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By G. W. Jones

"INTRODUCTION In a previous reports results were given of a manhole investigation carried out over a period from June,- 1929, to July, 1930, in cooperation with the Edison Electric Illuminating Co. of Boston, Mass., to determine the general hazards of combustible gases and vapors in manholes and other underground openings owned by this company. Considerable time was spent in this initial investigation in developing a suitable detector for determining the range of explosibility of the gases found in manholes. About 17,000 tests have been made with the detector since the investigation was started and its utility has been verified and its accuracy checked, by having complete analyses made of such samples that showed combustibles present equal to or above 25 per cent of the lower explosive limit, and those found deficient in oxygen.The initial investigation made in 1929 and 1930 demonstrated that the detection, control, and elimination of combustible hazards in manholes can best be obtained by a close cooperation of the interested parties through a systematic and continuous inspection of manholes, under proper supervision.COOPERATIVE INVESTIGATI0N DURING 1931The investigation carried out during the year 1931 has been along lines similar to that conducted during 1929 and 1930. In the present investigation the Edison Electric Illuminating Cc. of Boston and the Boston Consolidated Gas Co., have cooperated with the Bureau of lanes. The Boston Consolidated Gas Co. serves a major part of the territory under discussion with gas, but the tests covered the Edison territory irrespective of the gam company furnishing manufactured gas. A test crew consisting of two men, one an employee of the Consolidated Gas Co. and one an employee of the Edison Electric Illuminating Co., has been continuously employed during the year in the testing of games in manholes served by the Edison system. The test crew was under the direct supervision of John Campbell, superintendent of the special service department of the Edison Electric Illuminating Co., and F. M. Goodwin vice president of the Consolidated Gas Co.As in the previous investigation, all manhole tests were given test numbers. The test data sheets on which the information regarding the tests were recorded were prepared in triplicate, one copy going to the Edison Company, one going to the Gas company, and the third to the Bureau of Mines at Pittsburgh. These test data sheets were then filed (1) according to the town, (2) the street location, and (3) the manhole number; in this way a complete record pf each manhole tested was immediately available. A specimen test sheet is given below."

Sep 1, 1932

By J. R. Nettle

The purpose of these studies by the Federal Bureau of Mines was to determine the feasibility of refining low-grade hafnium by an inert-gas-shielded molten-salt electrorefining technique to produce a hafnium metal meeting reactor specifications. The techniques were adapted from those used success-fully for titanium electrorefining. Three electrolytes containing hafnium chlorides were developed from which deposits having a Brinell hardness of 170 or below were recovered. A KC1 + NaC1 + HfC14 electrolyte produced deposits in the hardness range of 140 to 165 Brinell. Deposits with a hardness range of from 132 to 152 Brinell were pro-duced from an electrolyte composed of KC1 + LiC1 + HfC14. A third electrolyte composed of NaC1 + K3HfC17 produced deposits with a hardness as low as 139 Brinell. In a fourth electrolyte, composed of NaC1 + K2HfF6, a measure of refining was accomplished, but under the test conditions no metal meeting specifications was recovered; none was softer than 174 Brinell. A number of metallic impurities were reduced in quantity by the electro-refining process, notably iron, which normally was reduced from 250 p.p.m. to less than 50 p.p.m. Magnesium generally was reduced from 680 p.p.m. to less than 80 p.p.m. Manganese content was also reduced by the electrorefining process. Sponge containing 90 p.p.m. Mn yielded deposits containing a maximum of 50 p.p.m.; some deposits contained only 10 p.p.m.

Jan 1, 1961

By Michael G. Zabetakis

Limits of flammability of normal propyl nitrate (NPN) vapor were investigated at ambient and elevated temperatures. Minimum spontaneous ignition and decomposition temperatures were determined with laboratory apparatus over the pressure range from 0 to 4,000 p.s.i.g. Flame speeds and the detonation susceptibility of NPN vapor were measured at elevated temperatures. Stable detonation was obtained with liquid NPN at elevated temperatures, and the detonation velocity was determined to be between 4,700 and 5,100 m./sec.

Jan 1, 1962

By Sam G. Demou

Drag bit cutting tests were conducted chiefly to determine bit forces encountered in rock types representing a range of compressive strength and hardness and thus enable the design engineer to estimate a continuous miner's performance in a range of rock types. Testing was carried out on the Bureau of Mines uniquely designed, instrumented rock cutting device (RCD). This device can make 3-ft-long cuts at various depths and speeds to approximate full-scale drag bit cutting by continuous miners. Point attack and cutter bits were tested on four rock types ranging in compressive strength from 7,200 psi (trona) to 29,600 psi (Valders white rock). Cutting tests were made at depths up to 1 in and speeds up to 70 in/sec. Data included normal and cutting forces, groove depth, groove width, and weight of rock broken. The effect of varying the cutting speed was determined, and specific energies were calculated for the various conditions. The bit wear was also observed. For the rocks tested, compressive strength and hardness are good indicators of forces, specific energy, and wear encountered. Results, especially bit wear observations, show the possibility of extending continuous miners, already being used in trona, to Indiana limestone (10,000 psi). Rapid bit deterioration precludes use in Tennessee marble (16,800 psi) and Valders white rock (29,600 psi).

Jan 1, 1983

This report presents the results of reconnaissance-level investigations of the mill refuse disposal systems for 15 plants throw-heat the conterminous United States. The sites visited represent a cress section f the copper, iron, lead and zinc, and phosphate industries' practices in the field of fine-grained refuse disposal. The reconnaissance-level investigations were carried out to gather supplemental data to tae in-depth studies of Kennecott's Magma and Phelps Dodge's Morenci tailings deposits and Kennecott's Chino leaching dump. The various sites visited were classified according to the different systems and techniques used by the mining industry. The probable effects and relationships between site conditions and disposal methods were determined and evaluated to the extent feasible by a reconnaissance level investigation.

Jan 1, 1974

By Karl C. Dean

All components of 15 automobiles manufactured between 1954 and 1965 were analyzed, and it was determined that a representative junk automobile would have the following composition (all figures in pounds): steel, 2,532; cast iron, 511; copper, 32; zinc, 54; aluminum, 51; lead, 20; rubber, 145; glass, 87; miscellaneous, 142. Time and motion studies and a cost evaluation were made to determine if such a typical vehicle could be economically burned in a smokeless incinerator and hand-dismantled, and if the resultant steel could be baled into a high-quality No. 2 bundle containing less than 0.10 percent copper. The cost evaluation showed that processing the composite car would cost about $51 to produce about $56 worth of marketable ferrous and nonferrous metal products and provide an annual rate of return on investment of 19 percent.

Jan 1, 1969

By William J. Campbell

Three types of X-ray analytical instrumentation were compared for applications in the secondary brass and bronze industry. The instruments were a conventional X-ray spectrograph, a portable X-ray spectrograph, and a radioiso-topic X-ray analyzer using balanced filters. The following two general applications were considered: Rapid identification for sorting scrap metals and quantitative analyses to provide guidance in the melting and casting of alloys. Twenty-three analyzed copper-base alloys were used as standards. Although the alloys varied widely in composition, matrix correction procedures were not necessary except for copper. The conventional X-ray spectrograph provides positive identification of the alloys and quantitative values for the six elements investigated--aluminum, copper, iron, lead, tin, and zinc. Equivalent results were obtained with the portable X-ray spectrograph for those elements whose characteristic X-rays are in the wavelength range of the instrument. The radioisotopic X-ray analyzer distinguishes certain groups of alloys and provides quantitative determinations for copper, lead, tin, and zinc. The sensitivity of the analyzer was marginal for the determination of small concentrations of elements of atomic number 26 or lower.

Jan 1, 1972

Minerals are vital to any industrialized civilization. Annually, the United States uses more than 4 billion tons of new mineral materials, or about 40,000 pounds per person-about half being mineral fuels and the other half being metals and nonmetallics. Stable and economic domestic mining, mineral, metal, and mineral reclamation industries are essential to the economy. The value of United States energy and processed materials of mineral origin exceeds $200 billion annually. Although a number of minerals are imported, especially some designated as "strategic and critical," most U.S. mineral supplies are derived from the domestic mines and processing facilities that you will be seeing, reading about, and visiting as you use this visitor guide. We hope you enjoy your experiences. This pamphlet, a guide to mining and mineral operations that may be observed or visited and some other points of interest relating to minerals, is intended to aid tourists and students who are interested in mining. Some may wish to study our Nation's romantic past; others may plan to enter the minerals industry as a career; still others may have a primary interest in conservation practices. The pamphlet is also intended to aid State and local officials, Chambers of Commerce, and mining firms in answering some of the many questions of tourists and students.

Jan 1, 1976

By N. A. Eilertsen

Procedures of mining high-calcium limestone underground at the Kimballton mine of the Standard Lime and Cement Co. in Giles County, west-central Virginia, are described. Drilling and blasting procedures arc discussed in detail, and direct mining costs are tabulated in percentage of total cost. Output, about 1,725 tons of limestone a day, is attained with heavy trackless equipment by the room and pillar method of ruining; modified by benching floors. Operating features include underground air compression, electric-eye control of curtained doorways, use of a single jumbo drill rig for all drilling, and an effective plan for maintenance of equipment. The company's safety program has contributed to an outstanding safe mining record. The mina is integrated with a plant on the property which converts the stone to metallurgical and chemical grade lime.

Jan 1, 1964

By J. P. Schmid

Results of a comprehensive investigation of the impact of underground mine waste disposal on the health and safety of miners are presented. Information was gathered through an extensive search of American and foreign literature and personal communication with professionals in private industry and government. All conceivable health and safety hazards directly or indirectly related to underground mine waste disposal are analyzed, catagorized, and ranked on an industry-wide basis. Positive health and safety effects are analyzed and ranked in a similar way. Both potential and known hazards and positive impacts are included. Recommendations on abatement techniques for the various hazards are presented. Case histories of a fill-related accident in a metal mine and a health hazard associated wtih coal waste backfilling are included and causes and possible abatement procedures are discussed. The rule of management in the promotion of health and safety in backfilling operation is discussed.

Jan 1, 1982

Presented in this volume are the basic mining techniques and production operations associated with underground bituminous coal mining. Chapter 2, "Multiflow Process Charts", presents, in sketch form, a description of the various operations characteristic of conventional and continuous mining. In order to focus attention upon the major components and operations in each work cycle, certain items are not shown in the sketches, e. g., machine electrical cables, brattice, and rib posts. The elapsed time shown for each sketch is considered representative for the various work elements summarized by the sketch. More detailed work element times can be found in Chapter 3, "Typical Work Cycle Times", and Chapter 4. "Standard Time Data".

Jan 1, 1971

By Doris M. Hyde

There were no significant changes in the mineral industries of the smaller Caribbean Islands during 1980. Imported petroleum requirements continued to erode economic gains that may have occurred in other sectors. Some relief may be forthcoming as more qualified Caribbean countries take advantage of Trinidad and Tobago's petroleum product financing program (see Trinidad and Tobago). There were no crude oil discoveries in these areas during 1980, although some geophysical testing around the British Virgin Islands and Antigua war underway. In March 1980, the Government of Antigua sold a 75% interest in the 16,000-barrel- per-day West Indies Oil Co. refinery to the Swiss Intermaritime Bank and Intermaritime Management Services for $6 million. The new refinery company is called the National Petroleum Co. Shutdown since 1976, it was originally planned for the refinery to reopen in 1980, but refurbishing has proved to be more extensive than anticipated. The reopening is now expected in 1981.

Jan 1, 1982

By Arel B. McMahan

The U.S. Bureau of Mines investigated 21 mines, prospects, and mineralized sites in and adjacent to a 38,713-acre portion of the 255,058-acre Kingston Range Wilderness Study Area in 1983. The study area is 35 miles north of Baker, CA in the Mojave Desert. Mineral deposits in and adjacent to the study area are in altered carbonate rocks intruded by diabase sills near monzonite porphyry contacts. Monzonite porphyry forms the core of the Kingston Range and underlies about 70 percent of the study area. Sedimentary carbonate rocks are exposed in bands on the north and east boundaries and as isolated roof pendants in the southeastern portion of the study area.

Jan 1, 1986

This publication summarizes, for potential contractors and other interested parties, the research, development, and demonstration contract projects programed by the Bureau of Mines for fiscal year 1982 (October 1, 1980 -September 30, 1981) under its Minerals Health and Safety Technology program. Contingencies may require that a significant port ion of the program be deferred into fiscal year 1983. The objective of these projects is to provide an ordered and sequenced series of advances toward the Bureau's overall goal of providing the systems technology required to create a healthier and safer working environment for the Nation's mining and minerals processing workers.

Jan 1, 1981

By Alvin Kaufman

To aid industry and Government in planning water developments the Bureau of Mines in 1963 canvassed mineral producers to determine water use in 1962. Water use by the mineral industry comprises only 2 percent of the water withdrawn by industry as a whole. The major water-using mineral industries are natural gas processing, phosphate rock, sand and gravel, and iron ore. Analysis indicated the following conclusions: 1. Total water use and new water intake is dependent on the quantity of material processed and the process water requirements of the particular industry or commodity. 2. Recirculation is dependent on the processing requirements of a particular commodity, the manner in which the water is used, cooling and condensing requirements in certain large industries, the quality of new water intake, and the need to treat new and discharged water. 3. Consumed water is dependent on the quantity of water recirculated, the temperature and humidity in the area, and the proportion of water used for cooling and condensing. 4. A threefold increase in water use by the mineral industry by 1985 is forecast

Jan 1, 1966

By R. J. Leary

The technologies of contemporary iron and steel production and of direct reduction processes have been studied to identify and estimate the potential effects of direct reduction on mineral consumption and the problems raised thereby for the Nation's mineral supply to the iron and steel industry. Contemporary patterns of mineral raw material and energy consumption were determined from a study of the 1964-70 period. Major changes were observed in requirements for 14 of 20 principal commodities. Average practice in 1970 was compared to best practice to estimate the potential effects of implementing existing technology without recourse to direct reduction. Potential effects of direct reduction were estimated by comparing the mineral requirements for 95 percent reduced pellets with 1970 best practice technology for two cases of use: (I) complete substitution for hematite pellets in blast furnace burdens, and (11) partial substitution (40 percent) for scrap in electric furnace steel charges. Effects upon mineral supplies are described; important collateral factors are analyzed, and the principal metallurgical, industrial, and environmental consequences of implementing direct reduction are discussed. Major effects of direct reduction on the domestic steel industry and its mineral supply system are foreseeable. Direct reduction will (1) create a large demand for low-gangue iron ore; (2) relieve the dependence of the steel industry on coking coal, and (3) permit great increases in furnace productivity, both in blast furnace ironmaking and electric arc furnace steelmaking.

Jan 1, 1973

By Alfred Wild

The Kraftile Co. plant, Fremont, Alameda County, Calif.--the largest producer of glazed, structural wall units west of the Rocky Mountains-- maintains modern processing facilities to evaluate and blend a wide variety of clays from several sources to produce quality products. The report desribes the prospecting, exploration, and test methods used to locate raw material sources and covers processing methods, cost factors, and trends. Also, the geologic and ceramic factors are considered in a general discussion of the economics, potentials, and requirements of clays as raw materials for ceramic tile manufacturing.

Jan 1, 1963

By Thomas J. Albin

U.S. Bureau of Mines research has found that maintenance of surface mining equipment is involved in slightly more than one-third (34.1 pct) of all surface mining accidents. Two groups of machines, haulage trucks and power shovels, accounted for over one-half of all surface mining mobile equipment maintenance accidents in 1978-84. Maintenance work-time histories for these machines were compared with accident records to identify the most hazardous-to-maintain systems within the machines. Recommendations to reduce the accident risk associated with maintenance of these hazardous systems are presented.

Jan 1, 1990

By M. Dattilo

The U.S. Bureau of Mines has been conducting research on the use of waste-derived zinc as a partial replacement for pure zinc in the electrogalvanizing process. The end product of this process is automotive sheet, which has enhanced cosmetic protection over previously used cold-rolled (CR) steel. In this study, primer-coated specimens of CR and electrogalvanized (EG) steel were subjected to the on-vehicle environment and monitored periodically by electrochemical impedance spectroscopy (EIS) during immersion in 1M NaCI solution. The results of these tests were compared with immersion-only conditions. Scanning electron microscope (SEM) and energy-dispersive X-ray (EDX) techniques were also used to evaluate the corrosion processes and compare them with atmospheric exposure specimens. EIS was found to measure the corrosion associated with on-vehicle exposure, thus providing an excellent screening technique for evaluation of the performance of EG automotive sheet steel.

Jan 1, 1990

By George K. Schenck

This Bureau of Mines publication describes and evaluates a Standard Industrial Classification (SIC) based end-use data system for minerals that is designed to link the demand for minerals to economic activity in commercial uses. The new data system is two-dimensional. The first dimension of technical product classes (TPC's) measures the consumption of minerals in major primary intermediate products. The second dimension measures the consumption of these TPC's in SIC end-use sectors in sufficient detail to identify the major determinants of demand for each TPC. Intercomodity comparisons are achieved at the level of SIC two-digit major groups. The methodology was developed so that all available sources of information from Government and industry can be utilized at minimum cost. This information will be supplemented with additional data to be obtained by modifying existing Bureau of Mines canvasses so as to elicit additional quantitative responses from mineral producers. The new data system is expected to improve significantly the ability to forecast demand for minerals, and provide an information base that would, for the first time ever, permit resolution of such questions as trends in substitution among materials and the intensity-of-use of materials in end-use sectors. For the 42 TPC?s identified in the report, data are available for the new system from current sources or, except for three TPC?s that require new canvasses, can be obtained by modification of existing Bureau canvasses.

Jan 1, 1982