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By J. Koster

In the western United States occurs deposits of low-grade chromite which, when concentrated, may be reduced to ferrochromiun in electric furnaces that derive energy from dams and hydro plants now in course of construction. Montana ore was chosen for the experiments. A 1-ton sample contained 26 percent Cr203, 17 percent Fed, and 17 percent SiO2, plus other constituents, and the concentrates therefrom assayed 44 -percent Cr203, 23 percent FeO, and 0.79 per cent SiO2, Gravity concentration was found to be the best method. Ferrochromiums are of two grades - high-carbon with 66 to 70 percent chromium and 4-112 to 6 percent carbon and low-carbor with 67 to 72 percent chromium and 0.6 to 2 percent carbon. Both are made in electric furnaces that use anthracite as a reducer and suit-able fluxes. The concentrates mentioned mere smelted under different conditions, and it was concluded that domestic ore could be reduced with anthracite to produce a ferrochromium of S to 10 percent carbon content at yields of 90 percent without retreating the slag. This carbon may be lowered to required proportion with calcium and silicon, but the former requires a great excess and the latter leaves an alloy high in silicon. INTRODUCTION Chromite occurs in several regions of the United States, but the known deposits of this mineral have not been large enough or high grade enough to permit them to compete under normal conditions with imported ores. There are numerous deposits of chrome ore along the West coast. These are generally conceded to be relatively small, although some -were worked during the World War. There are some indications of a revival of interest in California chromites. Montana contains large chromite deposits in Stillwater and Sweetgrass Counties. The utilization of chromite for ferrochromium and. the manufacture of stainless steels is distinctly an electrometallurgical problem; consequently, a study of methods for treatment of chromite might pave the way for the establishment of new electrometallurgical industries in the Western States. This thought is supported by the cheap power that is soon to become available from the western dams. Farther, submarginal domestic chrome deposits might thus be turned into profitable producers.

Jan 1, 1936

Productivity in underground metal and nonmetal mines is contingent upon work methods, mine layout, and ore handling techniques. One of the most important factors impacting productivity is the efficient movement of men, materials and supplies from the surface into and throughout the mine. Various transportation systems such as man-trains, service shafts, rubber-tired diesel equipment, etc. are currently used to transport men and supplies in underground mines. In many underground mines, it is not uncommon for a worker to spend 25% of his eight-hour working day traveling from the surface to his work area and returning to the surface.

Jan 1, 1975

By S. M. Shelton

Tests employing various ore-dressing methods were made on a manganese wad ore from the W. A. Chinn property in the Batesville-Cushman district of Arkansas in an effort to develop a practicable procedure for the production of ferromanganese-grade concentrates. The ore body occurs as a bed approximately 7 feet thick in the residual clay of the Ferndale limestone formation5/. The crude wad ores are soft aggregates of various oxides of manganese, which are loosely bonded together. Hard lumps of high-grade ore are disseminated throughout the wad. Hausmannite, pyrolusite, and psilomelane are the principal minerals. Some clay is present, but most of the gangue consists of leached fragments of the original siliceous and calcareous rocks in which the manganese occurred. In addition, hydrated oxides of iron, which axe present, also must be considered as gangue. Definite phosphate minerals have not been identified.

Jan 1, 1942

By Melford H. Salsbury

The maximum net return from the sale of ores and concentrates of gold, silver, copper, lead, and zinc accrues to the producer when these mine products are marketed to the best advantage. Data are presented that the producer, especially the small mine operator, can use to survey available markets and make a preliminary estimate of the net return to be expected from an ore, on the basis of typical mill, smelter, and freight schedules. A review of the industry is presented by States in which recent production statistics are given, marketing facilities are discussed, and locations of principal mining districts, custom mills, and smelters are shown. Explanations of treatment processes, ore types, treatment charges, payments for metals, and deductions are given. Published rail and truck freight rates for mine products, based on marketing patterns developed over many years, are listed and explained.

Jan 1, 1964

By Dale William Avery

Thirty mines and prospects were studied; 22 are within the Dolus Lakes RARE II area. Three properties within the area and one adjacent to it were determined to have indicated or inferred gold, silver, or molybdenum resources (fig. 1 and table 1) associated with quartz veins and shear zones or quartz-pyrite stockworks in granodiorite. Five other properties in the area and three just outside have potential for the discovery of gold and silver resources. Minor amounts of very fine-grained placer gold are in glacial outwash in and near the area. The John G. Carlisle Mine (fig. 1, no. 9) produced 120 oz (3.7 kg) of gold between 1897-1899. The Independence Mine produced 481 oz (15 kg) gold, 197 oz (6.1 kg) silver, and 189 lb (86 kg) of copper between 1926 and 1935. These mines are adjacent to the study area's northern boundary.

Jan 1, 1983

Researchers, medical organizations, statisticians, and others often use data on the nature and rate of occurrence of occupational diseases in directing their efforts and plans. Very often this information is developed from the reports of the States which describe the nature of work¬men's compensation claims and awards and the frequency with which they are made. To be meaningful, the statis¬tical information must be viewed in the context of the State laws involved. There is considerable variation among the laws of the different States. The Bureau of Mines has responsibilities for protecting the health of persons employed in the mineral industries and for the development of useful mineral products. To assist the Bureau in the accomplishment of its objectives, this compilation has been undertaken. For the benefit of the mineral industries, and any others who may have a similar interest, this volume is made available. An earlier compilation of the Bureau of Mines on this subject was published in 1952.4 However, during the intervening years, sufficient changes have been made in State laws to warrant completely recompiling the information. This publication includes the laws of the States, the District of Columbia, Puerto Rico, and the Virgin Is¬lands through 1964. Only those portions of the workmen's compensation laws which apply to or as ' related to occupational diseases are presented, and in each case enacted additions to and deletions from the basic law have been incorporated into the text of the law, thus snak¬ing it unnecessary to search out the various amendments made each year.

Jan 1, 1967

By David E. Siskind

The Bureau of Mines studied airblast from surface mining to assess its damage and annoyance potential, and to determine safe levels and appropriate measurement techniques. Research results obtained from direct measurements of airblast-produced structure responses, damage, and analysis of instrument characteristics were combined with studies of sonic booms and human response to transient overpressures. Safe levels of airblast were found to be 134 dBL (0.1 Hz), 133 dBL (2 Hz), 129 dBL (6 Hz), and 105 dB C-slow. These four air-blast levels and measurement methods are equivalent in terms of structure response, and anyone could be used as a safe-level criterion. Of the four methods, only the 0.1-Hz high-pass linear method accurately measures the total airblast energy present; however, the other three were found to adequately quantify the structure response and also represent techniques that are readily available to industry. Where a single airblast measuring system must he used, the 2-Hz linear peak response is the best overall compromise. The human response and annoyance problem from airblast is probably caused primarily by wall rattling and the resulting secondary noises. Although these will not entirely be precluded by the recommended levels, they are low enough to preclude damage to residential structures and any possible human injury over the long term.

Jan 1, 1980

The objective of this handbook is to provide the inspector with guidance for recognizing hazards from inhalation contaminants in above ground work areas of underground and surface coal mining and processing facilities and evaluating these hazards by collecting samples or making field determinations and interpreting the analytical results. There are several portions of the handbook which should prove most useful to the inspectors. The names and locations of these portions are listed below: Survey Check List (Page 2-3) Rules for Determining if Sampling is Required (Page 2-1) List of Most Frequently Encountered Contaminants (Page 2-2) List of Candidate Contaminants and their Sampling Conditions (Table 2, Starting on page 2-5) Interpretation of Results (Page 2-16) Procedure for a, Health and Safety Inspection (Page 2-25) For obtaining information not available from the above mentioned portions of the handbook, the inspector is directed to the Table of Contents, the Glossary of Terms, and the List of Commercial Products Encountered in Surveys.

Jan 1, 1975

By Edward W. Parsons

The transverse force developed by expansion-shell rock-bolt anchors on the wall of a drill hole as the bolt is tensioned was measured by the Bureau of Mines using a device specially designed and fabricated for attachment to a universal testing machine. Load cells equipped with electrical-resistance strain gages provided the data from which the transverse force, in pounds, was calculated. Seven different expansion-shell anchors were tested, and the ratio of transverse force to bolt-tension load was found to range between 0.98 and 1.94 to 1.0. The drag load appeared to be the major cause of the transverse-force variation, but the relative effects of individual factors that affected the ratio between the transverse force and the bolt tension were not determined.

Jan 1, 1968

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 1979 (October 1, 1978-September 30, 1979) under its Mine Health and Safety Research program. The objective of these projects is to provide an ordered and sequenced series of advances toward the Bureau's overall goal of providing the system technology required to create a healthier and safer working environment for the Nation's miners.

Jan 1, 1979

By Joseph D. Davis

Selection of a suitable coal or coals for the manufacture of coke of desired quality with due consideration of the purpose for which the coke is intended requires careful thought, and often it will pay to go to consider able expense in testing such coals as may be available. In general it will always be possible to obtain a satisfactory coal or blend of coals for the particular purpose in view, but in some places the cost of transportation would be prohibitive. It may then be necessary to consider a coal or coals inferior in grade, rank, or both. At times, in fact, only one inferior coal may be available, when the problem becomes mainly one of selecting equipment and operating conditions best adapted to that coal, keeping in mind that the end product of the plant must compete with the imported product in the market the plant will serve. This applies particularly to new projects for which it is necessary to build a plant and start with a clean slate, so to speak. However, it will pay every coke-plant manager to employ a force to continually test the coals used and the coke produced to make sure that the quality is not changing appreciably. Furthermore, if the supply of coals used becomes exhausted it will be necessary to use other coals. Continual testing is particularly necessary at plants using borderline coals or blends, where slight changes in the composition or in operation of the ovens may render them dangerously expanding. In this connection it should be stated that control in the newer coke plants is considerably easier than for those built a decade or so ago, consequently in the new ovens a given operating program can be maintained more precisely. This point is important, because one of the main requirements of the coke user is uniformity in both physical and chemical characteristics. For example, any appreciable changes in the quality of coke delivered to the blast?-furnace operator will involve changes in operation if the best results are to be obtained. Such changes are expensive usually they take considerable time and involve production of inferior iron.

Jan 1, 1942

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 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 Sam S. Taylor

Disposal of brines produced with crude petroleum and natural gas is a continually increasing problem. The necessity for studying this problem has been realized more generally in recent years, and in August 1934 an agreement was made between the Kansas State Board of Health and the United States Bureau of Mines to conduct a cooperative technical study of methods of brine disposal. To date one paper in the technical press4/ and three reports5/6/ 7/ have been published in which are given results of studies carried on under this cooperative agreement. In the Mid-Continent fields, the methods used most generally for handling oil-field brines are: (1) Impounding in evaporation ponds; (2) controlled diversion into surface streams; and (3) injection into subsurface formations through wells assigned for this purpose. Various States recognize one or more of the methods as legally authorized procedure. Impounding brine in ponds and solar evaporation have proved inadequate as a general rule, owing, usually, to the porous nature of the soil, the low rate of evaporation, or both. Diversion of

Jan 1, 1937

By James P. Ulery

Explosions in U.S. coal mines have caused death and injury to miners and destruction of workings since the first reported explosion in 1810. These explosions are caused when buildups of explosive gas and/or dust in the mine are ignited by the presence of a flame or spark. Methane gas is inherently generated and held by adsorption in coal and is normally liberated during mining. Because this gas is explosive in the range of 5%–15% by volume, fresh air is constantly supplied to the working face to prevent the methane/air mixture from reaching this explosive range. The required amount of ventilation air is based on estimates of gas release under normal conditions. Occasionally, unanticipated and unusually high emissions are encountered, which, despite normal ventilation controls, result in an explosive mixture that a spark from a cutting bit or electrical equipment can easily ignite. Investigations have shown that such emissions are often associated with anomalous geologic features or conditions. Although most operators are aware that certain geologic features may adversely affect productivity, few are aware of their potential as a gas emission hazard. This report presents a historical framework detailing the impact of geologic features on excess gas emissions and resultant mine explosions. It also provides operators with specific information on recognizing and alleviating potential hazards from methane emissions related to these geologic features.2

Jan 4, 2008

By Elaine T. Cullen

Miners, like many skilled blue-collar workers, are not traditional learners. They have not generally been successful in classroom-type settings, preferring to learn on the job in a hands-on environment. U.S. miners are required to have annual safety training, but they rarely view this positively. In fact, it has been called “safety jail” by many of them, who regard it as a time to get a little extra sleep. The challenge then, was to find a way to develop effective safety training for these people, particularly in view of the fact that their work is among the most dangerous of all occupations. Miners are born story tellers. They share “near-miss” stories, stories about master miners they have known, and stories about how things used to be. These stories not only pass along information about what will happen if a miner fails to respect the mining environ-ment, they also instruct listeners in the culture of mining and the values it embraces. Stories, it seems, are a way to get safety messages to miners, especially inexperienced ones, and using older, wiser miners in these stories is an obvious choice. This paper will discuss how the training videos created to get safety messages to miners were developed, how “master miners” and story lines were chosen, and how the resulting videos have been received in the mining industry.

[~lis is the f'fth in a ~erieG of reports on properties of commercial motor fuels, made in accordance 1,'Vi t:h fl cooperative ae,ree-ment betwGon tho Cooperative Fuel ReRRarch (e.F.R.) Committee and the Bureau of I ines of the Dcpart~ent nf the Interior. The first report gave data on motor r-asolino~ sold during the wintor of 935-36.31 Thi~ report covers 84 brands of ga~oline represented by l,722 samples exclurling the Pacific Coast. T 3)Se J.rom th~. ?~'tcific Coast IV .ro avnrL)f:od b~r tho Pacific Coa!3t tecilnical group "bofore o8ing submi ttcd ruld arc p~.lbl:'shcd GX Gtl~r as they were submi tted. In some areas r~lJort~ . erc roceivod f~om ~ ix to eicht compD.l1ie~ on the same brands of gasoline. whoruar. in other areas only one company reported on a brond. Thut., it CU .. "! be senn that BO .. 0 uf the dnt ;.U'e more rCY>l'c entat vc thM others. The inclusion of r~0rts fro:n several ci tie. w' thin somo of tho di stricts has ir.rpr,)vcd the report by reducinc; tr.e numb~r of brand rcportel by only ono company. ]

Jan 1, 1938

[~lis is the f'fth in a ~erieG of reports on properties of commercial motor fuels, made in accordance 1,'Vi t:h fl cooperative ae,ree-ment betwGon tho Cooperative Fuel ReRRarch (e.F.R.) Committee and the Bureau of I ines of the Dcpart~ent nf the Interior. The first report gave data on motor r-asolino~ sold during the wintor of 935-36.31 Thi~ report covers 84 brands of ga~oline represented by l,722 samples exclurling the Pacific Coast. T 3)Se J.rom th~. ?~'tcific Coast IV .ro avnrL)f:od b~r tho Pacific Coa!3t tecilnical group "bofore o8ing submi ttcd ruld arc p~.lbl:'shcd GX Gtl~r as they were submi tted. In some areas r~lJort~ . erc roceivod f~om ~ ix to eicht compD.l1ie~ on the same brands of gasoline. whoruar. in other areas only one company reported on a brond. Thut., it CU .. "! be senn that BO .. 0 uf the dnt ;.U'e more rCY>l'c entat vc thM others. The inclusion of r~0rts fro:n several ci tie. w' thin somo of tho di stricts has ir.rpr,)vcd the report by reducinc; tr.e numb~r of brand rcportel by only ono company.]

Jan 1, 1938

This report presents depth and producing rate statistics pertaining to oil reservoirs (or fields) in each of the 14 States that produced more than 20 million bbl of oil during 1965. The combined oil production was about 2.6 billion bbl, or 96 pct of the U.S. total. Data are presented for each of the 14 States, each Texas Railroad Commission district, and four geographical areas of Louisiana. About 8 pct of the total oil produced in the 14 States was from depths of lees than 2,000 ft, 24 pct from 2,000 to 4,000 ft, 22 pct from 4,000 to 6,000 ft, 16 pct from 6,000 to 8,000 ft, and 30 pct from 8,000 ft and deeper. The average production per well in the 14 States ranged from 4.4 bopd for wells less than 2,000 ft deep to 57.6 bopd for wells 8,000 it and deeper. Data indicate that 9.5 pct of the 460,968 wells produced more than 1.2 billion bbl or 46.6 pct of the total oil. Oil production from reservoirs (or fields) not undergoing stimulative recovery operations, such as steam, air, gas, or water injection, wee about 1.1 billion bbl or 42.1 pct of the total.

Jan 1, 1967

By Peter G. Kovalchik, Lawrence W. Scott, Thomas H. Dubaniewicz, Mark A. Fuller

Mine trailing cables operated above safe thermal limits can cause premature insulation failure, increasing electrocution and fire hazards. Previous U.S. Bureau of Mines Pittsburgh Research Center research showed that, under static test conditions, electrical current levels permitted under present regulations may not limit cable temperatures to less than the 90 °C rating of reeled trailing cable. Continuing research under the National Institute for Occupational Safety and Health (NIOSH) addresses thermal characteristics of reeled trailing cable under dynamic test conditions more representative of field conditions, where operators constantly reel in and pay out cable. This research is in support of efforts by industry associations and the Mine Safety and Health Administration to establish safety guidelines for cyclically rated reeled machines. This paper describes a unique approach to measuring temperatures within reeled cable under dynamic test conditions. Fiber-optic sensors embedded within the metallic conductors measure temperatures at 1-m intervals along the entire length of cable. Temperature measurements are reported to be accurate to within 1±° C. The test setup requires access to only one end of the trailing cable, allowing researchers to freely reel in and pay out cable while temperature measurements are made, simulating field conditions. Manufacture of a fiberoptic-embedded trailing cable is described, along with initial test results that indicate the fiber-optic approach is viable.