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By Peter J. Clarke

Afghanistan's mineral industry continued to be dominated by the production and export of natural gas, although several mining and related industrial projects, all under the supervision of Soviet technicians, were in the planning stage in 1982. Afghanistan produced minor quantities of barite, cement, coal, fertilizer materials, iron, and lapis lazuli, all for domestic consumption.2 Large-scale projects being investigated were a copper mine and concentrating plant at Ainak, extensive mining of the Hajigak iron ore deposit near Kabul, construction of an oil refinery at Angot, increasing production and processing of natural gas, and implementing an intensive geologic prospecting and exploration program for areas of mineral potential. Afghanistan's gross domestic product (GDP) was estimated at $2.76 billion3 and has remained stagnant for the past several years. Total exports in 1982 were estimated at $700 million, only a marginal increase from the 1981 figure of $694 million. Exports of natural gas to the U.S.S.R. earned $385 million in 1982, representing just over one-half of Afghanistan's total exports. Natural gas revenues were down approximately 11% from the 1981 level, owing primarily to increased antigovernment activity in the northern part of the country.4 About 90% of the country's natural gas production was exported to the U.S.S.R.5 About 38% of Afghanistan's development budget had been earmarked for mining and industrial projects in 1982.6

Jan 1, 1984

Reduce the dust levels to which jacksetters and helpers on auger mining sections are exposed by identifying viable, effective methods for control-ling respirable dust on these sections. Approach The Bureau of Mines con-ducted laboratory tests and respirable dust surveys to identify the factors that distinguish clean auger mining operations from dusty ones. Study Results Results of the Bureau's study revealed that ventilation is the most important element of auger mining dust control. The four must important venitilation parameters are airflow, curtain configuration, curtain setback, and curtain installation.

Jan 1, 1988

By W. H. Engelmann

The electrokinetic (zeta) potentials of a charcoal granite in an aluminum chloride (AlCl3) solution and in an oleylanunonium acetate (C18H35NH3+ -OCOCH3) solution have been correlated with the specific damping values as measured by the pendulum sclerometer. This investigation shows that the pendulum specific damping attains a minimum at the isoelectric point for the charcoal granite-aluminum chloride and charcoal granite-oleylammonium acetate systems, and thus indicates that the penetration of the diamond points is a maximum at the isoelectric point.

Jan 1, 1967

By Basil Dimitriades

The association of automotive fuel composition with exhaust reactivity was studied in an experimental program that involved testing with different automotive engines and with gasolines of varied composition. Results showed clearly the exhaust reactivity to increase with increasing levels of polyalkylbenzenes in the fuel. No other systematic patterns of high significance were detected in the association of exhaust reactivity with several broadly defined groups of fuel components. For the purposes of this study, had it been possible, fuel composition should have been defined and expressed in terms of component groups such that the potential for exhaust reactivity would be the same within each group and different from group to group. Classification of fuel components in terms of the paraffins-olefins-aromatics groups does not meet the latter requirements. For appropriate classification of fuel components more information is needed on the combustion .of hydrocarbons in the multicylinder internal combustion engine. Statistical analysis of the mass emissions data showed significant car and fuel effects on hydrocarbon, carbon monoxide, nitric oxide, total aldehydes, and formaldehyde emission levels and on total photochemical reactivity. Car-fuel interactions were not significant at the 90-pct level. Correlations were found between mass emission parameters and fuel composition.

Jan 1, 1973

By Robert F. Holub

The Bureau of Mines has made a study of the magnitude of the variations of radon daughter mixtures, with the objective of determining whether these variations reflect the existing physical conditions in uranium mine atmospheres or if they are merely random or systematic errors. To accomplish this, many data have been plotted using a triangular graphing technique which shows that plateout affects RaA more than RaB or RaC, and that it is impossible to find simple correlations between working level ratios, radon daughter mixtures, and age.

Jan 1, 1978

By J. C. White

A research study was conducted to devise a method for producing phosphoric acid directly from unbeneficiated Florida phosphate matrix. This research was performed as part of the Bureau of Mines, U.S. Department of the Interior, goals of improving minerals and metals recovery from domestic resources and of minimizing the environmental impact associated with mineral recovery operations. This report describes research in which unbeneficiated, dry, south-central Florida phosphate matrix was digested with sulfuric acid in a continuous-circuit, five-tank reactor to yield phosphoric acid and gypsum residue. Feed capacity of the reactor was 100 pounds (45 kg) of dry matrix per 24-hour day. When digestion was carried out at 185° F (85° C), acid filtration rates of up to 420 pounds of P20S per square foot per day were attained. Combined iron and aluminum impurities in the product filter acid were about 60 percent greater than values reported in commercially produced acid derived from concentrate. phosphate recovery was 87 to 90 percent of the phosphate contained in the as-mined matrix.

Jan 1, 1978

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Jan 1, 2011

By R. K. Koch

In seeking substitutes for such critical metals as chromium, cobalt, and nickel, the Bureau of Mines investigated techniques for shape-casting titanium in rammed sand molds. Castings were made in olivine, garnet, chromite, and, for comparison, zircon. It was found that commercial-grade castings up to 31 lb (maximum capacity of furnace) could be made in zircon or olivine molds if a zirconia mold wash was used. Castings up to 4 lb could be made in chromite molds, but heavier castings suffered from some mold-metal reaction. Garnet molds were found to be unsatisfactory for castings of all sizes because of gas blows and rough surfaces. In other tests shell castings of acceptable quality were produced in water-glass-bonded zircon and olivine molds up to weights of 8 lb, but chromite molds were unsatisfactory because rough casting surfaces were caused by mold-metal reaction. Unlike the currently used commercial processes, neither the rammed-sand nor the shell-molding processes developed by the Bureau of Mines generate noxious fumes at any step.

Jan 1, 1980

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 Peter F. Strong, Robert L. Lagace, Alfred G. Exslie

The theoretical study of WF 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 is the concern of this paper. Of prime interest are the nature of the propagation mechanism and the prediction of the radio frequency that propagates with the smallest loss. The theoretical results are compared with published measurements. This work was part of an investigation of new ways to reach and extend two-way communications to the key individuals who are highly mobile within the sections and haulageways of coal mines.

Nov 14, 1974

By Robert G. Yewen, Ronald S. Conti

Underground mines rely on alarm systems, such as stench gas, audible or visual alarms, pager phones, telephones, and messengers to warn miners of a fire or other emergency. These systems are often slow, unreliable, and limited in mine coverage. This report describes the evaluation of a wireless signaling and warning system for underground mines. This system is applicable to both coal and noncoal mines. The work was conducted by the National Institute for Occupational Safety and Health in cooperation with TeleMagnetic Signalling Systems (TSS) under Cooperative3Research and Development Agreement No. BOM-CRDA-6200-0119. A TSS wireless ultra-low-frequency electromagnetic signaling system was installed at the Experimental Mine at Lake Lynn Laboratory near Fairchance, Fayette County, PA. A commercial smoke sensor was interfaced to a remote portable transmitter, and the alarm of the sensor was used to trigger the central evacuation and paging transmitter system during experimental mine fires. The underground/surface receivers flashed cap lamps and activated remote devices, such as strobe lights, within 30 to 40 s after the encoded signal was received. Evaluation results showed full-mine coverage of the electromagnetic field and that the encoded signal was received at the farthest point underground and on the surface perimeter.

Jan 5, 1997

By Donald N. H. Chi

This Bureau of Mines report is concerned with a theoretical study of the aerodynamic response of a single mine entry to flame-induced disturbance. The unsteady, one/dimensional, compressible flow equations were solved using the method of characteristics. This study was primarily undertaken to determine the feasibility of extending the method of characteristics to study the aero-dynamic response of complex mine networks. It was demonstrated that although the technique has merit in studying the complex wave interaction in single entries, it appears to be too unwieldly and too expensive for network analysis. Effort was also directed at a further study of the dispersion and filtering characteristic of aerodynamic disturbances in mine passageways.

Jan 1, 1975

By A. May

Florida has accumulated about 400 million tons of phosphogypsum, a mineral process waste generated in the production of fertilizer, and is adding 30 million tons to this annually. To minimize storage of this waste and reduce potential environmental effects, the Bureau of Mines conducted research into utilizing the phosphogypsum, by identifying and developing high-volume uses for this material. Admixtures of phosphogypsum, fly ash, and lime that could produce a coarse aggregate suitable for road construction were investigated. Using phosphogypsum with asphalt, cement, cement-kiln dust, silica, clays, and oxychlorides to pro-duce aggregate was also examined.

Jan 1, 1985

By A. N. Styler

As part of its water-jet assisted rock cutting research, the Bureau of Mines has initiated a study into the mechanism of rock fragmentation by water-jet-assisted mechanical tools. The objective of this research is to increase coal extraction efficiency by seeking an improved understanding of the synergistic relationship between mechanical cutters and water jets, enabling the design of more effective cutterheads. Rock chips collected during laboratory traverse speed jet-assisted cutting tests were analyzed with respect to the size distribution of the chips and the forces measured during cutting. As the water-jet pressure was increased, the size distribution of the product became coarser with V-face type cutting tools producing less fine material than conical cutting tools. Fracture mechanics theory accounted for less than 10 pet of the energy consumed during fragmentation of the rock. The energy consumed by processes other than rock breakage decreased with the use of water jets and increasing advance rate.

Jan 1, 1987

By R. V. Ramani, C. B. Manula, A. Owili-Eger

This report was prepared by The Pennsylvania State University under USBM Contract No. G0111808. The contract was initiated under the Coal Mine Health and Safety Program. It was administered under the technical direction of DMRC, with Mr. G. R. Schottler acting as the technical project officer. Mr. J. A. Herickes was the contract administrator for the Bureau of Mines. These applications were developed initially as a part of the instructional material for the course Mng 422, "Mine Ventilation and Air Conditioning" at the Department of Mineral Engineering, The Pennsylvania State University. This ventilation simulator was developed under contract from the Department of Environmental Resources, formerly the Department of Mines and Mineral Industries, Commonwealth of Pennsylvania.

Jan 1, 1975

By Clarence O. Babcock

ROCK BEHAVIOR has proved of national interest in a variety of fields. The behavior of rock consequent to a nuclear blast was used to detect such blasts, as criteria for the design of underground military defense installations that would resist nuclear blasts, and for judging the feasibility for peaceful uses of nuclear explosives. An obvious peaceful application of nuclear explosives would be for large-scale rock excavation, and plans were presented during the year to improve the present Panama Canal or create a new canal by this method. These plans were based largely on earlier crater tests that demonstrated rock behavior when subjected to a buried nuclear blast. A knowledge of rock behavior under impact was used to evaluate the materials of the moon by means of the geometric configurations visible in the close-up pictures of the moon surface taken by the U.S. rocket Ranger 7. The composition of the moon must be considered in devising methods for taking samples of the surface layers or in designing underground shelters as bases for future explorations of the moon.

Jan 1, 1965

By Deborah A. Kramer

As part of the Nation's growing concern with the competitiveness of U.S. firms in the world economy, especially with respect to advanced materials, the Bureau of Mines assessed the actual and potential recovery and manufacturing capabilities for gallium and gallium arsenide (Gacis). GaAs has advanced from a laboratory curiosity to a material with important "high-tech applications within only the last few years, and although protected North American gallium supplies are currently considered adequate, consumption could grow to the point that this assessment would need reevaluation.

Jan 1, 1988

By W. W. Adams

luring the past two years the Bureau of ?,lines has been receiving from 100 to 150 coal mines in various States a report of each accident causing death, permanent total disability, permanent partial disability, or temporary disability lasting beyond the remainder of the day or shift on which the accident occurred. For each 100 accidents in these groups, there are perhaps from 35 to 45 accidents that do not disable the employee beyond the remainder of the day, and of these fraction-of-a-day accidents the Bureau has compiled no statistics. Information revealed by the reports is to the effect that falls of roof and coal in bituminous coal mines are responsible for 28 per cent of the temporary injuries to underground workers and 33 per cent of the days lost from all temporary injuries underground; they also indicate that falls caused 59 per cent of the deaths from all causes underground. Figures compiled by R. N. Hosler, of the Pennsylvania. Mine Rating Bureau, and covering accidents in bituminous; minis in that State, chow that 61 per cent of the deaths underground during the years 1917-1921 wore due to falls. Neither of these percentage figures includes deaths in major explosions; figures for all bituminous mines in the United States during the five years 1920-1024, inclusive of deaths in major explosions, show that 52 per cent of the deaths underground and in shafts were due to falls of roof and coal.

Jan 1, 1925

Synthetic dawsonite [NaAl(OH)2C03] has been prepared with crystallinity similar to that of dawsonite found in oil shale deposits of the Piceance Creek area of Colorado. Optimum experimental conditions were as follows: Na/Al atomic ratio, 43; temperature, 175° to 200° C; pCO2, 15 psig; and reaction time 5 hr. Chemical and spectrographic analysis revealed that the synthetic dawsonite was of high purity and Has essentially stoichwmetric. Similarity of the synthetic to natural dawsonite, demonstrated by X-ray diffraction, infrared spectrophotometry, and electron microscopy, suggests its suitability as a standard.

Jan 1, 1972

By Howard E. Parkinson

The mine pager phone to public telephone interconnect system permits mine paging telephones to be interconnected with the public phone system, thereby providing emergency and off-hours communications. The system, a push-to-talk, push-to-listen system, is compatible with any mine paging system utilizing dc voltage on the line to enable paging. A tone generator of the proper frequency enables an outside caller to page over mine pager system loudspeakers. A caller inside the mine can make an outgoing call to a preselected, preprogramed number with the use of a proper frequency tone generator. The system includes an automatic hangup timer that restricts the time off-line due to a wrong number or incorrect hangup to 20 seconds and 6 minutes, respectively.

Jan 1, 1974