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By W. P. Yang, L. B. Berger, G. W. Jones

"Any burning carbonaceous material, unless supplied with enough oxygen for complete combustion, will liberate carbon monoxide. Since tobacco in its many different forms consists largely of carbonaceous material, and duo to the conditions under which it is smoked (burned), carbon monoxide should be liberated. That this is true has been shown by Armstrong.***** who found that undiluted smoke from cigars contained in some tests more than 3.00 per cent carbon monoxide, the amount present depending upon the size and closeness of packing of the tobacco during manufacture and on the rate of burning.****** Cigarets gave much less CO, varying from 0.06 to 1.40 per cent. The rate of consumption and carbon content of the tobacco are not g.ven, so that a correlation of the values reported to conditions in closed spaces where people might be assembled are difficult, if not impossible.The Bureau of Mines is interested in the general question of carbon-monoxide hazards from tobacco smoke, mainly with regard to mine ventilation. In non-gaseous mines, especially metal mines, the question arises, whether, if groups of miners are permitted to smoke while working at unventilated faces or entries, would the accumulation of tobacco smoke in these places create an' additional hazards the to carbon-monoxide poisoning. The results should, in addition be of general interest in connection with ventilation of building and inclosed places where people may be assembled and smoking is permitted. The investigation described in this report was made with the above idea in view."

Oct 1, 1923

By Howard C. Turnage, Dana T. Updyke, Wayne C. Muhler

The objective of this project was to develop technical data and evaluate performance and utility of leaky feeder communications systems currently used in North American underground mines. The desired information was obtained principally through on-site surveys. Altogether, six of the seven mining companies known to be using leaky feeder communications were visited. This report covers the findings of these surveys. In addition, the report provides a brief background summary of mine communications, a technical discussion of leaky feeder systems, and conclusions and recommendations based on the results of the survey.

Jan 6, 1980

By T. E. Sterner

The Bureau of Mines investigated the use of a chromatographic gas analyzer in determining the concentration of combustion products in gas produced during field and laboratory thermal oil-recovery tests. Several parameters (carrier-gas flow, cell current, sample size, and temperature) known to affect quantitative analyses were studied using a commercially available dual-column, dual-detector chromatographic gas analyzer which had been modified to provide close control of these variables. The apparatus made possible a much closer control of air-and gas-injection rates and provided adequate data for performing material-balance calculations and for determining oxygen utilization during the laboratory and field combustion tests. The chromatographic analysis also aided materially in evaluating and measuring bypassing and gas travel times and in detecting high-permeability zones that were present in the reservoir.

Jan 1, 1965

By Ronald S. Conti

This U.S. Bureau of Mines report discusses the results of research conducted in the Bureau's experimental mine at Lake Lynn Laboratory on the response of fire sensors to simulated mine fires, which included (1) a slowly developing coal-conveyor belt fire, (2) a rapidly burning liquid fuel-belt fire, and (3) a liquid fuel-belt fire in the presence of diesel exhaust. During these tests, several mine fire sensors were evaluated with respect to sensor placement, spacing, and type. The data indicate that smoke sensors alarm several minutes before CO sensors do; and that, in the presence of diesel exhaust, a prototype diesel-discriminating smoke sensor can successfully function without being sensitive to the diesel contaminants. The vertical placement of sensors in the entry near the fire was also shown to be critical in terms of alarm times. Additional data showed that variations exist in response time and level of response for two brands of electrochemical CO sensor. Results also indicate that early detection of fires will improve the probability of miners' escape, because of reduced smoke concentrations during the incipient stages of the fire.

Jan 1, 2010

By Scott W. Hazen

METHODS of determining the grade and tonnage in a mineral deposit have not kept pace with scientific developments in certain other fields. The most commonly used methods of computing ore reserves and grade based on diamond-core-drill sampling are the cross section, the polygon, and the triangle. Tonnage and grade may be determined by these methods with acceptable accuracy, providing a sufficient number of samples is obtained; however, there is no means of determining when an adequate number has been taken or conversely if the deposit has been sampled excessively. It is demonstrated that, by using the techniques of statistical analysis, a mining engineer will be able to determine when a sufficient number of samples has been taken to determine the grade of a mineral deposit within a specified degree of confidence. Using statistical analysis to compute the estimated average grade of the ore makes it possible to compute a fiducial interval, when a distribution of the sample means is normally distributed, so that there is 95-percent confidence in the statement that the true average grade of the deposit is covered by the interval. This report utilizes data obtained from the Maggie Canyon manganese deposit, Artillery Mountains region, Mohave County, Ariz. Four separate exploration projects were conducted at Maggie Canyon between 1936 and 1950. Present economic conditions have made it desirable to determine the amount of 5-percent manganese ore developed by these projects.

Jan 1, 1957

By Wallace W. Roepke

The Bureau of Mines tested new designs of drag bit cutters with sintered diamond inserts instead of standard tungsten carbide tips. The bits were tested for orthogonal cutting forces, primary dust generation, and incendivity, with a standard plumb-bob type conical cutter (600 included tip angle) as the reference. Preliminary wear and impact-failure testing were also done. The results were mixed. Two new designs had forces similar to those of the reference bit, but one new design had about twice the normal force. This same design had almost twice the specific energy during shallow cutting but generated an equal or slightly lower amount of primary dust than did the reference bit. Incendivity was eliminated for two radial designs. One conical design had ignition only after more than 15 impacts, but the other conical design was incendive. Impact failure occurred, but not so quickly as anticipated. Over 7,500 impacts on a sandstone face, with a total cutting distance of more than 1,981.2 m, only scuffed the leading edge of the sintered diamond cutting face but put hairline cracks in the substrate mounting pad. Additional design and testing are needed to develop an optimum cutter, but prospects look good for this material.

Jan 1, 1983

By Arden D. Fugate

This work was conducted to determine a feasible process for converting siliceous fluoride offgases to a commercially usable product. The offgases were generated by pyrohydrolytic defluorination of low-grade fluorspar in a gas-fired rotary kiln, and fluorine was collected as a hydrofluoric-fluosilicic acid. A silicon-free fluoride solution for further processing was then produced by neutralizing the acidic scrubber solution with anhydrous ammonia, silicon being separated as orthosilicic acid. Ninety to ninety-nine percent of the fluorine originally present remained in solution as ammonium fluoride. Silicon was also separated from synthetic fluosilicic acids, having F-to-Si weight ratios ranging from 3.50 to 14.3. The solutions below a ratio of 4.06, the F-to-Si ratio of H2SiF6, containing dissolved silicon were desiliconized as completely as those containing less than the stoichiometric quantity of silicon. An electrolytic-grade cryolite was recovered from the ammonium fluoride solution by reacting with either sodium aluminate or alumina trihydrate and sodium hydroxide. A product containing 97 to 100 percent of the fluorine, represented by Na3A1F6, was recovered, and 94 to 99 percent of the theoretical yield was realized.

Jan 1, 1963

By R. L. Grayson, L. L. Probert

"A three-year project focusing on the depth profiling of respirable coal mine dust particles using scanning electron microscopy coupled with energy dispersive X-ray analysis resulted in the development of statistically classified particle-behavior models. The models depict the changing silicon fraction for particles at 5-, 7-, 9-, and 11-keV accelerating voltages, thereby giving a clear indication of the nature of various types of mineral particles. This paper focuses on the results for respirable quartz particles sampled from five underground coal mines across the US. Through statistical analysis of results the relationship between the fraction of surface available quartz in respirable dust samples and coal rank is established for three Pennsylvania coal seams. IntroductionThis is the last in a series of papers detailing the results of SEM/EDX-based analyses of respirable coal mine dust particles collected from field sampling. Previous papers have detailed preliminary results and the statistical validity of the methodology (Grayson, Andre, and Simonyi, 1990; Grayson, 1991). This paper presents the final results of the analysis of respirable dusts from five coal seams with a range of coal rank:• Lykens Valley seam (anthracite), eastern Pennsylvania• Brookville (A) seam (mid-vol bituminous), central Pennsylvania• Pittsburgh seam (high-vol B bituminous), western Pennsylvania• No. 6 seam (high-vol C bituminous), Illinois• Wadge seam (sub-bituminous A), ColoradoSEM/EDX-based techniques were applied to try to clarify the role of quartz as an etiologic agent in coal workers' pneumoconiosis (CWP). It was hypothesized that previous studies were hampered by the restrictions of bulk analysis techniques and that particle-level analyses were needed to answer a number of questions concerning the role of quartz in CWP and its progression.Since 1985, a large number of the respirable dust samples submitted to MSHA are analyzed for free silica (Tomb, Parobeck, and Gero, 1986). Our reasearch shows that conventional bulk analysis techniques may not give a true indication of the biologically available, or active, quartz in mine dusts. Analytical evidence indicates that respirable dust samples may contain many quartz particles that are occluded, or coated, resulting in a bulk analysis for ""free silica"" that may not be indicative of the biologically available quartz surface."

Dec 1, 1996

By Philip Thompson

A part of the Bureau of Mines mission is to help improve the Nation's mineral posture by providing the technology for utilizing low-grade ores. In this regard, laboratory testing by the Bureau of Mines has shown that the removal of insoluble slimes using selective flocculation and flotation is a viable method for treating low-grade potash ores that have a high content of water-insoluble impurities. Results indicated that over 82 percent of the insoluble slimes could be removed from sylvinite ore containing 5 percent water insolubles and 13 percent K20 by using nonionic or cationic polyacrylamide flocculants and cationic, anionic, and/or nonionic collectors. Subsequent potash flotation recovered 87 percent of the potash in rougher concentrates containing 57 percent K2O. Sizing and cleaner flotation of the rougher concentrates upgraded the products to 60 percent K2O. Filtration of the water-leached insoluble-slimes flotation concentrates on a bed consisting of leached insoluble-slimes concentrate mixed with potash flotation tailings recovered 80 percent of the brine. Filtration rates using the mixed bed were nine times faster than filtration rates obtained when the insoluble-slimes flotation concentrates were filtered separately.

Jan 1, 1979

By Fred D. Wright

Some new equipment for drilling vertical holes, cleaning blast holes, hauling explosives, and conditioning Diesel exhaust gas has been developed. at the Bureau's Experimental Oil-Shale mine near Rifle, Colo, The equipment has application, not only in oil-shale mining, but in many of the country's underground mines in which room-and-pillar methods of mining are employed. This report presents the Bureau's experience in testing the following equipment in the Experimental Oil-Shale mine: 1. A four-drill benching jumbo for drilling 23-foot vertical blast holes 2. A jet borehole blower for efficient cleaning of deep, vertical blast holes. 3. An explosives truck equipped with two compartments to provide safe conveyance for dynamite and detonators. 4. A mobile, electric substation to provide switching equipment, low-voltage and overload protection, and transformer facilities to remote locations in the mine. 5. A chemical conditioner for scrubbing the exhaust gases from Diesel-powered equipment used in underground operations. 6. Other units of equipment which have been tested at the Experimental mine.

Jan 1, 1951

By N. H. Snyder

THE Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the com-position as shown by proximate analyses. To these, when required, are added the fusing temperature of ash, Hardgrove grindability index, and the free-swelling index. Under most of these specification contracts the bidders guarantee the quality of coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions 4 issued by the Bureau; the samples are analyzed in the Bureau's laboratory to determine whether the coal is of the quality guaranteed by the contractor and, if it is not, a price adjustment is made. Analyses of delivered coal and "tipple" samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) are valuable data for use in evaluating future bids. Moreover, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1953

By Compiled by Staff

"The Bureau of Mines was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment, and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve material resources and prevent their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting those industries. The organic act of the Bureau, as amended by Congress and· approved February 25, 1913, made it the province, and duty of the Bureau of Mines to ""disseminate· information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with this directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non Bureau publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented in this special publication both necessary and valuable. This issue of the Bureau of Mines List of Publications and Articles describes reports and articles published during the period January 1, 1990, to December 31,1991. It, supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960;1 the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960;2 and the 5-year lists of publications and articles from January 1, 1960, to December 31, 1964,3from January 1, 1965, to December 31, 1969,4 from January 1, 1970, to December 31, 1974,5 from January 1, 1975, to December 31,1979,6 from January 1, 1980, to December 31, 1984,7 and from January 1, 1985, to December 31, 1989.8"

Jan 1, 1992

By R. Hogg, Y. Lee, D. E. Rannels

"Lee, Yu-Chen, Richard Hogg, and D. Eugene Rannels. Extracellular matrix synthesis by coal dust-exposed type II epithelial cells. Am. J. Physiol. 267 (Lung Cell. Mol. Physiol. 11): L365–L374, 1994.—Although integrity of the alveolar basement membrane may influence progression of lung injury induced by inhaled particulates, little is known about direct effects of coal dusts on the alveolar epithelium or its extracellu¬lar matrix (ECM). Effects of dust on synthesis of cell and ECM proteins by type II cells (T2P) was thus investigated. Three coal dusts (anthracite no. 867; bituminous no. 1451 and no. 1361) and mine dust MIT-3, of respirable size, were studied as a function of dose and time over 3 days of primary T2P culture. On day 1, 750 µg/ml of 867 were required to increase relative synthesis of ECM proteins (ECM/cell). MIT-3, 1451, and 1361 were without effect. By day 3, 867 or MIT-3 increased ECM/ cell 60-100% at 300 µg/ml; 1451 produced modest, dose-dependent stimulation, whereas 1361 remained without effect. None of the dusts caused significant cytotoxicity. The results show dose- and time-dependent effects of well-characterized coal and mine dusts to modify partitioning of newly synthesized proteins into the ECM and suggest that coal dust exposure may modulate structure or function of the subepithelial basement membrane.basement membrane; cell culture; inorganic dust; lung injury; extracellular matrix deposition; pulmonary epitheliumCHRONIC EXPOSURE to coal dust may be associated with development of pulmonary fibrosis and consequent loss of normal lung function (see Ref. 26 for review). Al¬though the pathways of inorganic dust-induced lung injury are recognized to involve an inflammatory re¬sponse, the underlying pathogenic mechanisms are not understood in detail. Acute and chronic responses to dust exposure involve a variety of interacting cells of the immune system, including macrophages, T cells, and B cells, along with pulmonary fibroblasts. These responses reflect direct effects of the dust particles, as well as indirect effects mediated by soluble factors, including cytokines and eicosanoids (see Ref. 41 for review).Studies of pulmonary macrophages and fibroblasts following silica exposure suggest that dust-induced damage at the airway surface may involve cellular injury through oxidant-mediated pathways. Coal dusts and related inorganic particulates can activate the alveolar macrophage (42) to produce fibronectin (15) and cytokines, such as interleukin-1 or tumor necrosis factor (4) and/or other soluble products which act locally (29) to cause acute cellular injury and to initiate the progression of fibrotic lung damage (16). Type I epithelial cells are typically more susceptible than type II cells to oxidant injury. Type I cell damage and subsequent death leads to denudation of the subepithelial basement membrane (2, 21) and can be associated with leakage of plasma constituents from the pulmonary vasculature into the alveolar compartment (13)."

Dec 1, 1995

By Rolland L. Blake

Petrographic and mineralogical studies were made on unoxidized samples from the Cuyuna and Mesabi districts to study occurrence and properties of the iron phyllosilicate minerals . Examination of 96 thin sections from the thinbedded facies of the main iron - formation of the Cuyuna district indicates that the most abundant minerals are Mn - Mg - siderite , stilpnome lane , and minnesotaite . Reconstitution and recrystallization of minerals has occurred along certain beds , and textures indicate that some minnesotaite apparently formed at expense of stilpnomelane . Three samples of stilpnome lane and one of minnesotaite were concentrated from fracture - fillings within iron- formation . Results of chemical , optical , spectrographic , X- ray diffraction , and differential thermal analyses on these samples are reported . The detection of ammonia in stilpnome lane samples is the first such occurrence reported , and its significance is discussed . New mineral data are presented on greenalite and probable septechamosite from the Mesabi district .

Jan 1, 1964

By Foster Fraas

Almost all minerals show irreversible changes in electrical conductivity after heating in the temperature range 100° to 800° C. This effect can be detected with only a limited number of minerals with the standard ionizing-electrode-type separator, which differentiates between nonconductors and conductors in the single-particle resistivity range of 1011 to 1013 ohms. Tests outside this range with other type separators, such as the static field type, increase the number of minerals with which the effect can be detected to almost all that were tested. Irreversibility may be the result of an alteration of adsorption layers, volatilization of surface cations or anions, or an oxidation or reduction. One example is limonite, which decomposes to hematite and passes through two minima and two maxima in conductivity in the temperature range 100° to 900° C.

Jan 1, 1959

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, 1991

By M. C. Malamphy

A general description of the activities and results of bauxite investigation by the Bureau of Mines at its bauxite project in Saline and Pulaski County, Ark., has been given in Report of Investigations 4251. The factual data obtained during the project are reported in a series of Reports of Investigations beginning with No. 4251, of which this is the eighth. The data are accompanied by maps showing the location of holes drilled and the deposits developed. Each area upon which work was done is reported by half townships. Each bauxite deposit investigated was assigned a name and a number for ready reference and identification, and its location and name are shown on the appropriate half-township map. The description of each half township is no followed by a description of each deposit developed in that half township. The 14 half township maps and 77 detail maps of the bauxite deposits in this series of reports give the locations and numbers of all the holes drilled on the project, except the deep holes drilled to test the geophysical anomalies. The locations at those holes show on figure 13 in volume I. The descriptions of the deposits developed are followed by complete detailed logs at the drill holes. Many at the widely spaced exploratory holes did not discover bauxite of minable thickness and gra.de. The pertinent information obtained from the widely spaced exploratory drill holes has been summarized and tabulated, and a table for each halt township is given with the discussion covering that area.

Jan 1, 1948

By G. Stecklein

This report summarizes the results of research into the areas of the fragmentation and entrainment of Airborne Respirable Dust (ARD). The objectives of this program were four-fold: first, to review the present state of knowledge regarding ARD; second, to expand this state of knowledge through the identification of hypothetical microscopic mechanisms by which the coal is fragmented and the dust becomes entrained; third, to specify the informational requirements to verify or nullify these hypotheses; and fourth, to relate experimental techniques that will produce that required information. Additionally, insights are provided regarding potential methods of extraction and/or treatment which may reduce the concentration of ARD.

Jan 1, 1982

By R. V. Higgins, A. J. Leighton

A computer program has been devised to calculate the reservoir performance of water floods of complicated well - spacing patterns . The method and program have been tested by calculating the waterflood performance of fivespot patterns using oils of different viscosities and the performance calculations agreed closely with laboratory results . The program on a high - speed digital computer will process the performance prediction in about 1 minute , which is very rapid for a prediction using so much fluid mechanics and nonlinear geometry . The program has been presented in such a way that one may use it as given and save the time required to write and " debug " one of his own . gram processes a complex reservoir analysis , many of the complicated steps are explained in detail , both for the fluid mechanics and the directions for the computer . The subtle features that originally delayed the application of the program to unusual combinations of permeability and viscosity relationships are incorporated and explained

Jan 1, 1963

By George Quackenbos

The principal objective of this Program is the design, fabrication and testing of an Environmental System for operation in underground mines, to assess the effect of various mining systems on the contaminant levels near the mine face and within return airways. In order to determine the effect on airborne contamination in mines resulting from the development of new mining techniques, equipment and control systems, a Comprehensive Monitoring System is required to assess such contamination levels at critical and strategic locations and relate this information with ventilation parameters. The three variables to be sensed on a continuous basis are airborne dust concentration, methane concentration and ventilation air velocity. Each Monitoring Station will consist of a self-contained unit containing a power source and sensors to monitor the three above mentioned parameters. Ruggedness, reliability, ease 'of operation and intrinsic safety are important design objectives. Data gathered by each Monitoring Station will be fed to a Central Data Acquisition System by means of a portable transfer unit.

Jan 1, 1982