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By Ivan F. Avery

DOMESTIC production of carbon black increased 4 percent in 1962 to 2,056 million pounds. Furnace black output was 8 percent, or 132 million pounds, above that in 1961 and accounted for 90 percent of total carbon black production. Channel black output continued to decline and was 55 million pounds less than in 1961. Carbon black shipments during the year totaled 2,082 million pounds and were 5 percent above those of 1961. About one-fifth of these shipments were exported; the balance were sold domestically. An increase of 180 million pounds in domestic sales was partially offset by a decline of 80 million pounds in exports. Total value of carbon black production in 1962 was $145 million. The average value per pound of 7.06 cents was 0.24 cent per pound less than in 1961. Producers' stocks declined 26 million pounds during the year.

Jan 1, 1963

By Robert L. Lagace

The objective of this task was to perform theoretical analyses related to identifying and increasing the understanding of wireless propagation mechanisms in mines, and for predicting the performance ranges and limitations of proposed systems. This was to be achieved by building on and extending previous ADL work* and utilizing experimental data as they became available in the radio frequency bands of interest. B. TASKS Theoretical radio wave propagation investigations undertaken on this task centered on three areas. The first area dealt with extending previous UHF wireless propagation results*: to estimate the losses caused by the presence of haulage vehicles such as trains in coal mine tunnels; to estimate the propagation losses and wireless communication ranges expected along a longwall coal face tunnel; and to assess the applicability of previous analytical approximations to tunnels having reduced crossectional dimensions, such as those found in low coal and in the presence of haulage vehicles. The second area dealt with the development of a suitable propagation model to adequately explain the unexpected, highly favorable LF to MF band wireless radio wave propagation behavior experimentally observed in Consolidation Coal Co.'s Ireland mine. The third area dealt with the formulation of a model for evaluating the overall system transfer function and transmitter requirements for a hoist shaft LF communications system, taking into account the hoist rope/shaft transmission line characteristics, the cage and sheave wheel line terminations, the signal inductive couplers, and hoist shaft signal and noise data.

Jan 1, 1975

By Edmund S. Leaver, R. S. Dean, T. L. Joseph

The metallurgy of manganese has developed along the lines of iron metal¬ lurgy. Enough high-grade ore has Been available so that by reduction with carbon it could be turned into an iron-ma.nga.nese alloy and a slag containing some 9 to 15 percent manganese. More siliceous ores have been smelted in the blast furnace to form iron-silicon-manganese alloys called spiegel. When lower-grade ores came in for serious consideration, which lias only been since l°l4, two types of processes received the most consideration — hydrometallurgical processes to produce a concentrate which could be smelted like the higher-grade ore and processes involving concentration of the manga¬ nese from manganiferous iron ores by preferential reduction of the iron (184)1. Special chapters in this bulletin are devoted to the production of ferro¬ manganese from ore, the hydrometallurgy cf manganese, and the Bureau of Mines modification of the preferential reduction process. Other methods of producing manganese alloys from low-grade or refractory ores have been suggested and may find future application. Manganese has a very high affinity for sulphur and is particularly adaptable to concentration by matte smelting. According to Betts (26), manganese silicate may be smelted with pyrite to give manganese sulphide and iron silicate. This method would be applicable to concentration of either the silicate or carbonate ores. The sulphide, once obtained, could be roasted to oxide and reduced in the usual way. Another possibility for the production of manganese from silicate ores involves their reduction by silicon or manganese silicides. Swedish Patent 52290, February 25, 1925. covers the reduction of a slag rich in manganese by silicon-manganese alloy containing more than 10 percent silicon, Joseph H. Brennan (38.) describes the concentration of manganese iron ores by partial reduction with silicon. Beckett (7,4,19) describes the reduction of manganese dioxide with a manganese silicide for the production of standard ferromanganese. Beckett gives as a typical alloy, manganese 64.4, silicon 24.6, and as a typi¬ cal ore, 5S.5O manganese as MnO^. The product of the reaction between these two is 80.11 percent manganese and 1.22 percent silicon.

May 1, 1934

By R. D. Leitch, W. P. Yant, A. C. Fieldner, R. R. Sayers, S. J. Pearce

"The detection of leakage is a recognized problem in the safe and economic distribution and use of natural gas. Natural gas is practically odorless and therefore lacks he property of indicating significant leakage by the sense of smell, the means most widely used by gas employees and consumers for detecting leaks of the more odorous types of fuel eases. In view of the recognized value of the odor of gas for indicating leakage at the time of occurrence the Bureau of Mines has studied' the possibility of adding small amounts highly odorous substances to types of fuel gas (such as blue water gas and natural gas) that lack warning properties. These studies revealed that the mercaptans were promising substances to accomplish this purpose, not only for odorizing fuel gases but for other purposes° where it was desired to give warning through the sense of smell.Since completing the studies mentioned, the Bureau of Mines jointly with the American Gas Association has conducted further investigations dealing with the use of warning agents for fuel gases. The results of this work will be published later.The Bureau of Mines had been desirous of observing the practical use of ethyl mercaptan for detecting leakage of natural gas, particularly to determine whether the odor would permeate the ground and give indication of lea's in underground pipes. Opportunity for making these observations was recently given by E. A. Munyan, manager, gas department, Union Gas t Electric Co., who requested the bureau's cooperation in making leakage surveys of the company's distributing systems at Franklin and Middletown, Ohio."

Jun 1, 1930

By Scott W. Hazen

METHODS of determining the grade and tonnage in a mineral deposit have not kept pace with scientific developments in certain other fields. The most commonly used methods of computing ore reserves and grade based on diamond-core-drill sampling are the cross section, the polygon, and the triangle. Tonnage and grade may be determined by these methods with acceptable accuracy, providing a sufficient number of samples is obtained; however, there is no means of determining when an adequate number has been taken or conversely if the deposit has been sampled excessively. It is demonstrated that, by using the techniques of statistical analysis, a mining engineer will be able to determine when a sufficient number of samples has been taken to determine the grade of a mineral deposit within a specified degree of confidence. Using statistical analysis to compute the estimated average grade of the ore makes it possible to compute a fiducial interval, when a distribution of the sample means is normally distributed, so that there is 95-percent confidence in the statement that the true average grade of the deposit is covered by the interval. This report utilizes data obtained from the Maggie Canyon manganese deposit, Artillery Mountains region, Mohave County, Ariz. Four separate exploration projects were conducted at Maggie Canyon between 1936 and 1950. Present economic conditions have made it desirable to determine the amount of 5-percent manganese ore developed by these projects.

Jan 1, 1957

According to reports in August, Botswana RST's copper- nickel-cobalt smelter at Selebi-Pikwe produced 7 percent above the rated capacity of about 3,500 metric tons of matte per month. This record production occurred after 2 years of plant production difficulties and was brought about by a new management team. A shutdown for furnace maintenance had been planned for this year, but was postponed because of the improvements in production and operations. However, the mining operation continued to face problems relating to higher costs and some outstanding claims. COPPER: Effective December 1, ASARCO, Inc. and Phelps Dodge Corp. reduced their domestic copper prices by 54 per pound. Within a period of 3 days, a11 other producers (Kennecott Copper Corp., Newmont Mining Corp., Cities Service Co. , Copper Range Co. , Duval Corp., and Inspiration Consolidated Copper Go. ) had either lowered or discounted their market postings by 5¢ to 65.625¢ per pound on electrolytic wirebar and 65$ on cathode plate. Between November 29 and December 3, New York merchants decreased wirebar quotations by 1.8¢-2¢ to within a range of 57.8¢-58¢ per pound. New York Commodity Exchange (COMEX) spot-contracted copper in the week was priced at 57. 1¢ on Monday, 56.7¢ on Wednesday and Thursday, and 57.4¢ on Friday, resulting in a 5-day average of 56.9¢, London Metal Exchange (LME) cash (prompt) wirebar averaged 56.3¢ last week, opening Monday at 56.6¢, falling from Tuesday?s high of 57.2¢ to Wednesday?s low of 55.6¢ and closing Friday at 56.1¢. Foreign producers, guided by LME market transactions, lowered wirebar quotes to 56¢ per pound. Copper stocks as of December 3 totaled 187,702 short tons at COMEX warehouses and 654,573 tons at LME depositories, compared to 97,413 and 537,481 tons, respectively, for the corresponding 1975 period.

Jan 1, 1976

By S. H. Ash

THE INVESTIGATION of barrier pillars in the Southern field is part of the comprehensive study of the mine water problem in the anthracite region of Pennsylvania by the Federal Bureau of Mines (1, 2, 5, 6, 7, 8, 9, 10, 11, 12, 15, 16, 18).4 Tim Southern field is in Carbon, Schuylkill, Dauphin, and Lebanon Counties, in eastern Pennsylvania; has an area of 200 square miles; is 70 miles long from Mauch Chunk on the east to the Susquehanna River on the west; and is 1 to 6 miles wide. In the Southern field are 37 underground water pools containing 37312 billion gallons of water (5). Most of these pools overflow to the surface because the barrier pillars controlling them are effective under existent, conditions. Abandonment of mines in the Southern field has resulted in the hooding of 34 percent of the field. The largest tonnage of reserves of anthracite lies in this field, where mining conditions are most difficult. Large reserves of anthra¬cite underlie the abandoned mine workings, and before a great part of these reserves can be developed and extracted, the abandoned workings must be unwatered and kept drained (5).

Jan 1, 1953

By Mary L. Pearson

Ibis report summarizes the results of the contract. Included are summaries of existing legislation pertaining to outcrop barriers and a state-of-the-art survey of outcrop barrier designs and related, mine closure techniques. Six sites were inspected in the field and are presented as case histories The data analysis presented includes a computer modeled seepage analysis, an overburden blew-out analysis, and a wedge stability analysis. The results tit these analyses are interpreted to form recommendations for coal outcrop barriers which will minimize seepage and the potential for failure. Supplementary support and reinforcement alternatives are also discussed.

Jan 1, 1981

By James Westfield

A brief resume follows of some recent activities of the Division of Coal-Mine Inspection that have had a favorable effect on health, safety, and the reduction of injuries at coal mines: 1. The Federal Mine Safety Code for Bituminous-Coal and Lignite Mines of the United States was issued originally by the Director of the Bureau of Mines on July 24, 1946, after consultation with management and labor representatives of the coal-mining industry. The code has been used by Federal coal-mine inspectors during their inspections of bituminous-coal and lignite mines as a basis for determining the existence of unhealthful and unsafe conditions and practices in these mines. A revised code was issued by the Secretary of the Interior October 8, 1953, following further consultations with representatives of management and mine workers, and was incorporated by reference in the 1952 and subsequent bituminous-coal wage agreements. The agreement of May 29, 1946, between the Secretary of the Interior, acting as Coal Mines Administrator under authority of Executive Order 9728, and the United Mine Workers of America, covering bituminous-coal and lignite mines in Government possession, charged Federal coal-mine inspectors with the responsibility of making periodic investigations of the mines and reporting to the Coal Mines Administrator any violations of the Federal Mine Safety Code. The inspectors were active in making prompt investigations of hazardous mines that had been closed by order of the Coal Mines Administrator to determine if enough improvements had been made to allow the mines to reopen. Federal coal-mine inspectors also had temporary authority to close mines they found to be imminently dangerous, but such authority (under Executive Order 9728) was removed on June 30, 1947, when Government control of the mines was terminated.

Jan 1, 1957

By A. B. Hooker, E. J. Coggeshall

"Dry cells are modified wet primary cells in which the electrolyte is held by absorbent material so that it does not spill aid the cell jars are sealed to prevent evaporation of the absorbed electrolyte. Most dry cells in commercial use are modifications of the Leclanche wet cell. In their usual form they have a hollow cylindrical zinc negative pole that constitutes the containing vessel. An absorbent material, either as a lining in the zinc jar or a bag, separates the zinc cylinder and a rod or flat plate of carbon placed axially inside. A mixture of crushed coke, graphite, and manganese dioxide is tamped about the carbon rod, and the whole mass is saturated with salaanoniac-zinc chloride solution.Dry cells are suitable for services that require minute currents continuously or larger, though limited, amounts of current intermittently. Though limited in this way, they have a wide use, even in underground mining. This paper details some of the applications of dry cells in mines, particularly from the standpoint of greater safety through their use.APPLICATIONSThere are four fields of application of dry cells to mining: (1) Electric shot firing; (2) auxiliary lighting; (3) signaling; and (4) testing.SHOT FIRINGFiring an electric detonator requires very little electrical energy because although the current flow may be 1 to 3 amperes the duration of flow is so small (1 to 4 milliseconds) that the energy withdrawal per shot is almost negligible. Batteries for shot firing need not be large; they may be used for firing either single or multiple shots."

May 1, 1934

By Joseph J. Wallace, William H. Tavenner, D. A. Reynolds, John M. Provost, James J. Dowd, R. F. Abemethy

"CONCLUSIONSThe investigation shows that there are 5 coal beds of major importance in Wyoming County from the standpoint of present production - Pocahontas No. 3, No. 2 Gas, Sewell, Beckley, and Eagle - and 5 beds of minor importance - Pocahontas No. 6, Cedar Grove, Winifrede, Douglas, and Chilton. The Pocahontas No. 3 bed contains the largest remaining known reserves.Known measured and indicated reserves in all beds, based on a minimum thick¬ness of 14 inches and on 1,800 tons per acre-foot of coal in place, are estimated at 2,665 million short tons as of January 1, 1951. Of this total, 2,121 million short tons is in beds 28 inches and more thick. Areas in each bed were omitted from the estimate because available data relative to the bed characteristics are too meager to make an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.Recoverable reserves of coal have been estimated in beds 28 inches and more thick. This thickness is about the minimum now being mined by hand loading onto conveyors in the Appalachian region. The weighted average recovery for all beds in Wyoming County, as determined by this investigation, is 55.0 percent. This percent¬age is based on the total thickness of coal (less partings 3/8 inch or more thick) in the bed rather than on the thickness of the coal mined. The known recoverable reserves are estimated to be 1,167 million tons as of January 1, 1951.4. Since most of the Wyoming coals are medium- and low-volatile bituminous in rank and expand during carbonization in modern ovens, they are blended with high-volatile contracting coals."

Apr 1, 1953

Several primary ingot producers have introduced price changes for July. Howmet Aluminum Corp., Revere Copper and Brass, Inc. and the Anaconda Co, will increase late-July prices of 99.5 percent unalloyed aluminum ingot by 3 cents to 56 cents per pound, Prior to this, Kaiser Aluminum and Chemical Corp. had advanced June ingot values by 4 cents to 57 cents and Consolidated Aluminum Corp., 4.5 cents to 57.5 cents. Domestic merchants held June quotes at a range nearing 50-50.8 cents per pound. ANTIMONY Although NL Industries, since April of this year, stopped publishing prices for RMM and Lone Star antimony grade, values of domestically-refined antimony in alloy are being made available to industry, The current price of this material is $1.75 per pound of antimony contained in alloy, New York dealer-marketed metal was available in June at $1 -13-$1 .20 per pound. Important industrial uses of antimony are for flame retardants, storage batteries, chemicals, pigments, rubber, plastics, glass, ceramics and machinery.

Jan 1, 1978

By Robert H. Peters

This U.S. Bureau of Mines report identifies the types of serious accidents that occur most frequently at small underground coal mines and describes the strategies that could help prevent these accidents. A wide variety of methods for improving safety are suggested, including improvements in the design of equipment, work procedures, work schedules, safety programs, and emergency response plans, as well as techniques for diagnosing the potential hazards associated with new technologies and work procedures. Some of the papers in this volume focus on preventing specific types of mining accidents-ones associated with materials handling (primarily back injuries), equipment maintenance, improper machine guarding, and ground failure during retreat mining. Although the recommendations in this volume are heavily influenced by research performed at underground coal mines in the Appalachian coalfields, most of the papers contain advice that is equally pertinent to almost any type of mine.

Jan 1, 1994

By Edward A. McClatchie

A novel nondispersive electro-optical gas analyzer has been designed, fabricated and tested. The instrument is based on a pressure modulated absorption technique. Key features of this new gas analyzer technique include long-term zero and calibration stability. The technique was investigated for the gases carbon dioxide (CO2), carbon monoxide (CO), methane (CH4) and nitrogen dioxide (NO2). The delivered analyzer was capable of measuring the three species CO, CO2 and NO2. It is a compact (300 cu in) package, is battery powered and weighs 15 lbs. Some thirty readings of each gas may be made on a single battery charge.

Jan 1, 1980

By J. F. Barkley

[There is a general concept in the, coal trade that the moisture- and ash-free B.t.u. of coal from the same seam, and. surely from the same mine, is substantially a constant; that calculation of the -moisture- and ash-free B.t.u. value from the proximate analysis and B.t.u. determined in the laboratory will reveal whether a coal came from a given area or sears; and that, having this constant, the B.t.u. value of a coal sample can be calculated fairly closely upon a dry or as-received basis from the moisture and ash values of its proximate analysis.]

Jan 1, 1941

By Avery H. Reed

RECORD production of portland cement, crushed limestone, marble, lime, and clays highlighted the mineral industry of Alabama in 1959. Among the States, Alabama ranked second in production of bauxite, and third in output of iron ore, scrap mica, and native asphalt. Alabama's mineral industry was dominated by the mining and processing of coal and iron ore, which accounted for 51 percent of the total value of production in 1958 and 1959. Other important industries were cement manufacturing, petroleum, and stone quarrying. Leading companies were Tennessee Coal & Iron Division of United States Steel Corp. (coal;. iron ore, limestone, lime, and magnesium compounds), Southern Cement Co. Division of American-Marietta Co. (cement, lime, limestone, and miscellaneous clay) , Woodward Iron Co. (coal and iron ore), Alabama Power Co. (coal), and Ideal Cement Co. (cement lime, and miscellaneous clay) .

Jan 1, 1960

By Ann G. Kim

Fires that occur in abandoned coal mines, waste banks, and in coal outcrops constitute a serious health, safety, and environmental hazard. Toxic fumes, the deterioration of air quality, and subsidence constitute the greatest hazards from these fires. Although tires on abandoned mined land (AML) occur in every coal-producing state, the severity of the problem varies. Methods to extinguish or control AML fires, including excavation, fire barriers, and sealing, are generally expensive and have a relatively low probability of success This U.S. Bureau of Mines report includes information from a variety of sources, i.e., agencies of the Federal Government, State agencies, research reports, conference proceedings, product information, and technical literature. This information has been collated into a comprehensive discussion of AML fire problems. Data on past fire control projects and on the estimated extent of the current problem have been compiled. Factors affecting the occurrence, propagation, and extinguishment of AML fires are discussed. Conventional fire control methods are described, and their probable effectiveness is evaluated. Information on the hazards of AML fires and safety considerations is included. The status of current technology, recent improvements in fire control methods, and areas of current research are discussed.

Jan 1, 1993

By F. S. Boericke

"INTRODUCTION The mineral found in natural-chromite deposits is never pure Fe0.Cr203, but rather one in which the Fe0 and Cr203 are in part replaced by Mg0 and A1203, respectively. The purest gravity concentrates from many domestic de¬posits consist of a mineral referred to as ""picotite,"" in which this isomorphous replacement is such that the ratio of chromium to iron is low. The Bureau of Nines has investigated methods of chemically beneficiating ores that contain too much iron to be classed as ""high-grade"" chromite 3/ Early investigations 4/ demonstrated that high-iron chromite or picotite ores can be roasted with carbon to obtain selective reduction of the contained iron, and that most of this reduced iron can be removed by acid-leaching the roast products to produce residues of higher chromium-to-iron ratios. tests 5/ indicated that commercially acceptable reaction rates cannot be obtained at roasting temperatures below 1,3000 C., using solid carbon as reducing agent. By this high-temperature reduction and subse¬quent acid-leaching, however, all ores investigated, regardless of the original composition, readily yielded residues considerably better than the minimum specifications for high-grade chromite.In an effort to obtain satisfactory reduction of chromite at lower temperatures, liquid and gaseous seducing agents were tested with varying success. Of the several reducing agents used, methane appeared to be the most promising and was shown to be highly effective at temperatures between 1,000º and 1,100º C., roughly 300º below the roasting temperatures necessary in solid carbon reduction. Further experiments indicated that mixtures of methate with some diluent (hydrogen or other nonoxidizing gas) gave better reduction than did methane alone."

Feb 1, 1946

By S. M. Shelton, W. A. Calhoun, M. M. Fine, T. L. Johnston

"INTRODUCTION An extensive test program is in progress by the Bureau of Mines to determine ways and means of recovering ferromanganese-grade ore 6/ from the wide-spread domestic manganese and manganiforous iron deposits. Samples for testing were received from the Interstate Manganese Co. in northeastern Tennessee, 11 miles west of Mountain City and 10 miles southwest of Damascus Va. The ore deposit occurs in the residual material of the Shady dolomite 7/ as an unconsolidated mixture of hard and soft manganese oxides and clay.Numerous tunnels and pits have developed a large reserve of ore in an area of about 15 acres. One pit 250 by 50 by 20 feet is being mined by rower shovels. The ore is hauled to a washing plant for log-washing, hand-sorting, and jigging. Coarse concentrates from the washing plant are marketed without further beneficiation.ACKNOWLEDGMENTSThe authors wish to acknowledge the assistance of R. F. Fisher, who made the roasting and magnetic tests."

Mar 1, 1942

By D. H. Platt

Gypsum and gypsite, used in the manufacture of plaster and plaster products, have been mined from deposits near Acme, Hardeman County, Tex., for more than 30 years. The Certain-toed Products Corp., 120 East Lancaster St., Ardmore, Pa., operates the Acme, Tex., mine. Underground hauling was done with storage-battery and Diesel-electric-powered shuttle cars. Many mining companies and individuals have manifested interest in all types of equipment powered by Diesel or Diesel-electric units, as attested by the recent increase in use of Diesel-powered equipment in underground metal and nonmetal mines. The purpose of this paper is to describe the manner in which a storage battery-powered Joy Model 60D2 shuttle car was converted to Diesel-electric power. The conversion was made, at the instance of the operating company, by Stewart & Stevens on Services, 4801 Lemon Ave., Dallas, Tex. This is believed to be the only such converted shuttle car in use.

Jan 1, 1950