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By R. A. Hatch

The United States depends mainly on foreign imports, principally India, for an adequate supply of sheet mica suitable for its many uses in the electrical and electronics industries. Sheet mica has, in fact, played an indispensable role in developing these industries,4/ and, in turn, the products of these industries (radio, radar, electric motors, and many others) have become indispensable to the military forces. Because or these conditions, sheet mica in its better qualities long has been classified as a strategic and critical material, and from this stems the wide-spread interest in substitute materials of which synthetic mica is one potential type. The United States Departments of the Navy and the Army entered into a cooperative agreement with the Bureau of Mines in 1947 to study ways and means of synthe-sizing and growing mica crystals. This is one of a series of reports5/ that describe the results of this program.

Jan 1, 1956

The Aluminum Company of America (Alcoa) announced that the second unit at its experimental facility at Palestine, Tex. would begin production -in 1979, increasing the capacity of the facility to 30,000 tons per year. The plant uses an experimental process based on the electrolysis of aluminum chloride and reportedly uses 4 to 5 kilowatt hours per pound of aluminum produced, compared to an industry average of about 7 to 8 kilowatt hours per pound. Alcoa has reportedly signed a letter of intent with the Chinese government under which Alcoa will conduct feasibility studies on two new integrated aluminum projects and modernization of an existing aluminum plant. If the study results are favorable, Alcoa Engineers Inc. and the Import and Export Company of the Chinese Ministry of Metallurgical Industry could negotiate agreements to provide Alcoa technology and services for the projects.

Jan 1, 1979

By George S. Rice

In 1911 the Director of the United States Bureau of Mines instructed the chief mining engineer of the bureau , during an investigation of coal-mine safety conditions in Europe, to ask the directors of the various mine-experiment stations whether they would favor a European conference . The majority of the officials in immediate charge of experiment stations favored the plan , and Victor Watteyne, inspector general of Belgium, suggested that the United States call such a conference to be held immediately after the Eighth International Congress of Applied Chemistry, which was to assemble in New York on September 3, 1912 . Accordingly, invitations were issued by the United States Government to those countries having mine-experiment stations , namely, Austria-Hungary, Belgium, France, Germany , and Great Britain, and to those that contemplated the establishment of such stations , Canada and Mexico . All but Great Britain and Canada accepted ; Mexico designated a representative , who later found it impossible to come. The Government of Great Britain in declining, expressed regret at its inability to accept ; an informal statement was made that the opening of the experimental gallery at Eskmeals , England , occupied the attention of the officials in charge . Delegates were appointed by their respective Governments as follows: Austria-Hungary, Julian Czaplinski , royal mining engineer. Belgium, Victor Watteyne , inspector general of mines . France, J. Taffanel, director of the Lievin experiment station . Germany, Carl Beyling, bergassessor, director of Dortmund experiment station. United States , Charles E. Munroe, consulting explosives expert and George S. Rice, chief mining engineer of the Bureau of Mines . Subsequently Mr. William O'Connor , a mining engineer and mine operator of Wales , who opportunely appeared at the Pittsburgh station with letters of introduction from the South Wales Institute of Engineers and from prominent mining officials of Great Britain , was unanimously invited to take part in the meeting as an unofficial representative of Great Britain . Messrs . Beyling, Taffanel , and Watteyne were met in New York on September 3, by George S. Rice, who accompanied them to Washington, where they were welcomed by Director J. A. Holmes , of the Bureau of Mines , and where , with the delegates to the Eighth International Congress of Applied Chemistry , they were presented to President Taft . Mr. Taffanel was unfortunately called back to France just before the scheduled time of the conference on account of a mine disaster ; the other delegates , including Mr. Czaplinski , convened at Pittsburgh on the morning of September 14. Mr. Rice, representing the Director of the Bureau of Mines , acted as temporary chairman , and called the meeting to order.

Jan 1, 1914

By W. M. Nabors

As part of a program to promote conservation and efficient utilization of petroleum resources, Bureau of Mines engineers at the Morgantown (W. Va.) Petroleum Research Laboratory are studying secondary oil-recovery projects in the Appalachian region. The increasing demand for petroleum and its products and the increasing cost of exploratory drilling tend to emphasize the importance of improving the recovery of oil from known petroleum reserves. Published reports setting forth the pertinent facts of these operations may help others to profit by the experience. This report presents the results of a study of secondary-recovery methods used in West Virginia by the Piedmont Oil and Gas Co., the Ryan Oil Co., and Water floods , Inc., on their Roane County leases in the Walton and Clover Rush Run pools. The principal oil-producing horizon underlying the area studied is the Big Injun sand, at approximately 2,000 feet. The sand is often referred to as blanket sand because it underlies much of the State and is oil-productive in many localities. Most of the pools in the area were discovered during 1907 to 1910 and were similarly developed and operated.

Jan 1, 1960

By John E. Conley

Of the three chemical elements most vitally essential for plant growth the United States, before World War I, had developed ample domestic supplies of but one-phosphorus. During and shortly after the war period, the fixation of nitrogen was greatly expanded in this country, as in many others, insuring a supply adequate for agriculture as well as for munitions. However, in spite of a search for sources of the third element, potassium, which began years before the war, attained almost frantic intensity between 1914 and 1919, and continued for 10 years thereafter, it was not until 1921 that the American Trona Corporation put its Searles Lake operations into continuous production. This company in 1926 became The American Potash & Chemical Co. but has never supplied much more than 15 percent of the potash consumed in the American market. Likewise, though discovered in 1921 in drill cuttings from oil wells, it was not until 1926 that domestic deposits of potassium salts adequate to render the United States independent of foreign sources of supply were proved to occur in the Permian Basin of Texas and New Mexico.

Jan 1, 1944

By Henry Kreisinger, WALTER T. RAY

This preliminary bulletin was written as the first of a series of several on the significance of drafts in steam-boiler practice, the succeeding bulletins to be along the same lines but of a more advanced character. The conclusions arrived at are tentative, and are the result of a study of one of the many problems growing out of a general plan of the United States Government to increase the efficiency with which the coals of the country are being used. Greater efficiency requires better boiler and furnace design. The experimental study of drafts on which the conclusions presented in this bulletin are based formed part of the fuel-testing investigations that were carried on by the technologic branch of the United States Geological Survey and have been transferred to the Bureau of Mines. The experiments made seem to indicate that it is possible to double or treble the capacity of a plant without making any radical changes the furnaces and boilers. These increases require about double and treble the quantities of air to be put through the fuel beds and boilers. It also seems probable that rebafHing the boilers will often permit the capacity to be doubled or trebled, while still getting more steam than formerly per pound of coal for uses outside the boiler room. These experiments were undertaken with the object of clarifying ideas concerning the passage of air through fuel beds and boilers. Measured weights of air were passed through two beds of lead shot, series, one of which remained always the same and represented a boiler; the other being varied as to size of shot and depth of bed, and representing a fuel bed. Careful observations were made of the weight of air passing through the beds per minute. All data were plotted in many charts, so as to permit the study of them from several points of view. A number of laws were deduced bearing on the relative amounts of power required to force air through fuel beds of various thicknesses, composed of various sizes of coal, and through boilers of various lengths and areas of gas passages. An important part of the discussion relates to an increase in the capacity of boilers by increasing the amount of power applied to pressure and exhausting fans and thus forcing several times as much air through the fuel beds and boilers. may be possible, as a result of these investigations, to raise the rate of working the boiler heating surface to three or even four times its present value. Such an increase would undoubtedly mean new designs of grates, stokers, furnaces, and boilers, especially fitted for high rates of working. Fan equipments designed to supply three or four times as much air under several times the pressure would be provided with more efficient engines, thus giving an additional factor favoring high-capacity working. It must be borne in mind, as stated above, that the results are tentative. It will cost money to force gases at high speeds through fuel beds and boilers, and there will soon be pressing need of such quantitative data as will enable the largest possible part of the energy imparted by the fans to be advantageously utilized. We desire, to thank our superiors, especially Messrs. L. P. Breckenridge and D. T. Randall, for their helpful criticism and suggestions.

Jan 1, 1911

By McHenry Mosier

This progress report on a national survey of the use of detachable bits in metal mines covers 10 mines. It presents comparative costs for drilling with conventional and detachable bits, describes the reconditioning of drill steel, and gives various data on rock drilling at these particular mines. Reports to follow will include similar data on drilling at other metal mines in the United States. ACKNOWLEDGMENTS This report is based on costs and data developed and furnished by the operators of the mines visited. The author is greatly indebted to the officials and staff members at these mines for their cooperation and assistance.

Jan 1, 1936

By Paul McIlroy

Costs of producing lead from various known resources in the United States are developed by the Bureau of Mines to define the future availability of domestic lead at various price levels. It is estimated that 60 million tons of primary lead (75 percent of the total resource) is available at $0.20 or less per pound; 72 million tons (90 percent of the total) is available at $0.50 or less per pound; and the 79 mil- lion ton total estimated resource can be obtained at a price or $1.82 or less per pound. The supply available at $0.20 per pound or less will meet demand for over 78 years at the 1970 annual consumption rate of 763,000 tons.

Jan 1, 1974

By Robert R. Perron

The U. S. Bureau of Mines is engaged in many diverse programs for improving mine safety. Of particular interest to the Bureau are new and improved means for minimizing the hazard of fire which can be initiated by prolonged low energy electrical faults on trolley line systems. When a high energy fault occurs on a trolley line, wherein the current exceeds the magnitude normally drawn by legitimate loads, such as locomotives, then the circuit breakers at close-by power rectifier sets trip. Tripping of the breakers not only protects the equipment at the rectifier sets, but also disconnects the energy source from the fault and thereby minimizes the fire risk. However, the fault current is frequently of a level substantially below that required to trip the overload breakers. When the fault is a substantial percentage of the set level of the breakers, the energy dissipated by the fault is frequently sufficient to clear the system by rapidly burning itself clear. Such a fault is often short-lived and does not present as serious a fire risk hazard as a prolonged, much lower energy fault, wherein the energy level is too low to clear the system. The breakdown of a trolley line insulator, in which there was a 15 to 30 ampere fault to ground, would represent such a fault or illegitimate load and a substantial fire risk.

Jan 1, 1975

By W. L. EGY, GEORGES. RICE, L. M. JONES, J. K. CLEMENT

This report has been prepared, not only for the purpose of recording the results of the first series of coal-dust tests conducted in the experimental mine of the Bureau of Mines, but also to place before the mining public a description of the mine and an account of the objects sought in its establishment. Soon after the organization of the technologic branch of the United States Geological Survey, J. A. Holmes, then chief of the branch, concluded that for the solution of various problems relating to the causes and prevention of mine explosions it would be best to carry on large-scale tests in a mine rather than in a surface gallery. The idea of utilizing the underground passage of a mine for making explosion experiments did not at' first meet with general approval among investigators in this country or abroad. Many thought a mine passage was not a proper place in which scientific tests could be conducted, as great difficulty in controlling conditions was expected. However, after all arguments for and against such an investigation had been carefully considered, plans for opening an experimental mine were definitely adopted by the Bureau of Mines in 1910, and an allotment of funds was made to carry out the project. The first endeavor was to find an existing mine suitable for the purpose, but the mines offered by owners were either worked out, were wet, had poor roofs, or presented complications of various kinds, so that it was finally decided to open a mine if a site could be obtained having natural conditions that would fill the various requirements. A most desirable location was found on property of the Pittsburgh Coal Co., near Bruceton, Pa. The president of this company, Mr. W. K. Field, the general manager, Mr. G. W. Schluederberg, and the chief engineer, Mr. E. J. Taylor, rendered every possible service in

Jan 1, 1913

By J. J. S. Sebastian

The process development described in this report was carried out at the Morgantown Station of the U. S. Bureau of Mines in cooperation with West Virginia University. An experimental laboratory-scale pilot unit to gasify coal dust in entrainment was constructed on the Campus of the University in Morgantown. The enormously accelerated demand for liquid and gaseous fuels and utilization of our immense coal resources require that a low-cost process be developed for the gasification of a wide variety of coals. Such a process would be a major factor in lowering the cost of synthetic liquid fuels. None of the proc3sses developed in Germany prior to and during World War II, such as the Winkler process, the H. Koppers dust gasification process, the Wintershall-Schmalfoldt process, etc., meet all the requirements for a low-cost process under American conditions. Nor has any other process designed and experimentally operated at atmospheric pressure during the post-war period in this country appeared to fulfill all of the necessary conditions for a low-cost process.

Jan 1, 1950

By George H. Holmes

This report describes the results of a reconnaissance survey of areas in California and Nevada considered favorable to beryllium mineralization. Pegmatite dikes, veins, intrusive sills, contact metamorphic, and disseminated deposits as well as tactite deposits in the former major tungsten-producing districts were investigated. A general geographic pattern of beryllium mineralization was found to be concentrated along a wide belt in eastern Nevada extending from the Ruby Mountains, Elko County, south through the Fish Creek Range, Eureka County, the Snake Range, White Pine County to the Virgin Mountains in Clark County, Nev., and Mohave County, Ariz. Sporadic occurrences of beryllium are in central and southern Nevada, and in the pegmatite dikes of San Bernardino, Riverside, and San Diego Counties, Calif., and the granite masses of the southern Inyo Mountains, Inyo County, Calif. Principal company activities are centered in the Snake Range, Fish Creek Range, and the Virgin Mountains, Nev., and the Inyo Mountains, Calif. Other areas in California and Nevada have been superficially explored with results indicating either limited or widespread, but submarginal, mineralization. Although beryllium was found to occur, to some extent, in many of the deposits, mining has been hindered by the lack of a market for beryllium ores and concentrates other than standard-grade beryl and also by the erratic pattern of mineralization and the high exploration and beneficiation costs required to produce a marketable product.

Jan 1, 1963

This Bureau of Mines investigation addressed two primary issues of air velocity measurement in mines: the determination and use of correction factors, and the development of guidelines for the selection of a suitable site at which the measurements should be taken. Other facets of the investigation included a comparison of measurement methods and devices, and aircourse cross-sectional area measurement. The study consisted of theoretical, laboratory, and in-mine investigations. The measurement devices included in the experimental phase were vane anemometer, vortex shedding anemometer, a prototype thermoan-emometer, smoke tube, and oil of wintergreen sprayer. The measurement methods included single-point centerline, timed-point traverse, continuous traverse for the anemometers, and various distances and cloud positions for the smoke tube and oil of wintergreen devices. The study resulted in guidelines for measurement site selection that are applicable to most inmine situations. It also showed that the use of correction factors is problematic. There are many potential pit-falls and there are cogent arguments against using certain correction factors. However, generalized correction factors were developed that can be successfully applied in routine ventilation work, provided that their use is properly understood.

Jan 1, 1985

By Raymond Derzay

This publication is intended to be of value to the mineral industry in establishing and maintaining effective programs for preventing noise-induced hearing loss. Factors involved in this loss and the need for and the requirements of an effective hearing conservation program are discussed. The legal and legislative history of compensation for hearing loss is briefly reviewed. A review of statutes is not attempted since several States have recently modified) or are in the process of modifying their laws regarding permissible noise exposures) required hearing protection) and/or compensation for hearing loss. A review of other aspects of the problem of industrial noise in terms of medical, physiological) and psychological frames of reference is included. A hearing conservation program is described in detail. Appendixes detailing the names and addresses of a few equipment suppliers are included. References are provided for those who may wish to delve more deeply into the medical, technical, and scientific considerations of noise and its effect on man.

Jan 1, 1972

By Paul T. Alexander

After evaluating preceding studies and designs of lightweight supports, ESD selected the all-hydraulic and the hydromechanical concepts for detailed design and fabrication. Further analysis and testing showed that the all-hydraulic design was economically justified and met all the crucial engineering, manufacturing, and design criteria identified during the evaluation phase. Following Bureau of Mines approval of the detailed design, four all-hydraulic support models were fabricated. Once functional and structural testing was successfully completed, 40 additional units were constructed and distributed for in-mine testing. The units were very well-liked by all three demonstration mines. The wide- spread interest in supports for seam heights greater than 8 feet led to expansion of the design data package. ESD designed four basic models to cover the new height range, but no hardware has yet been fabricated for the new design.

Jan 1, 1982

By M. J. Spendlove

A progress report is presented on a research program in which an attempt was made to develop a practical sulfide-volatilization process for recovering tin from low-grade Bolivian ores. Shaft-furnace designs and operating techniques were studied in a series of experiments in which the objective was to sulfidize cassiterite to stannous sulfide, remove the stannous sulfide by volatilization, reconvert the stannous sulfide to stannous oxide, and collect the resulting fume. A shaft furnace was developed and operated in a final test in which many of the previous difficulties were surmounted. Since the supporting funds were exhausted at this point, the project was discontinued; recommendations for further improvements in furnace design and operation were made on the basis of interpretation of experimental results obtained in shaft-furnace experiments and other related studies.

Jan 1, 1955

By K. Robert Dorman

Spray-applied polyurethane foam was used to insulate the walls of heated rooms excavated in permafrost. The experiment was designed to determine whether polyurethane foam can be sprayed successfully on frozen ground under freezing conditions and to measure the effectiveness of the insulation in maintaining--at elevated temperatures for an extended period--a room excavated in frozen ground. Two manufacturers' foams were investigated in the laboratory. Subsequently, one of the foams was employed to insulate two small rooms, one in frozen gravel and one in frozen silt, in an experimental tunnel belonging to the U.S. Army Cold Regions Research and Engineering Laboratory (USACRREL) near Fairbanks, Alaska. Following insulation, heat was introduced into the two rooms. Heat migration across the insulating barrier into the walls, in addition to wall closures, was monitored over an 8-month period. The results show that polyurethane foam can be successfully sprayed on frozen ground in below-freezing temperatures. Given this type of insulation, together with winter cold to supercool the surrounding ground, it should be possible to maintain a shaft or heated room in permafrost for several years.

Jan 1, 1970

By M. Jaffe

The data developed in this study establishes the technical and economic feasibility as well as the improved health and safety characteristics of a novel mining concept. The mining concept is a modified longwall technique using prestressed tendons for roof control, longhole blasting for fragmentation, and remote mucking. The technical feasibility was found to be dependent on the state of the art, while economic feasibility was found to be dependent on particular minerals and on supply and demand. Since these two conditions are not necessarily coincident in time the data is presented in the report in a manner that enables the mining engineer to perform a rapid preliminary technical and economic analyses for a specific property.

Jan 1, 1977

By T. Muldoon

Literature review and extensive field survey of line and check curtain materials and practices showed: ? Miners, in general, know how to set tight curtains, and do so when needed. ? The tradeoff is economic; tight ventilation is labor-intensive. Line and check curtain techniques found are catalogued and evaluated. A fieldworthy 10 ft extensible brattice to maintain a 10 ft setback was found in use in two mines on continuous miner faces. This technique was evaluated in the laboratory for leakage and methane control at the face. Significant results include: 1) Air leakage through a gap in the extensible curtain depends upon the ratio of the cross-sectional areas between entry and return as well as gap area; 2) Gap shape has no significant effect on methane concentrations at the face -increasing gap area diminishes ventilation effectivness; and 3) Substantial reductions of CH4 concentrations at the face were accomplished by brattice extensions with gaps of up to 5 ft2 in area. An "inby hook," inserted in the roof automatically to make possible the deployment of a longer (20 ft) brattice extension in the context of a remotely controlled miner, was tested in various roof types. Insertion of this design succeeded only in coal.

Jan 1, 1982

By R. H. Fernald

In 1900, as far as available records show, there were only two producer-gas power installations in the United States. In June, 1915, the number probably exceeded 1,000. Of this number, some 84.5 per cent comprised small plants using anthracite, and only about 15 per cent of the total number utilized bituminous coal and lignite. In addition to these, two plants used wood, and three or four used oil. In the main, however, the larger sized units are operating on bituminous coal and lignite. During the early years of these plants little success was anticipated from the use of bituminous coals and lignites, but in 1904 and 1905 it was fully demonstrated at the Government testing station at St. Louis that these fuels could be utilized to excellent advantage. However, although many producer-gas plants in daily operation are using bituminous coal and lignite, many power-plant men are still skeptical regarding the successful commercial use of these fuels.

Jan 1, 1916