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By E. Don Dilling, Wm. F. Hergert, J. W. Pennington, C. E. Wood, M. J. Slendlove, H. A. Doerner

"INTRODUCTION The Bureau of Mines began a study of various methods for producing magnesium metal from magnesite ores in 1936 at Pullman, Wash., with the cooperation of Washington State College. This work included a study of the basic principles involved in the reduction of magnesium oxide by carbon, which soon led to the development of a continuous process. In May 1939, a small pilot plant was operated, which included a small single-phase arc furnace with a hydraulic feed mechanism and an oil-spray device for shock cooling the metal vapor. 5/Subsequently, the Ford Motor. Co., Dearborn, Michigan, began a study of this process on a larger scale. A pilot plant with a nominal capacity of 10 pounds of magnesium metal per hour was constructed and operated intermittently. A larger unit with a nominal capacity of 100 pounds of magnesium per hour was partly constructed when war activities prevented experimental work.In the meantime, the process was greatly improved through continued investigation by the Bureau of Mines at Pullman, and these improvements were successfully tested by continuous operation in a small pilot plant having a normal capacity of 4 pounds an hour."

Aug 1, 1945

Laboratory tests were conducted by the U.S. Bureau of Mines to determine respirable dust reduction effectiveness of and interaction between face airflow and water sprays for a continuous miner. Increases in exhausting face ventilation from 3,000 to 9,000 cfm, in waterflow from 15 to 35 gpm, and in water nozzle operating pressure from 80 to 200 psi were evaluated. Results indicated that airflow had the greatest individual impact on reducing dust levels, with concentrations at return and operator sampling locations reduced by as much as 57% and 99%, respectively. Regression modeling was utilized to predict dust concentrations over the range of values tested for the control parameters. Interactions between the control parameters were significant and often defined an optimum level where further increases in that parameter failed to produce additional dust reductions. Increasing airflow to 8,400 cfm, waterflow to 25 gpm, and water pressure to 140 psi typically reduced dust concentrations at operator and return locations. Application of a control parameter above these levels can provide additional dust reductions if used in conjunction with appropriate levels of the other two control parameters. Otherwise, higher operator dust levels may result and can be attributed to increased rollback and/or airflow turbulence.

Jan 1, 2010

By K. Hennings

Noise from vibrating screens is generated in two ways: 1) Noise due to the material being processed and, 2) noise from the screen itself. Non-metallic decks had been shown previously to reduce material noise. The noise reduction and change in screening performance was quantified for six non-metallic decks using dolomite, granite and coal as the materials. The non-metallic decks were from 2 to 7 dBA quieter and from -1 to +10 percent less efficient as compared to a steel wire cloth deck of the same open area. Damping of the sidewalls and isolation of the drive mechanisms had been shown, in a development configuration, to reduce the noise of the screen itself. Tests of four prototype damping treatments gave reductions up to 4.9 dBA and the mechanism isolators gave an additional 2.1 dBA. The treatments were successfully life tested in two ways: 1) Lab tests to a simulated 25,000 hours were conducted on samples of the treatments in a corrosive salt spray to simulate coal plant wash water and, 2) the full size treatments were run on a full size screen for 5,000 hours.

Jan 1, 1980

By H. -F. Krausse

Roof failures in underground coal mines are related to the lithology and geologic structure of the roof. There are two distinct suites of roof rock above the Herrin (No. 6) Coal in Illinois, and each has distinctive patterns of structure and roof failure. In black shale-limestone roof areas, roof instability is correlated with thinning of limestone beds and presence of faults and clay dikes. In gray shale roof regions, the prime roof hazards are posed by rolls, shear bodies, and presence of coal or carbonaceous partings in the roof. Most structural features examined are believed to have formed during early stages of sediment diagenesis and compaction. Structural trends and lithologic patterns are strongly interdependent for this reason. In many cases geologic patterns are so complex and locally variable that prediction of roof stability far in advance of mining is difficult. The need for greater flexibility in roof control planning is apparent.

Jan 1, 1979

By R. Lusignea

A device has been developed for nondestructive testing the holding power of split tube friction rock supports. It operates by measuring the amount of decrease in internal volume when the support is forced into the drilled hole. The pullout force or slip load is a function of this decrease in volume. The device gives readouts of the average internal diameter and predicted pullout force or the support. Laboratory and field tests showed excellent repeatability and good correlation between predicted and actual pullout force. The device is hand-operated, lightweight (7.5 lb) and can be used on any friction support.

Jan 1, 1983

By James J. Dowd

During and immediately following World War II, the heavy demands for steel required the mining of unusually large quantities of coal for the manufacture of metallurgical coke. The largest demand for metallurgical coke is in the Appalachian region, which comprises central and western Pennsylvania, Maryland, West Virginia, Virginia, eastern Kentucky, Tennessee, and Alabama. This demand is satisfied by coke made from coals within the region; consequently, the reserves of coking coal in this region are being depleted more rapidly than reserves in other coal-producing regions. The supply A' high-quality coking coal during the war was inadequate, and some coke were forced to use inferior coals. The coke produced from these inferior coals adversely affected the rate of production. Another national emergency probably would produce a similar condition, and in the interest of -national security, the Munitions Board of the National Military Establishment requested the Bureau of Mines to evaluate the reserves of coals suitable for the manufacture of metallurgical coke. All bituminous coals in the Appalachian region are coking, and as the coal that produces the better metallurgical coke become depleted, other coal previously considered inferior will be used. The general trend is toward the use of lower-quality coals for metallurgical purposes.

Jan 1, 1950

By M. F. Koehler

[THE LITERATURE contains relatively few thermodynamic values for interoxidic compounds, and these often are unreliable. This is especially true of data for ferrites and aluminates for which heat of formation determinations may involve extreme experimental difficulties. This report contains the results of new experimental work for obtaining the heats of formation of five ferrites (Ca2Fe2O5, CaFe2O4, MgFe2O4,, NaFeO2, and LiFeO2) and one aluminate (CaAl4O7), and a review and revision of previous similar work of this laboratory on five aluminates (Ca3A12O6,, 12/7 CaO-Al2O3, CaAl2O4, NaA1O2, and LiAlO2), The results for the 11 compounds are combined with entropy and high-temperature heat content data to derive tables of heats and free energies of formation (both from the oxides and from the elements) for the temperature range 298° 1,800° K, The relative stabilities of the compounds are discussed. The presented data all have application to ceramic reactions, and those for the calcium and sodium aluminates are applicable in considering soda-lime sintering processes for extracting alumina from silicate minerals such as day and labradorite.]

Jan 1, 1961

By W. C. Phalen

During the search for deposits of soluble potash salts in the United States, carried on by the United States Geological Survey, much infor- mation was collected on the salt resources and industry of the United States. The more important features of the information thus gath- ered, compiled, and digested may be classified under five headings, as follows: 1. Geology of the salt deposits of the United States. 2. Theories relating to the origin and formation of salt deposits. 3. Chemical composition of saline materials in the United States, principally rock salt and natural and artificial brines. 4. Statistics of salt production in the United States. 5. Technology of salt production. The first four items are not discussed in this report, but their treatment will comprise a separate report published by the Geologi- cal Survey, which will supplement this report, relating to salt- making processes, and will describe comprehensively the salt resources of the United States. Persons desiring a copy of that report should apply to the Director of the United States Geological Survey, Wash- ington, D. C. In addition to the discussion of processes, this report gives a brief description of the more important sources of salt in the United States. This description has been abstracted from the much length- ier description contained in the report to be published by the Geo- logical Survey.

Jan 1, 1917

By J. Sammarco

The U.S. National Institute for Occupational Safety and Health (NIOSH) is conducting mine illumination research to determine if light-emitting diode (LED) cap lamps can improve safety by reducing glare. Glare can impede a miner?s ability to see hazards and to safely perform their work. Another objective is to determine if a person?s age is a factor. This is important because the workforce is aging ? the average miner is now about 43 years old. Three cap lamps were used to evaluate glare: an incandescent cap lamp, a commercially available LED cap lamp and a NIOSH prototype LED cap lamp. Thirty NIOSH personnel from the Pittsburgh Research Laboratory (PRL) served as test subjects. Three age groups were established with ten subjects in each group. Testing was conducted in the Mine Illumination Laboratory (MIL) of NIOSH PRL. The results indicate no statistically significant difference in discomfort glare among the incandescent and LED cap lamps. However, an analysis of variance for disability glare indicates that the LED cap lamps were superior for the older subjects. Disability glare scores for the oldest subject group improved 53.8% when using the NIOSH prototype LED cap lamp compared to the incandescent cap lamp and 36.5% compared to the commercial LED cap lamp. It ap­pears that, given the conditions of this study, LED cap lamps will not increase discomfort glare and can enable significant improvements in disability glare for older workers. It is also evident that not all LEDs are created equal. The disability glare improved the best for older workers when they used the NIOSH prototype LED cap lamp, which has a different spectral power distribution (SPD) (more short wavelength energy) than the commercial LED cap lamp. Therefore, for disability glare, the results suggest that the SPD is an important factor to consider in cap lamp design.

Jan 1, 2009

By K. L. Paciorek

Organic materials utilized as cable Jacketing, cable insulation, standoffs, insulating boards and potting compositions were identified and d literature survey performed to obtain the required thermal oxidative and moist tracking data. Thirty representative compositions were procured and subjected to thermal and moist tracking evaluations. Tracking was found to invariably result in ignition or glow of the test specimen. Influence of parameters such as electrolyte strength and composition, temperature, conductor spacing, and electrode material were investigated. Volatile s produced by selected insulators on thermal oxidative and electrical stress were identified, quantitated, and their potential impairment action upon a current interrupter assessed.

Jan 1, 1980

By C. M. Harrer

The location, features, qualities, and extent of iron occurrences and the associated resources--limestone and dolomite, bentonite, coal-lignite, petroleum and natural gas, power, and water--are evaluated. The results of pioneer beneficiation tests on South Dakota taconite are discussed. In addition, pertinent features of taconite development, cost factors, the Western and Central United States trade area and markets are reported. The State's production of iron ores until 1963 has been small and for purposes other than the manufacture of iron. This investigation disclosed the probability of large resources of taconite in Pennington and Lawrence Counties. The average iron content is 29 percent, and a 65-percent or better iron concentrate might be produced. Ample resources are available for mining and processing taconite. An investment of at least $26 million would be required for a plant capable of turning out 1 million tons of agglomerated iron concentrate per year. The feasibility of such an enterprise is indicated, but intensive investigation and research must be completed to justify such an investment,

Jan 1, 1966

By John Nagy

Dust explosion data obtained in laboratory tests by the Bureau of Mines are presented for 181 miscellaneous materials that present an explosion hazard. Data are given also for 50 dusts that present primarily a fire hazard and for 88 dusts that did not present an explosion hazard.

Jan 1, 1968

By Y. H. Cheng, D. M. Lewis, V. Castranova, M. W. Barger, J. K. H. Ma, J. Y. C. Ma, W. F. Xin

Bis-basic ethers off fluorene and fluoren-9-substituted derivatives such as tilorone have been reported to inhibit silica-induced fibrosis in rats. The potential antifibrotic potency of 2,7-bis (diethylamino) ethixy fluorine fluorenone (F-9-H.H), fluorenoxime (F-9-one), and fluorenol (F-9-ol) was F-9-axime > F-9-one ~ F-9-H,H > F-9-ol. Since the release of reactive oxygen species and growth factors from alveolar macrophages (AM) in response to silica exposure has been linked to the development of pulmonary fibrosis, the present study was carried out to determine the inhibitory effects of these compounds on rat AM activity in vitro. The following parameters were monitored: (1) cellular viability; (2) zymosan-induced respiratory burst activity (superoxide and hydrogen peroxide release, chemiluminescence, and oxygen consumption) of AM; (3) drug binding to AM; and (4) lipopolysaccharide (LPS)-stimulated interleukin- I (IL-1) release from AM. The bis-basic ethers, at 40 did not affect cell viability when incubated with AM for 30 min, but significantly inhibited zymosan-induced macrophage respiratory burst activity. The inhibitory effect of these agents was F-9-oxime > F-9-one ~F-9-H,H > F-9-ol. Binding of these drugs to AM was time and dose dependent, and exhibited the following binding affinity: F-9-oxime > F-9-one > F-9-H,H > F-9-ol. F-9- oxime was shown to inhibit LPS-stimulated IL-I release by AM in a dose-dependent manner. This inhibition of IL-1 release by AM cannot be explained as a decrease in viability. In addition, these drugs were also shown to impair human fibroblast proliferation in response to serum stimuli without impairing cell viability. These results indicate a positive correlation between drug binding to AM or other cell types and their inhibitory effects on cellular activities including oxygen consumption, superoxide release, hydrogen peroxide secretion, chemiluminescence, IL-I release, and proliferation. The ability of-these bis-basic ethers to modify AM and fibroblast functions in vitro suggests that further investigation of their reported antifibrotic potency in vivo is warranted.

Dec 1, 1996

By C. M. Romanowitz

This report deals with the factors which should be considered in evaluating a placer deposit and selecting a dredging system for mineral recovery. Overall dredging feasibility and the design of dredging systems are reviewed. Excavation methods, each with its advantages and disadvantages, are compared. Direct operating costs, both original and updated, of gold dredges with bucket capacities of 6 to 18 cubic feet are included. Costs vary with digging depth, changes in environmental conditions, and physical characteristics of the placer, all of which affect excavation rate and recovery. The costs, updated with appropriate indexes, should be used only as guidelines to evaluate potential dredging projects with similar characteristics. The relation of direct dredging costs to annual production is graphically illustrated by a family of curved envelopes that span dredge sizes from 2-112 to 18 cubic feet. A curve fitted to the data expresses the relation of direct costs to annual production for 151 dredge-years.

Jan 1, 1970

By Wilton Johnson

Native asphalt was produced in 1981 by five companies in three States, Alabama, Texas, and Utah. Texas was the leading State in production of native asphalt. Total production increased in 1981 to 1.26 million tons, while value increased 10.5% to $27.7 million. Bituminous limestone, used primarily for street and road repair, was produced by Whites Uvalde Mines and Uvalde Rock Asphalt Co., both in Uvalde County, Tex., and Southern Stone Co., Colbert County, Ala. Gilsonite was produced by American Gilsonite Co., Uinta County, Utah, and Ziegler Chemical and Mineral Corp., Weber County, Utah. This material was used for purposes other than road repair.

Jan 1, 1982

By Edward G. Cunney

Track in underground bituminous coal mines was investigated, and technology was taken from other industries in order to obtain information on conditions that impair the safety and efficiency of the track and to develop guidelines and useful information on the construction, inspection and maintenance of mine track. Volume 1 contains information on the investigations, observed track conditions, useful technology from railroads and other industries, derivations of track condition descriptors and recommended limits, conclusions, and recommendations. Volume 2, Guidelines, contains recommended standards and practices for mine track. It includes the relation of track conditions to safe speeds; descriptions and limits for measurable track features such as gage; descriptions of conditions for track components that are normally not measurable, such as subbase soils; construction requirements and techniques, inspection requirements and methods; and methods for managing and performing track maintenance work. As a research product, it does not repeat the summary or derivations. Volume 3, Inspection Handbook, summarizes recommended standards and procedures from Volume 2 and provides related information for' ready reference by inspectors in the mines. As a research product to be used in mines, it does not repeat the summary, derivations or references.

Jan 1, 1977

By S. J. Aresco

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 composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grind-ability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions4 issued by the Bureau of Mines; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor; if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1965

By E. P. Buxton, W. P. Yant, G. W. Jones

"Introduction. The data obtained in recent research work by the Bureau of Mines show that the analysis of the gases dissolved in underground waters may be used by the prospector or geologist as an additional aid in discovering new oil or gas fields. The hydrocarbons present in the water serve to indicate whether oil or gas sands exist in the region through which the waters have passed. A portable field apparatus has been developed by the bureau which can be used for removing and analyzing the gases dissolved in the waters. This apparatus and the method of u are described in this paper. Results are given of analyses made on waters from various localities, and the significance of these waters with reference to the detection of oil and gas.Any liquid, with the exception of mercury, if permitted to come in contact with eases or vapors will absorb a definite amount thereof. This action depends on the following factors: (1) The kind of gas; (2) the percentage composition of the eases in contact with the liquid; (3) the pressure of the gas; and (4) the composition and temperature of the liquid. For our present purpose it is only necessary is consider two of these factors - namely, the gas or vapor (natural gas and light petroleum vapor), and the liquid (water).If water of underground origin traverses a gas or oil sand it will absorb a definite quantity of hydrocarbon vapors, and will carry these vapors to the surface when tapped by a well. When the water is exposed to the air at the sur¬face, the eases and vapors will be given off and their place taken by oxygen and nitrogen from the air. Therefore, an analysis of the gases in waters reaching the surface from an underground source should be of value in determining whether these waters have traversed or came in contact with hydrocarbon-bearing strata. With the apparatus herein described it is possible to determine whether the vapors are mainly of natural gas on sition (methane CH1) and ethane (C2H6 ), or are come posed mostly of heavier petroleum vapors (ethane, propane (C3E8) and buttane (C4H10)."

Nov 1, 1923

By James L. Elder

Field-scale experiments were conducted at Gorgas, Ala., from 1951 to 1954. Three reaction paths were formed by electrolinking-carbonization, using electrode spacings of 150, 152, and 155 feet. The coal along these reaction paths was gasified, using air, oxygen, and steam separately or in various combinations. At the conclusion of operation, a drilling survey was conducted to determine the location and approximate area of the reaction zones. During the applications of the electrolinking-carbonization technique the maximum limitation on electrode spacing was not determined. Initial tests were conducted at 60-foot spacing. Successful path-preparation tests were made at 150-, 152-, and 155-foot spacings, and the indications were that much longer spacings were possible. The potential requirements appear to be constant, regardless of path length, while the gross power required probably will increase with path length. During the carbonization phase gas was produced that is similar in quality to coke-oven gas produced at low to intermediate temperatures.

Jan 1, 1957

By W. J. McConnell, C. P. Yaglaglou

"IntroductionThis paper on the kata thermometer is issued by the Bureau of Mines on account of the general interest in this instrument and the fact that it is frequently used in studies of mine ventilation conditions with regard to comfort and health of miners. It has been used in the studies being conducted along this line by the Bureau of Mines on the effects of high temperatures and humidities of air in mine working on the comfort conditions, as well as in studies of atmospheric conditions in mine, railway and vehicular tunnels.The study of the various physiological responses of the human body to different degrees of temperature combined with different percentages of relative humility in still and in moving air, now being conducted at the Pittsburgh experiment station of the bureau in the research laboratory of the American Society of Heating and Ventilating Engineers, cooperating with the Bureau of and the U. S. Public Health Service, presents an added opportunity of investigating the instruments that have been devised to measure atmospheric conditions as they affect the comfort and health of human beings.The ordinary mercury thermometer, as pointed out by Heberden3 almost hundred years ago is a very inadequate instrument for measuring the physiological effects of atmospheric conditions. It merely accounts for that part of the body heat lost by raliation and convection, while as a matter of fact greater part of the body heat resulting from the metabolic process within the body is eliminated by means of evaporation from the surface of the body."

Jan 1, 1924