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By W. R. Hardwick

This information circular describes open-pit mining methods and practices of the Bagdad Copper Corp., Yavapai County, Ariz. It is one of a series being prepared by the Federal Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. A brief history of the Eureka district and of early developments at the [gdad] mine is given, and the are deposit is described with particular emphasis on those characteristics (physical, economic, or engineering) that affected the choice of mining methods. Prospecting, exploration, and sampling and estimating the tonnage and grade are outlined. Development of the open-pit mine is shown. Mining methods, including breaking ground, primary drilling and blasting, secondary drilling and blasting, loading, transportation, engineering, and operating control, are described. A brief summary of mining equipment is given. Percentage of extraction, production rate, mine drainage and water supply, wage, contract, and bonus systems, safety and fire prevention, and the processing plant also are described. The last section gives a breakdown of such costs as are available for publication.

Jan 1, 1959

By F. E. Walker

The Bureau of Mines determined total sulfur and sulfur forms for coal in 283 counties in 29 States and 2 fields of the State of Alaska. Specifically, organic, pyritic, and sulfate sulfur were measured of approximately 2,900 samples, and they include most of the coalbeds in the United States.

Jan 1, 1966

By R. T. Sorensen

Research and testing in a small scale equivalent of a commercial flota-tion plant was completed on four low-grade, iron-bearing materials from the western Mesabi range. Closed circuit-flotation of calcium-activated silica with fatty acid collector developed data for comparison with the batch process and highlighted problems not evident from previous bench testing. The four ore samples contained from 27 to 39 percent Fe and were equally represented by nonmagnetic taconite and semitaconite type materials. Iron concentrates containing 6.0 percent, or less, SiO2 were made 5, all four samples. Of the two material types, the semitaconite was the ore amenable to treatment, yielding iron recoveries of about 90 percent as cc pared with 70 to 80 percent for the other. Pilot plant tests showed that concentrate grade made in batch tests could be duplicated in the closed circuit and demonstrated that the amount of recoverable middling iron varied considerably between ore samples. The continuous tests also showed that water temperature strongly influenced results in the treatment of one ore but apparently was of indifferent consequence in another. Progress in thickening and filtration of flotation concentrates was made through introduction of tapioca flour to serve the dual role of iron mineral depressant and flocculant.

Jan 1, 1966

By George W. Huseman, W. D. Mcmillan

"INTRODUCTION Feldspars represent one of the most abundant groups of minerals and constitute nearly Go percent of the material contained in the igneous rocks. They are grouped in a series of related aluminum silicates with varying amounts of potash, soda, and lime. .Approximately 85 percent of the feldspar produced in the United States is used as a flux in the production of glass, pottery, enamel and sanitary ware, brick, and tile. Notwithstanding the abundance of feldspar in the earth's crust, the only deposits that are worked to any extent are the pegmatites or coarsely crystalline dikes where natural segregation of the constituents facilitates recovery of the feldspar with a minimum of free quartz, mica, tourmaline, garnet, and other iron-bearing minerals that are detrimental in most ceramic industries.Although there are three glassplants and numerous other ceramic industries in Texas, all of the feldspar used in these plants is from other States. In the Llano region of central Texas, however, there are numerous coarse pegmatite dikes consisting primarily of feldspar and quartz in ratios up to 3 to 1. One of the more important of these dikes is the Badu Hill deposit in Llano County, Tex., which was first described by Carl Chelf 4/ in 1942. Following an examination of the deposit by W. D. McMillan, engineer in charge of the Texas field office of the Bureau of Mines, in January 1946, a proposal was made to investigate the deposit by core drilling in cooperation with the Department of Ceramic Engineering, University of Texas. This report presents the results of the cooperative investigation, which was begun April 24, 1946, and completed May 17, 1946."

Jul 1, 1947

By David K. Denton

Results of the mineral resource study of the Upper Priest Lake RARE II study area indicate a low potential for the discovery and economic recovery of silver and lead in the Prichard Formation near contacts with the Kaniksu Batholith in the vicinity of the Mountain Chief Mine (fig. 1). Silver and lead minerals locally occur disseminated and in irregular quartz fissure-fillings in the Prichard Formation. Between 18^6 and 1967, 105 lode raining claims were located in the study area. The area was designated for "further planning" in the Final Environmental statement but was later changed to "nonwilderness" by President Carter after work was scheduled for the area.

Jan 1, 1981

By Terry L. Muldoon

The report describes the development of preliminary requirement specifications for standardized operating controls for roof bolting machines used in underground coal mining. According to recent statistics, roof bolting continues to be one of the most hazardous occupations in underground coal mining. The two principal hazards to the roof bolter operator are the machine itself and roof falls during the bolting cycle. The lack of standardization of machine controls is a major contributor to this hazardous situation. Observations of roof bolting operations and discussions with roof bolter manufacturers coupled with detailed analyses of roof bolter control design specifications were performed during this study. Detailed roof bolter operator task analyses, commonality of control analyses, and classical link analyses were also performed. The results of these analyses were then used to produce preliminary requirement specifications for standardized controls.

Jan 1, 1980

By Arno C. Fieldner, Howard I. Smith, J. W. Paul, SAMUEL SANFORD.

Many mine samples of coal are analyzed each year in the laboratories of the Bureau of Mines. The analyses are made in connection with investigations relating to fuels belonging to or for the use of the United States Government, the causes of accidents in coal mines, the geologic relations of coal beds, and the character and the value of the coal and lignite in the public lands. The systematic collection and analysis of such samples in connection with fuel investigations was begun in 1904 at the Government fuel-testing plant at the Louisiana Purchase Exposition, and was under the direction of the United States Geological Survey for six years. Descriptions of the coal samples collected between the beginning of this work, July 1,1904, and the transfer of the fuel-testing and mine-accident investigations to the Bureau of Mines, July 1, 1910, were compiled and published in Bureau of Mines Bulletin 22.a Descriptions and analyses of samples collected during the fiscal years 1911 to 1913 were published in Bureau of Mines Bulletin 85.b The present bulletin presents analyses and descriptions of samples collected during the fiscal years 1913 to 1916. In order that the material in this bulletin may be used to supplement that presented in Bulletins 22 and 85, the same plan of geographical classification has been followed, the analyses and descriptions of the samples being grouped in alphabetical order according to the State, county, and town near which the mines or prospects sampled are situated.

Jan 1, 1918

By C. W. Davis

During the fiscal year 1935-36, the Ore-Testing Section has been active in carrying out a program designed to attain the objectives that have been set up for it. For the purpose of standardizing important testing methods, an attempt has been made to develop a rationalized scheme for ore testing, starting with preliminary investigations to determine the physical and chemical properties of the ore, following this with a logical selection and trial of processing tests to find out how the ore may be most effectively treated, and concluding with a discussion of what interpretation may be placed on the results in terms of plant design and operation. A selection of procedures that appear well-suited to the ore-dressing problems under investigation is included in the following paper of this report so that other experimenters may be enabled to verify our findings and to offer criticisms and suggestions for improving our practice. A tentative scheme for the evaluation of flotation reagents is being investigated, and some progress has been made in a study to determine the significance of small-scale testing. These projects have required 899 analyses. Papers on these and others on ore testing, such as testing for amalgamation and for cyanidation, will be included in future annual reports.

Jan 1, 1937

By C. W. Davis

During the fiscal year 1935-36, the Ore-Testing Section has been active in carrying out a program designed to attain the objectives that have been set up for it. For the Purpose of standardizing important testing methods, an attempt has been made to develop a rationalized scheme for ore testing, starting with preliminary investigations to determine the physical and chemical properties of the ore, following this with a logical selection and trial of processing tests to find out how the ore may be most effectively treated, and concluding with a discussion of what interpretation may be placed on the results in terms of plant design and operation. A selection of Procedures that appear well-suited to the ore-dressing problems under investigation is included in the following paper of this report so that other experimenters may be enabled to verify our findings and to offer criticisms and suggestions for improving our practice. A tentative scheme for the evaluation of flotation reagents is being investigated, and some progress has been made in a study to determine the significance of small-scale testing. These projects have required 899 analyses. Papers on these and others on ore testing, such as testing for amalgamation and for cyanidation, will be included in future annual reports.

Jan 1, 1937

By J. S. Berber

Bastnasite is a natural fluocarbonate of the cerium group and affords an abundant and high-grade source of the lighter rare-earth elements. As part of a broad research program in rare-earth element technology, the Federal Bureau of Mines directed extensive experimental work to separating and purifying the rare-earth elements in bastnasite. By the use of a combination of techniques--classical chemical, ion exchange, and solvent extraction--the processing of a bastnasite concentrate to obtain the individual rare-earth elements, or groups of elements, was accomplished. A bastnasite concentrate, containing about 60 percent rare-earth oxides, was sulfated with concentrated sulfuric acid to eliminate the carbon dioxide, fluorine, and silica. Calcination at 1,200° F. made the gangue matter insoluble, thus permitting the separation of the soluble rare-earth sulfates. Essentially 100 percent of the rare-earth elements were recovered by this procedure. Since the rare-earth sulfate solution contained only trace amounts of nonrare-earth elements, subsequent separation procedures were simplified.

Jan 1, 1960

By A. J. Kraemer

This report is one of a series dealing with oil-shale-operations in foreign countries visited and studied by Bureau of Mines oil-shale technologists within the past 4 years. Many oil-shale deposits have been discovered in Brazil and studied with various degrees of thoroughness. In this report the major emphasis is upon the oil-shale concessions of Companhia Nacional de Oleos Mineraes, in the River Valley of the State of Sao Paulo, because this oil-shale deposit is one of the most promising in Brazil for large-scale utilization for the manufacture of liquid fuels and other products of oil-shale processing, and because the opportunity was afforded to examine the concession area and to study mining, retorting, and. refining operations on these shales. Results of detailed analyses at the Oil Shale Research and Development Laboratories of the United States Bureau of Mines, Laramie, Wyo., are reported, Analyses and other date dealing with other oil-shale deposits in Brazil have been compiled from many sources. As many data have been reported as could be correlated to indicate the range of variation of the several types of shale end similar material. The oil-shale deposits in Brazil differ widely in size, richness of the shale, and of the oil. Some deposits are situate& more favorably for exploitation than others.

Jan 1, 1950

By W. A. Cole

This report covers the preliminary phase of an investigation of some clays and shales and other materials in North and South Dakota to determine the feasibility of lightweight -aggregate manufacture in the two States. The background of the light - weight -aggregate industry, on a national basis, and results of preliminary laboratory testing of samples of North and South Dakota clays and shales from various localities are presented herein. The countrywide search for lightweight aggregates was necessitated toward the end of the 19th century by the change in building design from thick, heavy, load- bearing walls to a framework of structural steel .beams and columns with thin walls, followed shortly by the use of reinforced concrete and structural concrete as materials for the load-supporting frame. Ordinary concrete, with sand and gravel aggregate, weighs about 150 pounds to the cubic foot. A lighter concrete was needed to relieve the dead load and make it possible to construct higher buildings or add stories to existing buildings.

Jan 1, 1954

By Bureau of Mines Staff

Coal research and related activities in 1964 by the Bureau of Mines resulted in many advances in the production, preparation, and utilization of this valuable natural resource. Mining research during the year was marked by work on hydraulic mining, coalbed degasification, mine drainage control, mine sealing, strip-mine rehabilitation, and quenching of mine-refuse fires. Bureau research continued to produce information leading to increased safety in underground mining. Such research included roof and rib control via bolting and bonding, pressure monitoring of coal and mine rock during mining operations, and development of safety devices for detecting conditions leading to roof falls. Other safety work was continued on methane detectors, coal-dust suppression, and mine venti lation equipment and techniques. Mine explosion and explosives research, mine equipment and materials, safety rule modernization, and safety education and training of mine workmen were continued. Coal storage and preparation work in 1964 ranged from freezeproofing of lignite for rail shipment, through washability studies of coals and washing equipment, to research on new ways to remove ash and sulfur from coal. Electric power production, which ,accounts for a major portion of the market for coal, received further study. Unique power generation systems, inc luding coal-burning gas turbine and megnetohydrodynamic generators, were intensively investigated. Conventional power systems were improved through continuation of work on furnace performance, powerplant stack gas purification, and engineering and boiler water service.

Jun 1, 1965

By C. H. Riggs, Kenneth H. Johnston

The application of modern secondary-recovery methods has made possible the the extraction of more than 13 million barrels of crude petroleum from the eastern part of the Delaware-Childers field Nowata County, Okla., over and above the production that might have :been expected by continuing primary production methods, including the use of vacuum. Foremost among the secondary-recovery methods used in this foil was the repressuring of the Bartlesville sand with air and gas through injection wells spaced on sym-metrical patterns. Between 1925 and 1945, about 51 billion cubic feet of air and gas were injected into the producing formation, and the total recovery was increased from, 25 million to about 40 million barrels of oil. To produce as much as possible of the 28 million barrels of recoverable oil remaining in the sand will require the initiation of systematic water-flooding projects on many properties and the continuation of air and gas injection on others.

Dec 1, 1946

By Kenneth Wardell

Criteria have been fully developed for determining the optimum size of oil and gas well blocks. The criteria lead to the formation of well barrier pillars which are, of themselves, inherently stable and take account of variable mine roof and floor conditions. The criteria ensure, through considerations of ground movement, that strains transmitted to well casings, are within tolerable limits of casing specifications. The criteria cater for well barrier pillars in multi-seam mining situations and where previous old mining has taken place. The criteria maintain flexibility in being adaptable to local mine design situations. The criteria are applicable to proposed extraction thicknesses up to 15 feet at depths up to 2,400 feet. The criteria are related to producing wells and to abandoned wells. In the latter connection, various states of well abandonment are recognised.

Jan 1, 1980

The Minerals Data Source Directory is a compilation of descriptive information on the availability, content, and location of minerals data in the Federal Government. It is intended to assist Government personnel and the general public in locating and acquiring minerals information. Included in the Directory are descriptions of data bases, publications, information systems, and information offices containing data pertaining to ail aspects of mineral production, consumption, trade, and related information. These mineral data sources include the Federal agencies such as the Department of the Interior's Bureau of Mines and Geological Survey whose major mission is the collection and dissemination of mineral information. Also included are agencies such as the Departments of Agriculture, Commerce, Labor, State, Transportation, and Treasury, the Central Intelligence Agency, the Environ- mental Protection Agency, the Federal Reserve System, the interstate Commerce Commission, and the Securities and Exchange Commission, whose primary mission is the collection of data in nonmineral subject areas, but in which the mineral industry is a component.

Jan 1, 1983

By J. R. Thoenen

This circular is the third of a series summarizing the technical problems involved in the production and preparation of sand and gravel. The first, Information Circular 6668, published in December 1932, discussed the problems involved in prospecting and exploration. The second, Information Circular 6689 (March 1933), dealt with the development of gravel deposits. This is part I of a paper designed to present a study of problems arising in the excavation of sand and revel and their delivery to the treatment plant. Other circulars are planned which will discuss preparation of the material for market, plant storage, and miscellaneous subject. Definitions For the purpose of this circular, excavation is defined as the recovery of sand and gravel from developed natural deposits and their delivery to a plant for market preparation.

Jan 1, 1934

By P. R. Jones

A computer program was written for design and cost of a shell and tube heat exchanger in which the total cost, which includes annual fixed charges and annual operating costs, was minimized. The program was written for the type of heat exchanger in which only the tube side pumping costs were significant and for triangular pitch, single or multiple pass, heating or cooling, and no change in phase. Tube diameter was not optimized since the tube dimensions do not affect the cost very much. However, the tube dimensions do affect the shell diameter, number of tubes, and length of tubes; and price optimum design was obtained for four standard tube diameters. Standard heat exchangers having at least the required area are also listed. The program was made adaptable to various fluids and to various tube dimensions by including many of the required data such as physical properties of the fluids, tube data, and standard shell data as input data.

Jan 1, 1969

By Irving Hartmann, John Nagy

"The pressures produced by dust explosions are frequently so great and are developed so rapidly that widespread destruction of manufacturing equipment and buildings results. Experimental data on maximum pressures and rates of pressure rise produced in a closed vessel by numerous metal powders and by dusts used in the plastics industry were published in two previous Bureau of Mines papers.4/5/One means for reducing structural damage is provision in the enclosing walls and/or roof of rapidly opening explosion-relieving devices or relief vents through which the pressure of an incipient dust explosion can be quickly dissipated. The vents can be simply unrestricted or free openings: hinged or pivoted sash which swing outward at a predetermined internal pressure; fixed sash, with light wall anchorages; scored glass panes; light wall panels; monitors or skylights; poppet-type vent closures; paper, metal foil, or other diaphragms that burst at low pressures; pull-out diaphragms, or other similar arrangements.The use of pressure-relief vents is recommended in the dust-explosion codes of the rational Fire Protection Association,6/ and recently a special committee on explosion venting has been organized. However, technical data on which the design and distribution of relief vents can be based are meager. An experimental study on venting grain-dust and cornstarch explosions was made by the Bureau of Chemistry and Soils, United States Department of Agriculture.7/ Tests on cork fines, cinnamon, starch, barley dust, and a phenolic plastic were made in a laboratory-scale (0.1-cubic-foot) apparatus by the engineering department of the Factory Insurance Association.8/ A study on the venting of explosions of acetone-air mixtures was made by the Bureau of Mines.9/The object of the present investigation is to extend the limited knowledge on the effectiveness of pressure-relief vents of different types, shapes, and sizes. The aim is to determine the venting requirements in equipment and structures of various dimensions and shapes for dusts of widely different explosive properties. On the basis of such accumulated information, together with theoretical considerations, it is hoped that ultimately it will be possible to recommend correct venting for most operations in which a dust-explosion hazard exists."

May 1, 1946

By John R. Benham

The Windigo Theilson RARE II area has a low mineral potential. There are no mines or claims in the area. The only observed results of mining activities were five prospect pits near Tolo Mountain. Samples from these pits contained no significant assays. The study area contains more than 190 million cu yds (145 million m3) of cinders in 17 cones. Development of these cinders is unlikely because their locations are remote, and other sources supply area needs. The Geological Survey has classified the area as prospectively valuable for geothermal resources. However, there has been no geothermal exploration activity.

Jan 1, 1982