, the mines are worked from openings turned off the main haulage drift on a grade to conform with the dip of the ore beds. The ore is predominantly fluorspar with smaller amounts of galena and sphalerite that contain traces of cadmium and germanium. The principal gangue minerals are limestone, calcite, shale, barite, and sandstone. The rock hardness ranges from relatively soft shale to hard, abrasive sandstone.

Jan 1, 1960

By G. J. Perrott, H. W. Clark

During the course of the cooperative smoke abatement investigation carried on by the Bureau of Mines , the city of Salt Lake and the University of Utah during 1919-1920 , a study was made as to the suitability of Utah coals for by-product coking with particular reference to low temperature coking . was done because it was realized that a smokeless fuel for domestic consumers was the best remedy for this class of smoke producer . A report of the technical side of the work was included in the final report of the cooperative investiga- Since this report was written (June 1 , 1920) further work has been done by other investigators .

Apr 1, 1922

By Gilbert L. Forst

The objective of this program is to identify and evaluate superior, lightweight substitutes for selected coal mine roof support concepts such as crossbars, posts, and crib blocks. Engineering analysis and concept design identified, through tradeoff studies, that some materials are promising, from a technical standpoint, as support substitutes: E-glass reinforced polyester resin, high strength low alloy steel, aluminum, and very high early strength (VHE) cement. An economic analysis indicates that none of the lightweight substitutes are economically competitive with wood on an initial cost basis; however, in terms of life cycle costs based on current dollars, the high strength low alloy steel appears competitive for crossbars, and the VHE cement and E-glass/resin appear competitive for posts.

Jan 1, 1978

By Richard A. Walker

This report describes the development and performance of a multi-level, multi-function Calibration Light Source designed for field-calibration of a group of specific photometers. The Calibration Source is capable of providing ±35% accuracy calibrations at all of the following levels: 0. 05 foot-Lamberts, 6 foot-Lamberts, 6 foot-candles and 20 foot-candles. The Source was found to provide constant light output to within 1% over 50 hours of lamp operation and for line voltage variations of ±25%. It is compact and light-weight (11 pounds), and can be easily transported and used by one man in normal office environments (without requiring a darkroom).

Jan 1, 1976

By P. R. Miles, J. K. H. Ma, J. Y. C. Ma, L. Bowman

"The bisbenzylisoquinoline alkaloids are compounds which can be isolated from plants and which exhibit a broad range of pharmacological activities. Perhaps the best known alkaloid of this group is tetrandrine (TT), a compound isolated from the root of a traditional Chinese medicinal herb, Stephania tetrandra. It has been tested for its effects on the cardiovascular system, tumors, and the lungs. For example, tetrandrine has been shown to act as a calcium entry blocker in cardiac sarcolemmal vesicles (King et a/., 1988) and has been used in China as a treatment for angina and hypertension. Its possible effects as a tumor-inhibitory substance have also been investigated (Kupchan and Atland, 1973). In addition, there are several lines of evidence to suggest that it is a possible therapeutic agent for the treatment of silicosis. Yu et a/. (1983) have shown that TT inhibits the development of experimental silicosis in rats when it is administered orally after intratracheal instillation of quartz. Other studies have shown that the alkaloid inhibits the synthesis of collagen by fibroblasts and the formation of silicotic nodules in rats exposed to silica (Huang et al., 1981; Liu et al., 1983). In fact, tetrandrine has been used clinically in China as an antifibrotic agent and has been shown to improve both the appearance of chest radiographs and the measurements of diffusing capacity in patients with silicosis (Li et al., 1981).Since tetrandrine may have a potential use as a therapeutic agent for fibrotic lung diseases, its effects on various pulmonary cells and tissues should be studied. Alveolar type II cells are located in the alveolar regions of the lungs and are important because they are responsible for the synthesis and secretion of pulmonary surfactant (Dobbs et al., 1982; King, 1984), regeneration of the alveolar epithelium after lung injury (Kauffman et al., 1974), and metabolism of foreign compounds (Bend et al., 1985). Furthermore, in silicosis, for which TT has been suggested as a treatment, there are increased amounts of pulmonary surfactant produced (Dethloff et al., 1986a,b) as a result of increased rates of surfactant synthesis by type II cells (Dethloff et a/., 1989; Miller et al., 1988). Because type II cells play a critical role in maintaining normal lung function and because type II cells are affected in silicosis, for which 'TT has been used as a treatment, we studied the effects of tetrandrine on energy metabolism in these cells in vitro. Energy metabolism was chosen because it is a basic cellular function which is neces-sary for other cellular processes to occur. Since type II cells depend on mitochondrial metabolism for energy production (Fisher et al., 1980), we examined the effects of tetrandrine on cellular and mitochondrial ATP production and oxygen consumption. Additional experiments were performed in an effort to determine if intracellular calcium levels may be involved in the TT-induced effects. A preliminary report of those results has appeared previously (Ma et al., 1991)."

Nov 1, 1995

By B. K. Shibler

A highly flexible laboratory-scale fluidized-bed reactor was designed, constructed, and successfully operated continuously at temperatures up to 1,300° C during an investigation of thermal methods for decomposing gypsum. This report discusses briefly the many problems encountered in developing the 10-inch-diameter reactor and describes its design and construction in sufficient detail to enable other research organizations to build a comparable unit. The reactor consists of a 10-inch-inside-diameter vertical tube which can be varied from 6 to 10 feet high; it is formed from 2-and 3-foot sections of silicon carbide pipe. The tube is surrounded by a 3-inch heating space formed by an outer 4.5-inch-thick circular wall of insulating firebrick. A cone-shaped fluidizing chamber is bolted to the bottom of the reactor. Fluidizing gas enters through the bottom of the cone, and ore is introduced by means of a screw feeder connected to an inlet located just above the gas port. A silicon carbide overflow tube of 1.25-inch inside diameter extends upward into the reactor. The depth of the bed is controlled by substituting different lengths of overflow tube. Twin dust-recovery systems, each composed of a cyclone and Fiberglas filter, are attached to two gas outlets at the top of the reactor tube. The reactor is designed for research on both exothermic and highly endothermic reactions. It can be fired externally by means of four natural gas burners that jet tangentially into the annular space at the base of the reactor. Alternatively, it can be fired internally, using a mixture of air or oxygen and natural gas as the fluidizing medium. A separate instrument panel contains flowmeters, manometers, an automatic program controller, and a multiple-point recorder for printing a record of the temperatures measured by thermocouples located at critical points in the reactor.

Jan 1, 1963

By C. T. Baroch

As part of a general program for investigating all phases of titanium production, argon was substituted for helium in the reduction step at the Bureau of Mines pilot plant, which employed a modification of the Kroll, or magnesium-reduction, process. Argon was substituted for helium in 108 of the 140 batches of sponge made during 1 month's reduction operations for July 1954. Argon was substituted for helium satisfactorily, with only slight modifications in technique. Metal quality, feed rate of TiC14, magnesium efficiency, and average production per batch were closely comparable with either gas. Argon runs were slightly more troublesome because of the formation of condensable chloride complexes, which tended to plug feed and vent lines and to entrap deposits of lower titanium chlorides on the reactor-pot lids. These lower chlorides were objection-able because they were pyrophoric and created obnoxious fumes when pots were opened. When feed and vent lines became plugged care was required in poking or unplugging these lines to prevent air from entering the reactor. These problems were relatively minor, and continued development of reactors and techniques for the use of argon should further minimize objectionable side reactions obtained when argon is used.

Jan 1, 1956

By T. A. Evans

The Bureau of Mines conducted a Laboratory and pilot-plant investigation of the flotation of iron sulfides from zinc-lead mill tailings near Platteville, in south-western Wisconsin, at the North Central Experiment Station, Minneapolis, Minn. The procedures used and the results obtained in this investigation are described in this report. Samples for laboratory tests were obtained from each mill in the district, namely, Calumet & Hecla, Inc., Eagle-Picher Co., Vinegar Hill Zinc Co., and Tri-State Zinc, Inc. The sample fat pilot-plant work was obtained from the Davis Mining Enterprises mill.

Jan 1, 1957

By W. S. Landers

This report presents a detailed study of low temperature, entrained-bed carbonization of an Australian coking coal. The coal studied was high-volatile B bituminous from the Foybrook mine, an open-cut operation in the Liddell seam, New South Wales, Australia. Carbonization was conducted in an 8-inch diameter, continuous vertical reactor at several temperatures from 960° to 1,300° F. It was demonstrated that this bituminous coal can be carbonized within this temperature range to produce tar and a nonagglomerated char, without prior oxidation or char recirculation. Carbonization rates from 138 to 287 lb/hr (as-carbonized basis) were investigated. It was found that the carbonization temperature and the air-to-coal ratio must exceed minimum values to insure continuous operation. At the higher air-to-coal ratios employed, all or most of the carbonization heat was provided by internal combustion with air in the reactor. At the lower air-to-coa1 ratios, part of the heat for carbonization was supplied externally. On the moisture-and ash-free basis, the yield of tar plus light oil ranged from about 26 to 44 gallons per ton, and the char yield ranged from approximately 1,160 to 1,370 pounds per ton. The heat in the gas ranged from about 900 to 3,000 Btu/lb of moisture-and ash-free coal. Carbonization product yields correlated well with air-to-coal ratio and carbonization temperatures. The volatile matter in the char was found to be temperature dependent. At 1,300° F carbonization, the volatile matter in the char was 8.7 percent (dry basis), whereas at 9600 F carbonization, the residual volatile matter was about 16 to 18 percent (dry basis).

Jan 1, 1965