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The general nature of the special constructional features that are required to provide safety from explosion hazards on machines approved as permissible by the Bureau of Mines is fairly well known to mining men who are at all interested in safety. These requirements are outlined in the schedules under the provisions of which the investigations of such machines are conducted. Also, the method of conducting inspections and tests of such machines has been described in Bureau of Mines Bulletin 305, Inspection and Testing of Mine Type Electrical Equipment for Permissibility, published in 1929. A more detailed knowledge of the special safety features of a particular machine is often useful and sometimes essential for inspectors, safety engineers, maintenance men, and engineers in selecting machines for a particular application. Three bulletins that give information of this nature have been-published by the bureau, viz., Bulletin 313, Permissible Storage-Battery Locomotives and Power Trucks. Bulletin 343, Permissible Coal-Handling Equipment. Bulletin 382, Permissible Coal-Cutting Equipment. Report of Investigations 3309, Permissible Electrically Operated Air Compressors, which contains similar information, was issued in August 1936, and a Report of Investigations 3326, Permissible Electrically Operated Room Hoists, was issued in January 1937. Thus, the present paper is the third to give detailed information concerning permissible machines of types not included in bulletins, and covers all the rock-dust distributors approved prior to October 1, 1936.

Jan 1, 1937

By R. S. Dean

"Interest in the nitrogen content of steel has increased sharply in the last few years. Investigations have indicated that its presence in steel has an important bearing on high temperature brittleness3, magnetic properties4, room temperature hardening5, and shock resistance. The steel producer may therefore look forward with certaintly to the necessity of controlling this element in a considerable proportion of his product. The literature, however, reveals a great many contradictory statements concerning the percentage of nitrogen which must be present to produce given effects on the properties of iron and steel. Most of these arise from a misunderstanding of the nature of the iron-nitrogen diagram near the iron end and a lack of recognition of the effect of state of aggregation on physical properties although both have been fairly well worked out.My thanks are due to Mr. J. L. Gregg, Prof. R. H. Dowdell, Mr, R. F. Mehl and Mr. H. C. Vacher for suggestions in connection with the preparation of this paper, and to Mr. C. H. Hefty and Mr. G. T. Motok for furnishing a valuable bibliography and translations of articles by Must and Duhr.The iron-nitrogen diagram in the solid state, so far as it concerns the nitrogen content of commercial iron and steel, consists simply in a solubility curve increasing with temperature. The important thing about this solubility curve is that without cold wore the iron nitride when precipitated does not go into solution on heating for long periods below 300°C. This slowness of solution is probably due to the fact that iron nitride when present as a separate phase has at these temperatures an equilibrium pressure of several thousand atmospheres7 and that therefore each particle of iron nitride surrounds itself with a layer of nitrogen. The precipitation of such an unstable crystal presents points of interest thermodynamically but we can not go into these here. It is quite well established that it precipitate. It can not diffuse then unless this layer is broken through or the temperature and pressure are increased to a point where the nitrogen is absorbed at an appreciable rate in the surrounding iron. This rate will depend on the degree of unsaturation of the iron and the excess pressure of the nitrogen above equilibrium pressure. The degree of unsaturation is determined by the temperature alone so that the temperature at which the rate of solution of the nitride becomes appreciable will depend on the pressure of nitrogen developed. This, in turn, will depend on the balance between rate of decomposition of the nitride and the rate o: flow of the iron. In annealed iron, this temperature of appreciable solution rate is between 300 and 350°C.8 By cold work, however, the elastic limit of the iron is increased, and conditions for the nitride to go into solution are reached at a much lower temperature, giving rise to the so-called blue brittleness. This brittleness and hardening is due to iron nitride going into solid solution and is not precipitation hardening."

Mar 1, 1931

By Floyd G. Anderson

This report reviews and summarizes information on prevention and suppression of dust in mining, tunneling, and quarrying published in the United States from 1961 through 1967. Unpublished pertinent data developed or assembled by the Bureau of Mines during this period also are included.

Jan 1, 1969

By Robert W. Van Dolah

The prevention of fires and explosions involving the combustibles and oxidants likely to be found in flight vehicles requires a knowledge of the flammability and related characteristics of these materials. This circular is a compilation of the available charactersilics data for a series of combustibles and oxidants of current interest. Vapor pressure data are presented for fluorine, oxygen, chlorine trifluoride, nitrogen tetroxide, nitric acid, hydrogen peroxide, ethylene oxide, hydrogen, ammonia, pentaborane, unsymmetrical dimethylhydrazine, monomethylhydrazine, hydrazine, and a series of hydro-carbons including decalin, tetralin, bicyclohexyl and other high-density fuels. In addition, flammability characteristics diagrams are included for each of the fuels in contact with air and, where available, other oxidants (for example, oxygen and nitrogen tetroxide). To assist in understanding these data, sections on definitions and theory and applications have been included. Each section is complete in itself and can be used separately. For example, a reader who is familiar with the general theory of combustion and detonation may find the data sections more useful than the definitions and theory and the application sections. However, since pertinent data are included in these sections, they should also prove useful to the experienced engineer interested in preventing fires and explosions.

Jan 1, 1963

By E. O. Wagner, A. W. Koth, V. F. Parry, J. B. Goodman, D. C. Gernies

"INTRODUCTION A commercial-scale pilot plant for gasification of lignite was completed by the Bureau of Mines at Grand Forks, N. Dak., early in 1945 as an extension of work on, gasification of low-rank coals initiated in a smaller pilot plant at Golden, Colo., during 1943. The development work on this plant was part of a program to make reducing gases from lignite for beneficiation of low-grade iron ores. The background of this project has been described in a previous report. 6/ The present report describes the major features of the large pilot plant, a record of experimental operating data during five runs totaling about 1,800 hours, .and results of experimental work on the small pilot plant at Golden during 1945.This project has created considerable interest because heretofore there has been little success in several attempts to gasify American lignites.Furthermore, the methed employed is a departure from conventional processes. Natural lignite is fed continuously into an externally heated annular retort and is converted into water gas by heat conducted through alloy metal walls. Because of the high thermal conductivity of metal, the rate of gasification is several times greater than can be obtained when employing refractory walls. The process has been developed to a part that leaves one major question unanswered. - ""How long will the alloy last under practical operating conditions?"" - and this question has aroussed the interest of the Coal Division of the Bureau of Mines in this new development.Owing to the high reactivity of the lower-rank fuels, the water-gas reactions proceed rapidly at medium temperatures of 1,650°F. to 1,800°F. These temperatures can be attained in a reaction zone heated by external means when the temperature of the retort does not exceed 1,900°F. while transferring from 6,000 to 7,000 B.t.u. per hour per square foot. Such rates are several times greater than can be attained through refractory walls as employed in the Didier-Bubaig 7/ and the Ahrens processes. 7/ Therefore, the investment cost of the gas generator per unit of capacity will be considerably lower for the higher-capacity process. However, the maintenance cost of metal vessels will be higher than that of refractory retorts, and this emphasizes the importance of large-scale operation to determine the life of an alloy retort under practical operating. conditions."

Sep 1, 1947

By G. W. Marks, A. H. Roberson

"Previous investigation 4/ has demonstrated that some of the aliphatic amines are suitable absorbents for 302, This paper reports the results of physical studies of a number of such amines with the object of determining which is most favorable as an absorbent.Monoethanol amine, diethylene triamine, and triethylene tetramine appear to be the most promising of all the amines studied, and most of this report has been devoted to studies of the physical properties of their aqueous solutions, which contain varying amounts of SO2.PURITY OF MATERIALSAll of the amines used were of commercial grade, because the primary object of this research was the investigation of a proposed works process rather than the accumulation of scientific data.The aminoethyl derivitives of ethylene diamine, namely, diethylene triamine, triethylene tetramine, and tetraethylene pentamine, only recently have been produced commercially. The chemistry of aliphatic amines is complex, and these newer derivitives have not been investigated, completely. Chemically pure material is not on the market, and since definite physical standards have not been published, one could not be assured of a pure product even if the commercial material was refined.The compilation of physical constants for the pure amines would involve much time—consuming effort without materially enhancing the value of this paper, as this work was not devoted to the development of fundamental standards."

Oct 1, 1938

By Annie G. Smelley

The Bureau of Mines is testing a dewatering technique for phosphatic clay waste that will recover a portion of the water lost using conventional waste disposal methods and produce solids suitable for land reclamation. The technique utilizes a flocculant, polyethylene oxide (PEO), that forms strong, stable flocs that can be dewatered on a static screen followed by further dewatering on a rotary screen. In field tests conducted in northern Florida, clay wastes containing a nominal 2.5 pct solids have been consolidated to greater than 20 pct solids. The rate at which PEO-treated material continues to dewater in a mine cut also was monitored. Preliminary results indicate that PEO--treated material will dewater to 30 pct solids in 140 days. Pretreatment of phosphatic clay waste with lime and H202 was shown to improve the dewatering technique for problem clay wastes.

Jan 1, 1985

The 1969 Lignite Symposium was held at Grand Forks, N. Dak., on May 1-2, 1969. Cosponsored by the University of North Dakota and the Department of the Interior, Bureau of Mines, the meeting was the fifth in this series. Registrants from many States and Canadian Provinces attended the meeting representing many segments of energy-oriented companies, State and Federal Government, and universities. At 2-year intervals, these symposia provide a common meeting place where recent research and developments in technology and utilization of energy resources with emphasis on solid fuels (lignite) are presented. Proceedings3 of the previous symposia including a Forum held in 1958 have been published.4

Jan 1, 1970

By William M. Knuth

This study involved a review of bonding and bond release practices in the states of the Eastern and Midwestern Coal Provinces. Data was collected from regulatory authorities and site visits to document the bonding and release procedures in the states related to achieving successful reclamation. The regulations related to PL95-87 were reviewed. The analysis included suggested modified or new bond release criteria, a review of applicable bond release inspection techniques was prepared, a conceptual graduated bonding system and incentive procedures for reclamation of surface mine sites to alternative or higher land uses. A number of conclusions and recommendations for further research were included. A detailed bibliography and a glossary are included in the report.

Jan 1, 1978

By Susan M. Moore

Many challenges are faced by workers in lower-seam (42 inches or less) mines. The lower-seam heights confine mine workers to their knees as they perform their daily tasks such as installing roof bolts, delivering supplies, repairing belt, or cutting coal. Miners working in these lower seams often consider kneepads to be their only line of defense against knee injuries. However, healthy knees do not start and stop with kneepads. Other interventions such as changing postures, proper hygiene, and work station design may also be used to reduce mine workers? risks for developing knee injuries. Incorporating these and many other interventions into a mine worker?s ?way of life? is an important step to ensuring a long, healthy career and retirement. Keeping knees healthy is also a key aspect to reducing costs in low-seam mines as the industry battles rising health care costs, and training/recruitment of replacement workers is time-consuming and costly. Educating the workforce about the possible interventions to reduce knee injury risk is a primary objective for the National Institute for Occupational Safety and Health?s (NIOSH) Pittsburgh Research Laboratory (PRL). Therefore, NIOSH researchers, along with industry and academia, developed a training package to educate the mining community about some possible interventions beyond kneepads that may be used to help decrease knee injury rates. Increased awareness and simple changes are the first steps to reducing knee injuries.

May 1, 2008

By William A. Beck

This paper is one of a series, describing current practice in diamond drilling for production at various mines throughout the United States. It describes the drilling and blasting methods, used at the Tennessee Copper Co., which started using deep-hole drilling for blasting in 1927, employing inde- pendent, rotation percussion drills with sectional drill steel. Since 1942 the company has employed diamond drills for deep-hole drilling. This method has now passed the experimental stage and promises to become permanent. The elimination of rock dust and safer working conditions for the drill crews are listed as the main advantages. The higher initial cost of equip- ment is the principal disadvantage.

May 1, 1948

By W. L. Barry

A review of the practices of analyzing for precious metals at the Reno Research Center, U.S. Bureau of mines, is presented. A general description of fire assaying, the physical layout of a fire assay laboratory, and the use of fire assaying in combination with atomic absorption, induction coupled plasma, and emission spectroscopy is reviewed. The combination of techniques significantly decreases the detection limits for precious metal analyses and simplifies the analysis of the platinum-group metals. Methods of protecting personnel from ingestion of lead are also discussed.

Jan 1, 1982

By R. A. Egen

The purpose of this book is to provide an indication of what good hoisting practice is and how it might be achieved. To this end the book contains discussions of equipment and inspection and maintenance procedures developed and used by mining people in striving for safe, reliable hoisting equipment. Most of this information comes from domestic practice; the rest is foreign, notably from Canada. Most things discussed have long proved their general worth, and others promise to; a few are beginnings. However, nothing is conjectural or theoretical; the practices described herein are in use somewhere in the mining world. The stress is on equipment in use; it is not a design-guidelines manual. Nevertheless, there are some sections dealing with design material since it may be of value in a maintenance/ replacement sense. Mine hoisting installations encompass such a wide variety of equipment and conditions that it is impractical to specifically cover them all. This book mainly treats conventional systems using conventional components with some discussion of the more common unconventional (special) systems in use. There is no recognized definition for a "conventional" mine-hoisting system. Herein the term means those systems most commonly used in daily operations for transporting men, materials, and product-electrically driven drum and friction hoists, with guided conveyances running in vertical or inclined shafts. Beyond this, what "conventional" means is probably best illustrated by the topics discussed.

Jan 1, 1975

By G. W. Jones

One of the major activities of the Bureau of Mines is the promotion of safety in mining and other industries, In this connection, the Bureau determines the explosion hazards' of combustible gases, vapors, and solids and investigates means of controlling and preventing explosions. Many dangers are likely to confront men who must enter a building immediately after it has been damaged. Rescue workers must watch constantly for common gases and vapors that may be present in dangerous concentrations in and about demolished, buildings. Fuel gas is the most common source of danger, although refrigerants, gases from furnaces, flues, fires, sewers, and industrial processes, and gas from bomb, explosions in confined places also constitute definite hazards. To rescuers and trapped casualties, these gases offer the hazards of (1) explosion, (2) toxic effects, including asphyxiation and death, and (3) displacement of air so that the oxygen content of the atmosphere is reduced to or below the danger level.

Jan 1, 1944

By J. J. Forbes

First - aid training is an essential part of safety programs in the mining industry , but it is only a means to an end ; first -aid training will not eliminate accidents , but unquestionably it is of considerable value in any accident prevention program . Numerous features should be incorporated in any efficient , well - developed safety plan ; in addition to first -aid training safety work , to be reasonably effective , should include the establishment and maintenance of a safety organization , safety competitions between mines or sections of mines , safety- inspection committees , accident - investigation committees , safety meetings of mine officials , safety bulletins and posters , employees ' safety publications , Holmes Safety Chapters (which provide for monthly safety meetings of all employees ) , and numerous other activities looking to safe operation of mine or plant . These features are supplementary to the fundamentals of safety-- adequate and effective supervision and discipline . Years of experience , however , have demonstrated that first - aid training is a good accident -prevention auxiliary and should be made an integral part of every company's safety program . Many safety-organization plans have failed because they have been based upon the assumption that the supervisory force should be given full authority and responsibility for achieving safety and eliminating accidents and that the workers , who are most vitally concerned , are nonessential . First -aid training causes the employees to feel that they have a personal and full participation in the safety program and is now available so readily that no individual or organization has any valid excuse for not having it . Early investigations made with a view to bettering health and safety conditions among the employees in the mineral industries demonstrated the need of prompt care of injured employees because , under the difficulties inherent in the occupation , seemingly unimportant wounds , when not treated promptly, became infected and caused permanent disability and even death . Many seriously injured persons , brought out of mines and plants by fellow workers who were ignorant of the approved methods of giving first aid or of safe means of transportation

Aug 1, 1934

By Reynold Q. Shotts

A study was made of the coal resources of an area in Jackson County, Ala., forming a part of the Flat Rock, Henegar, and Stevenson quadrangles. The area studied is a portion of the Plateau coalfield on Sand Mountain and is near the Tennessee Valley Authority's Widows Creek steamplant. Since no detailed geological study of this area had been published, some reconnaissance work was done. The coalbeds and adjacent strata such as sandstones, conglomeratic sandstones, and conglomerates were studied. Available drill logs, together with the areal geology, provided sufficient information to permit correlation of the coalbeds and an estimation of coal reserves. For all categories of reserves, computed on a regional basis, a total of 72,920,000 tons of coal more than 14 inches thick is estimated for the areas studied in Stevenson, Flat Rock, and Henegar quadrangles. Of this tonnage, 40,001,000 tons is estimated to have less than 60 feet of overburden. The total measured coal reserves for the above three quadrangles are 16,359,000 tons, with 12,411,000 tons under less than 60 feet of cover.

Jan 1, 1966

By Michael Rieber

The increase in f.o.b. mine prices of coal from $5/ton to over $18/ton in five years [1] has increased the significance of transportation costs. Coals produced in the vicinity of the consumer bear a much lower transport cost than those produced in the west. This differential may be used for flue gas desulfurization, other cleaning, or further processing of local coals. To the extent that western coals are cheaper to produce and have a lower sulfur content, they offset the locational disadvantage. To the extent that they have a lower heating value, the disadvantage is exercabated. Given the other conditions, an accurate analysis of transport costs will help suggest the location of coal mining and the moue of transport both transport costs and tariffs have risen. Together they have increased delivered coal prices, altered the balance between the use of coal and other fuels, helped to alter the location of mining activity, and put pressure on consumers to examine the cost effectiveness of alternative transport modes. Transportation options for long distance coal movements include rail, barge, pipeline, and EHV transmission lines. A summary of system parameters is shown in Table 2.1. Barge transport, pneumatic and slurry pipelines are discussed elsewhere in this report. Together with EHV, they have been the subject of previous studies [2,3,4]. Slurry pipelines have been shown to be especially useful where rails are not available [2] but the technical problems of dewatering, handling, and utilization of lines [5] remain unresolved. They are discussed in Section 3. Barge transportation depends on the location of the mine and consumer with respect to the waterway system. One drawback of barge shipment is interruptions due to winter, and low or high water conditions. Mine mouth power generation followed by EHV transmission of over 500 miles has been shown to be the most expensive means of delivering an equivalent amount of energy to consumers [2].

Jan 1, 1977

By James Ridenour

This report represents the first comprehensive accounting of lode mining sites in the Loon Creek mining district, Custer County, Idaho. Thirty-five mine and prospect locations have been added to the Bureau's Mineral Industry Location Subsystem (MILS) data base as a result of initial phases of a mineral appraisal of the River of No Return Wilderness; previously known locations were field checked and the updated information added to the data base. The district's major deposits are gold-copper-silver fissure-fillings hosted by biotite schist intruded by dikes ranging in composition from rhyolite to lamprophyre. These deposits contain a trace element suite similar to Tertiary pink granites and may be related to intrusion of the nearby Casto pluton. Continued firm gold prices could stimulate the search for precious metal occurrences in this and other mining districts in central Idaho.

Jan 1, 1983

By G. L. Oldwright, F. K. Shelton, W. E. Keck

"INTRODUCTION Zinc must be of high grade to satisfy the present demand. Even when the amount of premium paid is small, the purer metal as the buyers' preference. The following specifications for spelter were taken from the American Society for Testing Materials for 1927, Part I, pane 524. (The specifications for 1930, p. 582, are tile same.)Another specification for zinc of a much higher grade than any of the above has been established lately by the same society. The committee on zinc die-casting (Proc. Am. Soc. Test. Mat., vol. 31, 1931, p. 263) reached the following, conclusions: I. ""That the purest of zinc is necessary to produce stable zinc-base die castings, and as a result requested specifications for zinc spelter .with total impurities not over 0.02 percent."" Their tests showed that the die castings made of the purest zinc had the least elongation and the greatest tensile strength, and exhibited the least changes with temperature.Still more far-reaching claims are made for the properties of zinc containing over 99.99 percent metal. Zinc foil, for instance, may someday be made as a common commercial product. It would seem likely that the demand for zinc of high grades rill continue and that even purer varieties may be desired. This demand fits in with the modern trend in manufacturing plants of reducing the number of variables to a minimum by using pure materials, and of controlling the processing of metals during their various stages of fabrication by mechanical means instead of by expert laborers."

Jun 1, 1933

By Mark P. Meyer

During 1991 through 1993, the U.S. Bureau of Mines (Bureau) -Alaska Field Operations Center (AFOC) in cooperation with the Bureau of Land Management (BLM) -Arctic District Office and the State of Alaska, Division of Geological and Geophysical Surveys (ADGGS), conducted exploration, geological, geochemical, geophysical, mineral resource, and mineral potential investigations in the 6.7 million hectare Colville Mining District (CMD) study area. This mining district study area, located in northern Alaska, includes the Colville River drainage basin as well as 0.35 million hectares of the southern part of the National Petroleum Reserve in Alaska (NPRA). This investigation was conducted as part of the Bureau's continuing Mineral Land Assessment (MLA) mining district program. The Bureau's MLA mining district program is designed to provide reliable and comprehensive mineral resource information that supports mineral resource policy and land use decisions made by Congress and Federal land management agencies.

Jan 1, 2011