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By Rudolf E. Greuer

This report contains a theoretical study on the usefulness of fighting mine fires with inert gases. Four introductory chapters review the role of fires in the mining industry; the conventional fire fighting techniques, the influence of inert gases on the burning of gases and solids, and the well established inert gas fire extinguishing systems for buildings and machinery. A large chapter describes the use which inert gas has found so far for fighting mine fires in major mining countries. More applications have occurred than generally expected and the inert gas method has in the last years become routine in Czechoslovakia and the USSR. This chapter is based on an evaluation of the extensive literature as well as on personal information obtained from leading experts.

Jan 1, 2012

By D. Harrington

"FOREWORDVirtually all government agencies undertook many additional responsibilities during the period immediately preceding World War II; these responsibilities increased vastly in importance and scope after the actual declaration of war following the attack on Pearl Harbor. The Bureau of Mines was one of the agencies thus affected, and it was called upon to perform many duties foreign to its normal peacetime activities.The Health and Safety Division of the Bureau of Mines, at that time designated the Health and Safety Branch, was given several important and difficult duties and responsibilities of an unusual nature because of the war while of necessity-continuing its normal functions of assisting the mineral industries in the preservation of life and health and the protection of property, this being of especial importance in wartime because of the pre-eminent importance of having maximum output of essentially all types of mineral products. Some of these additional functions were given to the Health and Safety Division because the organization of the Division, with its field set-up dividing the Nation into districts with competent, experienced personnel in charge of its work, provided the nucleus of personnel and procedure through which rapid and smooth expanded functioning was feasible.In addition to the responsibilities directly attributable to definite war activities, such as the administration of the wartime Federal. Explosives Act and the Mineral Production Security Branch a new branch (then designated division) was formed to investigate coal-mine health and safety problems after the enactment of the Federal Coal-Mine Inspections and Investigations Act, which became a law on May 7, 1941, but which actually began to function actively after the declaration of war in December 1941.The purpose of this publication is to provide a brief historical record of the activities of the Health and Safety Division as a whole and of its individual branches during the war. The detailed record has been filed in the Archives Building, Washington, D. C."

Jan 1, 1949

By David White

This paper is the result of a comparative study of ultimate coal analyses made and published by the United States Geological Survey. This study, at first casually undertaken to devise an acceptable classification of coals based on chemical analyses, was continued in connection with a microscopic examination of a number of the coals. The initial comparisons, made from a relatively small number of analyses, not only confirmed a previous conviction that the elimina- tion of oxygen incident to the development of a coal is economically far more important than has been generally suspected, but also showed that oxygen is very nearly as harmful as ash in coal. The immediate purposes of the present study were: (a) To deter- mine more definitely, from a comparative examination of a large number of ultimate analyses, the relative importance of oxygen as an impurity in various coals; (b) to illustrate the transition between various grades of coal of similar origin-transition mainly due to progressive devolatilization, brought about more or less directly by dynamic influences; (c) to ascertain the relative proportions of oxygen, hydrogen, and carbon in coking coals, especially with refer- ence to a theory tentatively framed to explain the coking quality; and (d) to forecast the probabilities of successfully treating a large number of coals so as to render them amenable, in a softened condition, to satisfactory study under the microscope. Although the hypothesis as to coking quality finds but partial support in the chemical analyses, its consideration has led to a method of predicting from an analysis with a fair degree of certainty whether any given coal will coke by the ordinary process. The unbroken transition between coals originally similar but now classed in widely different groups, whether of the same age or of different ages, as a result of dynamochemical action, appears demonstrated by the analyses as well as by field observation. This subject will not be

Jan 1, 1911

By Slavoljub Makslmovic

One important element of the U.S. Bureau of Mines computer-assisted mining research program is the development of a reliable coal interface detection (CID) system. Several candidate CID concepts currently being investigated by the Bureau include use of natural gamma radiation (NGR), vibration, passive infrared, video, and radar. To help establish which CID sensor technologies need to be developed for a given seam, the Bureau has collected geological and mining practices data from over 460 underground and surface mines in the United States. Also, over 500 coal and rock samples have been obtained for laboratory analyses of ash content, sulfur content, heating value, and NGR. The Bureau's findings indicate that the immediate roof strata in 81% of the underground mines and 93% of the surface mines are made up of shale, draw slate, or claystone. The immediate floor strata in 88% of both the underground and surface mines consist of fireclay, shale, draw slate, or claystone. The results of the NGR testing indicate that the NGR method appears to be a potentially useful CID tool, provided that the immediate roof and floor are both composed of a high percentage of shale-type material.

Jan 1, 1993

By Howard B. Hamilton

A switching system for high fault current 300 and 600 volt DC trolley and haulage systems, as used in the mining industry is presented. The system consists of paralleled main and auxiliary contactor circuits with a liquid metal current limiting device (CLD) in series with the auxiliary contact-or. Upon detection of a fault, the current is commutated into the CLD circuit. The liquid-metal vaporizes, increasing the CLD resistance and Considerably decreasing the actual current to be interrupted. This system will materially reduce the wear and tear on contactors because of the reduced interrupting requirement. the CLD is pressurized; when the current is interrupted, liquid metal flows back into the bore. Thus, it is resetting. Electrical and mechanical design principles are presented as well as materials for use, as found satisfactory in field tests on the device.

Jan 1, 1982

By F. W. Wood

ORIGINAL experimentation in specially designed arc-melting furnaces and a comprehensive review of technical literature have helped with an understanding of electric arcs as used in metallurgical applications. Results relevant to the distribution of electric potentials and currents, temperatures, pressures, the consumption of electrodes, the identities of particles participating in electrical conduction, and the modes and mechanisms of discharge are presented and discussed. Present knowledge of high-current arcs is insufficient to test pertinent theoretical suggestions. However, the chief doubts concern the identities and the liberation or formation of current-carrying particles. It seems that either (1) novel formulations of existing concepts are needed, or (2) essentially new concepts must be recognized to explain observations. An analysis of the situation has led the authors to favor the latter possibility and to suggest the existence of supplementary conducting particles. The conduction of current by the streaming of charged agglomerates is postulated. Another outgrowth of analysis is an equation for the arc potential as a function of current densities in the arc. In lieu of conclusions, the potentialities of practical applications and specific needs for fundamental clarification are summarized.

Jan 1, 1965

By Timothy A. Clancy

To help reduce the Nation's dependence on imported chromite, the Bureau of Mines is conducting research on the use of dolomites as an alternate material. Dolomite is a plentiful domestic resource and offers certain advantages as a refractory raw material. A review of the literature has indicated that there are many sources of high-purity dolomite in this country and that European nations use a greater proportion of dolomite refractories, primarily in steelmaking, than the United States, The Bureau of Mines characterized 14 domestic dolomites as to chemistry, density, mineralogy, microstructure, and thermal behavior, to develop baseline data on their suitability as refractory raw materials.

Jan 1, 1983

By Joseph Grumer

The range of composition of gases synthesized from solid fuels which are exchangeable with natural gas on current gas appliances was evaluated by theoretical principles. These principles consider primarily the flashback, blowoff, and yellow-tipping characteristics of air-entraining burner flames. It was found that complete identity between the synthetic and natural product is not necessary. Gases such as may be obtained by hydrogasification of coal and other solid fuels without the removal of unreacted hydrogen offer advantages in flame characteristics. Between 25 to 37 percent hydrogen can be tolerated in the sendout gas.

Jan 1, 1965

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 Pedro Lilienfeld

The objective of this program was the development, design, and fabrication of six personal-sized completely self-contained dust monitors capable of real-time as well as time-averaged monitoring of the concentration of respirable particles in coal mines, in the range of 0.1 to 100 mg/m3. The operation of these monitors is based on light scattering and passive air sampling. The design stressed overall miniaturization, ruggedness, simplicity and versatility. These instruments incorporate a single-chip CMOS microprocessor to perform all signal processing, data display and storage, and timing functions. The overall dimensions of these devices are, approximately, 10 by 10 by 5 cm.

Jan 1, 1982

By Northcutt Ely

This volume- summarizes mining and petroleum legislation in 18 European jurisdictions. Within these jurisdictions, primary attention is given to requirements that must be met in each country for acquisition of rights to permit development of mineral resources. Coverage includes: First, identitication of the controlling laws or statutes governing minerals acquisition and reference to the administrative authority; second, analysis; of the laws governing mines and quarries and their products; third, analysis of laws applicable to natural gas, petroleum, and related materials; and fourth, mention of laws regulating offshore operations. Where pertinent, sections dealing with historical background or administration have been added in countries where minerals are subject to control of States or Provinces, those areas are considered separately from the central government.

Jan 1, 1974

By J. L. Henry

The development and status of technology for producing titanium from U.S. resource materials are summarized in this Bureau of Mines report. Commercially feasible processes and investigations of alternative procedures are reviewed in order to identify techniques that could make existing operations more effective or areas in which future research may lead to the development of new production methods. Procedures are described for producing concentrated titanium dioxide from starting materials such as sands, massive deposits, and mineral processing residues containing rutile, ilmenite, and perovskite; producing and purifying titanium tetrachloride from concentrated rutile, ilmenite, and titaniferous slags; reduction of titanium tetrachloride to titanium sponge metal using metallic magnesium or sodium; purifying and consolidating titanium sponge and scrap by arc melting or induction melting techniques; purifying sponge, scrap, and alloys by molten salt electrorefining; and electrowinning titanium from chloride salts.

Jan 1, 1987

By A. C. Fieldner

Much activity is called for in the present period of hightened national effort, and wise direction of such a program must always be conditioned by positive knowledge gained in years of slow and painstaking study and development. Research and technologic investigations on coal by the Bureau of Mines have been described in a series of annual

Jan 1, 1941

These proceedings consist of papers presented at two Bureau of Mines Technology Transfer Seminars in early 1980 for the purpose of disseminating recent advances in mining technology related to surface coal mining reclamation.

Jan 1, 1980

By T. T. Read, F. C. Houghten

"The bad effects upon the health and output of miners that result when the ventilating current in a mine lacks sufficient cooling power have been described by Harrington and Sayers in a previous report (1)*** The normal temperature of the human body is about 98.5°F. and whenever work is done by the muscles, indeed even when sitting still, the normal bodily processes generate heat which must be given off, otherwise the body will become overheated and a number of bad effects will be produced. If it were possible to so enclose a man that he could continue to breathe and no heat could escape from his body he would die within a short time. In a series of experiments made at the Pittsburgh Station of the Bureau of McConnell and Houghton (2) found that a dry-bulb and a wet-bulb temperature of 112.5°F could he borne for only 35 minutes, even when the subject was at rest. A wet-bulb temperature of 100.4°F (dry-bulb 157°F) could only be tolerated for 45°F minute. Under such conditions the bodily temperature rises as much as 45°F above normal and the pulse is accelerated. Very uncomfortable sensations are felt when the pulse rate exceeds 135. The human body, like any other internal combustion engine, must be cooled in order to function properly.Under ordinary circumstances the air surroundings people is enough coder than themselves to permit this heat generated within the boiy to be river off with¬out difficulty. At higher temperatures, or when the rate of work, with its corresponding generation of heat is high, the body can not throw off heat fast enough, so it begins to sweat and the evaporation of the sweat cools the body. But the results of the experiments cited above indicate that in still air, even with the body at rent, it can not adjust its temperature when the air is above 90° wet- bulb. J. S. Haldane (4) says ""at a wet-bulb temperature of 60°F the actual amount of work done by the miner begins to fall off; as the wet bulb temperature rinse farther the work Bona gradually diminishes to the vanishing point. Then the temperatures indicated by the wet-bulb exceeds 85°F hard work in a mine seems hardly or the commercial working of a mine the wet-bulb thermometer should not in generaI, be allowed to rise above 80°F, unless perhaps where there it a good current."

Dec 1, 1923

Senior staff representatives of the Bureau of Mines and the National Institute for Occupational Safety and Health (NIOSH) met in Washington on September 6, 1972, to review and evaluate their cooperative accomplishments to date and to consider the planning and conduct of future coordinated activities. The six presentations given at this joint staff seminar are published here for the benefit of those concerned with the problems of coal mine health, and especially those with responsibilities in administering the Coal Mine Health and Safety Act of 1969.

Jan 1, 1972

By Philip C. Tully

This bibliography contains 2,072 citations to technical and scientific literature about helium and alpha-particles abstracted by 12 abstract service publications during 1962. Citations are listed by 16 major subject classifications with several subclassifications to minimize areas of literature search. Automatic data processing was used to reduce the time and labor required to compile the bibliography.

Jan 1, 1969

This manual provides instructions for installing, operating, and maintaining a protective canopy on the Joy Mfg. Co. shuttle car. These instructions are based upon actual installations made in the mine on two shuttle cars, model 21SC-2E. The parts list and engineering drawings for the protective canopy are included at the end of the manual. And a discussion of some alternative design concepts is also included. The manual can also be used for retrofitting other shuttle cars with similar protective canopies. Skilled mechanics can determine if the instructions hexein would he applicable to the other shuttle cars and can determine any necessary modifications if they are not.

Jan 1, 1973

Commodities statistics and otter information are available through the following t et systems: Internet Access: To acccess the USBM Gopher server on Internet, connect to: gopher.usbm.gov port 70, using gopher client software. Or contact the Systems Administrator for technical questions: Matt Klevemann, 412-892-6499 (klevemmc@miner.usbm.gov) These USBM materials are available on Internet, with more to come in the future: Publications and other research findings, including this bimonthly publications list, newsletters, tech transfer updates, enviromental technology research, health and safety information. USBM software products Media materials and speeches. Mines Data: Computer bulletin board. Log on via modem through 202/501-0373, or call 202/501-0406 for technical assistance. Mines FaxBack: Return fax service. 1. Use the touch-tone handset attached to your fax machine's telephone jack. (ISDN [digital] telephones cannot be used with fax machines.) 2. Dial 202/219-3644. 3. Listen to the menu options and punch in the number of your selection, using the touch-tone telephone. 4. After completing your selection, press the start button on your fax machine.

Jan 1, 1995

By O. P. Hood, G. St. J. Perott, S. P. Kinney

"FOREWORD (By O. P. Hood, Chief mechanical engineer).During the war certain suggestions concerning power production were made by Mr. Walter E. Trent to the War Inventions Board, and at the request of the War Department facilities for experimental work were provided on the grounds of the. Bureau of Standards.The experiments were along the line of controlling the conditions of combustion in a closed space. In order to reduce slag troubles, experiments were carried out for removing ash from powdered coal. After the war, work along this line was continued, resulting in the Trent Process, which agitates or beats together powdered coal, water and oil.A new technology had previously been given to ore preparation by the use of small quantities of oil in water with froth flotation, and although the methods, results and mixtures of the Trent Process were quite different, yet the same physical phenomena of differential wetting used, and the possibility of there being interesting results in fuel technologic was evident. A cooperative agreement was entered into, whereby the Bureau of Mines was to investigate the underlying physical and chemical facts and make them public, and the Trent Corporation was to pay the cost of the investigation.The several reports as made have been available to any one interested, and are now to be published. While the Bureau of Mines felt justified in investigating the physical phenomena so far as might be done in a laboratory, and so far as public interest might reach, no attempt was made to discover the commercial possibilities which development might bring. The question of commercial possibilities must be left for commercial enterprise to answer."

Jul 1, 1921