Search Documents

By Jeffrey A. Shibe

A prototype Fire Safety Evaluation System has been developed and is ready to be evaluated by a Peer Consulting Panel and for performing field tests. The system can be used to determine combinations of widely accepted fire safety equipment and under-ground coal mine features that provide a level of safety equivalent to those required by the Code of Federal Regulations-Title 30 for underground coal mines. In this evaluation, equivalent safety performance is gauged in terms of overall level of safety provided rather than by a component by component comparison.

Jan 1, 1987

By R. Wiebe

During a recent investigation the authors were interested in determining: (1.) How many points were necessary to locate the deviation curve for copper-constantan thermocouples within an accuracy of about 0.05° C., used in connection with the "standard" thermocouple of L. H. Adams. (2.) Whether copper-constantan thermocouples showing considerable deviations from the "standard' were consistent throughout their calibration. (3.) How reliable the extrapolated portion is - that is, the interval between -183 and -220° C. of the "standard" thermocouple. It seems that a calibration between 0 and -193° C. can be made within the stated accuracy by determining experimentally the e.m.f. of the particular couple at -78.50°, the normal sublimation point of carbon dioxide, and at -182.97°, the normal boiling point of oxygen. Substituting the values found for the two fixed points in the simple quadratic. Equation

Jan 1, 1931

The lignite deposits of the United States represent a huge potential source of fuel for power generation. It has been estimated that lignite constitutes about 24 percent of the remaining National reserves of solid fuel on a tonnage basis and about 15 percent of the reserves on a B.t.u. basis. (See sec. 3, part 1.) The major portion of these reserves is in North Dakota. Lignite has been used locally for domestic heating since the first settlers burned it at forts and fur-trading posts as early as 1855. Some of the first studies of the use of lignite in steam boilers were conducted by the Federal Bureau of Mines from 1910 to 1920 (15, 19) 1/ However, the commercial utilization of lignite as fuel for producing power developed slowly. Not until about 1925 was any really successful lignite industrial fuel-blaming equipment developed. Since then the commercial use of lignite as a fuel for producing power has been increasing steadily.

Jan 1, 1954

By J. W. Paul

A study of mining methods and underground practices as they influence injury from falls of roof or coal reveals data as to the location in the mine where such injuries occur with the greatest frequency and as to some of the methods and practices which are in use for the prevention of injury. This paper, which presents statistics bearing on the frequency and place of occurrence of accidents and discusses regulations and practices which have resulted in a low-frequency rates from falls of roof and coal in a few representative mines, takes its information from mine-accident reports and from the results of studies conducted in a group of 80 mines in the bituminous coal fields of Western Pennsylvania, Ohio, and West Virginia. The statistics from this group of mines cover periods of one to four years but average 2 years and 7 months. During this time these mines produced over 110,400,000 tons of coal, equivalent to one-fifth of the annual production of all bituminous mines in the United States. The coal beds of the mines in the group studied are mostly flat, with local pitches of moderate degree. A number of mining plans are in use, each of which follows a general system of multiple entries, gross entries, and rooms. Room and pillar in panels either advancing, retreating, or half advance and half retreat, and the block system are employed. The methods of pillar extraction are by splitting, slabbing, pocket-and-stump, and open end. It is hoped that in presenting some of the details of the methods and practices at particular mines of this group which have commendable records in the prevention of injury some goad may accrue to many other bituminous mines which have similar natural conditions.

Jan 1, 1933

By Vern L. Kegler

This paper is one off a series dealing with mining methods and costs, sponsored and published by the United States bureau of Mines. ACKNOWLEDGMENTS The author acknowledges the, constructive and helpful suggestions and criticism of W. F. Lamoreaux, vice-president, and general manager of the Ducktown Chemical & Iron Co. United States Geological Survey Professional Paper- 139, by W. H. Emmons and F. B. Laney, has been drawn upon for some of the information contained in the paragraphs or history and geology.

Jan 1, 1931

By John Gross

Studies in grinding efficiencies carried out at the Midvale plant of the U. S. Smelting, Refining & Mining Co. and at the Tooele plant of the International Smelting Co. Were made possible by the cooperation of these two companies with the U. S. Bureau of Mines. Mr. Alan Probert of the U. S. Smelting, Refining & Mining Co. and Mr. E. C. Peterson of the International Smelting Co., devoted their entire time to the work during the respective tests, and their services are hereby gratefully acknowledged. It is a pleasure to acknowledge also the assistance and kindness of the staffs of both companies in making it possible, at considerable trouble and expense, to sample the entire mill circuits and in furnishing the necessary supplies and special apparatus required in the work.

Jan 1, 1929

By Secretary of the Interior

"INTRODUCTION The Bureau of Mines Synthetic Liquid Fuels Program again forged ahead during 1952, and important technical advances led the way to improved methods of converting coal and oil shale into liquid fuels. Marking the eighth year of activities under this program, the pact 32 months brought a new domestic industry nearer realization.The increasing demand for gasoline and oil and the rising cost of finding new petroleum, coupled with America's growing dependence on imports and the unsettled international situation, have continued to emphasize the importance of the Bureau's Synthetic Liquid Fuels Program. Oil, the indispensable material of wartime, likewise has critical importance in peacetime, touching as it does the life of every individual. Supplementing petroleum with synthetic liquid fuels will not only conserve this Nation's petroleum reserves but also will bring into greater use its tremendous reserves of coal, as well as the vast deposits of oil shale for which no other practical use has yet been found.The Bureau of Mines Synthetic Liquid Fuels Program is one of the most important and far-reaching of the Government's research projects. Through development of commercial synthetic liquid fuels, the United States can obtain oil products from its great inland reserves of coal and oil shale to supplement petroleum in any quantity that may be necessary, consistent with economic and other requirements, such as national defense. The use of raw materials from such deposits would be of highest importance in wartime, when shipping lanes are menaced by the enemy. The Synthetic Liquid Fuels Program of the Bureau of Mines and research efforts of industry have advanced. American technology to the point where it is now possible to begin the design and construction of prototype plants. Certainly, significant improvements will be made as the program continues, but this prospect in no way alters the fact that the start of prototype plants should be encouraged. These plants, as the first step in the development of a synthetic fuels industry, would serve a threefold purpose:"

Jan 1, 1953

By Walter Wood, J. T. H. Cannarella, H. F. Yancey, R. E. Zane

More than 50,000,000 tons of bituminous coal and probably about the same quantity of anthracite are cleaned annually in the United States by wet methods. The water, fine coal, and impurities from the water used for washing ordinarily are recovered by moans of various forms of settling tanks. Settling and clarification may be hastened markedly, thereby greatly increasing the capacity of clarification equipment already installed, by the addition of substances to the washery water that cause the fine particles in suspension to agglomerate and thus settle more rapidly. This phenomenon, although well known and applied in other fields, has been used at only a few coal washeries in the United States. It is widely employed, however, as an aid in the recovery or disposal of fine coal or impurities, as a means of preventing, stream pollution, and to enable reuse of washery water at many plants in Europe. Pioneering work in the United States has been done principally by two companies -- the Pittsburgh Coal Co., in Pennsylvania, 6/ and the Pacific Coast Coal Co., in Washington.

Feb 1, 1940

By M. R. Geer, H. F. Yancey

"INTRODUCTION Throughout the history of coal washing, the jig has been one of the most important coal-cleaning appliances. In 1935 34.7 percent of the 45,361,021 tons of clean coal produced was the product of jigging. 4/ Previous to 1928, most of the jigs used in the United States were of the piston type, with which sufficient mobility to allow stratification in bed is imparted by the reciprocating up-and-down movement of a piston in the water compartment adjacent to the screen compartment. In 1928, the Baum type of jig was introduces in this country and has since come into wide spread use. In this type, water pulsations are imparted by application and release of compressed air to the water compartment. All prior studies of the mechanism of seperating cleared coal from impurity by piston-type jigs. 5/ The same laws of settling, of course, apply to both types, piston or Baum, but the character of the separation with the Baum type may be modified more easily because of the flexibility with which air may be handled, as distinguished from the fixed action of eccentrics commonly used in piston jigs. Since no detailed studies are available to show the performance, that is, the character of the separation between coal and impurity, of the Baum type the Bureau of Mines undertook the investigation recorded in this report."

Jan 1, 1938

By Claude W. Sill

In the usual volumetric determination of uranium, the solution containing uranium is reduced in a Jones reductor, yielding a mixture of trivalent and tetravalent uranium; the trivalent uranium is oxidized to the tetravalent state by bubbling a stream of air through the solution. The resulting solution of. Tetravalent uranium is titrated with a standard oxidant, generally sulfatoceric acid, dichromate, or permanganate; It seemed likely that the, same general procedure could be used in determining semimicro quantities of uranium if the conditions affecting the variables involved were understood more clearly than at present. In the method described below, the use of ferric sulfate to oxidize tetravalent uranium allows the titration to be made at room temperature in an essentially colorless solution with sulfatoceric acid. The latter oxidant its turn permits the use of the very stable indicator, ferroin, with its sharp color.., change and exactly reproducible blanks. Solutions of uranyl sulfate were prepared by diluting a stock solution that had been standardized gravimetrically according to the method of Lundell and Knowles (8).3/ Solutions of sulfatoceric acid were prepared according to the directions of G. F. Smith (12) and were standardized against arsenic trioxide in the presence of osmic acid according to the directions of Gleu. The cerium solutions were stored in 18-liter carboys fitted with siphon arrangements so that the bottles did not need to be opened and protected from light in a dark cupboard. Under these conditions, even the 0.01 N solution changed by less than 1 part per thousand over a period of about 6 months.

Jan 1, 1952

By T. F. Mitchell

During the investigation or the occurrence of manganese deposits in western United States, Bureau of Mines' examining engineers collected samples from four manganese properties in the Death Valley region, California. These were supplemented by samples submitted by owners of two other properties in the same area. Extensive laboratory tests were made to determine the, amenability of the ores to standard ore-dressing concentration methods. A small sample of high-grade oxide manganese ore from the McWhinney property, San Bernardino County, Calif., was submitted by the owner. Although the sample would sinter directly to plus 48 percent manganese grade, it appeared probable that the ore, if mined in quantity, would be lower in grade and would require beneficiation. Therefore, testing was conducted to remove the chief gangue constituent, calcite. The National Resources, Inc., property (also known as the old Owl Hole mine) is in the Owl Hole Springs district, I mile from Owl Hole Springs, San Bernardino County, Calif., near the southwest corner of Death Valley National Monument. The ore deposits occur as small lenses or ,pockets, evidently .replacements in limestone and granite. Laboratory work was done on a representative sample of orb procured by Bureau engineers.

Jan 1, 1949

By F. A. Rutledge

Mercury deposits were discovered in 1941 in the sedimentary rocks of the Cinnabar Crook area, near the head of the Holitna River drainage in southwestern Alaska, by Russell Schaefer and Harvey Wincholl of Sloitmut, Alaska. High-grade float was found in both Canary Gulch and Cinnabar Gulch, and indications of other deposits wore found in Aldor and Broken Shovel Gulches. Schaefer and Winchell's exploration in 1942 and 1943 revealed placer deposits of cinnabar along Canary Gulch. During prospecting on Canary Gulch, 3,600 pounds of ore was recovered from the detrital material on the Lucky Day lode at the head of the gulch. When retorted, this ore was reported by the owners to have produced 26 flacks of quicksilver. During the summer of 1943, Wallace M. Cady and Charles A. Hickcox, of the U. S. Geological Survey, spent 4 weeks mapping and investigating the area. Bruce I. Thomas and Harold C. Pierce, mining engineers of the Bureau of Mines, examined and sampled several deposits in September 1943. Following their preliminary examination, in view of the exceptionally high-grade cinnabar present, additional investigation by the Bureau of Mines was recommended. A program of trenching, test pitting, and sampling to delimit the deposits was completed during the summer of 1947 under the direction of the author.

Jan 1, 1950

This report is in fulfillment of Contract H0230031 awarded to Bituminous Coal Research, Inc., on May 23, 1973. The scope of work to be performed under this contract was divided into four phases: Phase I - Design, Phase II - Construction, Phase III - Field Demonstration, and Phase IV - Analysis and Final Report. During Phase I, an agreement was finalized with the Rochester and Pittsburgh Coal Co. for conducting field tests of the proposed shearer spray systems on a longwall panel in the company's Jane Mine in Indiana County, Pa. A drum was then designed which could be used on the Eickhoff shearer, Model EW170-L, being used on this longwall and which would utilize the following spray systems: 1. One spray nozzle located in front of each cutter bit with the jet directed at the cutting surface. 2. One spray nozzle located in back of each cutter bit with the jet directed at the back of the bit. 3. Standard Eickhoff nozzles located in a header along the drum scrolls. 4. A fixed header mounted on the shearer directly behind the drum to simulate the spray system originally used on the Eickhoff shearer.

Jan 1, 1976

By D. A. Reynolds, A. C. Fieldner, S. H. Katz

"03-01-192403-31-2019RI 2591 - Reports of Investigations - Department of the Interior - Bureau of MinesBureau of MinesPittsburgh Experiment Station American Society of Heating and Ventilating EngineersU.S. Public Health ServicesTucson Experiment Station Introduction.""Carbon monoxide self-rescuers,"" or simply ""self-rescuers,"" are pocketsize gas respirators which protect the wearer from air contaminated with poisonous carbon monoxide gas. On March 6, 1924, the Bureau of Mines approved the ""M.S.A. self-rescuer’ manufactured by the Mine Safety Appliances Co., Pittsburgh, Pa., after the M.S.A- self-rescuer bad passed all the tests and requirements of the Bureau's Schedule 14A4.The purpose of the self-rescuer is to help miners to escape from mines in which fires are burning or explosions have occurred, by providing protection from carbon monoxide for at least one half-hour. The self-rescuer can be used similarly by workers above ground who may through accident become surrounded or entrapped by atmospheres containing carbon monoxide.no hazards threaten the miner, who escapes serious injury by fire or violence in a large mine fire namely, ( 1) asphyxiation by poisonous carbon monoxide gas; and (2) suffocation by insufficient oxygen to support life. In order to save himself, the miner must either erect a barrica4e5 against afterdamp and wait restoration of ventilation and rescue or take a long chance at getting out of the mine through entries not permeated by afterdamp.. The self-rescuer removes the hazard of carbon monoxide poisoning for one half-hour or more, and accordingly greatly increases the miner's chance of saving his life.This paper describes the construction and details of the M.S.A. self-rescuer as approved by the Bureau of Mines, and discusses its performance under test condition"

Mar 1, 1924

By J. M. Mutmansky, L. Xu

"IntroductionSince the establishment of the star,just concentration of 2 mg/m3, a strong effort has made by mining engineers and researchers to provide better dust control equipment and procedures for underground coal mines.Particular areas of success have been implementation of better coal-cutting strategy to control dust generation, better design of water sprays for dust suppression and air movement, use of scrubbers, and improved design of face ventilation systems. A drastic improvement occurred over time such that the average dust concentrations for continuous miner operators dropped from 6.5 mg/m3 in 1968 to 1.3 mg/m3 in 1980 and for auger, cutter, longwall, and roof bolter occupations from 2.7 mg/m3 in 1973 to 1.6 mg/m3 in 1980 (Niewiadomski, 1983).While dust concentrations in mining sections have been dropping considerably, one problem area has been mining sections where quartz is a considerable portion of the airborne dust. The federal regulations require that quartz content must be held below 0.1 mg/m3 in the air regardless of the concentration of the total dust. This legislation limits the allowable dust concentration to a ""reduced standard"" of 10/ (% quartz) when the quartz content of respirable dust in the mine atmosphere is more than 5%. Today, approximately one-third of underground coal mining operations have designated areas with more stringent dust standards in place, and many mines experience considerable difficulty in meeting these standards (Jankowski, and Babbitt, 1989).It is well known that metal miners subjected to respirable dusts high in quartz have a higher incidence of silicosis than those exposed to dust low in quartz. However, the role of quartz in the development of coal workers' pneumoconiosis is still a highly controversial question, in spite of the large number of research projects devoted to this subject over the last 20 years. Because coal seams contain less quartz than metal ores and quartz often comes from sources outside the coal seam (e.g., roof and floor), it is difficult to relate studies that deal with the quartz content in coal seams and the incidence of coal workers' pneumoconiosis. Hamilton, Ogden, and Vincent (1983) have provided a plausible explanation for the incidence of the disease by hypothesizing that the quartz content does not affect the probability of developing pneumoconiosis until some threshold value (generally thought to be about 10%) is exceeded.The objective of the research studies summarized here was to obtain a better understanding of quartz occurrences in airborne coal mine dust by studying the variations of the quartz levels in different dust sizes and the relationship between the quartz content in airborne coal mine dust and the quartz content in the mined material. The implications of the results to control of dust in high-quartz sections will also be discussed."

Mar 1, 1992

By G. R. Hopkins

According to reports received by the Bureau of Mines, Department of the Interior, as of January 1, 1934, there were 591 completed refineries in the United States, an increase of 86 ever the total reported at the beginning of 1933 and the largest total ever recorded. It should be noted that the 1934 total, although large, probably does not include more than half of the "pot-still" plants of 1 barrel to 50 barrels daily capacity which have sprung up within the last 2 or 3 years and about which very little information is available. However, the combined operations of these snail refineries are of negligible importance as altogether they refine less crude than one plant of average size. Of the completed plants, 454 were operating on January 1, 1934 and 137 were shut down. In addition, 13 refineries were under construction on January 1, 1934. Compared with the previous year these data indicate a marked increase in the number of operating plants, little change in the number of inoperative plants, but a decline in' the number being built. The material gain in the number of operating plants resulted primarily from the construction off approximately 25 refineries, averaging about 100 barrels capacity in the Kooky Mountain district, as well as from the addition of about 20 plants in the East Texas field.

Jan 1, 1934

By H. W. Earnest

This report covers the results of a two-phase study to determine the feasibility of underground disposal of retorted oil shale. Two mining methods, chamber and pillar mining and sublevel stoping, were specified for backfilling. Phase I of the study covered the evaluation of hydraulic, mechanical, and pneumatic transport and stowing systems, individually and in various combinations, and the selection of the most feasible methods. Conveyor transport and stowing and a combination conveyor transport and stowing with pneumatic topfilling were selected for detailed study of phase II. Phase II activities included detailed engineering analysis and design of the selected systems, an engineering economic analysis, and a cost comparison with total surface disposal of retorted oil shale. An extensive literature search was conducted and the bibliography is included in the report. Research done under Contract No. J0265052 by the Cleveland-Cliffs Iron Co. Available for reference at Bureau of Mines facilities in Denver, Colo., Twin Cities, Minn., Bruceton and Pittsburgh, Pa., and Spokane, Wash.; U.S. Department of Energy facilities in Carbondale, Ill., and Morgantown, W. Va.; National Mine Health and Safety Academy, Beckley, W. Va.; and National Library of Natural Resources, U.S. Department of the Interior, Washington, D.C. Order ONLY from NTIS:

Jan 1, 1978

The Bureau of Mines, through its Minerals Availability Program (MAP), investigates the mineral supply potential of the United States and market economy countries (MEC's) for a number of minerals considered essential to the U.S. industrial base. Major activities include identification of important mines and mineral deposits, estimation of their mineral resources and production costs, and availability and sensitivity analyses. Products include data print-outs of geological and engineering information, discounted- cash-flow rate of return (DCFROR) analyses of individual mining operations, commodity availability appraisals, and analytic services to Government agencies. These products are used in assessing the mineral supply position of the United States: in setting priorities for research aimed at reducing production costs and minimizing adverse environ- mental impacts and regulatory compliance costs of mining and mineral processing operations; and in formulating and evaluating Government policies that affect minerals. Bureau MAP data and analyses have been provided to the executive and legislative branches to aid in consideration of trade, tax, and stockpile policy issues. A study of the economic potential of selected seabed mineral resources supports the regulatory responsibilities of the Department of the Interior in the U.S. Exclusive Economic Zone. Analytic studies of mineral project viability, industry competitiveness, and import dependencies were also undertaken for, or in cooperation with, U.S. and foreign government agencies, industry and trade organizations, and international lending institutions.

Jan 1, 1987

By D. E. Van Dillen

Seven configurations for panel entries of a longwall coal mine are compared and ranked according to structural stability. These entry configurations are analyzed using three-dimensional finite element modeling The models include large dimensions to minimize boundary effects, elastoplastic constitutive relations, and simulated excavation and construction of support systems. The stability criteria are formulated in a quantitative manner to facilitate the ranking of the entry configurations. These criteria are based on the expected volume of caved rock in the entry openings. The stability ranking is applied to the entry excavation phase, the headgate phase, and the tailate phase of the entry life cycle. Parametric variations are applied using two-dimensional finite element models to determine the sensitivity to changes in mining and design parameters.

Jan 1, 1981

By C. Özgen Karacan

This study presents the results of core-log analyses from the exploration boreholes, the analyses of face advance rates, and the results of downhole monitoring studies performed in gob gas ventholes for calculation of changes in hydraulic properties in the longwall overburden at a mine site in southwestern (SW) Pennsylvania section of Northern Appalachian Basin. In the ?rst part of the study, coal measure rocks in overburden strata were analyzed and the locations where possible fractures and bedding plane separations would occur were evaluated. In the second part, the hydraulic conductivities were computed by two different slug test analyses methods using the water level changes measured in gob gas ventholes as longwall face approached. Hydraulic conductivities were analyzed with respect to the changes in overburden depth, the locations of the borehole, and mine face advance rates. These data were used to interpret the potential productivities of the gob gas ventholes as a result of fracturing and changes in hydraulic conductivities. The general results showed that the probability of fracturing and bedding plane separations in the overburden increase between strong and weak rock interfaces. Also, the probability of bedding plane separations increases as the interface is close to the extracted coal seam. Evaluation of slug tests showed that the hydraulic conductivity developments in the boreholes and their potential production performances are affected by the underground strata and the roof materials. In situations where the roof material is stiff and thick, the development of high permeability fractures around the borehole will be less. Results also indicated that borehole location with respect to face position affects the fracturing time and permeability evolution as well. Greater overburden depths generally cause earlier fracturing as longwall face approaches, but eventually result in lower hydraulic conductivities and potentially less effective boreholes. Increasing mining rates also resulted in generally lower hydraulic conductivities in the overburden. The results of this study were intended to improve the interpretation of gob gas venthole performance and to provide better siting of these boreholes.

Jan 1, 2009