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By Raymond B. Ladoo

Toward the end of 1920 , the average grades of ground feldspar offered to the pottery industry were so poor and so generally unsatisfactory that many of the largest consumers decided to take active steps for their own protection . A few of the potters made arrangements to grind their own feldspar , while others asked the Bureau of Mines to make a detailed study of the problem and to suggest methods of improvement . Accordingly such a study was undertaken, the partial results of which are outlined in this preliminary report . The outstanding features of the present feldspar industry which are of interest in this connection are stated below. (1 ) Many grinding companies do not own or control all or even a major part of their sources of crude material , but buy in job lots from many sources . (2 ) There is great need of more adequate engineering and chemical control over mines and mills . ( 3) ~ Out of date , inefficient methods and equipment for mining and grinding are in common use . (4) Little or no cooperation exists between feldspar producers , but on the contrary many feldspar companies are exceedingly secretive . This tends towards (a) preservation of obsolete methods ; ( b ) want of knowledge of the essential features of production , market requirements , and the relation between total milling and consuming capacities of the country; ( c ) inefficient and often mistaken trade practices ; ( d) unprofitable and even ruinous competition in dull periods . (5) The small size of many feldspar deposits precludes maintenance of an efficient organization at each individual mine . ( 6 ) Many of the best deposits of feldspar situated close to railroads are becoming depleted , which results in gradual lowering of grades , and increase in cost for better grades . (7) There is a lack of exact mowledge of the ceramic properties and behaviour of feldspar by some consumers , which results in ( a) purchase of feldspar on the basis of price alone , thus encouraging low production costs at the expense of quality , and ( b) inefficient and expensive cross- hauling of both crude and ground feldspar .

Jan 1, 1922

By August J. Kwitowski

This Bureau of Mines report summarizes the development of a protective operator compartment for a new generation thin-seam mobile bridge carrier. The developed compartment is commercially available and is currently employed on approximately 15 bridge carriers used in the mining industry. The design of the compartment, which employed human factors engineering and small- and full-scale mockup models, is fully described. Details of the compartment's fabrication, evaluation, and demonstration in a commercial low-seam coal mine are also provided.

Jan 1, 1986

By L. C. IlsLey

The United States Bureau of Mines has been conducting investigations of electrical equipment curing a period of more than 25 years in an endeavor to encourage the development of safer electrical equipment for coal mines. In order to conduct these investigations in an orderly manner they are carried out under a published schedule of tests known as Schedule 20, which specifies detailed requirements for motors, controllers, etc., and fees covering the various inspections and tests made as part of a routine investigation.

Jan 1, 1937

By L. C. IlsLey

The United States Bureau of clines has been conducting Investigations of electrical equipment during a period of more than 25 years in an endeavor to encourage the development of safer electrical equipment for coal mines. In order to conduct these investigations in an orderly manner they are carried out under a published schedule of tests known as Schedule 2C, which specifies detailed requirements for motors, controllers, etc., and fees covering the various inspections and tests made as part of a routine investigation.

Jan 1, 1937

By R. N. Roby

In the course of the Bureau of Mines investigations for suitable sources of high-aluminum clay for the production of alumina, the Whiteware clay deposit was examined in August 1942 by G.N. Bennett, mining engineer, Bureau of Mines, Montana District Office. This report presents the factual data obtained by the investigation, which also includes data on trenching and drilling, and the results of some refractory tests and chemical analyses of representative samples of the clay later taken from some of the best trench exposures and from adit dumps.

Jan 1, 1949

By Lyman C. Hitchcock

The objective of this program was to determine the minimum luminance requirements for underground coal mining work from the working face to the first transfer point. The resulting data encompasses 114 visual tasks from conventional continuous and longwall mining methods representing the salient visual tasks found in the jobs listed. Cutter Operator Roof Bolter Face Drill Operator Airdox Operator Longwall Jackman Shuttle Car Operator Loader Operator Shot Fireman Continuous Miner Operator Longwall Head Conveyor Operator Longwall Tail Conveyor Operator

Jan 1, 1973

By Don M. Coulter

"INTRODUCTION Bauxite, in Appalachian Alabama, occurs in the Rock Run and Goshen Valley districts in Cherokee County; in Nences Creek Valley near Jacksonville; near Anniston in Calhoun County; north of Fort Payne in DeKalb County; near Ashville in St. Clair County; and near Talladega in Talladega County.In February 1942, Preston E. Cloud, Jr., assistant geologist, Federal Geological Survey, began a study of these bauxite deposits and the geology relating thereto.The Bureau of Mines established field headquarters at Piedmont, Calhoun County, in July 1942. Mineral agreements covering a total of 11,097 acres were executed with 15 landowners in the Rock Run district; 38 in the Goshen Valley district, covering 7,575.5 acres; and 3 in the Nances Creek Valley district, covering 988.5 acres. Drilling was done on the properties of 9 land¬owners in the Rock Run district, and on the property of 1 landowner each in the Goshen Valley and the Nances Creek districts. Drilling began October 26, 1942, and ceased on May 17, 1943.Power drilling was supplemented by a labor crew that drilled hand-auger holes in shallow deposits and sampled .old shafts, mines, and mine dumps.In all, 222 holes for a total of 13,250 feet were drilled. Of these holes, 88 penetrated bauxite but too low in grade to constitute ore."

Mar 1, 1948

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 R. H. Church, William E. Webb, Walter E. Pittman, James R. Boyle

As part of the Bureau of Mines health and safety research program, a short-range locator system, capable of locating miners who have become trapped following a mine accident, has been devised, The system consists of a lightweight, low-power radio transmitter incorporated into a miner's cap lamp battery and a directional receiver carried by rescuers. Prototype transmitters have been constructed, and the propagation of their signals has been investigated, The detectability of the signal in underground coal mines has also been investigated, This research indicates that a short-range location system would serve as an economical and practical means of locating miners from within the mine following an accident,

Jan 1, 1984

By J. R. Thoenen

In June 1929 the Bureau of Mines issued a 13-page information circular entitled "Mineral Wool," which was one of the first publications to present to the public Rome technical aspects of the mineral-wool industry. Since then several articles on the subject have appeared in the technical press as well as in publications of State organizations. Inquiries for information on mineral wool have continued to be received by the Bureau of Mines in large number, and in 1935 it was decided to make a field survey of the plants then producing and to collect therefrom technical data to be compiled in a paper for nubile distribution. With the cooperation of the industry, this survey was made, and Information Circular 6984, Mineral Wool, was published in January 1930. The issue was exhausted after a few months, and requests for copies continued to come to the Bureau. As opportunity arose, further field studies were made in American as well as Canadian plants. The present circular contains the essential information in Information Circular 6994 together with date from later field studies.

Jan 1, 1939

By R. G. Nelson

This report covers investigations of the Bureau of Mines for the period of June 15, 1952, to June 15, 1953, on a research project for the Materials Laboratory, Wright Patterson Air Force Base, Dayton, Ohio. The primary purpose of this investigation was to make high-purity chromium-base alloys having room-temperature ductility and high-temperature strength. The Nonferrous Metals Branch of the Bureau of Mines, Albany, Oreg., has, during the past 7 years, developed on a laboratory scale a hydrogen treatment method for making high-purity chromium that can be fabricated into thin sheet and wire. This material can be bent at room temperature. The object of this investigation was to use this material to develop improved chromium-rich alloys for high-temperature uses.

Jan 1, 1955

By F. A. Rutledge

The Millet copper deposit is on the north shore of Iliamna Lake in southwestern Alaska. Copper mineralization occurs in a zone of altered limestone .adjacent to and intruded by a diorite porphyry with some diabase facies. During 1949 and 1950, the Bureau of Mines investigated this prospect as a part of the U. S. Department of the Interior program in Alaska for the development of critical and strategic minerals. Field work was begun August 8, 1949; it was recessed November 28, 1949, because of inclement weather. The work was resumed Nay 28, 1950, and completed July 3, 1950. The program of investigation by the Bureau of Nines included topographic surveying, machine and hand trenching, diamond drilling, and sampling the zones of mineralization. This report outlines the general geology of the area, gives a description of the deposit, and contains the factual data resulting from work by the Bureau of Mines.

Jan 1, 1952

By Grant R. Brown

The report provides guidance for determining those environmental impacts associated with the surface mining of steeply pitching coal seams. In addition to the environmental impacts, four additional issues are addressed, namely (1) Time and motion studies of those coal mining systems employed in mining seams which pitch in excess of 250, (2) Assessment of those mining techniques, (3) Development of rationale for the mining methods employed, (4) Identification of the reclamation practices and determine whether these practices were in compliance with appropriate Federal and State regulations. Five surface mines located in three geologically distinct basins of the United States were analyzed during the period of August through November 1979. The three basins include the Hanna Basin of Wyoming, the North Park Basin of Colorado and the Southern Anthracite Field of Pennsylvania.

Jan 1, 1980

Real economic growth for 1988 may fall short of the 3.3% projected by the U.S. Department of Commerce in August 1988 be-cause the summer drought and intense heat in many areas curtailed output more severely than expected. The economy grew at an average annual rate of 3.0% for the first three quarters of the year, slowing in the second and third quarters. Export growth, which occurred even as the dollar edged up com-pared with other industrial country currencies, was an important factor in the expansion. Notable gains were posted in sales of machinery, computers, aircraft, chemicals, and telecommunications equipment. Imports increased, but not as much as exports, and the U.S. trade position was still much improved from that of 1987. Personal consumption expenditures grew slightly faster than the economy as a whole. Purchases of consumer durables showed notable strength in the first half of 1988, but slowed down in the third quarter. [ ] Despite the moderate rise in interest rates, business spending for new plant and equipment also rose and contributed to 1988 gross national product (GNP) growth. Both new business investment and export demand spurred orders for U.S.-made machine tools. Orders for machine tools for the first 8 months of 1988 were almost triple those for the corresponding period in 1987.

Jan 1, 1988

The United States has not begun commercial operations to tap its largest poten-tial sources of oil supply - oil shale and coal. The reason is that domestic petrol-eum has been plentiful in the past and liquid products probably could be produced from it at the lowest cost. In view of the ever-increasing need for petroleum in the United States, the critical international situation threatening foreign supplies, the growing demands for steel, and the heavy costs to industry of constantly discovering and developing new oil fields, it is believed that the prompt development of a synthetic fuel industry based on oil shale and coal is not only requisite to safeguard our oil supply but is an economically sound course for the foreseeable future. To neglect its development is to close our eyes and minds to our own resources at a time when they are needed critically. It also is apparent now that neither the Government nor industry would be taking any considerable economic risk in starting the initial plants, especially as measured against their potential value in meeting critical oil and chemical demands and in building a new industry in the West.

Jan 1, 1951

By Gordon R. Sima

This contract is concerned with feasibility studies, design and fabrication of a prototype hand-held test instrument and a machine-mounted test Instrument for measurement of electrical shock hazards of mining machines. This report presents the proposed and detailed design of the hand-held test instrument and the machine-mounted test instrument. Theory of operation of each instrument is discussed and includes the operating parameters.

Jan 1, 1976

By Bernadette C. Michalski

THE RAPID GROWTH of the small Albanian mineral industry in the 1950's began to taper off by 1961 and slackened sharply in 1963. The abandonment of Soviet and East European technical assistance programs in mid-1961 greatly affected Albania's mineral development, since four-fifths of all technical aid personnel were engaged in mineral activities. Chinese assistance apparently has not been able to fill the void. Overall mineral production increases during 1961-63 averaged 1 percent per year in value, as compared with 3 percent in 1959 and 5 percent in 1960. Although by world standards Albanian mineral output, except for chromite, is insignificant, it is vital to the country's domestic economy. The mineral industry generated about 14 percent of the gross industrial product in 1962 and employed a notable share of the industrial labor force. In recent years, mineral products have provided about three-fifths of the country's exports by value. Chromite and iron-nickel ores together constituted from one-fourth to one-third of the total export value. In 1963, total trade turnover increased 12 percent over 1962.

Jan 1, 1964

By J. Fletcher Smoak

Consumption of abrasive materials in the United States decreased 23% in value from that of 1981 to $262 million, of which 53% was manufactured abrasive, 39% was industrial diamond (natural and synthetic), and 8% was natural abrasive. Production of natural abrasives, excluding industrial diamond, appeared to be stable when compared with that of 1981. Production of tripoli, a porous siliceous rock, increased slightly after decreasing steadily over the three previous years. The production increase of garnet, an abundant iron-aluminum silicate, was attributed to increased output from one plant that had completed an expansion program in late

Jan 1, 1983

By H. W. GILLETr, E. L. Mack

The production of small heats of alloy steels on an experimental scale is often desirable in beginning the study of new alloy steels before large amounts of expensive alloys are used in heats of commercial size. Such small heats can sometimes be made up at crucible-steel plants, but few crucible-steel makers care to undertake experimental heats for other firms. Small electric furnaces offer some advantages over crucible furnaces for experimental work. Hansen1 in 1909 described a small 100-kilowatt single-phase, direct- arc furnace with a capacity of 50 to 300 pounds of steel, and such furnaces, of 200 pounds capacity or larger, are being successfully used by various firms for experimental work. They have the advan- tage of using the same metallurgical procedure as is used in prac- tice for larger electric furnaces. The very small sizes have the draw- back of lack of precision in controlling the carbon content of the steel. Small Rennerfelt two-phase, indirect-arc furnaces of 40 to 60 kilo- watts and small Industrial Electric Furnace Co. furnaces, single- phase with one electrode embedded in the hearth, of 25 to 50 kilo- watts, are also in use by a few firms for experimental work or for production on a very small scale. Hoskins carbon-plate resistor crucible furnaces are also sometimes used. Little seems to have been published on the use of these furnaces in making experimental alloy steels. Keeney' has given data on the making of uranium steels in a tilting Siemens furnace of 25 pounds capacity, and has described a small stationary Siemens furnace.

Jan 1, 1922

1.0 SCOPE AND REGULATIONS 1.1 This specification covers the minimum requirements for material handling and associated equipment including design and materials. 1.2 This specification requires compliance with all federal, state, local laws and regulations which may be applicable including the Occupational Safety and Health Act, Construction Safety Act as well as rules, regulations and standards of the Secretary of Labor.

Jan 1, 1979