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By D. Harrington

"The fire boss in coal mining and the shift boss in metal mining, though held responsible to a large extent for safety of underground employees and of the mine, are, it seems to me, not always vested with sufficient authority nor given compensation commensurate with their duties. The metal-mine shift boss, although his position as regards his relations between employer and employee, is frequently an unenviable one, has as a rule much more authority than the fire boss and is not expected to perform the menial tasks required of the latter by many coal-mining companies.In most coal-mining States the coal-mine foreman and the fire boss are re¬quired to possess a certificate of competency obtained by passing an examination. The foreman is legally responsible for the safety of the miners, as in most instances the superintendent is not required to pass an examination. Although the foreman is held legally responsible for the safety of the miners, the law does not, in general, compel the superintendent or other higher officials to delegate sufficient authority to the foreman to enable him to put his wishes or judgment into effect; and this condition has tended in many instances towards perpetuation of unsafe conditions.The fire boss is held legally responsible for conditions in his ""beat"", but he is generally given only such authority as the mine foreman sees fit to delegate, frequently very little, Moreover, the fire boss is generally required to cover his ""beat"" within two hours before the entrance of the underground workers. Only too often his territory is so great that in order to reach all the working faces and chalk the required date at the face, he must travel at a rapid walk or even run. When such haste is necessary to cover the required ground, it is manifestly im¬possible for the fire boss to make a careful inspection or examination of the roof, timbering, wiring, gas, etc., at each place, and doubtless in his hurry many unsafe conditions escape his notice."

Sep 1, 1920

Develop a method to evaluate the effectiveness of coal scam fire surface seals so that potential problems may be corrected at an early stage, before the integrity of the surface seal is lost. Background Surface seals are the primary coal seam fire abatement method being used in the western United States. Surface seals smother a fire by denying it oxygen. The seal is usually constructed by placing a mantle of soil, four to ton feet thick, over a coal scam fire area to exclude air from the fire. The soil is compacted to increase effectiveness, and a soil cement may be used to augment the soil. In some cases, burning coal may be excavated and separately smothered or otherwise extinguished in another area; in other cases, a trench maybe excavated and backfilled with incombustible material to isolate a fire. More often, a surface seal is simply applied over and around the entire known burning area. In the 1950's, the Bureau of Mines administered a large program to treat numerous coal seam Fires across the western United States. Methods used in this program were described in Bureau of Mines Information Circular (IC) 7932, dated 1959. More recently however, various coal seam fires have been treated with surface seals under the direction of state Abandoned Mine Land Reclamation authorities. It has frequently taken years to evaluate the effectiveness of surface seals. By the time problems become evident, it has often been too late to take corrective action within the scope of the original abatement project. For this reason, the Bureau of Mines developed a means for tracking temperature trends at coal seam fire projects to obtain a better and earlier handle on the effectiveness of surface seals.

Jan 1, 1991

By Van E. Shaw

Fusion of an 86-percent euxenite concentrate with ammonium sulfate was investigated by the Bureau of Mines. Reaction for 4 hours at 400° C results in conversion of both the rare-earth elements and the titanium-columbium components to water-soluble compounds. Similar results are obtained with ammonium bisulfate. Stirring the fusion mass decreases the reaction time substantially. Alternatively, treating the fusion product with a 3-hour, 650° C calcining step renders the non-rare-earth constituents insoluble, thereby allowing selective leaching of a pure rare-earth fraction with an overall yield of 97 percent.

Jan 1, 1967

Provide the mining industry with a method for determining the gas content of ore bodies and associated strata for use in mine planning, Approach Samples of various rock types are collected and tested to determine gas content in conjunction with sample size, the collection method (i.e. whether the sample was collected from a core sample or by hand) mine gas emission, and the geologic location from which the sample was taken, such as near a fault, outburst area, or other geologic anomaly. How It Works Two methods were developed by the Bureau of Mines to determine the gas contents of rock samples. The first method developed involved dissolving minerals to measure gas emission. This method, however, can only be used with soluble minerals. A second method, therefore, was developed for use with insoluble minerals. With this method, the sample is crushed in a ball mill. Although the dissolution method is faster and more accurate to use, the crushing method is also advantageous because its use can more closely approximate a mining situation; the sample is crushed as in mining and the amount of gas released relates to the amount of gas that would be released during a mining operation. The dissolution method is applied to soluble minerals, such as rock, salt, or trona, in a sealed chamber. Gases released during dissolution are collected for analysis by gas chromatography. One advantage in using the dissolution method is that the test apparatus is relatively inexpensive. In addition, test can be performed at any scale, from single crystal samples to a solution mining operation.

Jan 1, 1983

Improve surface mine haul-age truck safety and efficiency by providing a means for sensing the weight and distribution of the truck's load. Approach The safety hazards and the economic implications of overloading mine-haulage trucks were analyzed to determine the net effect of that practice on mine operations. The analysis indicated that: Ten to 25 pct overloading is typical; Higher haulage, tire, and maintenance costs occur due to overloading (a 20 pct overload was estimated to increase operating costs 7 pct per ton); Ten to 15 pct of haulage? truck injuries and fatalities are attributable to overload conditions, at a cost over one million dollars per year to the mining industry. Vehicle-weighing technology that conformed to the performance specification for an off-highway haulage truck overload detection system was selected for in-mine testing. How It Works Normally, volumetric estimates are made during the loading sequence which do not account for the varying ore density. Hence, the actual weight of a load is never precisely known. By providing a precise measurement, an overload detection system will not only indicate vehicle overloading, but will also show under-utilization of the truck. One system tested by the Bureau of Mines was the ?Load Analyzer" manufactured by Pactronics Corporation in California. This system consists of a meter-type analog readout for the cab console and three "Electrosensors" (linear variable differential transformers) attached to the main frame. Using conventional welding and brazing techniques, two sensors are attached between the front members of the engine sub-frame and the top of the left and right trailing arms (one sensor per arm). The same techniques are used to attach the third sensor to the rear centerline of the truck. between the main frame cross member and the A-frame. The readout unit on the cab console indicates by color-coding whether each sensor loading is under (green), at (yellow), or over (red) the pre-set rated load. The three-sensor configuration with in-dependent readouts also detects uneven distribution of the load.

Jan 1, 1984

To provide accurate navigation and control of continuous mining systems.

Jan 1, 1996

By Wesley A. Grosh

The Sutherland copper prospect is situated in Floyd County, Va. The immediate area was prospected around 1850, and one of the adits possibly dates from that time. Little or no ore has been mined from the deposit. The deposit is a mineralized sulfide zone occurring in mica schist and consisting mostly of pyrrhotite with minor amount of copper. A magnetometer survey of the deposit by the American Metal Co. in 1939 showed an anomaly that was thought to indicate a zone: of secondary enrichment. The Bureau of Mines diamond-drilled 14 holes, totaling 913 feet, and opened an adit during February and March 1943. No appreciable copper values or indications of secondary enrichment were found.

Jan 1, 1948

To minimize the equipment operator?s respirable dust exposure in enclosed cabs of mobile equipment by install-ing cab filtration and pressurization systems and by keep-ing doors and windows closed. Background Enclosed cabs are used on mobile equipment to protect operators from health and safety hazards. The primary health concern is overexposure to respirable dust. Examples of such equipment in mining include drills, dozers, haul trucks, and other equipment. When equipment is new, the operator?s dust exposure is normally at acceptable levels. As the equipment ages and gaskets and seals deteriorate, the air quality inside an enclosed cab can reach a point where it is no longer at acceptable levels for the equipment operators. In an effort to improve the air quality in enclosed cabs of older mining equipment, NIOSH has been performing research to retrofit cabs with new filtration and pressurization systems. Over the past few years, this research has shown that retrofit systems can substantially improve the cab?s air quality back to safe and acceptable levels. How-ever, this is only possible when a positive cab pressure is achieved and maintained. Thus, when a cab door or window is opened, the cab pressure drops to zero and the cab filtration and pressurization system is rendered ineffective. During a recent field study, the magnitude of this impact was noted when a drill operator repeatedly opened the cab door throughout the course of the drill cycle. Upon closer examination, it was determined that the cab door was being opened to manually guide the next drill steel into place each time an additional section of steel was needed to drill deeper holes.

Sep 1, 2008

By Fred N. Kissell, J. E. Matta, J. C. LaScola

The Bureau of Mines made laboratory absorption measurements on oil shale samples, which showed that the amount of methane absorbed is proportional to pressure and oil yield, and can be much larger than would be predicted based solely on porosity. Oil shale cores collected in the field were also measured for their gas content using the Bureau of Mines direct method, Cores taken from deep locations and far from outcrops yielded more gas than cores from shallower locations or at outcrops, when taking into account variations in oil yield, and all data indicate that oil shale mines that are both deep and far from an out- crop will emit low levels of methane gas.

Jan 1, 1977

By C. K. Man

Coal dust explosions are routinely conducted within the full-scale experimental mine at the National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory?s (PRL) Lake Lynn Experimental Mine (LLEM) to meet the needs of numerous safety and health research programs. Many of these explosion tests over the years involved igniting different coal dust and limestone rock dust mixtures (up to 80% by volume rock dust). Following four more recent tests, floor dust samples have been collected and analyzed using the alcohol coking test and scanning electron microscopy (SEM) and the results compared to estimate the flame travel.

Jan 1, 2009

By R. A. Friedel

Data on compositions of natural substances are important in the study of possible interrelationships. The similarity of the low molecular weight alkane isomers from crude oil and Fischer-Tropsch catalytic synthesis product has been reported (8).3 A similar composition for the alkane isomers from high-temperature coal carbonization has been found. The composition of the C4 to C 7 alkane isomers from these three sources can be calculated quantitatively with the equations previously developed to calculate alkane isomers in Fischer-Tropsch product. An KM sting reversal of the concentrations of the monomethyl isomers from C6(2 Me > 3 Me) to C7 (3 Me > 2 Me) occurs in all three products; fragmentary comparisons at higher carbon numbers indicate some dissimilarities. Naphthene isomers in the C6 to C7 range for crude oil and high-temperature coal carbonization also have similar compositions. Aliphatic hydrocarbons from low-temperature coal carbonization processes are considerably different, consisting mainly of normal alkanes.

Jan 1, 1968

By A. Z. Dimitroff, A. C. Moschetti

An improvised rock- dust disseminator, consisting of a 10-gallon galvanized metal milk can that dispenses rock dust in return air currents by the injection of compressed air has reduced the float dust explosion hazards at the Koehler coal mine, Koehler, N. Mex.

Jun 23, 1964

By Edward W. Parsons

The explosive-expansion center-hole anchor was designed and developed for the specific purpose of use as a component of an instrument system that measures differential ground movement within a small drill hole in rock. Such anchors should have an unobstructed center hole, should be installed without a twisting action which could tangle connecting wires, and should be capable of being installed at depths in excess of 100 feet. The anchor has a thick-walled center tube and a thin-walled outer tube. Low-energy detonating cord, wrapped around the center tube and detonated with a mild end primer, expands the outer tube to produce anchorage. The explosive-expansion center-hole anchor can be installed easily in drill holes of any inclination but cannot be installed under water. Centering of the anchor is critical with regard to its subsequent holding power. The anchor is safe to make and handle.

Jan 1, 1965

By Charles E. Munroe

"It has been recently learned that certain foreign manufacturers are offering far importation into this country detonators at greatly reduced prices, some of these detonators being of such low grade (No.4), that their use would greatly increase the dangers in blasting.Detonators and electric detonators are used in initiating the explosion of the various high explosives that are now so extensively employed in a great variety of mining operations. Originally a large number of different grades (or ""strengths"") of detonators and electric detonators were marketed, the grade number indicating the weight of the charge of fulminating material contained in the copper case of the detonator. As late as 1914, a report of the Bureau of Mines (Bulletin 80, A primer an explosives for metal miners) shows that grades Nos. 3, 4, 5, 6, 7, and 8, containing from 0.54 to 2.00 grams each, were being offered for use. However, the writer bad observed as early as 1896, when the more insensitive types of explosives like nitro-substitution explosives began to be introduced for use in mining and other blasting operations, that use of a high-grade detonator was essential to insure certainty of discharge."

Mar 1, 1921

Objective: To enable mine operators and mine inspectors to make quick and accurate measurements of the explosible nature of coal and rock dust mixtures.

Jul 1, 2008

By D. B. Dow

"In the natural-gas Gasoline industry, the methods used in determining the amount of gasoline in natural gas are many and varied; they include the specific-gravity test, laboratory tests involving absorption, charge in volume of the gas or in the absorption medium, absorption in charcoal with subsequent distillation, compression of the gas which results in the condensation of the gasoline, and the absorption of the gasoline vapors in an absorption oil, from which the gasoline is distilled and measured. Each of these various tests has advantages, and disadvantages. It is however, conceded in the industry that the tests in which the gasoline is obtained and measured as such are the more reliable.This paper deals with certain factors which should be considered in making absorption tests using ""mineral seal oil"" as an absorbent; this method of testing is widely used not only in the field, but in control work in absorption gasoline plants where the gasoline content of the intake and discharge gas is determined daily. In control work it is frequently found that the plant produces more gasoline than the tests show, which gives the plant the appearance of making more gasoline than is actually present in the gas treated, or in other words operating at more than one hundred per cent efficiency. Obviously then, the tests as made in these cases are in error, and in hope of correcting some of these variances, the following factors have been studied at the U. S. Bureau of Mines petroleum station at Bartlesville, Oklahoma."

Aug 1, 1920

By Robert H. Peters

Are the safety rules in your work place effective? Do supervisors enforce them as they should? Do supervisors abide by these rules? Safety rules are an important aspect of many company safety programs, particularly if employees must work in an intrinsically hazardous environment such as a coal mine. However, for various reasons, supervisors sometimes fail to enforce safety rules (Arvey & Jones, 1985; Hartshorn, 1998). This paper presents some findings obtained from interviews with coal miners about why supervisors sometimes fail to enforce an important mine safety rule. It also contains a few suggestions addressing what could be done to help supervisors perform this job function more effectively.

By Launa Mallett, Charles Vaught, Michael J. Brnich, R. Lincoln Derick

After thoroughly covering the health and safety training subjects required under Title 30, Part 48, of the Code of Federal Regulations (CFR), mine operators often find themselves with little or no time left in the class schedule for other important topics. This paper discusses a technique developed in partnership with RAG Twenty mile Coal Co., Oak Creek, CO, for incorporating employee participation at all levels in fire prevention and safe equipment operation training outside of traditional classrooms. The process involves development of training modules consisting of short, 5- to 7-minute videotapes coupled with toolbox talks that ground the content of the videos within the context of a miner’s workplace.

Jan 1, 2002

By C. M. Mason

A series of gelatinous permissible explosives was prepared with increasing sodium nitrate content and subjected to an improved technique for evaluating incendivity in coal dust-air and coal dust-gas-air mixtures. Those explosives containing an appreciable amount of sodium nitrate were found to be very hazardous in coal dust-air and coal dust-gas-air mixtures.

Jan 1, 1969

By J. L. Ellenberger, P. W. Jeran

A deep longwall coal mine was instrumented with a three-dimensional microseismic system in order to help determine the exact strata mechanics associated with the rock failure, redistribution of stress and the associated gob formation from the longwall. Overall, 5,000 well calibrated seismic events were recorded during the mining of the panel. Analysis of these events showed a close correlation between the seismic activity and advance rate, and that the majority of the recorded seismic activity occurs in the immediate area of the advancing longwall face.