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Horizontal holes are drilled underground into coalbeds to control methane flow from ribs and active face areas and to make gas pressure measurements in coalbeds. Gas pressure measurements are made by drilling the same hole incrementally. After each increment, the hole is filled with some type of packers and allowed to reach equilibrium before a gas pressure reading is taken. As the length of hole increases, more packers are required to effect a seal and obtain a reliable pressure measurement. Problems have been encountered in obtaining satisfactory packer seals due to the friable nature of the coalbed. New methods of packing the holes must be used. Therefore, this project was established to evaluate materials and develop a new technique in which a semiliquid and/ or rigid type grout could be placed in the hole to provide satisfactory sealing.

Jan 1, 1972

By Mark P. Zaitsoff

The project involved design, construction, and testing of hydraulic models of culverts, decant and open channel spillways which are typical drainage structures used for protecting mine waste embankments. MSHA (The Mine Safety and Health Administration, U. S. Department of Labor) made a motion picture of the tests. Tests results and products in the forms of graphs, tables and films, demonstrate the principles and factors which govern the function and performance of the three types of drainage structures.

Jan 1, 1981

The Bibliographic Data Base is the result of a literature search con-ducted as one task of the technology assessment of current and advanced logging techniques, sponsored by the United States Bureau of Mines. After compilation, the bibliography was converted to an automated form for ease of utilization, and to allow for maintaining and updating the data base. The data base covers articles, symposia, books, patents, corporate and government reports, and other literature concerned with some aspect of borehole logging from January 1969 through December 1975. Periodic up-dating will be necessary to keep the data base contents in step with developments in the rapidly advancing field of application of borehole logging to mining. Many bibliographic indexes were scanned for entries relating to the subject of interest, and those entries which were included in our data base contain a reference to the bibliographic index in which they were listed (see Section 2.4.7). With the aid of these indexes, a vast number of publications, including foreign reports and publications, have been scanned for works relevant to borehole logging technology.

Jan 1, 1976

By R. W. Stahl

Burning coal-mine refuse banks were surveyed in 15 States. The following characteristics were tabulated for 495 hanks: County; name, population, and distance of nearest town; size and status of bank; status and stage of fire; and topography. Ways of controlling fires were reviewed, the compacting and sealing method proving most satisfactory. Means for preventing refuse-bank fires by proper construction of banks are described.

Jan 1, 1964

By George H. Holmes

The water situation in Nevada mineral and related industries is described in this report. It contains information on the sources and adequacy of supply to current operators, requirements and uses, quality and costs, geography, hydrography, precipitation and evaporation characteristics, and Nevada water laws. Also, information is given on the water requirements of one public utility powerplant, and the source and consumption of water in four major cities. Water distribution at 24 operations is shown on schematic waterflow diagrams. The mineral industries of Nevada in 1962 used 8.6 billion gallons of new' water and reused 3.8 billion gallons for a total usage of 12.4 billion gallons. The copper industry was the major water user. The 1962 value of all mineral production in Nevada was $85.5 million. The large amount of water required to maintain thin high production is obtained principally from ground-water sources in alluvial valleys and the permeable rock formations of some mountain ranges. Some water is also obtained from perennial streams and springs. Sources of water utilized by existing industry ire near most mineral industry operations; however, seven companies are forced to pipe water distances ranging from 2 to 8 miles. Although water supplies of presently operating companies are adequate at most operations, several companies resort to large-scale reuse of water as a matter of conservation and economics. Acquisition of water by new operators is possible but takes considerable negotiation. Water rights, surface and underground, are controlled by the State. The quality of the water is satisfactory for most purposes. Analyses of 19 samples, listed in the appendix, show the range in water quality at various plants throughout the State. Costs of delivering new water to current operations range from 2 to 26 cents per 1,000 gallons with an average of 10 cents per 1,000 gallons for power and maintenance. No firm costs for recirculating water were available; estimated costs range from 1.5 to 2.5 cents per 1,000 gallons. The mineral-product value of the entire Nevada mineral industry in 1962 was equivalent to $10 per 1,000 gallons of new water and $26 per 1,000 gallons consumed. Projection of the 1962 water requirements of the Nevada mineral industry indicates that the demand For new water will increase from 8.6 billion gallons in 1962 to 11.9 billion gallons in 1980, a 43-percent increase. Water requirements in the year 2000 are estimated as 14.8 billion gallons, an increase over 1962 water demand of 78-percent.

Jan 1, 1966

By J. G. Donaldson

Optimum conditions are given for chloridizing pyrite, marcasite, chalcopyrite, arsenopyrite, stibnite, and covellite with chlorine gas. The formation of metal chlorides is affected by the time and temperature of chloridizing, and by particle size of the sample. Chloridizing data also are given for chemically precipitated antimony (III) sulfide and copper (II) sulfide.

Jan 1, 1962

By A. R. T. Denues, A. P. Rowles

"INTRODUCTION Summarized data developed by J. E. Crawshaw and E.J. Murphy, 4/of the Explosives Division of the Bureau of Mines, suggesting marked variations in oxygen condition in three permissible explosives, have been reported 5/. Such variation is of interest in other work, it having been shown, for example, that the oxygen condition may have marked effect upon the products 3/ and the propulsive strength 7/ of explosives. It seemed that a more detailed presentation and more usual statistical analysis of these data might be of considerable general interest and not complemented in the literature.This report presents both the original data developed by Crawshaw and Murphy and the results of a simplified but seemingly acceptable statistical analysis of these data. The logical ground for this analysis might seem somewhat questionable because of the lack of systematic information concerning the extent of errors in the analytical procedure but the data show that there are several cogent and seemingly unequivocal indications of real heterogeneity in the explosives."

Jun 1, 1942

By Paul E. Loustaunau

This report describes a project in which three structured underground coal mine equipment operator training programs were developed. The project was carried out in two parts. In the first part, a research study was conducted to determine how on-the-job training is currently conducted in industry, and to determine the overall effectiveness of current on-the-job training. In addition, the possible application of the principles of social learning theory to on-the-job training was investigated. In the second part three prototypes on-the-job training programs were developed for shuttle car operation, roof bolter operation, and continuous miner operation. These programs were carefully structured to eliminate the shortcomings of current industrial on-the-job training identified in the research study and incorporated the application of relevant principles of social learning theory. The programs are prototypes which underground coal mine training personnel can use as models to develop their own customized equipment operator training programs.

Jan 1, 1983

By Thomas P. Mucho, Dennis R. Dolinar, Anthony T. Iannacchione

The Chestnut Ridge Anticline is a prominent structure in southwestern Pennsylvania, USA. This structure has brought two economically valuable limestone formations to the surface, where they are easily accessible to room-and-pillar mining. Nine active crushed stone quarries, an underground research facility, and one industrial facility currently operate along the linear trend that represents the axis of the anticline. The National Institute for Occupational Safety and Health (NIOSH) has identified significant variation in levels of horizontal stress within relatively short distances at shallow overburdens along the anticline. At one quarry, the horizontal stress is high enough to shear strata with a modulus of approximately 77 Gpa. Conversely, zones of extension were observed in parts of another quarry, indicating very low horizontal stress conditions. This study found that high levels of horizontal stress are to be expected in this very stiff rock formation and that local geologic and topographic structures are capable of altering the magnitude and possibly the orientation of the horizontal stress field.

By Rudolf E. Grauer

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Jan 1, 1981

By N. Kumar Kittusamy

ALTHOUGH MANYSTUDIES HAVE SHOWN an association between operating heavy construction equipment and symptoms of musculoskeletal disorders (MSDs), little research has been performed that systematically characterizes the exposure of operating engineers to ergonomic hazards. This study evaluated: 1) vibration at the seat/operator interface;2) transmissibility of vibration in the Z-axis; 3) psychophysical ratings of vibration level and vibration discomfort; and 4) postural requirements of the job. Results indicate that the digging operation had higher levels of total weighted acceleration than high- or low-idling conditions. Transmissibility data showed that the seat amplified vibration, particularly in the lower frequencies. Seats demonstrated that they may not be sufficient in protecting operators from long-term effects of vibration exposure. High positive correlation was found among subjective ratings (vibration discomfort and vibration level), but moderate positive correlation was found between subjective ratings and quantitative vibration levels. Postural evaluations revealed that the operators were required to assume awkward postures of the neck, shoulder and trunk while performing their jobs. Work-related injuries and illnesses pose a continuing threat to the health and well-being of American workers. The construction industry has been historically recognized as having higher rates of fatality, injury and illness than other industries (McVittie285+; BLS). In 1994, an estimated 218,800 lost-work-day injuries were reported in the construction industry (BLS). Construction also had the second-highest incidence rate for sprains and strains. Although the industry has made progress since then, injuries and illnesses, including MSDs, continue to because for concern.

By C. B. Barmore, B. W. Gandrud, B. M. Bird

"The Bradford mine of the Alabama By-Products Corporation is located in the Warrior coal field of Alabama, in the northern part of Jefferson County, about 25 miles north of Birmingham. The coal mined from the Black Creek bed at this point is not considered to be ideal for coke making by itself but because of its exceptionally low ash content is mixed with the higher-ash coking coals from other beds of the district to control the ash content of coking mixtures. Further reasons for using this coal only as a diluent of the higher-ash opals are that the thinness of the bed renders the production costs relatively high and the reserves are somewhat limited.This paper, which is the fourth of a series on the washability of Alabama coals, Like its predecessors dealing with the Mary Lee beds and the Clark bed,6 contains screen-sizing and float-and-sink tests of a representative sample of the raw coal, and flakiness tests showing the proportions of flaky particles in certain selected sizes. However, inasmuch as the float-and-sink tests of the coarse sizes showed excellent liberation of coal from impurities, crushing tests have not been considered necessary.The data on which this report is based have been obtained in connection with an exhaustive study of coal preparation in Alabama now being conducted by the U. S. Bureau of Mines and the University of Alabama with the cooperation of the different coal operators. As the work progresses other papers will follow containing further data on Alabama coals and giving results obtained in preparing these coals by various methods."

Apr 1, 1931

By Michael G. Pojar

This Bureau of Mines report estimates the population of the principal types of machinery in use by the coal mining industry during 1982 in surface and underground mines. Estimates were arrived at using 1976 coal equipment population estimates as baseline data with modifications made for new mine development, expansion, and closure occurring during 1976-82. Estimates were broken down into 3 regions which included all 26 coal-producing States. Modifications made to the baseline data were computed using (1) actual equipment information when available, plus (2) equipment information hypothesized from representative generic mine models, which were predicated on mine size and mine method. Roughly half of the equipment fleet at new or expanding coal operations was known; the remainder was hypothesized. The mine models used to generate equipment information are included in this report, along with the hypothesized equipment use data. The equations and various factors used to determine the equipment adjustments for mine closings, new mine openings, and small coal mine operations are also identified.

Jan 1, 1986

By F. Sillers, R. T. C. Rasmussen

"INTRODUCTION This is the fourth report of investigations dealing with the cooperative tests between the Bureau of Mines and industry on the use of electrolytic manganese in steelmaking. The first report dealt with the use of electrolytic manganese in the manufacture of stainless steel 3/ the second with its use in acid electric steel practice, 4/ and the third with its use in low-carbon basic open-hearth steelmaking. 2/ A résumé of those investigations E7 appeared in the magazine STEEL. 5/ The present report deals with the use of electrolytic manganese in the manufacture of four types of stainless steel and the new Timken 16-25-6 alloy. The Bureau of Mines supplied The Timken Roller Bearing Co. with 62,000 pounds of electrolytic manganese for use in the tests.The electrolytic manganese was produced at the Bureau of Mines pilot plant, Boulder City, Nev., by the process developed by the Bureau and described in Bulletin 463, Operation of Electrolytic Manganese Pilot Plant, Boulder City, Nev., by J. H. Jacobs. J. W. Hunter, W. H. Yarroll, P. E. Churchward, R. G. Knickerbocker, R. W. Lewis, H.A. Heller, and J. H. Linck. The workcarried out under the direction of R. S. Dean, formerly assistant director, Bureau of Mines, and R. G. Knickerbocker, formerly chief, metallurgical branch, as part of a long-range program involving the development, manufacture, and use of manganese from domestic ores. Preliminary arrangements for the plant tests were made by the late A. A. Dow. 7/"

Jun 1, 1947

By J. C. Engel

Recent innovations in mine safety include the use of mercury vapor lamps for mine vehicle illumination. Such lamps, however, extinguish whenever the line voltage at the machine momentarily sags or is interrupted. The lamps must then cool for several minutes before they will restart. By supplying reduced high frequency power to the lamps from an auxiliary source, it is possible to maintain ionization in the arc tubes preventing the lamps from extinguishing. Essentially an auxiliary high frequency supply, the keep alive system provides additional power to the lamps automatically whenever the lamps are in danger of dropping out. The system can also provide the operator with the ability to dim the lamps at will for periods of up to three minutes by simply interrupting the 60 Hz power to the conventional ballasts. Each unit, housed in a steel explosion proof enclosure with a volume of approximately 0.6 ft3, is capable of servicing up to six 175 watt H-39 mercury lamps and two 100 watt H-75 reflector flood lamps. A total of 16 units were produced for the USBM under this contract and its extension.

Jan 1, 1979

A preliminary study was conducted by the Bureau of Mines to determine the effect of humidity on salt mine airborne dust levels. Results showed less dust where the humidity was elevated. Dust reductions appeared to be dependent on the equilibrium between humidity and salt.

Jan 1, 1980

By Stephen R. Iverson, Bill M. Stewart, Michael J. Beus

The U.S. Mine Safety and Health Administration (MSHA) has identified ore pass hazards as a significant safety problem in underground metal mines in the United States injury and fatality data show that many injuries are related to pulling or freeing ore pass chutes and structural failures of control gates and ore pass walls. Researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health are investigating these hazards and developing methods to improve safety during transport of ore and waste. Particle flow analysis methods were used to simulate chute and control gate response to various material loading scenarios. Results from computer models indicate that dynamic impacts from ore and waste rock might be considerably greater than theory predicts. Static and dynamic loads were measured in a laboratory setting using scaled ore (sass mock-ups. Field tests were initiated in an active ore pass to determine actual static and dynamic loads. Field data were compared to computer results and indicated that impact and total static loads were substantially less than the computer model results suggested. Damping factors, normal and shear stiffness, and mass frictional characteristics have a significant effect on particle flow and resulting impact loads.

By H. A. Doerner

"The pure mineral chromite, FeO.Cr203, consists of ferrous and chromic oxides, chemically united in equal molecular proportions. Unfortunately, pure chromite as defined above appears to be a rare exception. In most chrome ores the mineral may be considered a combination of spinel, MgO.Al203, and chromite, with the latter predominating. The ratios between the four common constituents Fe0, Mg0, Cr203 and A203 vary greatly, and other minor constituents such as TiO2 and. Fe203 may also be present.In the mechanical concentration of chromite ores the maximum grade of concentrates that can be produced is thus limited by the composition of the chrome minerals present. Pure chromite contains 68 per cent Cr203, but the Cr203 content of the chrome minerals in commercial ores varies between 45 and 60 per cent and the average is not far from 55 per cent.Chromite is usually associated with serpentine. Other silicates, quartz, dolomite, magnetite, ilmenite and other iron Minerals are frequently present.The amenability of a chrome ore to concentration, depends upon the kind and amount of the various gangue minerals present and the amount .of crushing necessary to separate the chromite from them.A relatively small amount of chrome ore is concentrated by milling. In most cases the mine product is simply hand-sorted. Such chrome deposits as are known in the United. States can not be worked in this way on account of one or both of the following conditions: High cost of labor and finely disseminated impurities. There are, however, several deposits in the United States, Canada, and Alaska which may be able to compete with imported or by efficiently utilizing modern ore-dressing and milling methods."

Nov 1, 1930

By Glenn Adkins

This report characterizes pivoting joints in the structures of mining machinery and how the wear on the various components, i.e., pins, lugs, yokes and bushings, may affect the safety of mine personnel where these components are allowed to wear excessively before repair or replacement.

Jan 1, 1979

By H. D. Kline

This paper describes the methods of mining and washing brown iron are in 1957 at the Sawyer mine, leased by Wayne County Mining Co., and the Fore mine, leased by Four Mining Co., both in southern Missouri; it is one of a series prepared by the Federal Bureau of Mines on mining and milling methods and costs in various districts of the United States. The Sawyer mine is in Wayne County, about 10 miles north-northeast of Williamsville (fig. 1); the Fore mine is in Howell County, about 20 miles southwest of West Plains (fig. 2). Both are open-pit mines from which the crude are was upgraded by washing and hand-sorting to produce are of grade and quality suitable for sale to operators of iron and steel furnaces. The operations described are typical of many others that produce or have produced marketable brown iron are from small sedimentary deposits, several hundred of which outcrop on the crests or hill sides of southern Missouri (fig. 3). The 1957 production of marketable brown iron are by 40 separate operations in the southern part of the State was 281,427 wet long tons, valued at $1,637,243. Production from the Sawyer mine that year was 17,000 dry long tons of washed are, and from the Fore mine, 20,816 dry long tons.

Jan 1, 1960