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By H. S. Hardman, G. T. Adams, Will H. Goghill

"Usually a newly developed machine leaves the factory ""on a wing and a prayer."" The manufacturer hopes that the operator will hasten to report defects. In turn, when the suggestions arrive the manufacturer makes the required changes and maintains close collaboration with the operator. Thus the history of our machines of today is written.Laboratory concentration tables are exceptions to growth by experiment and collaboration. Their operation never enters directly into the cost sheet; they are seldom used for longer periods than 10 minutes; and the experimenter, while hurrying to another job, accepts the table, good or bad, for a quick test on his ore. Thus we go back about 50 years when we use the preset in factory-built laboratory table.The Southern Experiment Station, Bureau of Mines, in cooperation with the University of Alabama, recognized the existence of a tabling problem net usually considered. That is, instead of using the table to test the ore, the ore was used to test the table. In this critical examination of laboratory table six defects were encountered (and remedied). They are:"

Oct 1, 1945

By L. C. IlsLey

From time to time the Bureau of Mines has issued publications dealing with the various classes of explosion-proof mining machinery that have been tested and approved as permissible for use in mines having atmospheres that may become inflammable by reason of the inadvertent presence of gas or dust. These publications are confined almost entirely to description of the features contributing directly or indirectly to the prevention of explosion or shock hazards, and are intended to give inspectors, safety engineers, and others already familiar with the general safety requirements more detailed information on the safety features of the design of a particular machine. As a background for papers describing permissible machines and to avoid the necessity of duplicating descriptions of methods of conducting investigations and tests of such machinery, Bureau of Mines Bulletin 305, Inspection and Testing of Mine-Type Electrical Equipment for Permissibility, was pub¬lished in 1929. Three bulletins giving detailed descriptions of the three most numerous types of machines have been issued, viz., Bulletin 313, Permissible Storage-Battery Locomotive and Power Trucks. Bulletin 343, Permissible Coal-Handling Equipment. Bulletin 392, Permissible Coal-Cutting Equipment.

Jan 1, 1937

By Oliver Bowles

Wire saws have been used for many years in European travertine, marble, and slate quarries. This method of sawing found very limited use in America until 1927 when it was accepted as standard equipment in elate quarries in Pennsylvania where it has been remarkably successful. Details of its operation in slate have been published in a recent bureau report.3 The very limited extent to which the wire saw has been employed in limestone and marble quarries in the United States and the seeming lack of interest even in experimental work to determine its advantages are difficult to explain in vied of its wide use in cutting similar rocks in Europe and its unquestionable advantages in sewing slate in America. In order to encourage improvement in quarry practice the United States Bureau of Mines has endeavored to obtain information as to the extent to which wire saws are used in Europe together with data on the rate and cost of sawing. The information at hand is by no means complete either in territory covered or in details of operation; it nevertheless brings out certain significant features that may be of interest and advantage to quarrymen in the United States.

Jan 1, 1931

By Dean H. Ambrose

The U.S. Bureau of Mines recently developed computer graphics simulations to characterize mining scenarios, specifically for room-and-pillar mining operations in a three-entry longwall development section. These simulations compare productivity between shuttle car and continuous haulage systems concepts. One of the continuous haulage systems concepts has bolting capabilities that supplement haulage function. Simulations showed the continuous haulage system to be more time efficient than the shuttle car system. Researchers can reuse the simulation code (e.g., mining rates and equipment capacities can be changed) should investigators care to compare production of other mining scenarios. computer simulation, found computer model modification flaws and mining scenario conceptual errors. The fundamental rationale for three-dimensional computer is to cheaply, easily, and quickly obtain information about operation and of a current or proposed mechanical coal or metal/nonmetal mining system. This report documents the computer graphics model and simulation developments and discusses some of the results and observations from the simulations.

Jan 1, 1994

By L. C. IlsLey

Figure 1 is a reproduction of a chart recently prepared by the Bureau of Mines at its Pittsburgh Laboratory to show the Bureau's approval work in connection with electrically operated mining equipment. Nearly 27 years of approval work, covering 346 approved units, are shown on this chart. These approvals are arranged according to year of approval and the manufacturer to whom approval was granted. Forty-five manufacturers are represented, and a scheme of using various colored tabs permits the following subdivision of the equipment: Cutting machines, loading machines, conveyors, battery-operated locomotives, battery-operated power trucks, drills and drilling machines, rock-lusting machines, pumps, room hoists, air compressors,, and miscellaneous, The greatest number of approvals granted to a single manufacturer is 80; the next highest is 65, and the third is 49. Several manufacturers have been granted only a single approval. The chart shows all approvals granted for, motored equipment. Some of these units have since become obsolete, and a few are used to a very limited, extent if at all.

Jan 1, 1941

By A. W. Ambrose

"A need exists for men in oil-field production work who correspond to the mining engineer of a large mining property. Some oil companies prefer to call such an employee a resident geologist, resident engineer, or a petroleum technologist. He should perhaps be more correctly termed a petroleum production engineer. The duty of such a man is to apply his scientific and geologic training practically to oil-field development work.He should be, by education, a mining, civil, or mechanical engineer, with a knowledge of geology and chemistry. Upon completion of his education, such a man should spend several years in the oil-fields. There are two means of gaining proper experience. The first method is to work for an oil company in making a detailed study of each well, collecting data on the history and production, followed by a preparation of good records, from which well logs can be prepared. From the well logs, the geologic cross-sections, peg-models, and structure contour maps can be made. These allow a comparable, detailed study of each well, which is necessary to solve many of the problems. Along with this the engineer should visit drilling wells daily for collection of samples of formations and for a proper study of how they drill. He should form friendly relations with the drillers and production foremen. The second method of gaining proper experience is to start work as a roustabout, pumper, or on the pipe¬line gang, finally working up to a tool-dresser. After three or four years of such work, the engineer may be classed as a petroleum production engineer."

Jan 1, 1920

By Thomas A. Morgan, Louis A. Panek

This report describes a method for determining the stress in rock based on a requirement for static equilibrium ; namely , that the total load on a sufficiently large area must remain constant even after a drift or stope is mined in the area . The method is based on mathematical relationships that are independent of the elastic properties of the rock and the stress distribution near the underground opening . In addition to determining the preexisting stress (before mining ) , the method described can be used to determine the change in stress due to mining .

Jan 1, 1963

By Richard H. Oitto

The Bureau of Mines and Kaiser Steel Corp. are cooperatively demonstrating the shield-type roof support in the longwall mining of a 10-1/2-foot-thick coalbed at the York Canyon mine near Raton, N. Mex. As part of the demonstration, the shield supports have been successfully and safely moved from a completed longwall face to a new longwall face. When these shield supports were moved in 1976 they were the largest and heaviest longwall support system in use in U.S. coal mines. The shield supports, preparations for moving them, the actual move, and installation at the new face are discussed.

Jan 1, 1977

By C. Pritchard

John Marks said in his acceptance of the Hartman Award in 2008, "I guess that without the occasional complaint, your mine is probably over-ventilated" (Marks, 2008). Miners are seldom in this situation and spend much of the time trying to find enough air to keep an operation running. With examination, there are usually changes that can be made to increase the efficiency of ventilation systems. Mine ventilation air is a costly commodity, especially by the time it has been heated or cooled and moved to the bottom of the shaft and through the mine airways. Modifications that result in surplus mine ventilation air could bring financial and environmental benefits. Some issues mine operators have needed to address recently are increased airflow requirements to dilute diesel particulates in metal and nonmetal mines, to ventilate reserves that are deeper, hotter, and further away from fans and shafts, and to meet demands from increased production. This paper discusses successful methods to find additional usable air when there is no extra ventilation capacity. Most of the options presented in this paper are useful for metal/ nonmetal operations but some may be applicable to coal as well.

Jan 1, 2010

By H. B. Brunot, L. C. IlsLey

The chief object of the Electrical Section of the United States Bureau of Mines is the study of causes and means of preventing accidents resulting from the use of electricity in mines . A large part of this work for the last 20 years has been the inspection and testing of mining equipment under the provisions of schedules which give the minimum requirements considered essential for the safety of equipment intended for use at or near the working faces of dusty or gassy mines . During the first few years of this work , particular attention was paid to the explosionproof features of the various accessories such as motors , controllers , and other parts . The knowledge of the essentials necessary for safe designs of enclosures has since been augmented by field experience and by data obtained in testing a large number and variety of designs . With our present knowledge it would seem that a disproportionate stress was placed on making the various enclosures explosionproof , but not enough thought was given to the danger from wiring and connections outside of explosionproof enclosures . The list of equipment that has met minimum requirements for safety and has been approved as permissible by the Bureau of Mines includes storage - battery locomotives , power trucks , drills , loading machines , conveyors , cutting machines , room hoists , pumps , concrete mixers , and rock-dusting machines . The wiring on some of the machines is comparatively simple and sometimes , except for the trailing cable , may be entirely within the explosionproof enclosures . In general , there is outside wiring between enclosures , and on the larger machines the wiring may be extensive and complicated . In considering the safety of wiring for mining machinery , attention must be given the severe service and unfavorable surroundings imposed by mining conditions . Some of the matters that require consideration are : ground . The lack of care of the exterior wiring to be expected in the average mine . The lack of adequate periodic inspection of the wiring . The absence of adequate facilities for satisfactory inspection and repairs under- The severe conditions of moisture , dirt , mechanical injury , and low voltage encountered in mining service .

Apr 1, 1931

By G. L. Hopps

Various chemicals, including compounds of copper and lead, were added to a mixture of No. 2 and No. 6 fuel oils that was fired in an experimental furnace. Tests were made to determine (1) the effectiveness of these chemicals in removing soot deposits on probes devised to simulate heat-transfer surfaces in boilers and (2) the effectiveness of the chemicals in preventing the deposition of soot on the probe surface. Test conditions were regulated so that the temperature of the products of combustion adjacent to the probes was in the range of 625° to 700° F. The clean-metal temperatures of the air-cooled probes were comparable with the water-tube temperatures in boilers operated at 40 to 100 p.s,i.g. The dosages of the fuel oil additives used in these tests were generally larger than those usually recommended for most proprietary compounds.

Jan 1, 1962

Utilize innovative processing technology to prepare high-purity, ultrafine advanced ceramic powders with little or no contamination occurring during the milling process. Advanced ceramic materials made from these powders could substitute for high-temperature alloys containing critical materials such as chromium, cobalt, and nickel. Approach Modify and evaluate the Bureau's turbomill, developed earlier to grind a variety of ceramic raw materials (clay, mica, and talc), as a milling or size-reduction technique for hard and abrasive advanced ceramic powders, such as silicon carbide. Background Powders for producing ceramic materials, such as silicon carbide. silicon nitride, alumina, and zirconia, which arc being considered for use in severe applications requiring high-temperature and/or corrosion resistance, are very difficult to reduce to fine sizes for processing into finished parts. Traditional techniques of particle size reduction, such as ball milling and jet milling, are very energy intensive and/or slow. These traditional techniques often produce materials that have a nonuniform particle size distribution and are contaminated by the milling media or container.

Jan 1, 1989

Develop and evaluate a mechanical position and heading system (MPHS) that provides information about underground mining machine position and heading to aid in the remote positioning of mining machines during face maneuvers. Background While great improvements have been made in mineworker safety, progressive technology continues to create a safer, better working environment for miners by keeping them away from the dangerous face area. In maintaining such high standards of safety, the Bureau is investigating remote, computer-assisted operation of mining systems for underground, highwall, and surface mining applications. A key component of computer-assisted operation is a guidance system. Since there are no guidance systems on any commercial continuous mining machines, the Bureau itself developed and tested the mechanical position and heading system (MPHS). The MPHS is based on linear position transducers (LPT's), and operates on principles of triangulation to provide machine position (xy coordinate), and orientation in the xy plane (yaw or heading). These data are needed in order to keep the continuous mining machine in proper alignment before and during the cutting cycle. The MPHS theory development is in three parts: characterize the sensors used and their configuration; select and define the navigation reference frames; and derive a closed-form solution for determining the position and beading from sensor information. Application of the MPHS theory required the development of hardware, software, and system interfaces.

Jan 1, 1992

By L. C. IlsLey

From time to time the Bureau of Mines has issued publications dealing with the various classes of explosion-proof mining machinery that have been tested and approved as permissible for use in mines having atmospheres that may become inflammable by reason of the inadvertent presence of gas or dust. These publications are confined almost entirely to description of the features contributing directly or indirectly to the prevention of explosion or shock hazards, and are intended to give inspectors, safety engineers, and others already familiar with the general safety requirements more detailed information on the safety features of the design of a particular machine. As a background for papers describing permissible machines and to avoid the necessity of duplicating descriptions of methods of conducting investigations and tests of such machinery, Bureau of Mines Bulletin 305, Inspection and Testing of Mine-Type Electrical Equipment for Permissibility, was published in 1929. Three bulletins giving detailed descriptions of the three most numerous types of machines have been issued, viz., Bulletin 313, Permissible Storage-Battery Locomotive and power Trucks. Bulletin 343, Permissible Coal-Handling Equipment. Bulletin 382, Permissible Coal-Cutting Equipment.

Jan 1, 1937

By John J. Sammarco

The functional safety of programmable electronic (PE) mining systems is an international issue and concern. From 1995 to 2001, 11 PE-related mining incidents in the U.S. were reported by the Mine Safety and Health Administration (MSHA); 71 PE-related mining incidents were reported in Australia. MSHA does not have regulations for formal evaluations of the functional safety of PE mining systems. Hence, the National Institute for Occupational Safety and Health (NIOSH), in partnership with MSHA and the industry, generated the NIOSH safety framework for functional safety of PE mining systems. An overview of the NIOSH framework is given; the key framework elements, the safety life cycle and safety integrity levels are detailed. The safety framework approach has impacted the national and Australian mining industries by enabling the industries to advance from an ad-hoc approach to a formalized and systematic functional safety process. In retrospect, valuable lessons were learned for addressing functional safety and for changing industry perspectives and practices. These lessons continue to benefit mining and are applicable to other industries as well.

By F. W. Hoertel

Tungsten from the hydrogen reduction of WF was vapor - deposited to coat MERM (Material Evaluation Rocket Motor ) graphite and rhenium- lined graphite nozzles . These nozzles have surface configurations that preclude the conventional fabrication of high- density- tungsten liners . Operation at 550 ° C produced selectively placed uniform coatings of specified thicknesses at near theoretical density . An acceptable coating could not be deposited on a beryllia nozzle because of an undesirable side reaction between the substrate and one or more of the products of the reduction reaction .

Jan 1, 1964

By Jeffrey S. Walker

Abandoned underground mine openings are susceptible to collapse because of the mining methods used, the character of the overburden, and the typically large, wide entries with minimal roof support. The final effect of the collapse of the underground workings is surface subsidence. To reduce the probability of subsidence, methods to backfill the mine void with various types of materials have been developed. This U.S. Bureau of Mines report describes the available technologies for subsidence abatement and discusses their operation and application. The basis of these abatement methods is the replacement of the mined material with mine waste. Backfilling of mine voids is the most common method of stabilization used to abate subsidence and protect surface structures. Hydraulic flushing and grouting, using remote methods from single or multiple boreholes, are the most often-used methods for the placement of backfill material. Other subsidence abatement techniques are available and may be more appropriate under different conditions. These other techniques include pneumatic stowing, either by in-mine or remote methods, and various point support methods that do not completely fill the mine void and are used for the protection of small areas of the land surface and surface structures.

Jan 1, 1993

By Fred N. Kissell

This U.S. Bureau of Mines report is a guide for the control of air contaminants during tunnel construction. Topics discussed are calculating air quantity requirements, types of ventilation systems, planning ventilation systems, control of methane gas, control of dust, control of diesel emission, ventilation to remove blasting fumes, measuring airflow, and measuring gases. This report does not provide detailed design information, but seeks to answer practical questions on air contamination issues.

Jan 1, 1995

By R. V. Ramani, K. Bode

"IntroductionThe theory of particle dispersion and deposition in turbulent flow is important to many fields of science and engineering. Dispersion has been studied in some detail since the early fifties (Taylor, 1954; Fischer, 1967; Osipov and Grekov, 1968; Skobunov, 1970 and 1973; Klebanov and Martynyuk, 1974). A broad research effort has also been underway in studying the mechanics of dry particle deposition. Friedlander and Johnstone (1957) proposed a theory, according to which particle deposition from vertical pipe flow could be described by an eddy diffusion transport followed by a final flight to the surface. There have been numerous revisions and additions to this original theory (Owen, 1960; Liu and Agarwal, 1974; Liu and llori, 1974; El-Shobokshy and Ismael, 1980) The mining process essentially consists of breaking in situ materials and transporting them out of the mine. An inherent characteristic of this process is the generation of fine particles. Fine airborne particulates are associated with a number of threats to the health of the miners; fine coal dust can also result in mine-wide catastrophic incidents such as dust explosions. For these and other reasons, it is important to understand the behaviour of airborne dust particulates, particularly their generation, entrainment, transport, dispersion, and deposition in the mine environment for their control.Mine related studies on dispersion and deposition have been few. Yet, several studies of gas and dust dispersion, diesel exhaust contamination, and methane ingress into mine workings have recognized the need for developing reliable parameter values for fundamental understanding of the phenomena (Da""Yes and Slack, 1954; Hodkinson, 1957; Hodkinson and leach, 1958; Mass and Wildschut, 1966; Airey, 1969; Courtney et al., 1986; Stefanko, Ramani, and Thakur, 1974; Stefanko, Ramani and Kenzy, 1977; Bhaskar, 1987, Bhaskar and Ramani 1990; Qin and Ramani, 1989; Shankar and Ramani, 1990)."

Dec 1, 1995

By W. G. Bradley

THIS PAPER describing the quarrying, mining, and crushing of gypsum at the Blue Diamond mine, 11 miles from Arden, Nev., on the Union Pacific Railway, is one of a series on gypsum mining being prepared for and published by the Bureau of Mines. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total costs. It is recognized that publication of total production costs might in some instances cause embarrassment to individual producers as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue.

Jan 1, 1932