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By Morton Corn

The U. S. Federal Coal Mine Health and Safety Act of 1969 placed limits on the permissible concentration of airborne respirable coal mine dust. Evidence exists which suggests that the effects on health of respirable coal mine dust may depend on both host factors and dust properties other than concentration. Dust particle size, shape, density, specific surface area and chemical composition are among the dust parameters of interest in an epidemiological investigation of coal workers' pneumoconiosis and coal miner exposure to mine dust. The purpose of this investigation was to develop and demonstrate the feasibility of techniques to determine selected properties of respirable coal mine dust. An approved underground horizontal elutriator which samples air at 36 cfm was designed, fabricated and utilized in this study to collect respirable coal mine dust in three mines representing the Pittsburgh, Lower Freeport and Lower Kittanning coal seams. Analytical procedures for measurement of respirable dust sample particle size, density, random projected area, total surface area and chemical composition are presented. Results of analyses of three samples collected in each mine are presented. Up to five full work shifts of sampling were required to accumulate approximately five grams of respirable coal mine dust in each sample. Statistical tests were applied to determine the significance of differences between properties of dust samples collected in the same mine and between arithmetic mean values of dust properties representing three samples collected in each mine. A comparison was also made between

Jan 1, 1972

By Thomas Fraser

"INTRODUCTION The Santa River Valley of northern Peru contains extensive deposits of a good-grade anthracite that offer one of the most accessible sources of solid-fuel supply for South America. This region is served by the narrow-gage railroad of the Corporation Peruana del Santa, which taps the coal fields along the Chuquicara River and terminates at the port of Chimbote, where facilities have been provided for loading coal into ocean-going vessels.This Government-sponsored corporation is prosecuting a vigorous program of development in this region, envisaging an intensively industrialized area around Chimbot Bay, fueled and powered by the anthracite of the upper valley and a hydroelectric generating plant now being constructed in the Cahn del Fate, where the Santa River has cut through the coastal range of the Andes.This development also includes the construction of extensive irrigation works to greatly expand agricultural production in the valley and thus estab¬lish the basis for a prosperous, well-balanced, industrial and agricultural community. It is hardly necessary to point out the importance of the local anthracite-mining industry to this general plan.At the invitation of the Peruvian Government, through the agency of David Dasso, chairman of Corpoacion Peruana del Santa, a technical mission was sent to Peru in March, April, and May 1945 to examine these coals and assist the corporation in promoting preparation of the coal for most effective use in the contemplated expansion of industry and trade."

Feb 1, 1948

By J. W. Lyman

The U.S. Bureau of Mines investigated methods of separating valuable rare-earth materials from Fe in neodymium iron boron (NdFeB) magnet scrap. A selective oxidation treatment of the scrap oxidized the rare-earth portion while leaving elemental Fe. Magnetic and leaching procedures were tried for separating the metallic Fe and rare-earth oxides, but the extremely fine grain size of the oxidized scrap prevented recovery by either technique. The best separation of rare earths from bulk NdFeB magnet scrap was obtained by dissolution with H2S04 followed by precipitation of recyclable rare-earth salts. By precipitating neodymium-alkali sulfate double salts as an intermediate that can be converted to a variety of useful products, many materials-handling and economic disadvantages found with direct precipitation with fluoride or oxalate were avoided. Iron was removed from magnet leach solutions by precipitation as a jarosite, eliminating a major disposal problem. Research was also conducted with contaminated mixed SmCo5 and NdFeB swarf. Using a flotation-leaching technique allows the SmCo5 to concentrate in the froth, while the grinding-medium contaminant sinks and is removed as tailing. The NdFeB is dissolved by H2S04 during the process.

Jan 1, 2010

By D. A. Paice

A portable calibrator to check tie trip setting of dc circuit breakers within an accuracy of +5% has been developed for the Bureau of Mines. It operates from a 300 volt dc trolley wire to provide controlled current pulses of 120 milliseconds duration and continuously adjustable from 1400 to 3600 A. These current pulses enable a breaker dc trip current to be determined and subject the contacts to full current rating. The equipment is simple to use and weighs 86 pounds. Connections are made with protected, clamp-on leads which are separately connected and weigh about 22 pounds. An accurate calibration procedure takes less than 5 minutes to complete.

Jan 1, 1978

By J. H. Holden

Operations involving the processing of coal, oxygen, and steam into synthesis gas by means of two pressure-type gasifiers have demonstrated the effect of heat loss and operating variables on carbon gasified and oxygen and coal requirements. Carbon gasified is the fraction of carbon in the coal that is converted to gas. Oxygen and coal requirement is the quantity of each that is needed to produce a unit volume (M std. c.f.) of carbon monoxide and hydrogen. Operating pressure of the gasifiers ranged from 150 to 300 p.s.i.g. and coal was fed at 200 to 500 lb./hr./cu.ft. of reaction-zone space. Oxygen-to-coal ratios were 8.5 to 10.5 std. c.f./lb. Heat loss and residence time have opposite effects on carbon gasified; increasing the heat loss decreases the carbon gasified, but increasing the residence time (by raising the operating pressure or reducing the coal-feed rate) increases the carbon gasified. The effects of these two factors are difficult to separate because they usually change simultaneously. A comparison of the results obtained from the operation of two gasifiers with different levels of heat loss, however, permitted the effect of heat loss to be separated from that of pressure and coal-feed rate. When the results were deter- mined on the basis of constant heat loss, increase of the residence time increased the carbon gasified until the reaction virtually had come to completion. For example, at 150 p.s.i.g., decreasing the coal-feed ratio from 500 lb./hr./cu.ft. to 200 lb./hr./cu.ft. substantially increased the carbon gasified. At 300 p.s.i.g., however, changing the coal-feed rate had little effect on the carbon gasified because the reaction had almost reached completion and further increase in residence time resulted only in a negligible change.

Jan 1, 1962

By Paul M. Ambrose

Overall the domestic abrasives industry had one of its best years in 1965. Production and value of all commodities increased over that of 1964 which also was a good year. Production of tripoli that was down in the previous year rebounded and production from two new mines was reported. Plant capacities for production of silicon carbide and fused crude aluminum oxide and production from plants in the United States and Canada increased, but demand was high and yearend stocks were less than at the end of 1964. Foreign Trade.-Increases in value of most imports of abrasive materials in 1965 were offset by a decrease in the value of imported industrial diamond. Production of fused aluminum oxide and silicon car-bide in the United States and Canada and imports of these commodities into the United States increased, but combined exports of finished grain of these materials was virtually unchanged from the previous year.

Jan 1, 1966

By Ferdinand Roehlich

An evaluation of the use of manually activated, installed,. dry chemical fire protection systems on underground metal and nonmetal mine vehicles is described. In addition, an assessment of the possible health risks posed by the dry chemical extinguishing agents used in such systems is provided. Work involved installation of fire protection hardware on an operating piece of underground metal/nonmetal mine equipment and, via actual fire tests, a determination of the effectiveness of the hardware in extinguishing on-vehicle fires. Two fire protection systems were installed on a Caterpillar 988 front-end loader in St. Joe Mineral's Fletcher mine, near Viburnum, Mo. Both a fully pressurized Safety First CM-20 and a nonpressurized cartridge actuated Ansul A-101 were installed for comparative purposes. Both systems operated satisfactorily during an 8-month endurance trial period which preceded the actual fire tests. Each system was able to extinguish an 18" x 4" class B test fire placed in the engine area of the machine. The health hazards analysis of dry chemical powder consisted of a detailed search of published literature relating to these multipurpose agents. This data was verified via a controlled laboratory analysis of two monoammonium phosphate based powders (Safety First Unikem and Ansul Forey) and an analysis of air samples collected at various locations on the test vehicle during the fire tests. Although the powder was found to be nontoxic, two potentially dangerous thermal decomposition products were identified--ammonia and phosphoric acid. However, later analysis indicated that an operator would not be exposed to dangerous concentrations of either compound if he were to remain outside of the powder cloud. A "Selection and Use Manual for Manually Activated, Fixed Fire Suppression Systems on Underground Metal and Nonmetal Mining Equipment" was prepared both as an, appendix to the report and for distribution under separate cover.

Jan 1, 1977

By Eleanor Abshire

THIS PUBLICATION is the third to be prepared as a result of a cooperative project by the Bureau of Ships and the Bureau of Mines for accumulating literature published on zirconium and hafnium. The undertaking also resulted in the establishment of an information center on zirconium and hafnium at the Bureau of Mines station at Albany, Oreg., for the use of research organizations and others. The present bibliography consists of references (with abstracts) to pertinent literature on zirconium. The first publication in this series was Information Circular 7771, Bibliography of Zirconium, published in April 1957. It consists of 969 abstracted reports and 645 U.S. and foreign patents. The second publication, called a supplement to Information Circular 7771, is numbered Information Circular 7830 and consists of 844 abstracted reports and 62 U.S. and foreign patents. It was published in October 1958.

Jan 1, 1962

By Clarence Karr

RESINS from a bituminous pitch, a bituminous coal, a lignite tar, a subbituminous pitch, and an electrode binder pitch wore investigated by the Bureau of Mines. The compositions of these resins were determined by four independent methods of structural detemination: (1) Molecular formula and ring analysis, including ring (2) infrared and ultraviolet spectra; (3) combined pyrolysis/gas chromatography, and (4) catalytic dehyrogenation followed by spectra and pyrolysis. The resin structure was correlated with coal structure, and it was concluded that pitch resins probably consist of essentially unaltered coal molecules carried over with the tar vapors in low-temperature carbonization.

Jan 1, 1966

By S. M. Runke

"During the past three years the Bureau of Mines has carried on an extensive research program at the Rolla Laboratory for the beneficiation of low-grade Arkansas baixites by ore dressing methods. As a result of this study a 50-ton pilot mill was designed and constructed at Bauxite, Arkansas, by the Bureau to continue the investigation on a semi-commercial scale. The built both to reduce the experimental work to practice and to obtain operating data that cannot be determined by laboratory or small scaleTen samples of bauxitic material were mined and stockpiled at the plant site to ensure an ample supply of material for milling in the pilot plant. These samples were obtained from various bauxite deposits in Saline and Pulaski Counties, Arkansas. The deposits were selected as typical of a wide range of bauxitic material which would necessitate treatment under different conditions and by various concentration methods. All of the samples contained a higher silica content than permissible in Bayer-grade bauxite and several contained so much iron oxide that the available alumina content of the ore was mate¬rially lowered. From data obtained by milling operations on these ten samples, milling characterietics of most of the ores in the district should be predictable. This paper summarizes the results obtained in the laboratory testing of representative samples of each stock pile, and the results of small scale continuous testing of the composite sample of the ten stock piles in the gravity-flotation pilot plant at the Rolla Laboratory."

Aug 1, 1946

By W. W. Adams

Rock dust, as a preventive or limiting factor in explosions of gas and coal dust in bituminous-coal mines, was used in larger quantities in 1939 than in any other year except 1937 since annual figures first became available in 1930, Reports from mining companies to the Bureau of Mines revealed that 144,430,000 pounds of rock dust was applied to underground nine workings in mines that produced 126,635,677 short tons of coal during the year. This quantity of rock dust applied averaged 1.14 pounds for each ton of coal produced. Rock dusted mines were the source of 39.7 percent of the total production of bituminous coal from underground mines; 33.2 percent of the total number of underground workers were employed at rock-dusted mines, and 35.8 percent of the total number of man-hours worked underground at all bituminous-coal mines in the United States during 19719 can be accredited to mines so treated. Rock dust was employed chiefly in the larger mines, which numbered only 431 out of 6,016 underground mines in operation in 1935, according to reports from mining companies. The mines in which rock dust was used had an average of 288 underground employees per mine, whereas mines in which rock dust was not used averaged only 62 underground employees per mine.

Jan 1, 1940

By W. E. Cassan, W. L. Eaton, James Westfield, W. M. Romisher, Karl Hughes, S. H. Ash

"INTRODUCTION Funds were made available to the Bureau of Mines, United States Department of the Interior, for anthracite investigations during the fiscal year ended June 30, 1945. One of the approved projects was to conduct inquiries and scientific and technologic investigations having a bearing on the anthradite mine-flood problem. The investigative work done from July 1,1944, to June 30, 1946, is described in previous reports (5, 8, 10, 24, 28). 6/Purpose of Report The purpose of this report is to describe the investigative work conucted by the Anthracite Food-Prevention Section, Safety Branch, Bureau of Mines, during the period July 1, 1946, to June 30, 1947,Scope of WorkInvestigative work during the fiscal year ended June 30, 1947, was conducted under the direction of D. Harrington, chief, Health and Safety Division, and S. H. Ash, chief, Safety Branch, Bureau of Mines, Washington, D. C.The broad objective of the investigative work was to obtain factual day on: 1. Anthracite reserves of Pennsylvania.2. Underground water pools.3. Barrier pillars.4. The ""buried valley"" of the Susquehanna River.5. Infiltration of surface water into underground mine workings.The above-mentioned investigations are being continued during the fiscal year July 1, 1947, to Juno 30, 1948.In addition to the investigative work covered in this report, Ash end Eaton presented a paper on barrier pillars, which proposes a method for designing barrier pillars and has been Published by the American Institute of Mining and Metallurgical Engineers (5);"

Apr 1, 1948

By J. B. Rosenbaum

Prolonged laboratory and limited pilot plant tests have shown that the Bureau of Mines buffered S02 -H2S process is capable of removing 95 to 99 percent of the S02 from industrial waste gases. Most of the S02 is converted to elemental sulfur; only about I percent converted to sulfate The process comprises (1) washing the flue gas to remove particulates and S03, (2) absorption of the S02 in citric acid or other carboxylate solution, (3) reaction of the loaded solution with H2S in a closed vessel to precipitate the absorbed S02 as elemental sulfur, and (4) separation of the sulfur from the regenerated solution by oil flotation and melting. Two-thirds of the molten sulfur is converted to H2S for use in the sulfur precipitation step by reacting sulfur vapor with natural gas and steam in the presence of an alumina catalyst. The chemistry and mechanism of the process are described, initial laboratory and pilot plant data are summarized, and second-generation laboratory operation and pilot plant design are reviewed. Preliminary cost estimates are presented for recovering sulfur from copper smelter gas, powerplant flue gas, and Claus plant tail gas.

Jan 1, 1973

By D. O. Hamiltion

The ISMS program provided for the development and demonstration of equipment modifications in both conventional and continuous coal mining systems. This report describes activities during the demonstration of the conventional equipment and includes machine performance, results of data gathering, system evaluation, and recommendations for implementing improvements.

Jan 1, 1976

By Jr. Gabler

World resources of platinum-group metals appear ample for the foreseeable future; however, political and economic events in the last two decades have caused concern over the availability and reliability of an uninterrupted supply. Because of this concern, the U.S. Congress requested that the U.S. Bureau of Mines initiate a study of the flow of platinum-group metals in the economy that would delineate and quantify the production areas in which metal values are lost. As a result, the Bureau has developed a computerized commodity flow model for strategic and critical materials. Major attributes of this flow model are as follows: (1) it is generic and applicable to most commodities and (2) it can be updated as supply, demand, and/or production data change. The original model developed for cobalt, with slight modifications, was used to track the flow of platinum-group metals. This report follows the flow of platinum-group metals through their metallurgical, catalytic, and chemical applications and highlights areas in which significant losses occur because of downgrading, export, or disposal. The study indicates that materials containing about 63,426 kg of platinum-group metals were lost or could not be traced in 1989, representing about 63 pct of U.S. domestic consumption.

Jan 1, 1991

By Elaine T. Cullen

Human beings are natural storytellers and story listeners. We learn very early that stories entertain us, but also give us the ?rules? about what is expected of us and how to make meaning of our experiences. Stories are integral to our lives, and have great power to change or influence how we think or how we react. They are an innate part of how we learn, and have obvious benefits to trainers or educators who are trying to impact what and how we learn. This paper and presentation discuss the social and cultural power of stories, and how they have been used to develop training for skilled blue-collar workers. Included will be examples as well as suggestions for trainers on where to find stories, what type of stories to pay attention to, and how to use them to improve occupational safety training.

Jan 1, 2008

By E. H. Burroughs

HISTORICAL REFERENCES OCCURRENCE-GEOLOGY AND ORIGIN. 4. ARNOLD, RALPH. Conservation of the oil and gas resources of the Americas, Econ. Geol., vol. 11, Apr.-May, 1916, pp. 203-222; June, 1916, pp. 299-326; Proc. 2nd Pan American Sci. Cong., 1915-1916, vol. 3, Conservation of natural resources, pp. 207-237. Shows occurrence of oll, and status and possibilities of oil Industry in each country. Discusses briefly ways in which oll reserves may be conserved. 5. RUTIS, A. A. Petroleum known since remote times. Oil and Gas Jour., vol. 15, Nov. 2, 1916, pp. 33, 37. Gives historical reférences to the use of petroleum from Bible times to its discovery In America. See also Nos. 3, 257, 202, 337, 1843.

Jan 1, 1919

By E. O. RHODES

Germany's' wartime coal-tar industry had two main branches, which can best be considered individually because their raw materials, operations, and distributions were almost completely separated. One branch, old and well-established, was concerned almost entirely with processing coal tar produced by the high-temperature carbonization of caking bituminous coal. Carbonization was effected principally in byproduct- coke ovens and to less extent in vertical, horizontal, and inclined retorts. The high-temperature tar was all processed in tar-distilling plants that handled high-temperature tar almost exclusively.

Sep 1, 1947

By Allan E. Martin

As part of a comprehensive investigation of tie mechanism of desufurization of iron and steel by slags, the Blast Furnace Studies Section, Metallurgical Division, Bureau of Mines, in cooperation with the Institute of Technology-, University of Minnesota, has made a study of the forms in which sulfur occurs in blast-furnace slag. This report presents data on the three sulfides most important in iron smelting, namely, ferrous sulfide, manganous sulfide, and calcium sulfide. The tendency of these sulfides to form colloids in the molten slag was determined by an examination of quenched samples with an ultramicroscope. Vogt5/ conducted experiments on sulfide silicate melts and examined synthetic blast-furnace slags in a partly crystallized condition. His conclusions were that FeS, CaS, and bins, or isomorphous compounds, such as (FexCay)S and (MnxCy)S, were precipitated Prom the melt, depending on the composition of the slag. In all specimens sulfides were visible and were spherical.

Jan 1, 1941

By Christopher Mark, Anthony T. Iannacchione

Falls of ground continue to be one of the most serious causes of injury to U.S. miners. Of the 256 fatal injuries that occurred in mining between 1996 and 1998, 52 (20%) were caused by falls of ground (Table I). Falls of ground affect some sectors of the mining industry more severely than others. For instance, nearly 40% of the 98 coal mine fatalities between 1996 and 1998 were caused by falls of ground. Underground miners are at much greater risk than surface miners. Nearly half (45 out of 101) of underground mine fatalities were attributed to roof, rib and face falls, while less than 5% of the 155 surface fatalities were caused by falls of highwalls or slopes. Sources of Data All of the injury data examined in this study were derived from MSHA’s Fatal Investigation Reports (www.msha.gov)and the MSHA accident database. Because falls of ground often result in serious injury, MSHA Fatal Alert Bulletins and Fatal Investigation Reports provide a useful snapshot of ground control issues in the mining industry. MSHA requires that mines file a report on every reportable accident that occurs, containing information on the accident’s location, severity, classification, activity, and nature of injury, etc. A short narrative is generally included as well. Accident reports can be searched by many of the above fields. From 1996 to 1998, miners suffered a total of 55,096 injuries, which ranged in severity from death (degree 1) to injuries with no days away from work nor restricted duty (degree 6). Six percent of the total injuries were from falls of ground, including machine accidents where caving rock was coded as the source. As the data in Table II indicate, 98% of all non-fatal fall of ground injuries occurred in underground mines, with underground coal mines accounting for 83% of the total. Table II also shows the distribution non-fatal fall of ground injuries by severity and commodity. The injuries are classified into Lost Time Injuries that resulted in permanent disability (degree 2) or days off work (degrees 3-4), and Injuries Without Lost Time that resulted in no more than restricted duty (degree 5-6). Overall, groundfall injuries appear to be more serious than other types of mining injuries. 65% of all ground fall injuries resulted in lost time compared to 54% of all types of mining injuries.