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By E. D. Gardner

"Trolley lines used in connection with electric haulage in mines are a source of danger and many lives have been lost by men accidentally coming in contact with the wires. Usually the wires in metal mines are sufficiently guarded to prevent men from touching them with their person or by pieces of steel which they may be carrying or their shoulders, while walking along the level. However, it is difficult to guard effectively the wires at loading chutes along the haulage ways and in spite of safe guards, chute tappers have been electrocuted through loading bars accidentally touching the trolley line.To overcome this danger the Calumet & Arizona Mining Co., at Lowell, Arizona formely used a hinged V-shaped trough made of 1-inch by 6-inch lumber, that was dropped over the wire in front of the chute, when the cars were being loaded. This arrangement interfered with the easy operation of the chute, and a cut-out device for the trolley line was devised by W. R. Gibson, chief electrician for the company. This cut-out is efficient easily constructed and roes not interfere with the operations at the chutes or with the motors operating on the same level.When the cut-out is open the electric current is carried past the gap by an insulated wire on the opposite side of the drift. A hinged board drops down over the ends of the trolley guard when the slide is open and Prevents anything touching the live wires. About ninety of these cut-outs are now in use in the mine,The levels under the scopes are timbered with drift sets placed 5 feet apart, and the loading chutes take up the space between two sets. All trolley wires in. the company's mines are carried 6 feet above the rails and guarded by two 1/2 by 6-inch boards placed on either side of the wire."

May 1, 1921

By S. J. Aresco

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindablity index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions3 issued by the Bureau of Mines; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor; if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous of coal as delivered is a check on the practical results obtained in the coal.

Jan 1, 1967

By M. H. Kline

Round Mountain is one of a number of locations investigated by the Bureau of Mines in its search for manganese deposits during the early phases at the strategic minerals program. The Suiter mine, on Round Mountain, had provided some 5,000 tons of manganese concentrates during the period 1917 to 1919, and early in 1941 prospecting by the Virginia Hardwood Lumber Co. in this same area had discovered manganese on what later became known as the Hall Pit. These promising indications encouraged the Bureau to begin an exploration project in search of additional reserves of manganese on Round Mountain in January 1942 (fig. 1).

Jan 1, 1948

By Alvin Kaufman

Geothermal plants are competitive with conventional units. A geothermal plant can produce electric energy for 6.70 mills per kwhr, compared with 6.96 mills for coal, 6.74 mills for oil, and 7.04 mills for gas. These costs include fixed and variable charges. Potential for geothermal power exists in the Western United States, Alaska, and possibly Hawaii. Assuming that the current downward trend in cost per kilowatt of coal will cease and that the relative cost of gas and oil, already trending upward, may rise considerably more, geothermal energy will be utilized where available, in producing electric energy. It will be used in California first because it is directly competitive with gas-and oil-fired installations there. A long-term appraisal is difficult because little is known about the sources of geothermal power and the electric generating capacity which the steam fields will support. However, a market for geothermal steam-generated electricity exists within the Western States.

Jan 1, 1964

By Alvin Kaufman

Geothermal plants are competitive with conventional units. A geothermal plant can produce electric energy for 6.70 mills per kwhr, compared with 6.96 mills for coal, 6.74 mills for oil, and 7.04 mills for gas. These costs include fixed and variable charges. Potential for geothermal power exists in the Western United States, Alaska, and possibly Hawaii. Assuming that the current downward trend in cost per kilowatt of coal will cease and that the relative cost of gas and oil, already trending upward, may rise considerably more, geothermal energy will be utilized where available, in producing electric energy. It will be used in California first because it is directly competitive with gas-and oil-fired installations there. A long-term appraisal is difficult because little is known about the sources of geothermal power and the electric generating capacity which the steam fields will support. However, a market for geothermal steam-generated electricity exists within the Western States.

Jan 1, 1964

By Catherine C. Kilgore

The Bureau of Mines investigated the availability of lead and zinc from 104 domestic mines and deposits. Fourteen primary lead and fifty-three primary zinc operations with in situ demonstrated resources containing 27.3 million metric tons (t) of lead and 53 million t of zinc were subsequently evaluated. Potentially 17.5 million t of lead and 2.4 million t of byproduct zinc could be recovered from 14 primary lead operations. Economic evaluations performed in constant January 1982 dollars determined a long-run total cost per pound of recoverable commodity. Including a 15-pct discounted-cash-flow rate of return (DCFROR), 59 pct of primary lead was potentially available at or below $0.32 per pound of lead. Potentially 40 million t of zinc and 5.6 million t of byproduct lead could be recovered from 53 primary zinc operations. Ninety percent of the recoverable zinc is potentially available from currently nonproducing mines and deposits, and a weighted average of their long-run total costs was determined at $0.98 per pound of zinc. At a breakeven (0-pct) DCFROR, these non producing operations had a weighted average long-run total cost of $0.58 per pound of zinc. Sensitivity analyses illustrated that operations that recover byproducts were most sensitive to fluctuating metal prices, producing operations were more sensitive to increased smelter treatment charges, and nonproducing operations were impacted most by the DCFROR.

Jan 1, 1983

By C. P. Mishra

The Bureau of Mines performed a study of the availability of cobalt from market economy countries. The study entailed the detailed analysis of 97 deposits which contain 3.9 billion lb of cobalt at the demonstrated level; in 94 of the deposits cobalt is recovered as a byproduct, and in 3 it is considered the primary product. Since 97 pet of all recoverable cobalt is derived as a byproduct from copper and nickel deposits, the report focused on these two sources. At an assumed market price of $0.89flb for copper, $3.45/lb for nickel, $475/tr 021 for platinum, and $7/lb for cobalt, 1,330 million lb of cobalt at the demonstrated level are potentially available. This total includes 1,105 million lb of cobalt from copper properties, 190 million lb from nickel, 29 million lb from platinum, and 6 million lb from primary cobalt. This analysis indicates that the production cost for 589 million lb of cobalt can be totally covered by the revenues obtained from the other metals produced. The impacts of increases in capital investment and energy costs are also discussed.

Jan 1, 1985

By Elio Ferreira

This report describes the design, and development work performed to reduce the volume and weight of the miners caplamp battery, as well as a headpiece with a swivel mechanism containing a halogen bulb with two filaments. Work was also conducted in the development of a maintenance free battery. The design concept is based on non-sintered Ni-Cd technology, with an energy density of 22 Wh/lb. The cap lamp system developed has been approved by the Mine Safety and Health Administration (MSHA) and can be manufactured for mine use.

Jan 1, 1988

By Peter G. Kovalchik, Rudy J. Matetic, Susan B. Bealko, Adam K. Smith

Overexposure to noise remains a widespread and serious health hazard in the U.S. service providing and goods producing industries. Excessive noise can lead to poor verbal communication and reduce the ability to recognize warning signals. These dangerous work conditions can also cause stress and fatigue. Occupational hearing loss is a permanent illness, with no recovery currently possible. Method: National Institute for Occupational Safety and Health (NIOSH) has recognized Noise Induced Hearing Loss (NIHL) as one of the ten leading work related diseases and injuries in the United States, and has emphasized its importance as one of the critical areas expressed in the National Occupational Research Agenda. Results: One of the most serious noise problems in the goods producing industries is the operation of continuous mining machines during underground coal mining. In order to minimize occupational hearing loss, noise hazards are “designed out” early in the design process. NIOSH is leading a national initiative called Prevention through Design (PTD) to promote this concept. This paper describes the quiet by design approach of a noise control that reduced noise exposures of continuous mining machine operators by 3dB(A) using the four functional areas of PTD, namely Practice, Policy, Research, and Education.

By Joseph A. Conway

This paper is one of a series dealing with the mining and crushing methods and costs of the nonmetallic industries, prepared under the sponsorship of and in cooperation with the U. S. Bureau of Mines,. The quarrying methods described in this paper are those used at the Monocacy trap rock quarry which annually produces from 450,000 to 500,000 tons of crushed stone. This property is located 3 miles east of Birdsboro at Monacacy, Pa., and is one of the three quarries operated by the John T. Dyer Quarry Co. Throughout the paper an effort is made to explain the various methods used and the cost of operation.

Jan 1, 1931

By John C. Machisak

INJURY data and experience, with related employment statistics, at coal mines in the United States for 1958 are presented in this publication under the following general sections: (A) General injury experience: Tables 1 to 6: Current data on number of injuries, degree of injury, frequency and severity rates, average severity, and related employment and production data by work location. (B) Selected injury experience: Tables 7 to 38: Current data on principal agencies of injuries, distribution of injuries by part of body injured, days of disability, extent of hand and machine loading, experience by employment and production groups, and various other operating factors and physical conditions related to the occurrence of injuries at the Nation's coal mines. (C) Injury experience by States: Tables 39 to 43: Current data on injuries, their causes, rates of occurrence and severity; employment and production data by work location, by States. (D) Major disasters: Table 44: Data on major disasters from 1949 to 1958. A major disaster is defined as a single accident in which, or as a result of which, five persons or more are killed instantly or die at any time thereafter. (E) Historical coal-mine-fatality experience: Tables 45 to 49: Data on fatalities and their causes at bituminous coal, lignite, and anthracite mines from the earliest records through 1958.

Jan 1, 1961

By G. A. Appell

"INTRODUCTION During the summer of 1945, the Bureau of Mines conducted an investigation and program of churn drilling near the village of Tennyson in Grant County, Wis. The work was undertaken as part of a general investigation of the zinc-producing area of southwestern Wisconsin at a time when all effort was being made to increase the production of metals important to the war program.The area for special investigation was selected on the basis of favorable structural disclosures, evidence of widespread zinc mineralization, absence of any great amount of exploration to depth beneath the productive shallow workings, and the favorable results of several churn-drill holes in the village of Tennyson.During the Bureau's investigation, 30 churn-drill holes aggregating5,888 feet were completed.ACKNOWLEDGMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to-the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual. Investigative work, and prepares the final report.The work described herein was accomplished under the direct supervision of Francis C. Lincoln and the author, mining engineers of the Bureau of Mines. Final data on the investigation were prepared under the direction of Edward F. Fitzhugh, Jr., chief Minneapolis Division, Mining Branch."

Jun 1, 1947

By W. C. Holliman

This report on the characteristics of commercial aviation gasolines is one of a series of such reports. It presents compilations of' inspection data furnished on their products by 15 manufacturers of commercial grades of aviation gasoline and special data obtained in Bureau of Mines laboratories on 68 samples of these gasolines. Data are presented for 18 samples of grade 80, 20 of grade 91/98, 21 of grade100/130, and 9 of grade 115/145 aviation fuels. The gasolines are designated January 1948 production, although some of the samples actually were produced at a later date.

Jan 1, 1948

By J. P. Powell

Since the beginning of waterflooding in the Midcontinent area, the Bureau of Mines has published many reports3-6/ describing in detail the results obtained on individual waterflooding projects in the area. These are intended as guides for operators in the selection of well-spacing, water-treating, and other techniques, as well as an indication of the results being obtained in waterflooding in various areas, fields, and horizons. In addition, Bureau personnel has arranged a tour of selected waterflooding projects each year for the past several years so that actual operating conditions may be observed and an additional opportunity provided for exchanging information. Each of these tours has been supplemented by a published

Jan 1, 1959

By O. C. Blade

This report on the properties of motor fuels sold through service stations in the United States was made in accordance with a cooperative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Department of the Interior. By agreement with the American Petroleum Institute, identification of the items is confidential. It presents analytical data for 4,680 samples, representing the products of 130 companies. The samples were collected during December 1953 and January and February 1954. As in previous surveys, the gasolines covered by this survey include those from both large and small suppliers. The data were obtained by laboratories of various refiners, motor manufacturers, and chemical companies and submitted to the Bureau of Mines for compilation. A list of the National Motor-Gasoline Survey reports published during the past ten years is given on page 5.

Jan 1, 1954

By Thomas O. Glover

Cameroon continued to enjoy sustained economic growth that began with its independence in 1960. Growth in the gross domestic product (GDP) averaged 2.8% per year during the 1960's and the first half of the 1970's. Starting in 1976 and for the succeeding 10 years, the GDP accelerated rapidly owing to the coming on-stream of Cameroon's small but domestically significant offshore oil industry. In 1985, the GDP grew by 7.8%, but in 1986, it was only up 5.5%. The country's sustained economic growth in dollar terms of gross national product (GNP) per capita reached $1,075 in 1986. The ranking in GNP per capita by the International Monetary Fund put Cameroon in the middle-income category for developing countries. The sustained economic growth rate up to 1986 was due to the injection of income from oil into the economy, but crude oil price reductions in 1986 brought a slowdown. In 1986, crude oil production grew to 200,000 barrels per day, an increase of 8.2% from that of 1985. Most of the oil came from the Société Nationale Elf Aquitaine (SNEA) wells in the multifield Rio del Rey complex. Additional output came from the Moudi Field operated by Compagnie Française des Pétroles S.A. Proven oil reserves in Cameroon were 540 million barrels. At 1986 production rates, and in the absence of further discoveries, Cameroon will have exhausted its recoverable oil reserves by the year 1995. Owing to worldwide crude price reductions, the country's oil income fell 60% between 1985 and 1986, from $1.82 billion2 to $0.72 billion. Cameroon's refinery operator commenced operating the Sonara refinery in 1981 at Point Limboh. Sonara's capacity of 43,000 barrels per day was small by most standards. In 1986, natural gas reserves, estimated at 100 billion cubic meters, were not produced commercially because there were no domestic users. Proposals for a multibillion-dollar liquefied natural gas plant at Kribi had been submitted; however, work on the plant had not commenced.

Jan 1, 1988

By W. J. Crawford, P. M. Gruzensky

"Several experiments have been carried out in efforts to evaluate qualitatively a variety of electrolytes for refining bismuth. Most extensive work was done with the basic tartrate, hydrochloric acid, and hydrofluosilicic acid electrolytes. Deposits that are smooth and adherent can be obtained from these three electrolytes if low cathode current densities are employed. All three electrolytes were effective in purifying crude bismuth considerably, with additional purification indicated in each instance by a reelectrolysis step.With the basic tartrate electrolyte best results were obtained when the electrolyte was at 40° C. and contained at least 100 grams of bismuth per liter. An apparent disadvantage was depletion of bismuth from this electrolyte, causing the deposits to become spongy and nonadherent.The hydrochloric acid electrolyte had the greatest tendency to yield rough, dendritic deposits. Best deposits were obtained at cathode-current densities below 2 amperes per square decimeter. A small amount of glycerin helped to produce a smoother deposit, and adding sulfuric acid or methyl sulfuric acid retarded the deposition of impurities. Very good results were obtained in electrowinning bismuth from a bismuth trichloride-hydrochloric acid electrolyte.Smooth and adherent deposits were obtained from a hydrofluosilicic acid electrolyte, with very good refining as regards lead and silver impurities; however, higher reagent costs and slow decomposition of the electrolyte have discouraged its use.INTRODUCTIONMethods of recovering bismuth from ores and byproducts were underdeveloped for many years because of the limited uses for bismuth, the pharmaceutical industry being the chief consumer. In the past decade or so additional uses for bismuth, particularly in the metallurgical field, have brought about increased demand for the metal with the result that bismuth is being recovered from byproducts that were once discarded. In addition to such uses as low-melting alloys, solders, bearings, die setting, etc., some interest has been indicated in bismuth as a possible coolant for nuclear reactors. The advent of ductile bismuth and bismuth-alloy thermocouple wire has contributed greatly to temperature measurement, particularly in the below-zero range."

Jan 1, 1956

By G. E. McElroy

The purpose of tins paper is not to present new date on the pressure losses due to bends and chances of area in mine openings through which air flows, but rather to correlate existing data, determined mainly on small duct systems and expressed in a variety of ways, according to uniform methods that facilitate their use in pressure-loss computations. These are required in such, air-flow problems as determining the quantity that will flow through is mine openings under a certain pressure difference or, conversely, the pressure difference that will be required to maintain a certain rate of flow. Air flowing through h ducts, such as mine airways, encounters resistance to flow due to interference of the individual air streams with each other caused by the wall surfaces. The result is that part of the kinetic energy of the flowing stream is converted to heat; and constant renewal of the kinetic energy from the total energy of the flow is required to maintain it. This process manifests itself by a decrease of the total pressure (static pressure plus velocity pressure; of the air in the direction of flow; in order that flow pray occur, there must necessarily be a differences in total pressure between the two cads of the air-ay equivalent to the pressure losses occasioned by the flow, which automatically adjusts itself in magnitude to the pressure difference maintained.

Jan 1, 1932

By Madan M. Singh

This report presents the results of an investigation of inclined roof bolts, anchored over pillars, in room-and-pillar coal mines susceptible to shear failures of the roof. Although the field data do not support this contention, it is believed on the basis of analyses and other work that inclined roof bolts do offer potential under some circumstances.

Jan 1, 1978

By A. Aly Selim

This report describes the feasibility of predicting percussive drilling rates by equations derived from statistical regression analysis. The least squares statistical method was used and the analysis was performed both by direct and by stepwise linear regression analysis. The predicted penetration rate is a function of the drill power and the physical properties of the rocks penetrated. The results show promise that the technique may be of value in providing a mathematical model by which percussive drill manufacturers and users can predict the performance of a given drill. Experimental work involved two mining type percussive drills. Penetration data for these drills were determined from nine rocks drilled in the laboratory. Drill work rates (power) were determined in a separate series of experiments. Rock physical properties were measured from diamond-drill core samples taken from the same blocks used for percussive drilling.

Jan 1, 1970