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By G. Hakes

A data bank on bolter technology was assembled which included state-of-the-art industrial equipment as well as new equipment currently under development for the U.S. Bureau of Mines. This information was augmented by field visits to selected USBM contractors, mine operators and others for the purpose of obtaining a thorough understanding of present coal mine roof bolting safety and productivity problems. These direct contacts provided valuable insight regarding requirements for new bolting equipment necessary to assure wide user acceptance. Using this background material and information, a series of roof bolter concepts was developed offering improved operator safety with minimum impact on productivity. The concepts developed utilize existing componentry and technology wherever possible. All of the concepts feature a fully protected operator station located 6' to 10' outby the active bolt line and the hazardous rotating machinery.

Jan 1, 1978

By M. E. Poad

Structural properties of steel-fiber-reinforced shotcrete and polymer-impregnated shotcrete, both plain and fiber-reinforced, were investigated by the Federal Bureau of Mines, Spokane Mining Research Center. The research center has found that flexural strengths can be increased by as much as 106 percent, and splitting-tensile strength by 50 percent, by introducing randomly oriented steel fibers. A slight decrease of compressive strength was found in the fiber-reinforced shotcrete. Polymer-impregnated shotcrete exhibited a threefold to fourfold increase in compressive and splitting-tensile strength. The techniques of preparing shotcrete with the dry process, using both fast-set agents and regulated-set cement, are described, along with the results of physical-property testing. Physical properties include compressive and splitting-tensile strengths, tangent and secant moduli, and stress-strain curves for plain shotcrete, fiber-reinforced shotcrete, and polymer-impregnated plain and fiber-reinforced shotcrete. Flexural strengths for plain and fiber-reinforced shotcrete are also reported. Steel-fiber shotcrete is the more promising of the new structural materials for ground support, and additional research is recommended.

Jan 1, 1975

By Laurance L. Oden, Jack C. White, Alan D. Hartman

The U.S. Bureau of Mines, under a Memorandum of Agreement with the American Society of Mechanical Engineers (ASME), established design criteria for a facility to field residues from municipal waste combustion. This facility, which is available to potential users on a cost-sharing basis, is also applicable to a variety of inorganic waste materials from smelting or melting operations. The design consists of a mechanical feed handling system, electric arc melting furnace, fume-off gas handling system, and thermal oxidizer for final off gas treatment. Screw conveyors and a bucket elevator deliver up to 2,000 Ib/h of minus I-in material to a three-phase electric arc melting furnace. This unique 800-kVe A furnace has a water-cooled shell and roof to minimize interaction of the melt with the refractory lining. The volume of the hearth below the slag taphole is approximately 1.2 st of steel. The furnace is sealed, allowing atmosphere control within the furnace and fume duct by nitrogen or inert gas injection. A jet-pulsed baghouse removes particulate from the off gas and serves as an acid gas scrubber. The clean off gas is heated to 1,800' F for 1 s in a propane-fired thermal oxidizer before being vented to the atmosphere.

Jan 1, 1993

By Loren R. Anderson

This is an Appendix of Volume I. In contains the results of the electric cone penetrometer soundings from the second phase of the testing program.

Jan 1, 1982

By Bill York-Feirn

The Colorado Mine Safety & Training Program (MSTP), in late 2005, completed and began distributing two new training tools; one geared to underground coal mine foremen and the other to surface aggregate employees. Through strong partnerships with MSHA, Colorado Coal Mine Board of Examiners, Colorado Mining Association and the Colorado Rock Products Association, the MSTP continues to create innovative and interactive training tools for not only Colorado, but for the national mining community. "Although we shoot and produce these materials in Colorado, it's important to us to make sure they are useful nationally," said Bill York-Feirn, MS TP Manager. The interactive DVD program "Underground Mine Foreman Certification Study Guide (Coal)," was completed in October 2005. It won the 2005 Grand Prize at the MSHA National Training Materials Competition in Beaver, West Virginia. [ ] This program is fully based upon the requirements of Title 30 Code of Federal Regulations (30 CFR) Parts 48, 50, 70 and 75 for underground coal mine foremen. It contains eight modules plus immediate access to relevant laws in the appendix. Topics covered include: Federal Law, Practical Math Skills, Mine Gases, Ventilation Maps, and scenarios addressing a variety of practical mining concerns. The DVD is designed for self-¬paced study and practice.

Jan 1, 2006

The investigations reported herein comprise preliminary studies to evaluate large scale mining systems adaptable to the thicker oil shale deposits in the deeper central portion of the Piceance Creek Basin. The studies include an evaluation of the geology, hydrology and resources of the Basin., evaluation of a potential prototype mine site, synthesis of rock mechanics data on Green River Formation oil shale, selection and preliminary design and cost evaluation of six potential mining systems and a ranking analysis to aid in selecting the most promising system. Results of the ranking analysis indicate the following four systems to be most promising for large scale underground oil shale mining: - Chamber and pillar (using spent shale backfill) - Sublevel stoping with spent shale backfill - Sublevel stoping with full subsidence - Block caving with LHD's Recommendations for phase II are to investigate the above systems in greater detail, refine present cost data, and perform economic evaluations of oil shale mining using these systems.

Jan 1, 1975

Electrical trailing cables are frequently damaged in usage, especially on continuous minors, and because of their weight and damaged condition present a safety hazard to personnel required to handle them. The U.S. Bureau of Mines and FMC Corporation signed Contract No. HO 122011 in August 1971. One of the contract tasks was to study the feasibility of techniques to improve trailing cable support and handling of power cables on underground coal mine machinery and to design a cable-handling device for a continuous mining machine. This report presents the results of the feasibility study, describes the design for a proposed cable handling device and concludes with a recommendation for future action to construct a test rig to evaluate the cable reel system.

Jan 1, 1972

By Daniel R. Walton

A study to explore the potential of utilizing the transport time required to move coal miners to and from the working sections. Consideration was given to all forms of training and presentation media, taking into account such environmental factors as noise, dynamic interferences, visibility, physical constraints, and contaminants. Indications of managements? and workers' attitudes toward man-trip training were also assessed. The final product was a proposed prototype training system for man-trip training. Includes Bibliography.

Jan 1, 1979

By George T. Faust

The petrographer engaged in examining the products resulting from the beneficiation of ores, and rock minerals is constantly required to develop new means acid methods of assaying microscopically the results of such operations. From time to time investigators have published descriptions of apparatus that have aided in solving problems in processes of physical separation. Thus, in 1919, Coghill and Bonardi 3/ published a paper covering the application of the binocular microscope and camera lucida to the microscopic analysis of pulverized ores. Similar work has been published by Schneiderhohn 4/ Schwartz 5/, and Head and his associates 6/, 7/, 8/. The present paper goes further and considers application of the polarizing comparison-microscope to problems directly concerned with mineral dressing where it is desirable to compare analogous products, and in addition it suggests new uses in various related fields. This work was conducted under the cooperative agreements of the Southern Experiment Station of the Federal Bureau of Mines and the University of Alabama.

Jan 1, 1940

By C. L. Brown

"INTRODUCTION The heavy loss of life from mine fires in some coal mines recently has focused attention on the importance of maintaining reliable communication systems between the active working sections of mines and the surface. A study of conditions following disasters in mines indicates that in several instances lives could have been saved if telephone communication had been available. Communication systems were not installed in some of these mines where disasters occurred, and in other mines they were installed in such a manner as to be rendered useless following a mine explosion or fire. Lives have been lost because of the inability of the rescue crews or persons di-recting the rescue to communicate with trapped men. Cases are known where many lives might have been saved had it been possible to give instructions for escaping or for location of barricades.More than 500 major disasters in which 5 or more lives have been lost have occurred in mines in the United States. The total number of lives lost in these disasters has exceeded 13,000. Some of the victims died instantly; but for many it was hours and in some instances days before death occurred. Evidence found in recovery operations following some of the disasters indi¬cates that many died needlessly because of the lack of suitable means of communication between the underground working areas and the surface.A localized gas and dust explosion in a coal mine in 1930 resulted in the death of 82 men; 2 were killed outright by the force of the explosion, 6 by a combination of burns and afterdamp, and 74 by afterdamp. About 140 men escaped or were rescued following the explosion, Of these, 119 escaped with little or no assistance, 2 were rescued promptly following the explosion, and 19 were rescued from behind a barricade. Seven bodies were re-covered from behind an ineffective barricade in another place; subsequent investigation proved that these men might have been guided to a safe location had an effective communication system been available."

Oct 1, 1946

By Duane L. Abata

This work, conducted under Bureau of Mines contract, deals with the development of a computer graphics software package that will: 1. display mine ventilation schematics and other representative Illustrations for a real-time data acquisition system under development by the Bureau, and, 2. utilize the Bureau-owned Minefire and Ventilation Code for display of ventilation on and contamination predictions. The software package has been written try operate on a 64K, Z-80 based microprocessor-computer. The project has been divided into two phases. The first phase dealt with the development of the graphics software The sec rind phase dealt with the retrofit of the Minefire and Ventilation Code to the Z-80 microprocessor-computer.

Jan 1, 1984

By Arthur V. Petty

In Bureau of Mines research on recycling chrome-containing refractory wastes, used refractories from argon-oxygen decarburization and electric steelmaking furnaces were beneficiated. By means of dry magnetic separation on minus 6-mesh crushed wastes, a concentrate was produced. After minor adjustments to the particle size distribution, full-size refractory brick were dry-pressed by a commercial producer and fired to 1,450° and 1,730° C. Standard testing procedures were used to determine the cold-crushing strength, modulus of rupture at 25°, 1,300°, and 1,500° C, hot load, thermal shock resistance, thermal expansion, and slag resistance. Optical and electron microscopy were used to determine grain-bonding mechanisms, and energy-dispersive analysis of X-rays was used to determine elemental distribution. The test results indicate that the beneficiated material could be used to produce a refractory product suitable for moderate-temperature applications.

Jan 1, 1982

By Frank E. Cash

The work of the United States Bureau of, Mines is concerned primarily with the prevention of accidents in the mining, petroleum, and allied industries. This report analyzes the fatal accidents in the coal mines of Tennessee and gives the pertinent factors in tabular and descriptive form, with interpretations and suggestions to operators, workers, and the State Division of Mines for the future prevention or reduction of accidents in coal mines. ACKNOWLEDGMENTS This study was made possible through the cooperation of A. W. Evans, chief mine inspector of Tennessee, and his secretary, Miss Hiliary Penny, who made available the department records and assisted in the segregation and assembly of the data.

Jan 1, 1935

By James W. Hendrix

A survey of endomycorrhizal fungi occurring on orphan coalmine lands in Western and Eastern Kentucky revealed a great diversity of species present. Thus a large number of fungi are available for isolation and evalution for enhancing revegetation of mined land. Endomycorrhizal fungi isolated from orphan mines stimulated growth of sweetgum seedlings on mine soil at low fertilisation but inhibited growth at high fertilization; this growth inhibition at high fertilization did not occur with plants growing on peat-perlite. Banding of endomycorrbizal inoculum was not advantageous, compared with incorporation of inoculum throughout the growth medium, for production of mycorrhizal sweetgum seedlings. Newly reclaimed mine spoils were nearly nonmycorrhizal, compared with land reclaimed four or eight years earlier. A procedure for isolation of single-spore cultures of endomycorrhizal fungi was developed; this procedure is necessary for studies of ecotypic variability. A practical procedure using container-grown Pisolithus tinctorius-infected shortleaf pine seedlings for production of large numbers of bareroot pine seedlings infected with P. tinctorius for mined land reclamation was demonstrated.

Jan 1, 1982

By Gerald P. Scanlan

Control of the dust produced by continuous mining machines in coal mines is generally obtained by water sprays from fixed nozzles mounted on the frame of the machine in back of the cutting head. Mounting the nozzles on the rotating head of the machine closer to the coal cutting bits may improve the efficiency of dust suppression. To test this concept, respirable dust measurements were made during 39 regular production shifts in an underground mine using a Joy 11CM continuous miner. The equipment used, difficulties encountered, and measurements obtained are described.

Jan 1, 1974

By Michael S. Miller

In 1984, at the request of Bureau of Land Management, the Bureau of Mines studied 8,500 acres of the 20,250-acre Seven Blackfoot Wilderness Study Area (WSA) consisting of all 3,950 acres of MT-024-657A and 4,550 acres of the 4,850 acre MT-024-657B in order to evaluate the mineral resources. Within this report these 8,500 acres are referred to as the study area. Located about 30 miles northwest of Jordan, MT, the study area is underlain by outcrops of Quaternary alluvium and Cretaceous to Paleocene sandstones, shales, clays, and coal. No mines or prospects were found in the study area. Except for some current interest in petroleum and natural gas, there has been no mineral exploration activity in the study area. The study area contains subeconomic clay, placer gold, and coal. Land within the study area is leased or under lease application for oil and gas.

Jan 1, 1986

By James C. Barker

Unverified reports of rare earth element (REE) concentrations in gold placers and radioactive mineral prospects in the Zane Hills were investigated by the U.S. Bureau of Mines as part of the Alaska critical minerals program. REE is reported to occur in dredge concentrates at the Hogatza mine and up to 1.2 pct REE was previously analyzed in alkalic syenite (bostonite) dikes marginal to the pluton. In addition, numerous thorium-rich veins, explored for their uranium content but unevaluated for REE, occur on the western margin of the Zane Hills. The Bureau mapped and sampled all of the reported or suspected REE occurrences. Dredge concentrates contain abundant uranothorianite, a mineral species which incorporates cerium subgroup REE. Bostonite dikes occur in conjunction with a multi-phased zoned alkalic intrusion, however, no significant REE concentrations were found. Thorium-rich veins contain nil to 0.5 pct Y but resource potential is limited by this relatively low grade, the ultimate low tonnage potential, and the lack of uranium as a major economic element. The Zane Hills exhibit attractive exploration targets for uranium deposits, primarily in a sedimentary form. Gold may be found peripheral to the pluton in both placer and lode deposits. Resource potential of REE, however, appears limited to a placer by-product of REE-Zr-Ti that is recoverable only during large scale gold placer mining. Placer exploration of the lower Wheeler and Dakli Creeks is suggested.

Jan 1, 1991

By Terry J. Close

A mineral resource survey of the 236-mil (611-km2) Hyalite-Porcupine-Buffalo Horn wilderness study area (RARE 11 Areas No. 1-155 G, Gallatin Divide; and H, Hyalite) between the Gallatin and Yellowstone rivers in Montana, indicates there are phosphate rock and petrified wood resources (fig. 1). The area also has some potential for oil, gas, and geothermal resources. Stone and alluvium are abundant but appear to have little potential for development because other sources are available nearer to markets.

Jan 1, 1981

By Paul J. Remington

The field data gathered as part of the measurements described in Volumes I and II were re-analyzed in the low frequency regime (.1 Hz to 1 Hz) where motion sickness normally occurs. These data were compared co the international standard ?ISO 2631 Addendum 2: Evaluation of exposure to whole body z-axis vertical vibration in the frequency range 0.1 to 1.0 Hz." For both underground mining machines and surface mining machines the results showed that one would not expect motion sickness to .be a severe problem. New field data were gathered on the vibration reduction performance of various seat designs found on surface coal mining machines. The vibration during normal operation was measured on the seat using the standard seat pad accelerometer package described in the previous two volumes and simultaneously on the floor of the machine at the base of the seat. Preliminary indications are that the so-called high performance seats used for operator vibration reduction do not offer significant improvement over conventional seats.

Jan 1, 1984

By Joseph Grumer

An instrumented spherical vessel has been used for many years to study laminar combustion waves. Concurrent measurements of flame speed and pressure-rise rates have led to evaluations of burning velocities, the pressure dependence of the burning velocity, and the expansion ratios of the gases passing through the combustion wave. For the most part, these studies have involved flames initially at atmospheric or subatmospheric pressure. The old spherical vessel used by the Bureau of Mines was not designed for use at elevated pressures. Moreover, being made of wrought iron, it was susceptible enough to corrosion to prohibit its use with many combustible mixtures that figure in industrial research. In mid-1956, under sponsorship of the Office of Naval Research, the Bureau undertook the development of a stainless steel spherical vessel capable of withstanding explosions of gaseous mixtures at initial pressures as high as 20 atm. and initial temperatures as high as 250° C. The design called for a double array (cross) of closely spaced small windows for observation of the flame as it traversed the vessel and a piezoelectric transducer to measure concurrently pressure-rise rates. Because no commercial contractor was willing to bid on the construction of such a vessel, it was built at the Bureau's Bruceton machine shop.7

Jan 1, 1961