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By Forrest T. Moyer

THE injury data and experience in this bulletin are presented in three general sections. The first section contains general and detailed data relating to 1948 injury experience in bituminous-coal and Pennsylvania anthracite mines, separately and combined into totals for all coal mines. The related employment, worktime, production, and productivity data are given in each breakdown of the statistical data. Tables 1 through 22 constitute a subsection and present statistics on number of injuries, frequency and severity rates, average severity, detailed and major causes of injuries, injury records of the coal-producing States, distribution of injuries by part of body, and distribution of injuries by days of disability. Tables 23 through 45, the second subsection, present injury experience in bituminous-coal mines by various selected factors of physical or operating conditions that ma contribute to the occurrence of injuries. The degree of mechanical loading, productivity, size of mine by number of men working and by tonnage mined, thickness of bed, length of shift, number of shifts, type of cap lamps, rating of mine as gassy or nongassy, type of ventilation, and combinations of these factors influencing mine safety are presented in this group of tables. Similar data on Pennsylvania anthracite mines are listed in tables 46 through 63, which comprise the third subsection. The second section of the report contains the generalized annual injury records of bituminous-coal, Pennsylvania anthracite, and all coal mines from the earliest available data through 1948. Tables 64 through 97 list the number of fatal and nonfatal injuries, injury rates, and causes of injuries on an industry basis, the long-term injury records of each coal-producing State, and the related employment, worktime, and production data.

Jan 1, 1952

By Walter R. Storms

"The New Mexico potash exploration described herein was begun in February- 1944 by the Federal Bureau of Mines with the object of determining the amount of potash ore in the United States Potash Reserve in Eddy County, N. Mex., by exploring the deposit from the surface with vertical drill holes. The work was completed in October of the same year after 16 holes had been drilled on the reserve and in the immediate vicinity.The Potash Reserve is located in secs. 26, 27, 34, and 35, T. 20 S., R. 29 E., Eddy County, N. Mex., about 14 miles northeast of the city of Carlsbad. Drilling was done in secs. 26 and 35 of the reserve, in sec. 14 to the north, and secs. 25 and 36 to the east. All work was done on Government-owned, unleased land.The reserve may be reached from Carlsbad by traveling northeast by automobile for about 14 miles on paved U. S. Highway 62. This highway passes through the southern part of the reserve. Other parts may be reached by a State highway which passes along the eastern side of the area, then by poor dirt roads to various drilling sites. A branch of the Atchison, Topeka and Santa Fe Railroad also passes across the southern part of the reserve en route from Carlsbad to the plant and mine of the Potash Co. of America, a few miles northeast of the Project and 22 miles from Carlsbad.Work on the project was greatly facilitated by the help of Ralph H. King, associate geologist, R. K. Bailey, geochemist, H. C. Spicer, geophysicist, Hope Bunker, junior geologist, and R. H Allport, district mining supervisor, all of the Federal Geological Survey; and Charles H. Johnson, who at that time was district engineer for New Mexico for the Mining Branch of the Bureau of Mines."

Apr 1, 1946

By Charles H. Simmons

Two versions of a VF transceiver to aid in location of trapped miners has been developed and tested. The belt worn model was produced in both transmitter and transceiver configurations. In addition, a quantity of the belt worn models were fabricated using aluminum wire instead of copper in order to reduce unit weight. Ten prototypes of a battery cap model VF transceiver were also fabricated demonstrating further unit size and weight reduction while maintaining electrical performance. Samples of- both versions were tested environmentally and the test data is included in this report. While both versions of the VF transceiver are similar electrically, and are constructed using convential manufacturing techniques, the battery cap model realizes a lower total weight, smaller volume and production cost than the belt worn version. Operationally, the battery cap model assures that the VF transceiver will always be with the miner.

Jan 1, 1981

By Oliver Bowles

Limestone is the most widely used of all racks and is essential to a great many industries, including tae building trades, highway construction, metallurgy, agriculture, end many chemical and manufacturing enterprises. It occurs in some form in every State and is produced in thousands of quarries. Production in 1930 exceeded 134,000,000 tons. It has more numerous and more diversified uses than any other rock. This paper is designed to furnish general information on the various branches of limestone quarrying and their economic importance. Brief reference is made to dimension stone, and a more complete discussion follows of the uses, requisite qualities, quarry methods, grid processes of preparation of crushed and broken limestone. Footnote references serve to guide the reader to more detailed information.

Jan 1, 1933

By Mark Davis

As a follow-on to previous investigations, reduced treatment levels for the optimum fire retardant/preservative system were evaluated. An impregnation of 3.5 lbs/ft3 of Fyreprufe followed by 3.5 mils of Albi 107A plus an Albi 144 top coat provides adequate flammability and flame spread protection. However, there is a significant loss in compressive strength at this retention level, particularly parallel to the grain. A pilot-size pressure impregnation cell was installed for use in treating larger quantities of wood. Based on the optimum fire retardant/preservative treatment system - Fyreprufe/ACC impregnation followed by Albi 107A/144 intumescent paint - a model treatment pro¬cess was developed, capable of handling 3 million board feet per year. Associated annualized costs per thousand board feet (K bd. ft.) for treating 12" x 12" timber were calculated to be: Impregnation: $-63.00/K bd. ft. Coating: $112.00/K bd. ft. A literature search was conducted to identify materials and techniques suitable for a localized stench warning system for heated mine timbers. Based on this review, a number of stench warning concepts were developed. Those based on surface coating were given a preliminary laboratory evaluation.

Jan 1, 1982

By Christopher Mark

Perhaps the most significant development in coal mine ground control during the last century was the introduction of roof bolting during the late 1940’s and 1950’s. From an engineering standpoint, roof bolts are inherently more effective than the wood timbers they replaced. Roof bolts promised to dramatically reduce the number of roof fall accidents, which then claimed hundreds of lives each year, and they were initially hailed as “one of the great social advances of our time.” Roof bolting also emerged at a time of rapid technologic transformation of the coal industry, and greatly accelerated the transition to trackless, rubber-tired face haulage. The U.S. Bureau of Mines quickly became the new roof support’s strongest advocate. Some state agencies and miners were skeptical at first, but nearly everyone was soon won over. Case histories were reported showing that roof falls could be largely eliminated while productivity increased dramatically. Little wonder that, in the words of one contemporary observer, “roof bolting has been adopted more rapidly than any other new technology in the history of coal mine mechanization.” Yet by the end of the 1950’s, it was clear that roof fall fatality incidence rates had actually increased. It would be another decade before the superior ground support provided by roof bolts would clearly save lives. The story of how roof bolting was implemented by the mining industry, but took so long to live up to its promise, is a fascinating example of the interaction between economics, technology, regulation, and science. It still has important lessons for today.

By Richard F. Hewlett

The purpose of this Bureau of Mines paper is to provide the mineral industry with current information on high-speed data processing and to illustrate how some of these techniques can be applied to the industry. The need for applying these techniques is generally recognized, but not much information is readily available on specific applications. This paper briefly describes high-speed data processing and reduction equipment in an effort to familiarize the reader with the functions of the equipment. A list and explanation of some of the possible applications of high-speed data processing for the mineral industry are included. A few of these applications are illustrated by the use of specific examples of existing computer programs or processing methods, including their calculation times and costs. Some of the programs cited herein were developed by the author at the University of Arizona for a Masters thesis in mining engineering. When a reference is made to a specific computer, the reference is given to make the information that is being presented as factual as possible; most of the manufacturer's equipment that is mentioned in the references was available at the University of Arizona, and no specific endorsement of that manufacturer is intended.

Jan 1, 1962

These proceedings consist of papers presented at two Bureau of Mines Technology Transfer Seminars in early 1980 for the purpose of disseminating recent advances in mining technology related to surface coal mining reclamation.

Jan 1, 1980

By Charlie Wyche

Principal mineral products in the Dominion of Fiji were gold, silver, pit and quarry construction materials, and cement. In the years 1978-79, the combined total value of these commodities accounted for some $15 million,2 or 85% of the total mineral output. Production of cement, sand and gravel, and quarry products increased substantially, but gold and silver output from Fiji's only operating metal mine continued the down-ward trend of recent years. Mineral exploration by several international mining companies as well as by local prospectors was being carried out over much of Fiji, and a number of interesting prospects were discovered. One of these, a medium-size porphyry-copper prospect in the Namosi area of Viti Levu, W88 at a mining feasibility study stage. At Mount Kasi on Vanua Levu, an extensive program of geological sampling and mapping W88 being conducted, and surface sampling and drilling W88 taking place at some base metal prospects in the south-central parts of Viti Levu. Also, high gold values in surface samples were reported at Vuda in western Viti Levu.

Jan 1, 1981

By Ronald P. Hollenbeck

Shales in the Appalachian Region of Kentucky and Tennessee were sampled and tested to determine their use as raw materials for the manufacture of lightweight aggregate by the rotary-kiln method. Nine samples were obtained from eastern Kentucky and 143 samples were obtained from eastern Tennessee. As a result of preliminary testing of these samples, two sources in eastern Kentucky and 11 sources in eastern Tennessee were resampled for rotary-kiln tests. The rotary-kiln tests showed the two sources in Kentucky and seven sources in Tennessee contained shale that would produce satisfactory aggregate. Lightweight aggregate processed from these nine sources was tested in concrete shapes and was found to be suitable for use in structural concrete.

Jan 1, 1968

By James P. Rider

Significant advances in longwall mining technology and equipment have occurred over the last decade. By the late 1990s, longwall mine output accounted for 40 percent of all underground output in the U.S., and today longwall mines account for approximately 50 percent of coal produced underground in the United States. A 53 percent increase in average shift production rates has occurred over the last fifteen years. This increased longwall productivity has meant that far more dust is being produced and controlling respirable coal dust provides an ongoing challenge for coal mine operators. The National Institute for Occupational Safety and Health (NIOSH) has completed a series of benchmark surveys at longwall operations across the country to identify current operating practices and the types of controls being used. Gravimetric and instantaneous dust sampling was completed to quantify dust generation from major sources on the longwall section and to determine the relative effectiveness of the different control technologies in use today. Substantial reductions in dust levels were realized at sampling locations on the face when compared longwall surveys conduct in the 1990?s. This paper summarizes the results from the underground dust surveys and discusses current longwall dust control technology and operating practices.

Jan 1, 2010

By G. L. Oldright

As sponge iron is much like porous, coarse sand, it is a tempting material to use in place of coarse scrap iron as a precipitant of metals, for scrap iron is relatively awkward to handle and exposes only a small amount of surface to pregnant solutions. The results of the experiments described in this bulletin are largely a record of the behavior of sponge iron as a precipitant of lead and copper under laboratory conditions comparable to those that would obtain in a commercial plant were it attempted to secure the maximum contact of surface between solution and precipitant. Physically, the study is largely one of the rates of diffusion of the metal ions in the solutions and through the metallic coatings surrounding the sponge iron particles. The practical objectives are to remove completely the valuable metals from solution and at the same time to obtain a precipitate of good grade. In order to fulfill this latter requirement, the precipitant should be almost completely consumed. These practical ends are usually secured by having the two substances involved pass each other counter-currently-that is, in such a manner as to have the strongest precipitant in contact with the most impoverished solution, and vice versa. EXPERIMENTS WITH LEAD SOLUTIONS In nearly all of the schemes involving the leaching of lead from its ores the metal has been put into solution as the chloride, and fairly concentrated liquors have been employed. The solubility of lead under such conditions is comparatively small at best; the hot pregnant liquors from which the metal is to be precipitated are then made nearly saturated with respect to lead, and only a very small amount of acid is used. Therefore it was not as necessary to learn the behavior of the sponge iron in precipitating lead from solutions of widely differing composition as to learn under what conditions, and with what mechanisms, this precipitation might be carried out most readily.

Jan 1, 1928

By J. L. Stauffer, L. Gaydos, L. M. Demers, D. C. Kuhn

"Eicosanoids and cylokines produced by the pulmonary alveolar macrophage (PAM) are key mediators for the defensive role this cell plays in neutralizing the inhalation of particulate dusts and foreign microbes. However, these factors are also mediators of inflammation and their uncontrolled release may cause the lung injury and liorotic changes observed in individuals exposed occupationally to mineral dust. In vitro studies have suggested a link between the production of certain eicosanoids and cylokines released from the activated PAM. To this end, we have studied the release of eicosanoids (PGE2, TXB2 and LTB4) and cylokines (IL-1 and TNF) by cultured PAM, obtained from healthy human volunteers by bronchoalveolar lavage under basal culture conditions and following acute exposure to provocative agents such as the endotoxin lipopolysaccharide (LPS) and mineral dusts including silica. Studies were also carried out in the presence of specific cyclooxygenase inhibitors. The addition of LPS (10 µg/ml) to the culture medium produced a significant increase in PAM release of the eicosanoids: PGE2 (3.5 fold over baseline), TXB2 (2.8 fold over baseline) and LTB4 (4 fold over baseline). LPS also elicited a 2.5 fold elevation in IL-1 from these cells and a 9 fold increase in TNF release. The cyclooxygenase inhibitor, ibuprofen, significantly inhibited the LPS-induced rise in PGE2, TXB2 and TNF but had only a modest suppressive effect on IL-1 release. Exposure of these cells to silica dust elicited a similar augmentation in eicosanoid and cylokine release which was neutralized by prior exposure of the cells to ibuprofen. These results suggest that the enhanced production of eicosanoids and cytokines by PAM exposed to endotoxins and/or mineral dusts may be linked and that inhibition of eicosanoid release is linked to the production of TNF. IL-1 release however is not effectively neutralized by cyclooxygenase inhibition.INTRODUCTIONThe initial pulmonary cellular response to inhaled mineral dust involves the elaboration of potent inflammatory mediators from the pulmonary alveolar macrophage (1). These mediators include the eicosanoids (oxygenated metabolites of arachidonic acid) and cytokines (intercellular peptides) which are released into the alveolar space by the interaction of mineral dust with the PAM surface membrane. The eicosanoids and cytokines promote local nonvascular and vascular smooth muscle contractility changes, elicit the recruitment of additional mononuclear cells into the alveolar space, and enhance the activation, growth and differentiation of lung fibroblasts (2). In this study we sought to examine whether eicosanoid release and metabolism are linked to cytokine release when PAM are activated upon exposure to endotoxin or mineral dusts. Modulation of these pathways through inhibitory pharmaceutical agents may help attenuate the Injurious effects caused by a sustained release of these proinftammatory intercellular factors (3). To that end, we have studied the in vitro effects of endotoxin and silica on eicosanoid and cytokine release from cultured PAM obtained from healthy human volunteers."

Mar 1, 1992

By David A. Lipton

In 1983, U.S. Bureau of Mines personnel examined mines, prospects, and mineralized areas to determine the mineral resources in the Carrizo Gorge Wilderness Study Area (WSA). The 14,571-acre WSA, located 42 miles east of El Centro, CA, is underlain primarily by Mesozoic granitic rocks and pre-Cretaceous metasedimentary rocks. Six prospects were found within the WSA and two mines are adjacent to it. Mineral deposits within the WSA have had insufficient development and rock exposures for calculating resources. The WSA contains no identified mineral resources; however, further exploration may disclose gem quality minerals. Two mines adjacent to the WSA, the Pack Rat and Beebe Hole, have produced gem quality kunzite and aquamarine from pegmatite dikes. According to the owners, a significant amount of gem minerals have been mined here in the last decade. Based on past production and the characteristic minerals indicating gem-bearing pockets, additional pockets are likely. Similar pegmatite dikes occur from Mt. Tule to Carrizo Gorge and may contain gem-bearing pockets. Pegmatite dikes also occur in the WSA near Rockhouse Canyon, but contained few of the mineral associations indicative of gem-bearing pockets. Manganese occurrences north of the Beebe Hole and Packrat Mines and within the WSA contain low concentrations of manganese. Significant sand and gravel were not identified. There is no evidence of deposits of oil and gas, or geothermal energy.

Jan 1, 1985

By John C. Holtz

"The Federal Bureau of Mines serves the mining industry by approving equipment that is designed to prevent explosion, fire, shock, or toxic hazards in mines when such equipment is used and maintained in a proper manner, through research, consultation, testing, and inspection, the Bureau studies machinery and component parts submitted by manufacturers and others. Before receiving the Bureau's approval as permissible for safe use in mines, equipment must pass exacting tests and must meet strict requirements established through research and experience and listed in the Bureau's various permissibility schedules. An important phase of the Bureau's research is the testing of diesel engines.Mobile diesel-powered equipment can be used safely in underground noncoal mines and tunnels when mechanical ventilation is provided to dilute and remove the exhaust gas and to replenish oxygen in the underground atmosphere. Safe ventilation is determined by suitable tests of each engine used in a diesel machine. This ventilation cannot be predicted safely, accurately, and economically from any general empirical relationship.In determining safe ventilation, the quantities of carbon dioxide, carbon monoxide, and oxides of nitrogen generated by a diesel engine must be ascertained. These quantities are related to the displacement of the engine, its speed of operation, the design of the combustion chamber, and the fuel:air ratio needed to produce useful power. At overrich fuel:air ratios, all diesel engines generate excessive quantities of toxic carbon monoxide and smoke. The results of engine tests are used to determine a maximum fuel-injection rate at or below which carbon monoxide can be controlled by a reasonable ventilation and smoke is essentially eliminated. Toxic oxides of nitrogen are related to fuel:air ratio and the design of the combustion chamber. Their concentration in the exhaust cannot be controlled by engine adjustments, and each engine appears to have individual characteristics concerning formation of these oxides. Production of oxides of nitrogen frequently is the most important factor in determining safe ventilation."

Oct 1, 1959

By A. C. Richardson

The mine of the Porter Coal Co. is located at the town of Porter in the northwestern part of Jefferson County, Ala., about 20 miles west of Birmingham. The operations in this mine are confined to the middle and bottom benches of the Mary Lee bed. The coal from the Porter mine is handpicked and washed before being placed on the market. The handpicked lump coal and the washed egg and nut coal are sold chiefly as domestic and steam-raising fuel. The coal finer than 1 inch is washed in 2-compartment jigs and utilized in the manufacture of metallurgical coke. The coal company has found that, when coal ranging in size from 1 to 0 inch is washed in jigs, a considerable amount of high-ash material finer than 3/16 inch remains in the washed coal. This paper gives the results of an investigation which was conducted for the purpose of determining the washing characteristics of the through 3/16-inch raw coal and the extent to which the ash might be reduced by means of coal-washing tables. This investigation has been made in connection with an extensive study of the coal-washing problems now being conducted by the United States Bureau of Mines and the University of Alabama, with the cooperation of the coal-mining companies of the State.

Jan 1, 1933

By Jon C. Volkwein

The U.S. Bureau of Mines investigated a method of using inert gas to prevent the formation of explosive gas mixtures in auger highwall mining of coal. A combination of gasoline and diesel engine exhaust gases was introduced into the auger drill hole using a short section of pipe located at the collar. Gas samples were taken and analyzed on-site with infrared detectors for oxygen, carbon dioxide, methane, and carbon monoxide. Evacuated bottle samples were also taken and analyzed by gas chromatography in the laboratory. These gas results were analyzed for explosibility. Coal samples from various depths were used to obtain the gas content of the coal using the modified direct method. Personal expo- sure to carbon monoxide was also monitored. The highest methane level observed was 9.55%. The levels of inert gas (carbon dioxide and nitrogen) were sufficiently high to prevent any ignition of the methane. Results showed that for all conditions during mining, gas concentrations were nonexplosive. The gas content of the coal was about 0.30 cm3/g. The maximum personal time-weighted average Sample for carbon monoxide was 20 ppm. This system provides a safe, inexpensive, simple method for preventing explosions during auger mining.

Jan 1, 2010

By A. George Stern

[In the examination of bentonitic clay suspensions used for oil-well drilling fluids3/ (and for other purposes, such as a core binder for foundry sand) it is important to have comparative tests for evaluating them. A satisfactory clay for these and other purposes should have the property of forming what is commonly called a "gel," but the measurement of this property has been a real problem. To date the solution has not been satisfactory, and some of the difficulties are considered in, this, paper, which describes a simple form of instrument (identified as an eykometer) for measuring the yield point under hydrostatic conditions of non-Newtonian clay suspensions, including those muds that are thixotropic. An oil-well drilling mud serves several functions, many of which depend on the "gel" characteristics of the mud. Among the more important functions are: (a) To plaster the sides of the hole to prevent caving of the walls; (b) to prevent the loss of the circulating fluid out of the hole by seepage; (c) to carry sand and cuttings out of the hole to the surface as they are formed by the rotary drill; and (d) when circulation of the fluid stops for shut-down or other unavoidable cause, to hold the cuttings in suspension by the setting up of the gel, thereby avoiding the difficulties that result when these cuttings are allowed to fall through the fluid and pack at the bottom of the hole.]

Jan 1, 1940

By Galen H. Clevenger, MARTINUS H. CARON

Although there are exceptions, oxidized silver ores containing the higher oxides of manganese are generally refractory to hydrometallurgical methods of treatment. When these ores are of high enough grade they can be smelted; indeed, some rather low-grade ores of this type have been smelted at a profit because of their fluxing value. In the past, when these ores could not be smelted, they either were not treated or were treated at low efficiency, generally by cyanidation. The need for thorough investigation of the problem was therefore evident for some time before the writers began their research. The problem of treating manganese-silver ores seems to have been recognized first about 35 years ago by C. W. Goodale in applying pan amalgamation at Tombstone, Ariz. He attributed the low extraction of silver to the fouling of the mercury by manganese rather than to the presence of a refractory compound of manganese and·silver. Although definite knowledge as to the cause of the poor extraction of silver was lacking, a more or less effective preliminary treatment, that is, a chloridizing roast, was applied. E. M. Hamilton, in 1909, was perhaps the first to define clearly the problem as it affects the cyanidation of silver ores and to suggest possible methods of preliminary treatment. Most of the work done in the interval between the appearance of Hamilton's paper and the assumption of the investigation by the authors was in the nature of routine tests covering suggestions already made rather than of research directed to a fundamental study of the problem. No practical application has so far been made of any of these proposed processes. The investigation described in this bulletin has proved that there s a refractory compound of manganese and silver-probably a manganite- insoluble in cyanide solution and other common solvents for silver. Although this compound has not been isolated from natural ores, it has been made synthetically, and shows all the characteristics of the natural product. Furthermore the authors have shown definitely that heating in air a relatively small amount of a silver compound with a large excess of silica (in the proportions ordinarily occurring in a commercial silver ore) renders

Jan 1, 1925

By Michael J. Magyar

This report contains a cost estimate of the Bureau of Mines process for dewatering Alaskan placer effluent streams with polyethylene oxide (PEO). In this process effluent slurry is withdrawn from the placer plant pond system after a primary settling stage. A dilute PEO solution is injected into the slurry line to flocculate the fine, suspended solids. The flocculated solids are dewatered on a stationary screen. Clarified water is returned to the placer operation or discharged, while the 35 percent solids waste is pumped back into the mine cut. Cost estimates are presented for dewatering plants processing 1,000 gallons per minute of effluent slurry at three representative turbidity levels. Both the placer and the dewatering plants operate on the same 1-shift-per-day, 6-day-per-week schedule for the 100-day Alaskan operating season. Estimated fixed capital costs for these plants processing placer with effluent turbidities of 1,000, 3,000, and 5,000 nephelometric turbidity units (NTU) are approximately $29,000, $31,000, and $34,000, respectively, on a fourth quarter 1986 basis. Operating costs are estimated to be $0.34, $0.37, and $0.40 per thousand gallons of effluent slurry.

Jan 1, 1987