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Provide optimum visibility of mining operations while maintaining protection and comfort for machine operators. Approach A cab with hydraulically powered variable-height control was developed and used on a loading machine in underground operations. How It Works The cab is attached to the vehicle on a horizontal trunnion located near the forward end of the cab. A hydraulic cylinder, controlled by the operator from inside the cab, pivots the cab about the trunnion providing variations of up to 16 inches in elevation. The nominal tramming position of the cab is with its underside 6 inches above the mine bottom. From this position the cab can be pivoted up, or down, so that its back end is elevated 10 inches, or lowered to the floor. (See Figure 1.) The cab encloses the operator for protection against both overhead and lateral obstructions, and it raises or lowers, allowing the operator to select the most advantageous cab height. The cab is angled inboard 30 degrees to the machine line of direction. The operator's seat swivels to allow view of the conveyor during loading. All controls are located within the cab and move up and down with it.

Jan 1, 1978

"The major thrust of this research is directed towards a better undstanding of the behavior of airborne dust particles in underground mine airways. Figure 61 shows a schematic of dust flow in mine airway. The work included development of a mathematical model of dust behavior in mine airways, experimental study of the behavior of dust clouds and comparison of computer model output and experimental results. Re-entraiment is a secondary source of dust in mine airways and factors affecting re-entrainment are being identified.Investigations have encompassed both experimental and theoretical research into the behavior of dust in mine airways. Experiments were performed in mine airways under both controlled and normal operating conditions (Figure 62). The controlled experiments included the documentation of the concentration and desposition patterns for two types of dust under three different velocities. Real-time dust concentration data were obtained using real-time aerosol monitors (RAM-1) (Figure 63).On the theoretical front, a convection-diffusion model of the dust flow phenomenon in mine airways was developed considering dominant mechanisms affecting dust transport and deposition in mine airways. Mechanisms modeled include turbulent and gravitational deposition, coagulation, and dispersion. Comparative analyses of results of the controlled experiments with the predictions of the mathematical model were carried out. In addition to the overall validity, the adequacy of the individual components of the model, such as deposition in the total and respirable range, and dispersion were examined in light of the experimental observations."

Nov 1, 1988

By P. C. Good

The work reported here was undertaken by the Federal Bureau of Mines to investigate new methods of preparing high-purity metal. Tungsten hexachloride was prepared by direct chlorination of scrap tungsten metal and by treating tungstic oxide with carbon and chlorine. The resulting tungsten hexachloride was purified by distillation and reduced win: sodium, magnesium, or hydrogen. The metal prepared by these techniques was at very high purity after arc melting but of variable quality prior to arc meIting. Metal recovery ranged from about 40 to 90 percent of theoretical values, It was found possible to deposit a smooth, dense coating of high-purity tungsten on the inside of a heated tube by vapor-phase reduction of tungsten hexachloride at reduced pressure.

Jan 1, 1961

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

To reduce needless paging of persons by all phones in a mine or mill, while retaining all-location page capability. Approach Standard pager phones of any manufacturer are modified to include the option of selective calling and message holding. How It Works All commercial mine pager phones presently rely upon voice paging via a loud-speaker. When a page is initiated, every phone in the system broadcasts the audible voice page, even phones in locations where the desired person could not possibly be. The advantage of this scheme is that whole-mine paging occurs. The disadvantage is that persons soon begin ignoring pages because they occur all the time, and most are for someone else. Also, it requires considerable battery power from all phones making it necessary to change batteries very frequently, even in phone locations where personnel rarely go. In addition, if a voice page is made and not heard, there Is no way to leave the message. Therefore, persons who at a later time come near a phone, have no way of knowing a page was made and was not acknowledged. This results in situations that often have a direct bearing on safety and productivity.

Jan 1, 1980

By John A. Breslin

Three scale models of coal mine entries and mining machines were constructed by the Bureau of Mines to study the effects of ventilation parameters on dust concentrations where mining personnel would be working. A one-fifth-scale model of a coal mine entry with a drum-type continuous-mining machine and a one-sixth-scale model of an entry with a twin-borer-type machine were used as well as a one-fifth-scale model of a longwall face with a double-drum shearer. Methane was used as a tracer gas to simulate respirable dust in the models. The distance of the end of the brattice or tubing from the face was found to be more important than the airflow rate for the drum-type machine. Dust reductions greater than 90 pct were shown to be possible with a secondary ventilation system used with the twin borer and a dust collector mounted on the longwall shearer. Cutting-head speed had a significant effect on concentrations at typical positions of miners with the drum-type machine and longwall shearer but not for the twin borer.

Jan 1, 1976

By Elaine T. Cullen

Educating the public about the role of mining and minerals can be a challenge. While it sometimes seems that little is being done to counteract negative publicity, there are many exciting things happening across the country that are helping meet this challenge. This paper will discuss existing minerals education activities and will provide tips for developing successful programs for a variety of groups, from students to industry to minerals educators themselves. The paper will also include an overview of the 9th annual National Minerals Education Conference held in July 2000 in Spokane, WA.

By Frank A. Peters

This description of process evaluation techniques used by the Bureau of Mines for studying proposed processing techniques has been prepared to provide those interested in using these studies with an understanding of the methodology. The methods used for preparing both capital and operating cost estimates are described. Each step in preparing the evaluations is described. Types of equipment costs are shown and factors used in the estimates are defined. Uses of the estimates are suggested and several examples are included. The accuracy of various types of estimates is discussed, along with an explanation of the reason for selecting the type used in the Bureau's process evaluation studies.

Jan 1, 1987

By F. L. Wideman

SPURRED by demands of a buoyant economy for mineral products, output from mines in the United States established a new record. Removal of waste material, necessary for the extraction of economic minerals, kept pace with mine production. Earth moving by these two activities exceeded 3 billion tons, an increase of 5 percent over that of 1963. Crude materials from which metal or nonmetal products were derived accounted for 75 percent of the total. The remainder, mostly worthless, was classified as waste. Changes in the minerals industry result from many causes. Technological trends and labor productivity are among several significant and interrelated indexes that assist in the analysis of the changes. Therefore, a. study of productivity is helpful in measuring technological growth in mining. Concepts of productivity tend to vary with the purpose for which the term is used; frequently, productivity is expressed in terms of units of output per unit of labor, such as tons of ore per man-hour or man-shift. Comparisons of levels of productivity for a group of products are usually made using composites of output. Data for all metal and nonmetal mines except gold, silver, mercury, platinum metals group, and sand and grave were used to compile the composite for determining productivity for 1960-64. Copper ore, iron ore, and phosphate rock are mined mainly by surface methods, but characteristics of the deposits and differences in processing the crude material affect production of the commodities. Therefore, productivity data for these selected segments of the minerals industry reflect the influence of physical conditions on the exploitation of them.

Jan 1, 1965

By Richard Havens

Samples of low-grade oxide manganese ores were procured from two southern Utah properties by examining engineers of the Bureau of Mines during an investigation of manganese mineral deposits of continental United States. A 2-ton lot of ore was obtained from the Blackbird group of mining claims in Paiute County, 11 miles southeast of Marysvale, Utah. The deposit was described as an intrusive sheet or sill of altered brecciated rhyolite cemented together by manganese oxide minerals. A 2-ton sample from the Black John property, situated 32 miles northeast of Kanab, Kane County, Utah, was taken from open cuts on the vein. The blanket-type vein deposit consisted of nodules and streaks of manganese imbedded in compact gray clay.

Jan 1, 1949

By F. E. Spencer

This Bureau of Mines report provides a complete mathematical description of the algorithm employed by a general multiphase chemical equilibrium program developed particularly for the purpose of studying problems in coal combustion, although the generality of the program will allow its application to any equilibrium system in which an appreciable gas phase is present. When applied to coal combustion problems, the program predicts composition and quantity of slag and unconsumed carbon phases as well as calculates accurately the composition of the gas phase including trace species such as free electrons and ions which are important for predicting electrical properties.

Jan 1, 1973

By Thomas Varley

"Concentration, ore-dressing, or the dressing of minerals are common terms used in metallurgy and indicate processes of separating valuable minerals from worthless gangue. It is understood, of course, that the products from such processes, being separated from the various minerals and gangue, are ready for commercial sale or for further treatment by smelters and refineries.Gravity concentration takes advantage of the difference in specific gravity of the various constituent minerals and gangue of waste material in the ore. The two most common forms of concentration by this means are jigging and table concentration. Jigs usually are used in the separation of relatively coarse material and the tables for the finer material, the line of division in general being about 20 mesh.There are mar factors to be considered .before a decision can be made as to what method would be best adapted to the successful treatment of an ore and only by careful experiments can this be determined. Among the important factors to be considered are. The nature of the minerals present, their physical and chemical relations to the gangue material, and the gangue material itself. Perhaps the most important is the number of minerals present and their relation to each other.Metals exist in ores in three principal forms -- sulphides, oxides or carbonates, and native. Concentration by gravity methods is in general best suited to sulphide ores, although in some places considerable success has, been obtained in the concentration of oxide ores by gravity methods."

Apr 1, 1920

By Manuel Gomez

Areal distributions for ash, total sulfur, and sulfur forms were developed for the top 12 inches, the middle section, the bottom 8 inches, and the total seam of Pittsburgh coal in southwestern Pennsylvania. The sulfur and ash exhibit an apparent high local variability. As a general rule, both the sulfur and ash show high concentrations in the top 12 inches and in the bottom 8 inches of the seam relative to the concentrations observed in the middle section of the seam. The high-low sulfur and ash concentrations in the top 12 inches of the seam are not coincident with the high-low sulfur and ash concentrations in either the middle section or the bottom 8 inches of the seam. With respect to sulfur and ash, it is suggested that the top and bottom sections of the Pittsburgh coal may reflect both a syngenetic and epigenetic origin. Present data support the belief that paleotopography controlled Pittsburgh seam deposition. Evidence is presented to show that channels were cut at various times into the semilithified sediments that buried the Pittsburgh seam. In this channeling process, portions of the Pittsburgh coal may have been eroded away. Following channel development, the lower part of the Pittsburgh sandstone filled the complex system of braided channels to produce the "want areas" encountered in present mining operations. In localized areas of the Pittsburgh seam, impingement of Pittsburgh sandstone may be responsible for the lateral displacement of the coal. Information of this type becomes important in the assessment of exploration data, in the development of a quality control system for mine output, and in mine life planning.

Jan 1, 1974

Although the technology involved in removing material from below the earth's surface has a long history, communication systems in underground workings are relatively new to the industry. Communication equipment did not begin appearing in underground mines until the early 1900's. Figure 1-1 shows a miner using a Western Electric standard telephone set for underground mines in 1913. These early phones were essentially the same as those used aboveground, except that they were enclosed in cast-iron boxes as protection against moisture, acid fumes, and gases. In the 1950's, the Chesapeake and Potomac Telephone Co. of West Virginia introduced a telephone set for use in explosive atmospheres that was designed around the philosophy of explosion containment. To contain an explosion within the telephone set required a 39-pound casing, which greatly limited portability. [ ] Both of these telephone sets required "pipe" or conduit, not a very practical item for a 100-squaremile coal mine. A common thread prevalent in the first 40 years of design and development is that the primary effort was placed on the telephone set. In the early 19701s, as work began on the design of modern communication systems for use in underground mine environments, the following requirements were established: 1. Must meet intrinsic safety standards .--This applies not only to coal mines, but to other explosive environments. 2. Must be compatible with the environment.--The system must with- stand dust, moisture, and corrosive conditions. 3. Must be rugged in structure.-- The system must withstand maintenance by 10-inch pliers and 4-pound hammers, as well as impact from a falling piece of roof. 4. Must be size-flexible.--Whatever is built must be sized for the small operator as well as the large companies. 5. Must be a total system in design.--The system must be intrinsically safe, including cable, power supply, and station set. 6. Must work with present telephone system.--The system should be compatible with aboveground communications already in place; it should not be the single cause of change in aboveground communications. 7. Value-added pricing.--The system should be reasonably priced so that savings created by its introduction will more than offset the installation cost.

Jan 1, 1984

By G. B. Shea

The accident experience of the California petroleum industry for 1927 was characterized by a decrease it .the number of fatalities. The year closed with a total of 41 fatal accidents, as compared with a total of 54 for the preceding year. 3 In percentage, the figure for 1927 represents a decrease of 24 per cent from that of 1926 and evidences the promising results of organized safety work, in which the industry in California has taken an absorbing interest. The percentage of decrease for 1927 is the largest recorded in any one year since the compilation of the fatality record in the California petroleum industry was begun. Although good progress has been made during the past few years, much remains to be done to reduce still further the human and economic waste caused by accidents. This review is intended to show the employee, as well as the employer, the proximate and contributing cause of accidents. To increase the value of the report, preventive measures in various instances are suggested, on the theory that accidents of a similar nature will occur unless remedial action in taken to remove the cause.

Jan 1, 1928

By Peter F. Strong, Robert L. Lagace, Alfred G. Emslie

This paper is concerned with the theoretical study of UHF radio communication in coal mines, with particular reference to the rate of loss of signal strength along a tunnel, and from one tunnel to another around a comer. Of prime interest are the nature of the propagation mechanism and the prediction of the radio frequency that propagates with the smallest loss. Our theoretical results are compared with measurements made by Collins Radio Co. This work was conducted as part of the Pittsburgh Mining and Safety Research Center's investigation of new ways to reach and extend two-way communications to the key individuals that are highly mobile within the sections and haulage ways of coal mines.

Jan 1, 1973

By John C. Edwards

Chapman-Jouguet detonation calculations were carried out for pentaerythri-tol tetranitrate (PETN), TNT, and ammonium nitrate-fuel oil (AN-FO) explosives using the compressibility form of an equation of state of hard spheres based upon Percus-Yevick (PY) theory, and a chemical equilibrium detonation code called TIGER. Similar calculations were also carried out with the Becker-Kistiakowsky-Wilson (BKW) equation of state. For PETN, the BKW equation gives somewhat better agreement with experimental values of detonation velocity and pressure. However, in terms of experimental temperatures and concentrations of the minor product species (NO), the predictions of the PY equation are shown to be more satisfactory. Similar comparisons of experimental and theoretical results for TNT and AN-FO indicate that the PY equation has general utility in predicting the detonation properties of condensed explosives at moderate loading densities (Po < 1.3 g/cm3).

Jan 1, 1974

By G. W. Eiger

Bureau of Mines laboratory tests show that ilmenite concentrates with titanium dioxide contents as low as 33 wt--pct can be beneficiated to produce a crystalline substitute for natural rutile suitable for direct chlorination. The synthesized product prepared by a three-step procedure was comparable with natural rutile in titanium content. Reduction smelting of ilmenite removes iron as a pig iron byproduct, and the remaining slag phase is greatly enriched in titanium. Oxidation of the slag in the presence of phosphorus¬bearing slag additive converts the titanium-bearing phases to discrete rutile crystals and a glass phase containing most of the associated impurities. Rutile is separated from the glassy impurities by attrition scrubbing ground slag in dilute phosphoric or sulfuric acid solutions. Tests made in a laboratory fluid-bed reactor show that synthetic rutile responds to chlorination at the same rate as natural rutile and that more than 95 pct of the titanium contained in the feedstock was extracted as titanium tetrachloride.

Jan 1, 1974

By Raymond M. Kacmar

This report presents the Bureau of Mines research on the hardware reliability prediction for two Bureau monitoring projects. The basic concepts of reliability predictions are introduced along with the reliability models and assumptions used for this particular evaluation. The results of the reliability predictions are for ground-fixed and naval-sheltered environments.

Jan 1, 1986

Reduce longwall equipment transfer time between panels by utilizing a predriven recovery room, and thus eliminate the premove preparation associated with most equipment recovery methods. Background and Approach The recovery point for a retreating longwall is a predetermined position near the end of the panel where mining is terminated and equipment is disassembled and removed. However, to prepare for equipment removal at the recovery point, bolting and wire meshing arc required before the recovery point is reached. Usually, preparations for equipment recovery begin about 35 ft from the recovery point, significantly impeding the normal rate of advance of the longwall and, consequently, production. Recently, BethEnergy Mines, Inc., and the Bureau of Mines cooperated to evaluate the applicability of utilizing predriven recovery rooms to improve longwall equipment recovery. A predriven recovery room is an entry driven parallel to the longwall face at the end of the panel, having standard dimensions (for that particular mine) and supported with bolts, wire mesh, and supplemental support. The preparation of this entry is completed before it experiences mining-induced effects from the approaching longwall face. This enables the face to continue to mine at its normal rate of advance until the panel is completed. The supplemental support is required to control the loads imposed by the front abutment and is the most vital component of the recovery room.

Jan 1, 1989