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By A. R. T. Denues

"INTRODUCTION The orienting phases of the current investigation of cushioned blasting in the Explosives Division of the Bureau of Mines were indicated in a previous publication (5) 3/. Pertinent literature reviewed therein indicated a highly controversial field. This emphasized the need for experimental studies of many factors that affect the health and safety of miners and the efficiency of mining operations. Results of some orienting tests showed marked effects on practical hazards. Further, they emphasized the necessity and importance of the contemplated investigation. The scope and general plan of these practical inquiries into the safety of cushioned blasting were indicated.This investigation of cushioned blasting relates to the various means employed to reduce the intensity of application of energy from explosive actions in boreholes. It has been suggested (from p. 19 of reference that the divisions of this work would correspond to the salient hazards affected by cushioned blasting. These include the ignition hazard, hazards from poisonous gases, and other practical hazards in the blasting technique. The ignition hazard was resolved into two components of approximately equal weight. These include studies of effects upon (1) the incendivity of blown-out shots and upon (2) the occurrence of such shots. Experimental studies of effects on the incendivity of blown-out shots were first undertaken. Questions of the best procedure for making these evaluations have been adduced, and the interpre-tation and utilization of the results of gallery testing seemed to require detailed attention; some preliminary general considerations of such testing were therefore necessary."

Jan 1, 1943

By C. J. Hall

Twenty eight pulse release sulfur hexafluoride tracer gas field tests were run in a multi-level multi-vein hard rock mine to measure leakage ventilation. The mine had numerous underground booster fans and gob filled old stoping areas and consequently numerous leakage paths. The tests proved that the equipment and methods developed by the USBM can be used successfully in complicated ventilation circuits. The leakage quantities varied each time a major change was made in the main ventilation circuit. Usually leakage quantities had to be remeasured after a main ventilation change, but measurements could be duplicated for anyone configuration except under certain defined circumstances. The characteristics of an individual leakage path could be determined from the difference between the measured sum of two paths and the calculated characteristics of one of the paths. Many leakage paths could not be evaluated accurately on one shift. Comments are made on equipment performance and field techniques. Programs for the calculation of gas concentrations and recirculation from measured data and for the mechanical integration necessary for a calculated leakage characteristic have been written for an HP 9810 and are included.

Jan 1, 1975

By E. J. Gleim

An important phase in the Bureau of Mines investigation of electrical machines designed for operation in gassy coal mines is testing enclosures of electrical components for explosion-proof qualities. In brief, this testing consists of filling and surrounding the enclosure with an explosive atmosphere of methane and air and then igniting the atmosphere within the enclosure to determine (1) Whether the resulting explosion is confined without discharge of flame; (2) whether the enclosure walls are permanently distorted; and (3) whether excessive pressures are developed within the enclosure. Ordinarily, the pressures encountered in routine testing do not exceed 100 pounds per square inch gage. Hence, the designer of the machine does not have too much difficulty in taking corrective measures to prevent flame discharge and distortion of the enclosure. Occasionally, however, the explosion pressures greatly exceed 100 pounds. Then the goblet of the designer may not be solved so readily, From experience over the year 0, the testing personnel often can predict that certain construction will result in high. Pressures, but, only in a very general way, has it been possible to advise designers what modifications might be made to reduce the explosion pressures to normal values. For example, if high pressures were developed in a motor starter having a partition with an opening through it, some enlargement of the opening may appear to be the logical procedure, but it has not been- possible to give information concerning the exact amount the opening should be enlarged to prevent development of high pressures .

Jan 1, 1952

By J. W. Walkiewicz

The Bureau of Mines investigated alloys containing lanthanum (La), praseodymium (Pr), neodymium (Nd), cobalt (Co), copper (Cu), iron (Fe), and magnesium (4g) as possible components of a permanent magnet mate¬rial utilizing a cerium-free synthetic mischmetal (M) as a substitute for scarce samarium (Sm) metal. Magnets containing M-Co-Cu-Mg and M-Co-Cu-Fe-Mg were fabricated by powder metallurgy techniques and evaluated. A synthetic mischmetal (M20) containing 20 pct La, 60 Pr, and 20 Nd yielded the best overall magnetic properties. The M20-Co-Cu-Mg alloys had energy products as high as 13.2 MGOe, remanences as high as 7.89 kG, normal coercivities as high as 6.26 kOe, and intrinsic coercivities as high as 13.4 kOe. The best value of intrinsic coercivity, 22.9 kOe, was obtained with an M-Co-Cu-Mg magnet in which the synthetic misch¬metal contained 30 pct La, 50 Pr, and 20 Nd. These values compare favorably with those of the Sm-Co magnets fabricated and measured at the Bureau's Reno Research Center, which had energy product of 15.1 MGOe, remanence of 7.8 kG, normal coercivity of 7.5 kOe, and intrinsic coercivity of 27.4 kOe. Iron substitution for part of the cobalt resulted in a decrease of magnetic properties, although several percent iron can be added before a drastic loss of magnetic properties occurs.

Jan 1, 1983

By Dennis J. Grigal

The objective of this contract was to monitor operating conditions of, four flooded, fibrous-bed filter panels used during normal underground mining operation and to analyse clogging and structural problems. After observing structural and clogging problems and conducting laboratory and field tests, a final, Flooded, fibrous-bed filter design which minimizes clogging and structural problems was recommended to the Bureau of Mines. This report also describes the dust sampling procedures used to determine the dust concentration at the flooded, fibrous-bed scrubber intake duct.

Jan 1, 1979

By Hillary W. St. Clair

Mining activity began in colonial times with ironmaking operations scattered along the eastern seaboard. Iron furnaces and forges manufactured iron implements from bog iron ores using charcoal from the extensive forests as a fuel. Lead ores were mined in the Mississippi Valley and copper ores in the Lake Superior region. However, the real beginning of the American mining industry did not occur until the 19th century. The history of American mining is organized around three epochal events. The first was the discovery of gold in California in 1848, which marked the beginning of a period of apprenticeship in mining and metallurgical techniques. The second was the discovery of the fabulous Comstock Lode in western Nevada in 1859, which expanded mining throughout the Far West and led to large-scale underground mining and the development of smelting techniques for lead, silver, and copper ores. The third event was the building of a transcontinental rail-road system after the Civil War, which brought about the consolidation of the industry from a large number of independent mines, mills, and smelters into integrated operations run by large corporations. Thus developed the mining industry that today supplies the energy and critical materials for the great-est industrial complex the world has known.

Jan 1, 1977

By W. F. Faragher

The principal equipment in the catalyst plants at Ludwigshafen-Oppau was inspected and is presented in the form of flow sheets for the manufacture of four of the principal catalysts. The equipment is in many cases of special design rather than stock items that was built by the company and modified in the coarse of the growth of the high-pressure synthesis of hydrocarbons in Germany. It is believed that if the manufacture of catalysts were to be undertaken elsewhere, the selection of equipment for the operations involved could be made successfully from the guidance furnished by this rather general report. Five additional catalysts are described, also. II. CATALYST 5058 FROM FRESH TUNGSTIC ACID In a supply tank of about 2,000 liters capacity, 500 kg. of tungstic acid (W03.H2O) that contains about 92-93 percent of W03 is dissolved at 60-70° C. in 1,500 liters of mother liquor. The solution is-effected by stirring for about 1-1/2 hours. The mother liquor is obtained from a previous, lot of catalyst and is first adjusted to a concentration of 13 percent 1H3 by passing in gaseous ammonia. The solution is allowed to stand without stirring for 1 hour, then is pumped into the saturating vessel through a cloth filter (three-quarters hr. to one hr.). The saturator is purged with H2S and thereafter the solution, which has been cooled to about 75° C., is heated in an atmosphere of hydrogen sulfide with stirring to about 70° C. This charge is slowly cooled to 50°, and then more rapidly to about 20° C. (time of cooling 6-7 hours).

Jan 1, 1946

By J. J. Dowd

1. The Pittsburgh bed is the most important bed in Marshall County, and virtually the entire production of coal in the county comes from this bed. 2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and 1,800 tons per acre-foot of coal in place, were estimated at 3,158 million short tons as of January I, 1954. Of this total, 3,071 million short tons is in beds 28 inches and more thick. Areas in each bed except the Pittsburgh 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.

Jan 1, 1956

By Paul M. Tyler

One by one new metals come to share the burden of modern industry. Long before the Christian era potters and glass workers employed fine and costly blue pigments that contained cobalt. Cobalt blue class has been found in the tombs of the Egyptians and in the ruins of Troy, and many of the colors used by the ancient Greeks and Romans contained cobalt. The ancients, however, were apparently unaware that the colors they used were caused by cobalt, and it was not until late in the 17th century that the existence of the element was recognized, Writers in the Middle Ages referred to "cobalos" as an evil spirit that haunted mines and caused trouble to the miners. Subsequently the German worms "Kobold," meaning goblin, came to be applied to any baffling mineral and particularly to minerals that resembled ores but failed to yield metal when smelted. Even to-day there is something of an air of mystery about cobalt, and a medieval cloak of secrecy still surrounds many of the metallurgical processes employed in its production. "Zaffre" was mentioned about the middle of the sixteenth century by Biringuccio, and in 1735 the metal war, first prepared by G. Brandt. To preparation of cobalt compounds, however, must have been carried on in at least a small way ever since the opening of the silver-cobalt deposits of Schneeberg in 1470. By 1790 there were 25 works engaged in the industry, rust of them located in Saxony, but the total output of these works probably did not exceed 300 tone of cobalt annually, mostly in the fore of smalt. The smalt which contained approximately 6 per cent cobalt was sold in Venice in 1520 at about 16 cents a pound. A few refineries in Holland supplied the Irish linen trade, contributed a farce amount to the Dutch linen industries, and alto provided smaller quantities for the manufactuer of litmus in Holland. A complete description of the early [histor,] of the cobalt industry in Saxony, is given by Mickle in the Deport of the Bureau of Mines of Ontario, vol. 19, 1913, pt. 2, pp. 234-251.

Jan 1, 1930

This appendix contains the list of equipment selected for the capitol cost estimate, with the respective quotations from their vendors/manufacturers. A vendor response report along with a separate equipment and motor list has been included in the first part of this appendix.

Jan 1, 1979

By J. A. Organiscak

Quartz dust is one of the most significant ongoing health concerns in coal mining today. Since the early 1980's, the U.S. Bureau of Mines has conducted numerous studies in underground and surface coal mines to identify the sources of quartz dust and its fundamental characteristics. This report presents data and conclusions obtained from these studies. The two most significant quartz dust sources were found to be the continuous miner excavating rock and the highwall drill operating in a rock overburden. The percentage of quartz was found to be higher in the smaller size fractions of dust when significant amounts of rock were mined by the continuous miner. Another factor theorized to affect quartz dust generation and size characteristics is the morphology of the quartz-bearing rock. Several laboratory studies were conducted to investigate capture efficiency of water spray technology and flooded-bed scrubbers with respect to the particle size of the dust. Water sprays and flooded-bed scrubbers were both found to be less efficient on smaller dust particles, and the scrubber was particularly less efficient on quartz dust. These results indicate that quartz control technology should be directed at controlling smaller sized dust particles.

Jan 1, 1990

By A. U. Miller

For many years Illinois has been one of the leading coal producers in the United States and as such its safety record has compared very well with the other large coal producing States , both in tons produced and millions of man -hours of exposure per fatal accident . ( See Table 25 in Bureau of Mines Bulletin 293. ) During the 10-year period from 1917 to 1926 , inclusive , the average production in the United States per fatal accident was 278 , 109 tons . The aver age for the State of Illinois for the same period was 409,249 tons . Illinois produced 450,464 tons per fatal accident, and in 1928 produced 390,630, tons , or an average of 419,721 tons for the 12- year period from 1917 to 1928 , inclusive . In 1927 During the year 1929 , the shipping mines of the State made a decided improvement in their record over any previous year . Table 1 shows the monthly production and the tons produced per fatal accident . During 1928 and 1929 safety work was actively carried on in Illinois . Safety meetings were held with mine officials , representatives of the State. De partment of Mines , and the United States Bureau of Mines . At these meetings mine hazards and accidents were discussed and remedies suggested for : their elimination in the future . It is believed that first - aid training was to a considerable extent instrumental in reducing accidents and in making the good safety records in Illinois during 1928 and 1929. During these years ( as well as in 1926 and 1927 to a somewhat less extont ) en intensive rirst-aid training campaign was con ducted in Illinois by the officials and members of the United Mine Workers of America , coal companies, State Department of Mines and Minerals , and the U. S. Bureau of Mines , Every first -aid class was made a safety meeting ; where accidents and general safety were discussed freely while teaching first aid. During this time , anproximately 25,000 persons were trained in first aid, and 17 coal companies were issued certificates for having 100 per cent of their employees. trained in first aid. Since January 1 , 1926 , more than 40,000 have received first -aid training in and around Illinois mines , and including those who received training previous to this date , it is believed that at least 90 per cent of the miners in Illinois have received first -aid training . This state ment is based on the fact that the labor turnover in Illinois is not large .

Apr 1, 1931

By Katherine A. Klein

Refuge chambers may potentially save the lives of miners during a mine emergency. For this reason, it is crucial that miners know how to operate them. Unfortunately, because refuge chambers provide so many services, they can be very complicated and difficult to operate. Therefore, NIOSH has created this document with suggestions for developing manuals and educational materials. A multidisciplinary team comprised of NIOSH engineers, sociologists, psychologists, health communication professionals, and geologists developed the recommendations contained in this document. These recommendations are based on an evaluation of manufacturers? instruction manuals from both the U.S. and globally, interviews with over 20 mining and safety experts, and an extensive literature review. This research, focused on the best practices for refuge chambers, led to the formulation of this document. It is intended to offer suggestions to manufacturers and mine operators on how to create effective and easy-to-understand training manuals for miners as well as tips to create the most comfortable and usable refuge chambers. It should be noted that these recommendations are not meant to substitute for manufacturer-supplied materials but rather to be used in conjunction with manufacturer?s materials. Manufacturers should always be consulted for up-to-date information about their chamber. Although different states and different mines refer to underground refuges by different names, this guide will simply refer to underground refuges nearest to the face as refuge chambers, whether inflatable from a skid or constructed from steel. Other popular terms for refuge chambers are rescue chambers, rescue shelters, and refuge shelters. Refuges that are nearer to the shaft, whether a prefabricated refuge chamber or one built into a crosscut, will be referred to as outby refuges because of their location in the mine. Outby refuges can be permanent, semipermanent, or portable and are usually located at every other SCSR cache. Outby refuges are sometimes called hardened rooms, outby shelters, and in-place shelters. When discussing outby refuges and refuge chambers collectively, this guide will refer to them as underground refuges. Other terms for underground refuges include refuge alternatives, locations of safety, and safe havens. This document is designed to be read either cover to cover or by specific section. It is recommended that on first read, this guide be read cover to cover. In subsequent readings, manufacturers and mine operators may find it easier to use the table of contents page to locate specific information on parts of the refuge chamber.

Jan 1, 2009

By Robert T. Mann

This paper is one of a series being prepared for and published by the United States Bureau of Mines on the quarrying, crushing, and grinding of limestone for cement manufacture. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total coats. It is recognized that publication of total costs might in many instances cause embarrassment to individual producers, as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue. ACKNOWLEDGMENTS The author wishes to acknowledge the assistance of J. B. Thoenen, mining engineer of the Bureau of Mines, in the preparation of this paper.

Jan 1, 1933

By Jennifer Riefenberg

A family of personal computer programs that calculate the Coal Mine Roof Rating (CMRR) has been developed by the U.S. Bureau of Mines. The CMRR rock mass classification system provides a link between the qualitative geologists' description of coal mine roof and the quantitive mine engineers' needs for mine design roof support selection, and hazard detection. The program CMRR is a user-friendly, interactive program into which raw field data are input. A CMRR is calculated and output along with two graphic displays. The first graphic display is a plan view trap with the CMRR's displayed on a color-coded scale. The second display shows a stratigraphic section of the bolted roof interval and its resultant CMRR. In addition, a Lotus 1-2-3 worksheet, computer file BOM-CMRR.WK3, has been developed for easy storage of field data. The worksheet includes four macros that automatically calculate CMRR's, store field test data in a database format, and print a two-page report of the field data and CMRR parameters. Production of summary port; for analysis of site-specific information are readily generated using Lotus 1-2-3 software. These programs help to facilitate the engineer in utilizing the CMRR in ground control studies.

Jan 1, 1994

By A. H. WHITE, PERRY BARKER

In a consideration of the various means whereby more economical and more efficient use may be made of the fuels in the United States, the possibility of obtaining for the production of illuminating gas other and cheaper fuels than the Pennsylvania coals demands attention. For the Government, as well as for private corporations and the householder, there can be no more economical and efficient way of using some coals than through the medium of illuminating gas. In the stove, gas reduces the labor cost of heat production and lessens the drudgery of the kitchen; burned in the Welsbach mantle, it is an excellent and cheap illuminant. In addition, the coke that remains after the gas has been recovered furnishes a smokeless fuel that has about the same heating value as anthracite. Hence any investigations that will indicate how local coals through proper treatment may be substituted for the higher priced and rapidly vanishing Pennsylvania gas coals will bring about lower prices for both gas and coke and will also aid to conserve for use in metallurgical processes the coking coals of Pennsylvania and of ot,her States. The annual drain on the gas-coal resources of this country and the importance of the gas and coke industries are indicated by the fact that 8,390,129 tons of coal were carbonized in retorts in the United States in 1909. The resulting salable products from by-product ovens were 15,791,220,000 cubic feet of coal gas, 6,254,644 tons of coke, and 60,126,000 gallons of tar. The total value of all by-products was about $28,508,637.

Jan 1, 1911

By F. R. Lee

THE Bureau of Mines was established in July 1910 to conduct research and to establish standards for mining equipment and practices which would conserve human life, natural resources, and property in the mineral industries. Several lists of equipment approved by the Bureau as permissible for use in gassy coal mines have been issued since then. The lists covering all approved equipment except breathing apparatus and explosives have born consolidated into two publications: Bulletin 343. Permissible Equipment Approved to January 1, 1953, and Information Circular 8220, Permissible Mina Equipment Approved By The Bureau of Mines During 1953-62. The, purpose of this publication is to supplement Bulletin 343 and Information Circular 8220 with a listing of permissible equipment approved during 1963 and 1964. The schedule, (standards) under which equipment listed herein have been approved are, as follows (cities and dates of approval and revision are, given in footnotes) : Schedule 2F,3 schedule 6D,4 schedule 7C,5 schedule 8C,6 schedule 9B,7 schedule 10C,8 schedule 12D,9 schedule 22,10 schedule 24,11 schedule 25B,12 schedule 25B,13 schedule 29A,14 schedule 30,15 and schedule 31.16

Jan 1, 1966

By R. T. C. Rasmussen

"INTRODUCTION This is the second report of investigations describing tests in full-scale commercial heats of steel-using electrolytic manganese having a purity of about 99.95 percent, produced in the Bureau's pilot plant at Boulder City, Nev. The first report dealt with tests in cooperation with two companies can the use,of electrolytic manganese in the manufacture of stainless steel. 3/ Plans aril cost estimates for reasonably large commercial, electrolytic plants based upon pilot-plant experience, as well as the comments of a number of concerns where electrolytic manganese has been tried, are contained in another publication.4/ The tests in cooperation with industry are part of the Bureau of Mines program of investigations of methods of utilizing low-grade domestic manganese ores, thereby the United States leas dependent upon foreign sources of manganese for metallurgical use. The Boulder City pilot plant already has demonstrated the feasibility of producing electrolytic manganese from several of the most important reserves of low-grade manganese ore. As the ferromanganese normally used by the steel industry represents the bulk of the Nation's manganese requirements, the usefulness and possi¬ble advantages of electrolytic manganese in the manufacture of steel must be established if electrowinning from domestic ores is to become an important factor of manganese supply.Preliminary arrangements for the cooperative tests at the Atlas Steel Casting Co., Buffalo,. N. Y., were made with E. L. Altenburg, vice president and general manager of the company, by A. A. Dow. 5/ The data on the tests at the Atlas plant presented herein are based upon reports of E. L. Altenburg and information obtained by the author during a visit to the plant to observe the initial trial heats with electrolytic manganese in the open-hearth and the electric furnace."

Nov 1, 1945

By Robert Goldstein

A computer program for calculating the illumination on coal mine surfaces due to machine-mounted lights is described. Utilizing numerical models of mining machinery and measured data on luminaire output characteristics, the program computes the ft-candle levels incident on the mine entry surfaces for any desired machine/luminaire/ entry configuration. Shadowing effects of the machine are taken into account. Results are provided at 2 ft. intervals on the face, left and right walls, floor and roof. To provide a data base for these calculations, eleven 3-D machine models were prepared and the outputs of three luminaire types were measured. Calculations were done for thirty different configurations.

Jan 1, 1977

By S. D. Cramer

Corrosion research is being conducted by the Federal Bureau of Mines to determine suitable construction materials for geothermal resource recovery plants. As part of this research, the corrosion resistance of 31 iron-nickel-, aluminum-, copper-, titanium-, and molybdenum-base alloys was characterized and evaluated in laboratory corrosion studies in low-and high-salinity geobrines representative of those found in the Imperial Valley, Calif. General, crevice, pitting, weld, and stress corrosion were measured at 105° and 232° C in deaerated brines and brines containing dissolved 02, C02, and CH4 General corrosion rates in deaerated brines at 105° and 232° C were usually below 5 mpy for the alloys tested except carbon steel, the low-alloy steels, Monel 400, 70-30 cupronickel, and the aluminum-base alloys. Dissolving carbon dioxide and methane in the brines at 2320 did not markedly alter these results. However, the introduction of oxygen, which can enter the brine during process operations, seriously degraded the corrosion resistance of many alloys by increasing the incidence of stress corrosion cracking, crevice corrosion and, except for the titanium-base alloys, pitting. In deaerated brine at 2320 C, the general corrosion rates for carbon steel and the low-alloy steels were relatively unaffected by pH in the range of 6.1 to 3.0. However, general corrosion rates increased sharply below pH 3.0. In deaerated brine at 232° C, welds in several iron-, nickel-, and titanium-base alloys corroded at rates comparable to the general corrosion rates of the alloys, but the addition of oxygen to the brine increased corrosion rates for welds in Inconel 625 and E-Brite 26-1. Alloys exhibiting good corrosion resistance in the deaerated Salton Sea KGRA-type brine at 232° C were E-Brite 26-1, Inconel 625, Hastelloy S, Hastelloy G, Hastelloy C-276, TiCode-12, Ti-0.2Pd, Ti-2Ni, Ti-1.7W, and TZM. The alloys most resistant to corrosion in oxygenated Salton Sea KGRA-type brine at 232° C were the titanium-base alloys. These alloys appear the most suitable for use in the construction of geothermal resource recovery plants. Carbon steel and the low-alloy steels are unsatisfactory for high-temperature, high-salinity brines and alternative low-cost materials with improved corrosion resistance should be sought.

Jan 1, 1980