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To evaluate the potential for dust reduction, during blasthole drilling, of water or foam applied directly into the drill hole. Approach The Bureau of Mines tested a through-the-drill-steel water and foam injection technique in two noncoal mines to evaluate the method's potential for greater dust reduction. The tests were performed by drilling a series of blastholes for an entire face (a 90 minute time-period). For the first 45 minutes of drilling, foam or water was applied through the drill steel. Blowing ventilation was supplied to the entry about 50 feet from the face. The dust concentration measurements were made by a Real-Time Aerosol Monitor (RAM-I), and the data were read out on a strip chart recorder. The evaluation test results showed that the water or foam injection technique, when used on localized dust sources, can be an extremely effective dust control method. Small amounts of water used in this method have also allowed it flexibility to be used in water-soluble ores such as salt, gypsum, anhydrite, and trona. How The System Works Water or foam is mixed with compressed air (approximately 100-120 psi) with suitable metering systems and forced through the drill steel into the blast hole at the point of dust generation. Because the water or foam is applied at the source, minimal quantities of liquid are needed (0.2 to 0.6 gpm). These low flowrates are sufficient to just moisten the dust emerging from the blast hole, thus eliminating a major source of airborne dust. The wet drilling procedure also eliminates a second source of dust. With dry drilling, the dust from the blast hole falls to the floor. Since this can be a 15-ft drop or more, the impact can send the dust billowing up from the floor, adding to the airborne dust. With wet drilling, the moistened dust merely dribbles down the face.

Jan 1, 1982

By M. B. Cooke

An analytical method for the determination of the gum-forming material in gasoline has been developed by the Bureau of Mines, during a study nor in progress to determine the best rays for elimination of such constituents from gasoline. This method is similar in principle to that previously described by Smith end Cooke,2 which involved evaporation of e sample of gasoline in a small glass dish. The evaporation was started on an actively boiling steam bath and completed in an air oven at 105°C. In the improved method described below, the stem bath has been replaced by a steam heated oven in which an inert atmosphere is maintained. Air is excluded from the oven, consequently the precision of the determination is increased. Furthermore, evaporating dishes different from those previously described may be used.

Jan 1, 1925

By S. D. Maksirnovic, Fred N. Kissell

The use of vertical surface degasification boreholes with bleeder systems and the use of a timbered bleeder system to degasify gob areas were studied by (the Bureau of Mines. This report describes three gob degasification studies ,conducted in the Pittsburgh coalbed. One study was conducted to determine the number of panels degasified with one large borehole . The study showed that the borehole provided degasification for three panels. Another study was conducted during the retreat of a 35-acre panel with a single-entry and a two-entry bleeder system and a large surface borehole. A major portion of methane emitted from the panel was carried away by the bore- hole, leaving the bleeder entries relatively free of methane. The last study was made to determine the effectiveness of a timbered bleeder system. The bleeder entries successfully degasified the gob area when enough entries were available and adequate pressure was available to force the air through roof falls.

Jan 1, 1980

By M. Kanefsky, A. Q. K. Rajput

Two channel polarity coincidence and polarity difference statistics are analyzed. The signal, common to both channels, consists of sinusoidal bursts where the exact frequency of the signal is nearly known, but other parameters such as amplitude, phase, and pulse starting time are unknown. The noise inputs are dependent, narrow band, Markov processes. It is shown that the performance depends not only on the signal uncertainties but on the precise shape of the cross-correlation functions between the noise inputs. By using two polarity difference statistics in addition to the polarity coincidence statistic, it is shown that the decrease in performance, as well as the cost of hard limiting due to correlated inputs, can be made small.

Jan 11, 1981

By T. E. Gray

This report describes the preparation characteristics of the more significant coal beds in Washington County, Pa. It is one of a series planned to determine coals suitable for producing metallurgical coke, either as mined or after beneficiation. More than 15 million tons of coal was produced in Washington County in 1956; 89.8 percent was cleaned mechanically in 10 cleaning plants. The Bureau of Mines has estimated that 2,280 million tons of recoverable coal remained in beds 28 inches thick or more as of January 1, 1954.

Jan 1, 1959

By Doris M. Hyde

Mineral industry activity in many of the smaller Caribbean Island countries has remained minimal. For this reason, specific references to Bermuda, Guadeloupe, Martinique, and the Netherlands Antilles have been removed from textual and trade table presentations. Any significant future developments will be reported as they occur. Readers are referred to earlier Minerals Yearbook editions for previous information. Table 1 production statistics have been modified in some instances. References to certain nonmetal commodities were eliminated because information has often been unreliable. Their inclusion in table 1 was not considered important to either an overview of the area or to compatibility with volume I of the Minerals Yearbook.

Jan 1, 1984

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

MINE VENTILATION NETWORK ANALYSIS

Jan 1, 1977

By Michael J. Gallagher

Diamond-bit performance data accumulated by the Bureau of Mines in core-drilling limestone and dolomite show that the physical characteristics of the diamonds and the sizes and types of bits used are economically significant. An analysis of the data establishes one trend of particular significance to those engaged in core drilling: Bits set with small, low-quality drill bort are the most economical. Detailed analysis of the factors that affect diamond-bit performance, such as size and quality of diamonds, sizes and types of bits, percentage of core recovered, and physical characteristics of bit matrices are assessed in the tables, bar charts, and discussion.

Jan 1, 1958

By L. W. Higley

Particulates generated in electric furnace (EF) steelmaking constitute approximately 1 to 2 pct of the charge. This flue dust is a rich source of zinc (values are substantially higher than in ore), but although there are several processes for recovering the metal, none are considered economic in the United States. This report reviews extraction technology and presents results of Bureau of Mines reduction-volatilization tests on pelletized EF dusts which achieved high recoveries of zinc. The data are sufficiently encouraging to warrant consideration of EF dusts as raw material for primary zinc smelters.

Jan 1, 1977

By John P. Coughlin

Software techniques developed by the Bureau of Mines Denver Research Center for real-time microseismic data analysis are presented. These techniques focus on the simple acquisition of P-wave arrival times and their use in event location. The paper discusses in detail software techniques to separate microseismic events from mining noise such as drilling and from very large events such as rock bursts. Incorporation of these techniques has enhanced the reliability and accuracy of computer-based monitoring of microseismic activity in ongoing research by the Bureau.

Jan 1, 1982

By G. M. Molinda, J. P. Ulery

Since 1970, abnormally high methane emissions have been observed in eastern sections of the Federal No. 2 Mine operating in the Pittsburgh Coalbed in northern West Virginia. The nature and volume of these emissions indicate a source other than the coalbed. An investigation was undertaken to delineate probable methane sources. Gas well information and stratigraphic correlation of corehole data indicates that a sandstone directly above the main coalbed is an additional source of methane emissions. The sandstone body appears to be an ancient stream channel, infilled with fine-grained sand and organic matter. Coalification of the organic matter produced methane as a byproduct. Additional methane presumably migrated into the sandstone unit from the subjacent coalbeds. The methane became trapped in the porous clasticunit by the surrounding impermeable strata. Mine development near this unit creates a significant pressure gradient, triggering abnormal methane emissions into the mine along naturally occurring fractures. Pre-development methane drainage of the sandstone could be accomplished by completing vertical boreholes along its trend.

Jan 1, 1984

This chapter describes the adverse health effects associated with exposure to respirable coal mine dust. Epidemiological studies of underground and surface coal miners in the United States and other countries are discussed. Also discussed are animal studies that add to our understanding of particle deposition and retention in the lungs and associated disease responses. This chapter emphasizes studies that (1) were performed since the passage of the Federal Coal Mine Health and Safety Act of 1969 [P.L. 91- 173], (2) used standardized methods of exposure monitoring and disease classification, and (3) investigated exposure-response relationships between respirable coal mine dust exposure and disease. Several published review articles contain further discussion of health effects studies of coal miners [Attfield and Wagner 1992b; Petsonk and Attfield 1994; Cotes and Steel 1987; Merchant et al. 1986; Morgan and Lapp 1976; Morgan 1975].

Jan 1, 1997

By Robert L. Lagace

The attention of this group was focussed on four through-the-earth communication systems that are presently of high interest to the U.S. Bureau of Mines; four systems for providing operational/emergency communications on the working sections of coal mines, indeed up to the very face of the section. The systems are: uplink-data, downlink-voice, sidelink-call alert coded page, sidelink-roof bolt voice page. Each of these systems makes use of the mine overburden as the signal transmission medium, as opposed to the guiding wires, cables, and tunnels treated by the operational communications working group. Each of these systems satisfies one or more of the Bureau's objectives for mine communications systems; namely • reliable links for monitoring the mine environment under both operational and emergency conditions. • reliable links for communicating with miners during emergencies. • special links for increasing the efficiency of day-to-day operations of the mine. Each of these systems has been successfully demonstrated on a limited experimental basis, and prototypes of all these systems are installed and operating in the USBM experimental mine in Bruceton, Pa. Each of these systems must now be optimized regarding its performance, and engineered for practical routine application to the working sections of actual operating coal mines, particularly those of the room and pillar type. This optimization and engineering must take place subject to the principal constraints listed by Howard E. Parkinson in his Workshop paper entitled, "Objectives and Constraints of Through-the-Earth Electromagnetic Communications Systems'' and enumerated below. • Depth of Mine Overburden • Overburden Conductivity • Electromagnetic Noise In and Above Mines • Limited In-Mine Electrical Energy (Stationary or Man Carried) During an Emergency • Intrinsic Safety for In-Mine Equipment • Practical and Rugged Equipment for Use Under Both operational/Emergency conditions • Severe Weight Limitations for Man Carried Equipment • Reasonably Low Costs Especially for Man Carried Equipment Part II of this paper provides a brief description of each system, while Part III summarizes the present status of developments related to these systems and some recommendations for future work needed to advance these systems to the practical application stage.

Jan 1, 1973

By James A. West

THE South Asian countries of India, Ceylon, Pakistan, Afghanistan, Nepal, Bhutan, and Sikkim have a large variety of mineral resources; however, in spite of mineral industry growth during 1964, development of resources remained far short of possible development, and, in terms of value of trade in minerals, the area remained a sizeable net importer. India's mineral industry is by far the most significant; its minerals production in 1964 accounted for more than 90 per cent of the total value of all minerals produced in the area. The total value of all minerals produced in South Asia in 1964 was only about 1 percent of the area's estimated gross national product of $55,125 million. Despite the rather small current contribution of minerals to the economy, development of mineral resources figures prominently in plans for the industrial development of the nations of this area.

Jan 1, 1966

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 F. D. Osgood, A. C. Fieldner, W. A. Selvig

In connection with investigations being conducted by the Bureau of Mines regarding pulmonary disease which is prevalent among metal miners in certain districts , a large number of rock- dust samples have been collected , and have been examined in the Bureau's laboratories . The earlier work has been described in Bureau of Mines Technical Paper 105 , " Pulmonary disease among miners in the Joplin district , Missouri , and its relation to rock dust in mines " by A. J. Lanza and Edwin Higgins , 1915 , and in Bureau of Mines Bulletin 132 , " Siliceous dust in relation to pulmonary disease among miners in the Joplin district , Missouri , " by Edwin Higgins , A.J. Lanza , F.B.Laney , and Geo . S. Rice , 1919. The methods of collecting and examining dust samples have been greatly improved during the investigation , much valuable information having been made available by similar investigations conducted by the Miners ! Phthisis Prevention Committee , Union of South Africa . The latter are described in the " General report of the Miners ' Phthisis Prevention Committee , Johannesburg, Union of South Africa , 1916 " , and " Final report of the Miners ' Phthisis Prevention Committee , Johannesburg, Union of South Africa , 1919. " The investigations by the Bureau of Mines and the South African committee show that by prolonged inhalation of air containing minute particles of sharp and insoluble rock dust , the lungs retain sufficient dust particles to cause decided injury to the lung tissue , the injured lung becoming very susceptible to the development of tuberculosis .

May 1, 1920

Federal lands often contain extensive mineral resources and decisions affecting access to those lands are made with knowledge of the possible minerals-related consequences. Information is provided to the Bureau of Land Management (BLM) in this report for use in preparing environmental impact statements on the Western Mojave Management Area (WMMA) and the Desert Tortoise Priority Habitat (DTPH). To augment U.S. Bureau of Mines (USBM) efforts such as the Mineral Assessment of the Planned Foil Irwin Expansion, Modified Silurian Valley Alternative, San Bernardino County, California which is in progress, and the Economic Analysis of the Minerals Potential of the East Mojave National Scenic Area; California, the USBM studied mineral deposits and estimated the potential impacts of mining in a segment of the California desert; the 8.7-million-acre WMMA, an area which includes the 1.2-million-acre Desert Tortoise Priority Habitat (DTPH). In addition, this information is intended to assist administrators, legislators, and the concerned public in understanding the economic importance of mineral resources in the California desert, especially that portion designated as the WMMA. See figure 1.

Jan 1, 1993

By S. J. Broderick

"INTRODUCTION Dark soils are commonly believed to be better for agricultural purposes than light-color soils. Much of this feeling may be purely psychological, as many persons have unconsciously acquired the habit of associating richness of soil with color light soils, however, may be just as rich in humus and plant foods as the best of the dark soils. A dis-cussion of the manifold attributes that play an important role in soil technology is beyond the scope of this paper, but the color factor will be considered, as it has a particular bearing on some field experiments using coal-mine waste as a darkening medium.It has been established that dark soils absorb more of the sun's radiation, consequently are maintained at a higher temperature than light soils. This physical principle is applied in our daily lives in the choice of clothing. White clotnes in summer are cooler than dark ones. Conversely, dark clothes in winter are warmer than light-color clothing. A decided advantage of dark soils over light soils is the higher average temperature of the former, resulting in an earlier maturing crop. This advance of the maturing season may range from a few days to a month, depending on such factors as climate, crop, and degree of color of the soil. It has been reported that in parts of Russia where the growing season is short, perhaps comparable to that in Pennsylvania and. New York, cotton has been grown successfully on soils originally of light color, but darkened with coal, dusts. The growth of cotton is, accordingly, speeded up a full month. 3/"

May 1, 1940

By Sarkis G. Ampian

The Bureau of Mines has developed a method for identifying fine particles of beryl in mineral samples by preferentially staining the beryl grains. The sample is first subjected to a heated sodium hydroxide solution to etch the beryl particles, which are subsequently stained an intense blue color in a boiling alkaline solution of quinalizarin. Positive identification of beryl grains permits quantitative analyses by microscopic techniques. INTRODUCTION Beryl, a beryllium aluminum Silicate, is the principal ore mineral of beryllium. The only known commercial concentrations of this mineral are found in pegmatite dikes of granitic composition. Normally beryl is associated with muscovite mica, quartz, and the sodium-and potassium-bearing feldspars (orthoclase, microcline, and albite). Other beryllium-bearing minerals which are found occasionally in minor amounts with beryl are phenacite, a beryllium silicate, and chrysoberyl, a beryllium aluminate.

Jan 1, 1962

By R. H. Sprute

This report describes Bureau of Mines laboratory test results in electro-kinetic dewatering and consolidation of metal-mine mill tailings from five mines in the Coeur d'Alene, Idaho, district. Classified (coarse) tailings, slimes, and unclassified material were separately tested. Tailings were placed in 0.3 ft3 plexiglass models, and dc potential was applied until dewatering ceased. Time-oriented measurements of water removal, changes in resistivity, and power consumption were recorded during the dewatering process. Moisture content and density of the dewatered material at test end indicated the method to be generally effective for all materials examined, but best results were achieved with well-mixed unclassified tailings.

Jan 1, 1974