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By J. C. Edwards

Fire experiments were conducted in the Safety Research Coal Mine (SRCM) at the National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory, with coal, diesel-fuel, electrical-cable, conveyor-belt, and metal-cutting fire sources to determine the response of fire sensors to products-of-combustion (POC). Metal oxide semiconductor (MOS) and smoke fire sensors demonstrated an earlier fire detection capability than a CO sensor. This capability was of particular significance for a conveyor-belt fire in which the optical visibility was reduced to 1.52 m with an increase in CO of less than 2 ppm at a distance of 148 m from the fire. Application of a neural-network program to the sensor responses from each type of fire source resulted in correct classifications of coal, diesel-fuel, cable, belt, and metal-cutting combustion with a mean of 96% of the test data correctly classified.

Jan 1, 2000

By J. C. Edwards

Fire experiments were conducted in the Safety Research Coal Mine (SRCM) at the National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory, with coal, diesel-fuel, electrical-cable, conveyor-belt, and metal-cutting fire sources to determine the response of fire sensors to products-of-combustion (POC). Metal oxide semiconductor (MOS) and smoke fire sensors demonstrated an earlier fire detection capability than a CO sensor. This capability was of particular significance for a conveyor-belt fire in which the optical visibility was reduced to 1.52 m with an increase in CO of less than 2 ppm at a distance of 148 m from the fire. Application of a neural-network program to the sensor responses from each type of fire source resulted in correct classifications of coal, diesel-fuel, cable, belt, and metal-cutting combustion with a mean of 96% of the test data correctly classified.

Jan 1, 2000

By C. W. Smith

The Bureau of Mines conducted laboratory beneficiation tests on four samples of waste. granite sludge to devise a method of recovering silicon carbide (SiC). Froth flotation using creosote as a collector in an alkaline circuit resulted in concentrates containing over 91 pct SiC from each of the samples. Recoveries ranged from 43.1 to 86.6 pct. Single-stage flotation of sample A using a column flotation cell produced a concentrate containing 92.0 pct SiC with a recovery of 71.4 pct. Flotation using petroleum sulfonate as a collector in an acid circuit resulted in a concentrate containing 95 pct SiC from one of the waste granite products with a recovery of 97.5 pct .?

Jan 1, 1987

Are you afraid of the dark? Of course not, at least not since you were about six years old, anyway. But early man was - afraid of the dark, and he had good reason to be. Since he had no illumination other than fire and moonlight, he was at a disadvantage when it came to mixing it up with some of his fellow creatures. Sabre-toothed tigers, for example, could probably see quite well In the dark, and they were very real enemies. Sabre-toothed tigers haven't been seen in mining country for some time now; but it's st111 dark In a mine and, make no mistake about it, there are still enemies in the dark. The enemies are all the things that can injure you if they are not seen. Modern mines can be safe places to work for the trained miner who follows good work practices. But there are mining machines that make sabre- toothed tigers look like pussycats, and if you can't see well enough they can be ten times more dangerous.

Jan 1, 1976

By C. H. Elder

An experimental degasification program using a vertical borehole and vacuum pump to drain gas from the gob area of a longwall panel was successful at Bethlehem Mines Corporation, Cambria Division, No. 33 coal mine. Sixty-one million cubic feet of methane has been exhausted during a 9-month period. Daily production time in the panel increased as a result of lower methane levels in the returns. Removal of large quantities of methane in this way and the exclusion of it from the ventilating system will provide reduced cost in mine ventilation and provide a safer environment for the mine.

May 1, 1969

By Thomas V. Falkie, R. Venkataramani

The method of analysis was to test a large model containing potentially significant variables and on the basis of the results obtained, to reduce the model to one containing only the essential significant variables. This stepwise procedure of "scanning" a large proposed model and subsequently condensing the model consisted of two cycles of the same series of computational procedures. Data Preparation A majority of the variables measured were continuous over a specific range of values; for example, the variable "Width Ratio" varied in practice from 0.25 to 1.00. However, "dummy" values were assigned to certain operational variables in order that these varia¬bles would have numerical expression. The following variables were described in this manner. Variable "Dummy" Value x3: Development/Pillaring 0, if pillar extraction was being done 1, if development mining was being done x4: Boxcut/Open Cut 0, if a box cut was being made 1, if an open cut was being made The variables under consideration are represented symbolically as follows: Y: Loading rate (tons per minuts): TONS/MIN x1: Ratio, width of cut/width of cutter: WDRATIO x2: Ratio, height of cut/diameter of cutter: HTRATIO x3: Development or pillaring: D/P

Jan 1, 1972

In 2001, a total of 2,144 coal mining operations reported employment to the Mine Safety and Health Administration (MSHA). Coal mines comprised 14.7% of all mining operations. • Bituminous mines comprised 92.0% (n=1,972) and anthracite mines 8.0% (n=172) of coal mining operations. • More than 71% of coal mines were located in three states: Kentucky (29.5%), West Virginia (21.3%), and Pennsylvania (20.6%).

Apr 1, 2003

By John N. Murphy

In fiscal 1996, the US Congress directed that the US Bureau of Mines (USBM) be closed. Certain functions were reassigned to other agencies. The remaining employees were separated and the unoccupied sites were decommissioned. As a result, 12 locations were closed and about 1,200 employees were terminated in March 1996. About 600 employees at five locations were reassigned to other federal agencies. This article provides a summary of the continuing functions, the agencies involved and the points of contact for each continuing function. The functions that were discontinued are also identified.

By Alex C. Smith, Thomas P. Mucho, John B. Walsh, Alden Ozment, Michael R. Thibou, Michael A. Trevits

The National Institute for Occupational Safety and Health (NIOSH), with US Foam Technologies, Inc. and On Site Gas Systems, Inc., conducted research on the remote application of extinguishing agents with the intent of improving deployment strategies to limit miner exposure and to help ensure the best possible outcome during a mine fire. Full-scale in-mine were conducted at the NIOSH Lake Lynn Experimental Mine to determine the flow characteristics, stability and fire-suppression capability of gas-enhanced foam. The in-mine experimental work was designed to evaluate movement of gas-enhanced foam through mine workings closely simulating an underground coal mine environment and how long gas-enhanced foam would remain stable. This paper presents results of the experiments and provides valuable insight into mine fire deployment strategies for gas-enhanced foam technology.

By Northcutt Ely

Jan 1, 1961

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

B 3 Principle Program Nomenclature The principal variable names used in the computer program are defined below. The following dimensions are applicable, unless otherwise indicated. Distance - Ft Velocity - Ft. /Minute Time - Minute

Jan 1, 1976

To increase awareness of float coal dust explosion hazards in the mining industry.

Jan 4, 2006

By J. S. Peterson, G. P. Cole

The National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Center (PRC), has conducted research to improve electrical fault detection on coal mine direct current (dc) trolley systems. Present circuit breaker protection systems are current-magnitude-based and cannot discern between normal traffic and high resistance electrical faults. Tests were conducted at cooperating mines to assist in developing a neural-network-based detection algorithm for distinguishing between electrical faults and normal operation. The Fast Fourier Transform of the trolley rectifier current signature served as baseline data for the neural network. During field tests, the algorithm performed with greater than 90% accuracy.

By Albert E. Schreck

THIS CHAPTER concerns such minor nonmetals as greensand, meerschaum, mineral wool, staurolite, and wollastonite. GREENSAND Output of greensand (glauconite) was slightly higher than in 1958. Open pits of The Kaylorite Corp. (Calvert County, Md.), National Soil Conservation, Inc. (Burlington County, N.J.), and Inversand Co." (Gloucester County, N.J.) accounted for the entire production. Soil conditioning used about 72 percent of the greensand sold. The remainder was used as a water-softening agent. Prices for greensand, f.o.b. mine, ranged from $13 to $70 per short ton.

Jan 1, 1960

By Thomas L. McVay

The Bureau of Mines made laboratory batch and small-scale continuous flotation tests of a sample of pegmatite rock from a deposit of the Lithium Corporation of America, Inc., near Kings Mountain, N.C., to determine the feasibility of producing commercial-grade spodumene concentrates. Various reagents and flotation procedures were tested to determine the optimum conditions for floating the spodumene and retarding the gangue minerals. The best results were obtained when sodium fluoride and lignin sulfonate were used as the pulp conditioner and oleic acid was used as the spodumene collector. The continuous flotation tests indicated that commercial-grade. spodumene concentrates analyzing 6.4 pct. Li2O could be produced with recovery of 77 pct. of the lithia in the ore.

Jan 1, 1962

By David J. Ellis

The mineral industry of Benin continued to be confined to the production of cement, crude oil, salt, and sand and gravel. Only crude oil and cement were exported, with the value of crude oil exports and cement exports constituting about 20% and 2% of export revenue, respectively. The value of crude oil exports was less than the cost of imports of refined petroleum products. Production of crude oil was unchanged from 1986, averaging 5,500 barrels per day (bbl/d). The Government managed the facilities at the Semé Oilfield while actively seeking a new manager to replace Pan Ocean Oil Co. of Switzerland, whose contract was canceled in 1986. Recoverable reserves of crude oil were estimated to be between 18 and 30 million barrels.

Jan 1, 1989

By John C. LaScola

The Bureau of Mines repeatedly surveyed a grid of monuments over an active longwall mine panel in southwestern Pennsylvania during a 1-year period. Both conventional ground surveying techniques and photogrammetry were used. The objective of this investigation was to compare elevation measurements of subsidence obtained from aerial and ground survey methods under dynamic ground conditions. The results of a statistical analysis of the survey data show that the mean of the differences between 372 matched pairs of elevation measurements was 0.20 ft (61 mm) with a 95-pct-confidence interval of 0.05 ft (15 mm). The mean of the absolute values of the differences was 0.38 ft (116 mm) with a 95-pct-con-fidence interval of 0.04 ft (12 mm). Ninety-five percent of the absolute values of the differences were less than 1.11 ft (338 mm).

Jan 1, 1988

1. PURPOSE The Temporary Face Support System (TFSS) consisting of beams, posts and carrying-emplacing equipment was developed to provide temporary supports between the working face and the permanent roof supports. 2. GENERAL DESCRIPTION The system consists of: ? A Beam And Post Carrier And Deployer (BAPCAD), a self-propelled machine that carries as well as emplaces the beam-and-post sets. ? Lightweight mechanically self-deploying posts designed to safely support a load of 10,000 pounds each. ? Lightweight constant strength beams (bars) capable of sustaining an approximate equally distributed load of 8500 pounds. Note. All referenced figures and drawings are found at the back of this manual.

Jan 1, 1980

By C. B. Manula, R. L. Sanford, R. A. Rivell

PART I. FLOW CHARTS

Jan 1, 1974

By R. V. Ramani, R. Stefanko, G. W. Luxbacher

MINE VENTILATION NETWORK ANALYSIS

Jan 1, 1977