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By H. R. Shell

The work on synthetic mica and related subjects is being reported in a series of technical articles (see Supplementary Bibliography), each of which describes some special aspect of the subject. This is the final report on chemical analysis of the fluoride-containing silicates. A condensation of this report has been published (26).3/ Chemical analysis affords one of the best means of ascertaining the final com-position of either a heterogeneous mass or a single pure crystal, particularly where some constituents may be volatile. The analysis of fluoride-containing silicates was not so well known or understood that highly accurate results were commonplace. For example, on synthetic mica a university laboratory reported 11.6 and 9.2 percent fluoride when at least 13.3 and 11.3 percent were present, respectively; a commercial testing laboratory reported 9.14 percent as compared to 12.6 percent; and a glass company reported 7.0 percent as compared to 9.0 percent present. No intimation is made that these analysts could not have done better, but the point to be stressed is that the methods in use were long, tedious, and generally required a certain familiarity for best results.

Jan 1, 1956

By Lloyd H. Banning

ELECTRIC smelting tests were conducted at the Northwest Electro-development Experiment Station, Albany, Oreg., to develop a feasible process for producing silicomanganese from siliceous manganiferous material. The Jackson County, Oreg., material used was massive and contained rhodonite as the most abundant mineral. Both raw and beneficiated materials were tested; various proportions and types of fluxes and reductants were used to make up the furnace charges. The silicomanganese product was used successfully in manufacturing various steels at industrial plants. The manganese content of the samples ranged from 23 to 28 percent; silica plus alumina content was as high as 55 percent-about four times the maximum specification for Metallurgical-grade ore. Sink-float laboratory tests indicated that the manganiferous material was amenable to beneficiation. Over 2 tons of rhodonite concentrate was prepared for smelting tests in a sink-float operation. Only the minus-3/4-inch, plus-8-mesh fraction was fed to a heavy-medium cone; over 97 percent of the manganese was recovered in the sink product, which contained 32.4 percent manganese and 44 percent silica plus alumina. About 25 percent of the silica was removed in the float product.

Jan 1, 1959

By Dennis R. Dolinar

The National Institute for Occupational Safety and Health?s Pittsburgh Research Laboratory conducted a full-scale test of a composite polyurethane-aggregate seal in a hydrostatic chamber at the Lake Lynn Experimental Mine. This composite seal consisted of a polyurethane and limestone aggregate core that was formed between two concrete block walls. In the hydro-static chamber test, water is used to pressurize the seal. During the test, the maximum average water pressure the seal was able to withstand was 18.9 psi. Further, the seal began to yield at an average water pressure of only 17 psi. At the time of the test, the minimum seal design requirement was 20 psi under 30 CFR4 75.335 (2005). Therefore, based on this test, the seal did not meet the regulatory minimum design requirement. Uniaxial compressive tests conducted on samples from the polyurethane-aggregate core revealed that both the compressive strength and the elastic modulus of the material were much less than that for polyurethane only with a density of 10.0?12.0 lb/ft3. The significant reduction in the strength and stiffness of the polyurethane-aggregate mixture results from the formation of a soft polyurethane foam around each piece of aggregate. The formation of the soft foam seems to be caused by residual moisture from the aggregate. The moisture also caused the density of the polyurethane in the polyurethane-aggregate mixture to be less than the design requirements. The lower density of the polyurethane in the mixture, along with the formation of zones of pure polyurethane only, resulted in the overall seal density being less than the design requirements. During seal construction, steps were taken to control the moisture, but were not successful. An analysis of the seal failure showed that the calculated shear stresses at failure and the estimated shear strength of the polyurethane-aggregate mixture are fairly close. This suggests that the strength properties of the polyurethane-aggregate mixture along with a weak zone of poorly bonded aggregate controlled the maximum pressure the seal could withstand. At the time of the seal testing, the minimum design requirement was 20 psi, as specified at 30 CFR 75.335 (2005). New emergency temporary standards for seal designs were promulgated on May 22, 2007, with a minimum requirement of 50 psi under specified conditions. However, it will be shown that the evaluation of the polyurethane seal performance as designed to meet the older 20-psi criterion can be relevant to the design requirements under the new standards.

Jan 1, 2008

By R. Lusignea

This report describes the development of a device for the nondestructive testing of resin grouted roof bolts by means of mechanical frequency response. Various alternative methods were evaluated and the mechanical frequency response method was selected. An interactive program of design, testing, and development culminating in the current prototype instrument demonstrated the capabilities of the method and suggested potential applications of the instrument. The resin bolt testing device utilizes a swept frequency dynamic compliance measurement in the 1 to 2 kHz range which is interpreted by an electronic signal processor to give a "GO" or "NO GO? readout. Field tests have shown that the device can reliably determine the bond quality of the front half of the bolt (nearest the roof surface). Tests were carried out on both experimentally installed bolts and typical mine bolts installed by a conventional bolting machine. The development program has led to recommendations for improvement of the prototype and future development work.

Jan 1, 1979

By Raymond G. Travis

This report describes coal-mining methods, power requirements, coal production and distribution, and coal resources of the Bull Mountain coal field in Musselshell and Yellowstone Counties, south-central Montana Investigations in the field, were conducted by Bureau of Mines engineers The report contains a short summary of the geology and geography of the field and discusses the following information secured during the field study: Method of mining practiced at each mine, including a description of each phase of the mining cycle. Coal produced and its distribution at each mine. Power requirements and the consumption of electricity per ton of coal produced by mines. Number of non employed by mines, and the production per man per shift underground and the over-all production per man employed. Estimates of future production and power requirements for the field as a whole. This information should be of benefit to any company or individual planning the development of now coal mines in the area or the expansion of present operations.

Jan 1, 1950

By Serge Rudchenko

A study to determine the potential use of retaining structures in open pit backfilling. Research and review of the open pit mine environment, mine waste disposal, and past and current use of retaining structures. A development of specific structures, the culvert/ tunnel concept, and an anchor block retaining concept. The cost benefit of retaining structures used for in-pit backfilled waste.

Jan 1, 1981

By McMillan W. D.

Vermiculite is the name of a group of micaceous minerals characterized by their property of exfoliating when heated and thereby increasing many times their original volume. The resulting product has excellent heat-and sound-insulating properties, is used as a lightweight aggregate, and has numerous other industrial applications. Deposits of vermiculite occur in areas of pre-Cambrian rocks of the Llano uplift of central Texas, particularly in Burnet and Llano Counties. Because of the growing economic importance of vermiculite products, the Bureau of Mines undertook a detailed investigation of several deposits in Llano County. This investigation was completed in February 1947. The work comprised topographic surveys of five deposits, drilling with a 4-1/4 inch Parmanco power auger drill, and laboratory evaluation of samples. 342 drill holes, aggregating 4,905.5 feet, were completed, and 377 samples were taken. Laboratory evaluation of the vermiculite comprised expansion tests on both crude and beneficiated samples. The products obtained were compared with commercial-grade vermiculite from Montana.

Jan 1, 1949

By Edwin B. Cook

This report presents the results of calculations of the equilibrium composition of the products of combustion with air of six different mixtures of octane CgH18, plus PbEt4 and halogen-bearing scavengers at three air-fuel ratios, at pressures of 5 and 30 atm., and at temperatures of 350°, 1,000°, 1,800°, and 2,000° K. The air-fuel weight ratio has the values 12, 15:12, and 18. The concentration of PbEt4, M, in milliliters per gallon of iso-octane, has the value 1 or 3. The word "case" is used to designate the halogen concentration. Three cases have been considered [ ]

Jan 1, 1953

By S. S. Clarke

This paper on methods and costs of mining at the Westside mine, in the Tri-State zinc-and lead-mining district (Missouri-Kansas-Oklahoma), is one of a series being prepared by the Bureau of Mines on mining practices, methods, and costs in various mining districts of the United States. Methods and equipment used in drilling, loading, and underground transportation have changed radically since the latest Bureau of Mines publications2/ on mining methods in the district were published more than 20 years ago. More efficient methods and machines have been developed in order to maintain low operating costs in the face of rising labor and supply costs and lower grade ore. The rate of conversion to mine mechanization was disappointing at times; local conditions required the development of special equipment, and available rock-moving machines had to be remodeled and strengthened.

Jan 1, 1957

The Leuna Factory of the I. G. Farbenindustrie A. G., situated near Merseburg, is the biggest heavy-chemical plant in Germany and produces a very wide range of products, mainly based on hydrogen or hydrogen and carbon monoxide. Its principal products are ammonia, synthetic petrol derived from the hydrogenation of brown coal, and synthetic alcohols made from hydrogen and carbon monoxide. The plant was first, visited on April 21, 1945, by a team including E. Cotton, V. Haensel, E. B. Peck, P. K. Kuhne, H. M. Weir, L. L. Hirst, W. W. Odell, G. U. Hopton, H. Hollings, J. F. Ellis, and H. G. Simpson. It was again visited on May 8-24, 1945, by a combined British and American team consisting of R, Holroyd, M. A. G, Banks, D. A. Howes, A. J. V. Underwood, R. A. Taylor, W. F. Faragher, H. Schindler, and J. G. Allen. This team was later joined by J. F. Ellis and R. J. Morley. A third visit with particular reference to catalyst manufacture was made by W. F. Faragher and W. A. Horne, and the notes of these latest investigators have been taken into account in preparing the report. This report was edited by Dr. R. Holroyd.

Jan 1, 1946

By R. V. Higgins, H. C. Miller

"INTRODUCTION The development of methods for determining the total quantity of crude oil that a given pool could be expected to produce in the future and the well-spacing and drilling programs most likely to result in the recovery of the maximum quantity of oil at the minimum cost became problems of acute concern to American oil producers and petroleum engineers during the second decade of the twentieth century, The United States faced what seemed at that time to be a serious shortage of petroleum, and it appeared that the constantly increasing demand for petroleum and its products could not be adequately supplied. Undrilled prospective acreage, which until then had been plentiful, seemed to be getting scarcer, competition was increasing, the margin of profit to the producer was shrinking, and the need for developing constructive policies of conservation appeared paramount. As a result of physical and economic changes then taking place within the petroleum industry prompted by the seemingly uncertain future, accurate knowledge pertaining to the probable future production of oil wells and of oil lands especially was needed and greatly desired. Furthermore, the need for obtaining the maximum quantity of oil from known fields caused technical information - which up to that time had not been deemed essential to the successful and profitable operation of oil lands - to be sought eagerly. The need for technical information, such as methods for determining future reserves of oil and the rate at which the oil could be obtained under a specific program of drilling, was emphasized further with the passage of the Revenue Act of 1918, and oil producers with enough income to place them in the taxable class were compelled, for the first time, to report their taxable income 4/ to the Treasury Department."

Nov 1, 1939

By L. D. Tracy

This paper represents work conducted by the Bureau of Mines in cooperation with the Illinois Geological Survey and the Engineering Experiment Station of the University of Illinois.

Jan 1, 1926

By J. Kruttschnitt

This paper, describing milling practice at Mount Ira Minis, is one of a series covering milling methods and cost that is being published by the Bureau of Mines, United States Department of the Interior. The Mount Isa concentrator began operations in day 1931 by treating a mixture of oxidized and sulfide ores. Since March 1935 only sulfide ores have been milled; this change involved major alterations to the flow sheet. The maximum capacity on mixed oxide and sulfide ores was 2,650 tons per day; the present capacity is approximately 1,880 tons of sulfide ore per day. The installation of additional crushing, grinding, and flotation equipment when completed early in 1939 will increase the maximum capacity of the concentrator to 2,240 tons of sulfide ore daily.

Jan 1, 1939

By Noel N. Moebs

This report summarizes a Bureau of Mines study on the use of geotechnology to identify and reduce ground control hazards at slate quarry operations in eastern Pennsylvania. The major ground control hazard is falling rock, attributed to weathered bedding plane faults, which weaken quarry highwalls. It was demonstrated that these faults can be detected outside of the quarry perimeter using surface resistivity measurements. Falls of ice from quarry highwalls constitute a second major hazard, which requires water diversion as a basic control method. In situ stresses seemingly cause only minor problems in slate extraction although they could interact with developed stresses and lead to failure of barriers between quarries. Pull tests showed that rockbolts anchor firmly in slate and should prove effective in securing loose rock.

Jan 1, 1986

By D. Harrington

This paper is a revision of Information Circular 7380, by D. Harrington and J. H. East, Jr., published in 1946, entitled ?Safe Storage, Handling, and Use of Commercial Explosives in Metal Mines, Nonmetallic Mines, and Quarries.? Issued soon after the close of World War II, this earlier circular described the unprecedented increase in the production and use of commercial explosives during the war as a result of expanded industry and the tremendous demand f or metals and minerals. In the years following World War II, the production and use of commercial explosives in the United States have continued to rise. Hence, the Bureau of Mines presents these revised figures through 1952. In rewriting this Wormation circular, most of the text prepared by Harrington and East has been retained, with newer statistical information compiled by Seth T. Reese, Accident Analysis Branch, and V. E. Wrenn, of the same branch.

Jan 1, 1954

By M. M. Gilkey

This report on water requirements for the New Mexico mineral industry includes data on industrial operations closely related to mineral production. It contains general information concerning public water supplies at five principal cities and a short discussion of water needs for agriculture. Background data are presented regarding the geography, hydrography, and water laws of New Mexico, as well as precipitation and evaporation characteristics of the State. Most of the information on source, quantity, distribution, cost, and treatment of water was obtained in interviews with company representatives. Water systems at 46 operations are illustrated by schematic waterflow diagrams. The study revealed that the New Mexico mineral industry in 1962 used about 16 billion gallons of new water and reused 152 billion gallons, a total usage of 168 billion gallons. Consumption amounted to 7.6 billion gallons. Of the 16 billion gallons of new water, 11.9 billion gallons was "self- supplied" from ground water sources, and 2.6 billion gallons was self supplied from surface sources. Approximately 1.5 billion gallons was purchased. Some of the water from company-owned wells is piped as far as 30 miles. Reported costs of the self-supplied new water range from 1 to 20 cents per 1,000 gallons and average 8 cents per 1,000 gallons for power and maintenance. Inadequacy of the supply of new water at many operations necessitates large-scale recirculation. Reported costs for recirculating water (power and maintenance) average 1.8 cents per 1,000 gallons. For the entire New Mexico mineral industry in 1962, the value of product was $42 per 1,000 gallons of new water intake and $88 per 1,000 gallons consumed. Analyses of 40 water samples, listed in the appendix, show the wide range in water quality at plants throughout the State. Projection of the 1962 water requirements of the mineral industry indicate that the total demand for new water will increase from the 16 billion gallons used in 1962 to 24 billion gallons in 1980, a 50 percent increase; and to 36 billion gallons in 2000, which is 125 percent more than the 1962 intake of new water.

Jan 1, 1965

By M. M. Gilkey

This report on water requirements for the New Mexico mineral industry includes data on industrial operations closely related to mineral production. It contains general information concerning public water supplies at five principal cities and a short discussion of water needs for agriculture. Background data are presented regarding the geography, hydrography, and water laws of New Mexico, as well as precipitatton and evaporation characteristics of the State. Most of the information on source, quantity, distribution, cost, and treatment of water was obtained in interviews with company representatives. Water systems at 46 operations are illustrated by schematic waterflow diagrams. The study revealed that the New Mexico mineral industry in 1962 used about 16 billion gallons of new water and reused 152 billion gallons, a total usage of 168 billion gallons. Consumption amounted to 7.6 billion gallons. Of the 16 billion gallons of new water, 11.9 billion gallons was "self- supplied" from ground water sources, and 2.6 billion gallons was self supplied from surface sources. Approximately 1.5 billion gallons was purchased. Some of the water from company-owned wells is piped as far as 30 miles. Reported costs of the self-supplied new water range from 1 to 20 cents per 1,000 gallons and average 8 cents per 1,000 gallons for power and maintenance. Inadequacy of the supply of new water at many operations necessitates large-scale recirculation. Reported costs for recirculating water (power and maintenance) average 1.8 cents per 1,000 gallons. For the entire New Mexico mineral industry in 1962, the value of product was $42 per 1,000 gallons of new water intake and $88 per 1,000 gallons consumed. Analyses of 40 water samples, listed in the appendix, show the wide range in water quality at plants throughout the State. Projection of the 1962 water requirements of the mineral industry indicate that the total demand for new water will increase from the 16 billion gallons used in 1962 to 24 billion gallons in 1980, a 50 percent increase; and to 36 billion gallons in 2000, which is 125 percent more than the 1962 intake of new water.

Jan 1, 1965

By William O. Vanderburg

This report3/ gives the reconnaissance of a reconnaissance of the mining districts in Churchill County, Nev., made in the fall of 1938 and spring of 1938 All of the mining districts in the county were visited, but no attempt has been made to include all the mines and prospects within the area; inclusion or omission of a property in this paper has no bearing on its merits, The report gives the situation of the various districts, mineral production, and ownership of properties; describes the ore deposit, mines, and prospects; contains information on past and current activity; and includes other data likely to be useful to those interested in the development of our mineral resources. The various district, were named when they were organized for purposes of record and regulation. When established, the districts embraced large areas n without well- defined borders, so that the names have little geographical significance.

Jan 1, 1940

From time to time the Bureau of Mines has interpreted and applied certain provisions of the Federal Coal Mine Safety Act and Federal Mine Safety Codes, primarily for the guidance of Federal Coal Mine Inspectors. Although interpretations of the Act have appeared in the Federal Register, the Code interpretations and practical applications have not been published. In response to many requests from representatives of the coal-mining industry, the Bureau is publishing this information to promote better understanding of those provisions that may be misinterpreted or misapplied. INTERPRETATIONS AND APPLICATIONS Two Federal Mine Safety Codes are discussed in this report, namely the Federal Mine Safety Code for Bituminous-Coal and Lignite Mines of the United States, Part 1, and the Federal Mine Safety Code, Anthracite Mines of the United States, Part 1. In this circular the word Codes refers to both directives; Code* refers to the code for bituminous-coal and lignite mines; Code? refers to the one for anthracite mines. Act* refers only to bituminous-coal and lignite mines.

Jan 1, 1963

By H. B. Carroll

The Bureau of Mines has designed and built a controlled-environment test chamber specifically for instrument evaluation in simulated work atmospheres. The atmosphere inside the 300-liter stainless steel chamber can be controlled at any selected temperature and relative humidity in the range of 2° to 93° C and 20 to 95 percent, respectively. Instruments placed inside the test chamber are subjected to an atmosphere at a preset temperature and humidity containing various concentrations of toxic gases such as CO, C02, NO, NO2, S02, and H2S. Toxic gas losses resulting from wall reactions, monitoring instruments, and instruments under evaluation are compensated by the use of a dynamic gas blending system.

Jan 1, 1973