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By R. L. Grant

[p(,ton~to'rs 'ar-IV uscG.. to explode 9crnli .... sible c}:plosivcs, dynamites, or other hiGh uxplosives. This ?,...!xplosion or detr)nation is brought about by th\.:J energy which i liberated as a cOl":"Lb' nation of concusBion and heat wl1en the ? detonator is fired. 'm Ot:18t? I'l(jrds~ liThe detonator is the key VI: ich unlocks the enerGY of a llgh? explosIve""? (8) :1/. Being sensitive nd latently dangerous, detonators ITl.ust lTIeet t\V0 primary requirerDentr: They must be ..;.afe to handle and IT. list? detonate' when (l,esired, the ... eby iIr.parting deton:l.tion to the explo8ivc cJ.1Cire-e.]

Jan 1, 1941

By Steven C. Goddard

Since the passage of the Federal Coal Mine Health and Safety Act of 1969, the need for improved duet control methods has become imperative. It has been proposed that one promising dust control technique would be the application of water through the cutter drum. In November of 1972, the Jeffrey Mining Machinery Co., who had been pursuing the development of wet drum miners since 1969, completed the manufacture of a 120M HELIMINER which had sprays in front of the cutting bits on a fixed width drum. On June 27, 1973 Jeffrey and the Bureau of Mines signed the contract numbered B0232060 for the purpose of evaluating "the effectiveness of respirable dust control on a Jeffrey 120M HELIMINER by use of water piped through the head." This evaluation, as described by the contract, was to be accomplished by the collection and analysis of dust samples at various locations of an operating mine production section.

Jan 1, 1974

By B. I. Ferber

Sodium chloride aerosol was employed to determine respirator filter penetration in a manner suitable for use in Bureau of Mines approval and certification procedures. The aerosol was produced by an ultrasonic generator and treated to yield the proper conditions of relative humidity, particle size, and concentration. Respirator filters were exposed to the aerosol; filter penetration (down to 0.02 percent) was determined with a flame photometer. Results are comparable with those obtained in another laboratory using different equipment.

Jan 1, 1970

By Steven J. Schatzel

Prior research has suggested that the source of respirable silica dust in underground coal mines is typically the immediate top or bottom lithology adjacent to the mined seam, not mineral matter bound within the mined coal bed. Geochemical analyses were applied in an effort to identify the specific source rock of respirable quartz dust in coal mines. The analyses also demonstrate the compositional changes that take place in the generation of the respirable dust fraction from parent rock material. All six mine sites were mining coal with relatively low mineral matter content, although two mines were operating in the Fire Clay coal bed which contains a persistent tonstein. Interpretations of Ca, Mg, Mn, Na, and K concentrations strongly suggest that the top strata above the mined seam is the primary source of mineral dust produced during mining. One site indicates a mixed or bottom source, possibly due to site specific conditions. Respirable dust compositional analyses suggest a direct relationship between the quantity of mineral Si and the quantity of quartz Si. A similar relationship was not found in either the top or bottom rocks adjacent to the mined seam. An apparent loss of elemental Al was noted in the respirable dust fraction when compared to potential parent rock sources. Elemental Al is present in top and bottom rock strata within illite, kaolinite, feldspar, and chlorite. A possible explanation for loss of Al in the respirable dust samples is the removal of clays and possibly chlorite minerals. It is expected that removal of this portion of the Al bearing mineral matter occurs during rock abrasion and dust transport prior to dust capture on the samplers.

Jan 1, 2009

By Robert A. Cortese, Henry E. Perlee

Coal dust and float coal dust, produced during normal mining operations, in underground coal mines, are carried from the point of origin downstream by the ventilating air, where it deposits on the surfaces of the mine entry. In an explosion, this dust is lifted from the surfaces by the aerodynamic disturbances and, if of sufficient quantity, can continue to propagate the explosion. To prevent the surface coal dust from contributing, it must be inerted, typically by spreading pulverized limestone, i.e., rock dust, over the coal dust surface. To facilitate the dusting operation, the National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory(PRL), developed an automated system that continuously monitors the accumulation of coal dust. This system could activate a rock-dusting machine that disperses rock dust into the ventilation air when dangerous deposits accumulate and deactivate the machine when sufficient inert has been deposited on top of the coal dust. The system consists of a microprocessor-controlled optical float dust deposition meter. This device measures the light intensity reflected from a deposited layer of dust. A standard cap lamp is used as a fixed-position light source. From the reflected light signal, the microprocessor determines the hazard level of the deposited layer and performs the appropriate action. Full-scale studies conducted in the Experimental Mine at PRL's Lake Lynn Laboratory, using alternating thin layers of rock dust and coal dust, successfully demonstrated the operation of the device. Based on the statistical data from these studies, a mathematical model was developed to predict long-term error in total rock dust content using this inerting procedure. Downwind dust dispersion was also examined to provide optimum placement of the dust sensors and to determine the need for better rock dust dispersion techniques.

Jan 5, 1998

By E. L. Singleton

This Bureau of Mines investigation was initiated to study and establish some of the chemical and physical characteristics of the condensed Mno-Si02 system. To prevent oxidation of the manganous ion, I atmosphere of purified helium was used in the furnaces. Solidus-liquidus curves and invariant points were established from melting-point determinations and were supplemented from data obtained by the static-quenching method. Experimental findings and data are for the intermediate compounds of tephroite and rhodonite with their respective eutectics represented at 25.5 and 37.2 weight-percent silica. Tephroite melts congruently at 1,347° C., and rhodonite melts incongruently at 1,286° 8.. A metastable transformation was determined to exist at the 1,347° C. isotherm, the congruent melting point of tephroite. A composite X-ray-diffraction pattern was formulated for synthetic rhodonite. This investigation contributes fundamental data leading toward a better understanding of the more complex slag systems.

Jan 1, 1962

This chapter presents proportionate mortality ratios (PMRs) derived from death certificate data in the National Occupational Mortality Surveillance (NOMS) database for the years 1986 through 1993. At the time this report was prepared, 1993 was the latest year for which data were available. Industry is classified under the 1980 U.S. Bureau of the Census classification system [Bureau of the Census 1982]; cause of death, under the International Classification of Diseases, Ninth Revision (ICD-9) [World Health Organization 1977]. A PMR of 100 indicates a mortality risk for a particular industry group that is similar to that for all industry groups combined. A PMR over 100 suggests a higher risk; a PMR under 100 suggests a lower risk. PMRs are subject to many factors that affect their reliability and validity and may not be comparable across populations with very different causes of death. An elevated PMR for a specified cause of death among an occupational or industry group may indicate a relationship between a work exposure and the cause of death specified. However, there are many limitations of PMRs as a measure of risk; they are most useful for generating hypotheses about exposure-disease relationships, which can then be tested in other studies. Selected PMRs are presented separately for males and females for coal mining, metal mining, nonmetallic mineral mining and quarrying (which includes nonmetal, stone, and sand and gravel), and for oil and gas extraction. All PMRs have been adjusted for age and race. In general, PMRs are presented only if the lower 95% confidence limit exceeded 100. If a PMR in an ICD-9 subcategory was above 100, however, the PMR for the larger category into which the subcategory falls is always presented and may be less than 100. PMRs can be expected to be elevated for conditions that have a high prevalence in particular occupational groups. PMRs showed elevated values for conditions known to affect miners, such as coal workers' pneumoconiosis, pneumoconiosis due to silica, tuberculosis, chronic pulmonary heart disease, and injuries. Additional findings of interest were- • An elevated PMR for myocardial infarction among male coal miners (table 2-1); • Elevated PMRs for neurologic disease in general and anterior horn cell disease, in particular among male metal miners (table 2-3); • An elevated PMR for rheumatic heart disease in male metal miners (table 2-3); • Elevated PMRs for malignant neoplasms of the digestive organs and peritoneum and for malignant neoplasms of the colon and rectum in female nonmetal miners (table 2-6); and • Elevated PMRs for non-A, non-B hepatitis and arteriosclerotic heart disease among male oil and gas workers (table 2-7).

Jan 5, 2000

By Frank E. Federspiel

In 1992, the Bureau of Mines conducted a mineral resource investigation of the 78,000-acre Garns Mountain study area in southeastern Idaho. The area had been proposed for Wilderness. It is underlain by Paleozoic to Mesozoic-age sedimentary rocks about 11,000 feet thick. Rocks have been faulted, offset, and folded as part of the northerly-trending Idaho-Wyoming Overthrust Belt. Study area mineral occurrences are: phosphate in the Permian Phosphoria Formation; coal in the Cretaceous Frontier end Bear River Formations; and uranium in carbonaceous and phosphate-bearing shales and coal of these formations. Four zones of phosphate are estimated to contain about 528 mitt ion tons of rock with over 10% P205; samples of phosphate-rich rock also contained as much as 3950 ppm chromium, 3280 ppm vanadium, 23 ppm gallium, and 5540 ppm zinc. Fragments of poor-quality coal and carbonaceous shale were found in the area; coal was mined near the northeast border. Uranium content up to 0.016% U3O8 is in carbon-rich shales. Oil and gas were drilled for, with minimal success, in folded sedimentary rocks (frontier and Nugget Sandstone) in the Horseshoe anticline, near the east border. Examined workings included 12 dozer cuts, 4 trenches, 2 prospect pits, and 2 caved adits. No production is known, and no leases or claims are held for the area.

Jan 1, 1992

By James Noll

Total carbon (TC) is sometimes used to measure or characterize diesel particulate matter (DPM) in occupational settings such as underground mines. DPM samples are collected on quartz fiber filters. When using quartz fiber ?lters, adsorption of gas phase organic carbon (OC) has been reported, causing a positive bias in the particulate TC results (adsorption artifact). Most of the data on the sampling artifacts and corrections apply to environmental air sampling, where samples are collected at a much higher filter face velocity and the OC concentrations are generally much lower relative to occupational sampling. In this study, we investigated the effects of adsorption artifact on samples from occupational settings. Samples were collected with and without denuders to determine the amount of gas phase OC collected and the accuracy of certain corrections. In underground stone mines, the adsorption artifact was found to positively bias the particulate TC by greater than 20% for filter loadings below 25 µg/cm2 TC (8-h time weighted average) 262 µg/m3). The tandem ?lter correction reduced the effect of the artifact, as high as 60% of the TC value, to less than 11% for laboratory data. It also significantly reduced the effect of the artifact obtained for field samples.

Jan 1, 2008

By C. H. Johnson

The Big Jim mine of the United Eastern Mining Co. is at Oatman, Mohave County, Ariz. Oatman is in the foothills on the western side of the Black Mountains, at an elevation of about 3,000 feet. It is on a paved highway about 30 miles west of Kingman, the principal distributing; center for mining supplies in the district, and 25 miles from Topock, en the Colorado River. Both latter towns are stations on the Santa Fe Railroad; Oatman has no roil connection. Mining conditions are typical of western Arizona; water is scarce, no mine timber is available locally, and the winters arc mild and the summers hot. The supply of a killed labor is usually adequate, but in 1933-34 it w not more than sufficient for the restricted operations. Wages have been $4.00 to $4.50 for miners. Electric power was supplied from Kingman and cost about 2.6 cents per kilowatt-hour.

Jan 1, 1935

By N. L. Wimmler

"INTRODUCTION The Southern Cross district in Deer Lodge County, Mont., has been chiefly a gold producer. Most of the production has come from gold-bearing hematite-limonite ores. Some of these ores were mined and shipped to smelters for use as flux in smelting copper ores. A magnetite deposit in the Pomeroy property, containing no gold or other economic nonferrous minerals, was mined from 1921 to 1923, the ore being shipped to smelters for flux.The iron-bearing deposits in the Southern Cross area were examined by Bureau of Nines engineers/ on June 28, 1943, and October 14, 1943. As a result, a Bureau exploration project was recommended; it was conducted during 1944. A magnetometer survey was first made of the magnetite-bearing area at and in the vicinity of the Pomeroy property. Exploration by diamond core drilling was then conducted within this area, and in the Southern Cross and Hold Fast properties. The cyanide tailings dump at the Hold Fast mill was sampled by auger drilling.This report presents the data obtained by the Bureau of Mines exploration."

Dec 1, 1946

By James M. Stuckey

In a search for improved methods of upgrading tar obtained by low-temperature carbonization of coal, monoethanolamine (MEA) was found to be effective in extracting tar acids from coal tar distillates derived from a subbitunwous and a lignite coal. Patch extractions showed that both yield and purity of the extracted acids improved with increasing volume ratios of monoethanolamine to tar acid, varied from 1:4 to 8:1. Yield improved, but purity decreased as the concentration of monoethanolamine was changed from 30 to 70 volume-percent, and as the concentration of tar acid in distillate was increased ad from 14 to 45 percent. In a continuous countercurrent extraction employing a double solvent (monoethanolamine and hexane) approximately 80 percent of the tar acids was extracted from 170° to 350° C. tar distillate when using 1.6:1 volume ratios of amine:tar acids. Tar acids isolated from his extract, although of improved purity, contained appreciable quantities of neutral oils and some tar bases. Aqueous monoethanolamine was not effective for extracting the last 10 to 15 percent of tar acids in 170° to 350° C. distillate oil from lignite coal. The highest yield of isolated tar acids and the best recovery of monoethanolamine were obtained by diluting the extract with water and saturating with C02. Some losses of solvent were encountered when aqueous monoethanolamine solutions were heated through decomposition of the amine with the liberation of ammonia.

Jan 1, 1960

By E. P. Youngman

Titanium ranks as one of the more abundant elements, is widely distributed, and occurs in concentrated form in numerous deposits. This substance was discoveres 140 years ago; but despite the efforts of metallurgists and chemists to find a place for it in industry, only within the last 10 or 15 years has the increased use of titanium pigments provided any extensive outlet for titanium ores. Even to-day titanium is confined to a few highly specialized industrial applications. The metal itself is now quoted regularly in trade journale, but scarcely yet can it be said that the production or use of the metal. has progressed very far beyond the laboratory stage. Ferroalloys containing the element were largely used for a time, especially in connection with the manufacture of Bessemer steel rails; but as American rail- ways adopted open-hearth rails in preference to Bessemer rails, the demand for the alloys in the rail manufacture gradually dwindled into insignificance. New outlets for ferrotitanium have been found in the steel industry; and the production of titanium alloys, both in the United States and in Europe, has increased in recent years. By far the largest use of titanium at the present time, however, is in pigments. The manufacture of titanium white began in Norway, but at present the United States is the leading producer. One of the two companies now operating in the United States is also the leading factor in European production. Although titanium occurs, in many minerals, the principal commercial sources are rutile (the natural oxide, Ti02) and ilmenite (iron-titanium oxide, FeO. TiO2). The latter is a coal-black mineral, but it is the one used in the manufacture of the titanium white of commerce, as well as in the manufacture of ferroalloys and arc-lamp electrodes. Rutile, the natural oxide, is not pure white and, being less common in nature, costs more; it is, therefore, reserved for use in the manufacture of titanium chemicals employed in relatively small amounts in dye works and bleacheries and for sundry minor purposes. This paper summarizes the titanium industry, with special reference to its economic aspects. It is offered as a survey of current trade literature and as a digest of material in the files of the bureau and is presented in response to numerous inquiries from prospective producers as to ways and means of exploiting deposits. (At present, much of the ilmenite consumed in this country comes from overseas, principally from British India..). A forthcoming circular, devoted to deposits of titanium-bearing ores, deals with foreign and domestic sources of supply.

Oct 1, 1930

By Edward L. McHugh

In 1986, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied the 5-acre Zwagg Island Wilderness Study Area (OR-12-14) in order to evaluate its identified mineral resources. The study area is located in Curry County, OR, immediately west of Brookings. There is no evidence of mining activity on or near Zwagg Island, and no mineral resources were identified. The steep-sided, flat-topped island is normally accessible from the mainland by way of a sandy beach. The island consists mainly of marine sandstone, mudstone, and conglomerate of the Jurassic Dothan Formation. Dothan Formation sandstone has been used locally as construction material. Rock along the coast has also been used for construction of jetties to improve harbor access; additional work has been proposed at the port of Brookings. Although suitable for other construction uses, stone from Zwagg Island would probably not meet physical requirements for jetty stone. Development of a stone resource on the island is unlikely.

Jan 1, 1987

By R. R. Wells

For several years the Klukwan deposit near Haines, Alaska, has attracted interest as a potential source of iron. Limited field and laboratory investigation has indicated that the deposit contains a large amount of Iron that is recoverable as high-grade concentrate. This report summarizes the results of laboratory beneficiation testing of the Klukwan ore, as represented by six samples submitted to the Alaska Experiment Station of the Bureau of Mines, Juneau, Alaska, Iron is present in the ore as a fine-grained magnetite associated with a pyroxenite type basic rock.. Satisfactory magnetic-separation procedures were developed for the production of concentrates assaying more than 60 percent Fe and 2 to 4 percent Ti02. During the investigation many data were obtained and compiled, but for convenience and clarity data of secondary importance have been omitted or condensed; only the more pertinent test results are discussed in detail.

Jan 1, 1953

By E. R. Andersen, F. E. Block, T. T. Campbell

This work was done to develop methods for increasing the yields and purity of vanadium prepared by bomb reduction of vanadium compounds . Compounds reduced were V₂ 05 , V203 , VC , and VC13 . Sodium , calcium , and magnesium were used as reductants . Variables considered included reductant form , bomb size , pressure during reaction , method of ignition , and the use of slag fluidizing additives . It was concluded that yields of 85 to 90 percent can be effected by the calcium reduction of V205 in reactors measuring as much as 14 inches in diameter and 60 inches in height . Optimum charge composition included V₂05 , 65 percent excess calcium , and 0.4 moles sulfur per mole vanadium . Purity of the vanadium produced in large reactors varied from 99.5 to 99.8 percent . The higher purity metal , depending upon the amounts of interstitial impurities present , was usually cold ductile . Although high yields of up to 99.5 percent can be effected by bomb reduction of VC1 , the high pressures developed in the bombs and attack of the reactor walls by the byproduct chloride slags discourages this method of preparing vanadium . It was found that significant purification of impure regulus metal occurred when it was hydrided , crushed , acid leached , and vacuum dehydrided . Metal so treated can readily be converted to ductile sheet . A cost estimate based on the production of 100 tons of vanadium per year was prepared . It was concluded that pure ductile vanadium could be produced for approximately $ 20.00 per pound .

Jan 1, 1964

By Tignor E. M.

The Brenneman oil field in Grant District, Hancock County, W. VA., was selected for study by Bureau of Mines engineers because it was typical of many of the smaller petroleum reservoirs in the Appalachian region. In 1906, E. W. Marland & Co. discovered the Brenneman field by drilling a well that readied the oil-bearing .Berea sandstone at a depth of 750 feet and initially produced 200 barrels of oil a day. Most of the oil-productive area (348 acres) of the field was developed in a comparatively short time, and the initial daily production rates of some of the wells were as high as 1,000 barrels of oil a day. Although the field was a prolific producer of oil for several years, it was abandoned in 1923 when the production rate was less than 1,000 barrels of oil a year and 705,000 barrels of oil had been produced. Secondary-recovery operations were started in the Brenneman field in 1927 after useable old wells had been repaired and unsatisfactory wells had been plugged; drilling of new wells was started in 1929. The peak of the redevelopment program was reached in 1942 when 92 oil-producing wells and 26 injection wells were in use; both air And mixtures of air and natural gas were used for injection purposes. It is estimated that approximately 357,000 barrels of oil, equivalent to 1,030 barrels per acre, 105 barrels per acre-foot, 8.5 percent of the total pore volume, or 11.9 percent of the original oil in place will be produced as a result of gas-injection secondary-recovery operations. Engineers of the Bureau of Mines Petroleum Field Office, Franklin, Pa., are studying secondary-recovery projects in the Appalachian region as a part, of the Bureau's secondary recovery research and are reporting these studies so that others: can profit by the experience gained from the operations. In common with most of the other Appalachian oil fields, there was no natural water drive in the Brenneman field. The estimated oil saturation in the Brenneman reservoir at the end of economic gas-injection operation indicates that additional oil might be recovered economically by water flooding and that a pilot flood would be warranted.

Jan 1, 1950

By W. S. Landers

This report presents a study by the Federal Bureau of Mines of technical factors related to the production of special carbon and tar from selected Wyoming coals. Certain Wyoming high-volatile bituminous and subbituminous coals were processed in bench-scale apparatus to determine potential carbonization yields and in pilot plant retorts to produce sufficient char and tar for testing. These tests have shown that a critical selection of coal is necessary when the coal is processed for a specialized carbon. Generally high yields of tar are obtained from low-temperature carbonization of Wyoming high-volatile bituminous and subbituminous coals, and the yield of tar usually increases with increase in rank within this range of coals. The production and evaluation of industrial carbons from Wyoming coals by using pilot plant and bench-scale techniques is part of the continuous program of upgrading western coals. It has been found that: 1. Most Wyoming coals are nonagglomerating and may be carbonized in fluidized systems. Chars produced in pilot plant retorts at low temperatures contain about 17 to 23 pct, residual volatile matter and are easily ignited. These chars appear suitable as power plant fuel. The tar-plus-light-oil yields range from 14 to 40 gal./ton of raw coal processed. 2. Wyoming high-volatile coals produce a slightly smaller and somewhat weaker coke than currently mined Western United States high-volatile coals used commercially as blending stock in metallurgical coke production.

Jan 1, 1961

By R. J. Evans

The generation and disposal of solid waste from electric utility plants using a lime or limestone wet-scrubbing system and the potential effects on the environment were estimated for 1975 and 1980. The study indicated that in 1975 approximately 5.8 million tons of desulfurization solid waste (50 percent solids) will be generated. In 1980, when it is estimated that desulfurization will become commercially accepted, approximately 71.4 million tons of this material will be generated for disposal and/or utilization. The desulfurization waste material when combined with lime, fly ash, and water may have potential for use as a roadbase material, landfill reclamation, and synthetic aggregate.

Jan 1, 1974

By A. J. Kraemer, O. C. Blade

This report on the properties of commercial motor fuels sold in the United States is a continuation of a series of reports made in accordance with a cooperative agreement between the Cooperative Fuel Research (C.F.R.) Committee of the Cooperative Research Council (C.R.C. ) and the Bureau of Mines of the United States Department of the Interior . The first report contained data on motor gasolines sold during the winter of 1935-364 . Further reports on motor gasolines sold during the succeeding summers and winters to the summer of 1941 have been issued . No reports were made on motor gasolines sold during the winter of 1941-42 and during the summer of 1942 . The present report presents analytical data for 1,120 samples , representing the products of approximately 88 companies . As in previous surveys , these companies include both large and small suppliers . In addition, the Pacific coast is represented by data averaged by the Pacific Coast Technical Group before being submitted and are published exactly as they were received . Conforming to previous surveys , the data cover three groups of samplesregular - price , premium - price , and third - grade gasolines and each group has been averaged separately. The number of samples , items and brands comprising each group, exclusive of those of the Pacific coast, are as follows : Regular price , 641 samples , 250 items , and 64 brands ; premium price , 439 samples , 222 items , and 68 brands ; third - grade gasoline , 50 samples , 50 items and 19 brands .

Jun 1, 1943