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This study was conducted to determine the effects of a machine-mounted scrubber and water sprays on face methane levels. Testing was conducted in the NIOSH ventilation test gallery which was designed to simulate a full-scale mine entry. In the test entry, a model mining machine, equipped with water sprays and a simulated dust scrubber, was located at the face of a 20-ft box cut. Blowing ventilation was provided using a curtain with a 40-ft setback distance. Methane released from a pipe manifold located inby the mining machine was monitored at six locations that were 1 ft outby the pipe manifold. Tests were first conducted to evaluate the effects of using sprays and scrubber separately on face methane levels. Additional tests were conducted to determine how a scrubber used with various water spray systems would affect face methane levels. The use of either sprays or scrubber reduced face methane levels significantly. The combined use of sprays with the scrubber further reduced face methane levels a small amount. Primarily the sprays affected methane levels by changing airflow distribution close to the face.

By Lars Skogsberg

Work with hand-held power tools can be found in most industries all over the world. This type of work exposes the operators to different kind of loads like gripping-forces, feed-forces, exposure to vibration and noise, holding hot or cold surfaces and the exposure to dust. Designing a power tool with good ergonomics is a matter of finding the best compromise. As a simple example, increasing the mass is not acceptable because it will increase the forces needed to handle the tool. At the same time increased mass will in most cases reduce the vibrations. Vibration disorders related to the use of hand-held power tools has been known and reported since long. It is therefore essential that low vibrating tools are developed and used. The new vibration regulations in Europe, based on the Physical Agents (Vibration) Directive, have put increased focus on the vibration control in industry. Forces acting on the tool cause vibration Tools for industrial use must be of very robust design to withstand the very hard use they are exposed to. Industrial tools are therefore normally designed with the main parts made of metal. From a vibration point of view this means that most tools can be regarded as rigid bodies, especially because the dominating frequency normally is equal to the rotational frequency of the tool spindle or the blow frequency for a percussive tool. These frequencies are with few exceptions below 200 Hz. Handles however can not always be regarded as rigidly connected to the tool. There are several examples of weak suspensions designed to reduce vibration transmitted to the hands of the operator. There are also examples of designs where the handles just happened to be non-rigidly connected and in some cases even in resonance within the frequency region of interest. Oscillating forces act on the tool and the result is vibration. Design principals In all cases forces are the source of vibration. This leads to the three basic principles to control vibration: • Control the magnitude of the vibrating forces. Examples are the balancing unit on a grinder or the differential piston in a chipping hammer. • Make the tool less sensitive to the vibrating forces. Examples can be when the mass of the guard on a grinder is rigidly connected to the tool to increase the inertia of the tool. • Isolate the vibrations in the tool from the grip surfaces. Examples are vibration-dampening handles on grinders or pavement breakers, the air-spring behind the blow-mechanism in a riveting hammer or the mass spring system in a chipping hammer.

Jan 6, 2006

By J. R. Sweet

The paper describing the raining operations at the Mt. Hope mine, Mt. Lope, N. J., is one of a series being prepared by the United States Bureau of Mines on mining methods, practices, and costs of various mining operations in the United States. Mt. Hope mine produces magnetite ore. It is situated in the general northern part of the State of New Jersey. The towns of Rockaway, Wharton, and Dover lie within a radius of 4 miles from the mine. Dover is 40 miles from New York City.

Jan 1, 1932

To provide a means for accurately and reliably warning of impending roof falls or rock bursts and for evaluating support systems. The Approach: Development of a device for measuring rockbolt loads which is not affected by harsh environments nor by eccentric loading conditions and is easily adapted to various size rock bolts. How It Works: The Rock-Bolt Tension Load Cell, developed by the Bureau's Spokane (Wash.) Mining Research Center, is installed on a bolt and sandwiched between a conventional doughnut washer bearing plate and a torqueing nut (Fig. 1). As the bolt takes load, the bearing plate transmits the load axially to the cell through a ball and socket arrangement, compensating for uneven bearing surfaces. The cell body strains in proportion to the applied load: the strain is sensed by welded strain gages as change in electrical resistance. The resistance change is read through a Wheatstone Bridge and, through calibration, the applied load is determined.

Jan 1, 1974

Ten years ago we surveyed in "Uspekhi Khimii" the mechanism of the synthesis of hydrocarbons from CO and H2 (1).5 With new data obtained since then, mostly by Soviet researchers, our previous work (2), dealing with new forms and catalysts of the synthesis, is brought up to elate by reviewing research in this field. FORMATION OF CARBIDES The hypothesis that carbides are intermecliates in the synthesis assumes that carbon monoxide reacts with the metals of the eighth group and that this reaction is connected with the reversible reaction 2CO[=]C +CO2 (1) in a certain range of temperatures (3).

Jan 1, 1958

By Arthur V. Petty

The Bureau of Mines has researched the utilization of mining and pro-cessing wastes as raw materials for the production of glass-ceramic pipe. Characterization of various wastes as to occurrence and chemical composition is reported. A computer program was developed and used to identify waste materials and mixes that would result in glass melts from which glass-ceramics could be produced after cooling and subsequent heat treatments. The production of abrasion-resistant pipe from inexpensive and readily available domestic resources could offer an economical substitute for high-alloy steels containing the critical and strategic materials cobalt and chromium.

Jan 1, 1984

By Charles L. Kimbell

The final 26 tables of this chapter, tables 25-50, extend and expand the statistical series on production that was started in the 1963 edition of the "Area Reports: International" volume of the "Minerals Yearbook" and that was subsequently updated and expanded in the 1965 and 1967-89 editions. Continuing the practice started in 1989, a column has been included in each of these tables providing a 5-year average for 1986-90, inclusive. This should provide a clearer picture more rapidly of the role of each major producer over the 5-year period. The listing order of major producers, however, continued to be, as in past years, in descending order of rank in the year of review, 1990. With the inclusion of silver and uranium in the 1988 edition of this chapter, this group of tables now includes each of the crude minerals that ranked from 1st to 19th in 1983 terms of value of their output (as well as four others of lesser rank). These 23 crude mineral commodities accounted for 93% of the estimated value of world crude mineral production in 1983. In addition, world output of five key downstream products-aluminum, steel, cement, nitrogen in ammonia, and refined oil-are included because of their significance as products.

Jan 1, 1993

By Thomas E. Lobb, Harry C. Verakis

This article examines the factors related to injuries due to inadequate blasting shelters and blast area security, and identifies mitigation techniques. The key concepts are:(a) accurate determination of the bounds of the blast area, (b) clearing employees from the blast area, (c) effective access control, (d) use of adequate blasting shelters, (e) efficient communications, and (f)training. Fundamentals are reviewed with an emphasis on analyzing task elements and identifying root causes for selected blasting accidents. Mitigating techniques are presented along with discussions and examples.

By N. F. Le] [Jaune

[ ]

Jan 1, 1923

By E. J. Gleim

In the mining of coal the trend is toward more and more mechanization. This increased use of machinery to replace hand labor is assuming many new forms and presents a constantly changing aspect. Safety engineers must be alert if the many electrical problems resulting from these new installations are to be handled safely. Some of these problems present possible electrical hazards that may be overlooked by the safety engineer unless they are called to his attention by one who has made a special study of the conditions. The foregoing is especially true of conveyor systems of mining. The terms "conveyor systems" and "conveyor mining" as used in this paper refer to those systems in which various types of conveyors are employed to transport coal away from the working place. In some mines this means complete elimination of track, cars, and locomotives. In others it means that conveyors take the coal from the working place to a convenient loading point, from which transportation is completed by cars and locomotives.

Jan 1, 1941

By Dana C. Reinke

Jan 1, 2005

By Charles Anema

The Mancarried and Helicopter Receivers were developed under the contract for trapped miner location. This program was a five phase program with 15 mancarried and 5 helicopter production receivers delivered under Phase IV and equipment documentation required under Phase V.

Jan 1, 1976

By Frank B. Fulkerson

Three of the five primary aluminum producers in the Pacific Northwest have facilities in the region to make aluminum mill products. Only one of the three, however, produces a variety of shapes and forms. The principal reason for the lag in development of an aluminum mill products industry was found to be transportation cost. The long range outlook is for expansion, based mainly on growth of the western market for aluminum used in construction, containers and packaging, electrical applications, diesel trucks, mobile homes, and irregation pipe. Consumption of western aluminum mill products in 1985 is projected at 1.1 million tons, compared with estimated consumption of 250,000 tons in 1961.

Jan 1, 1965

A preliminary program dated April 25, 1974 was prepared for Development Engineering, Inc. (D.E.I.) on research and development, laboratory; field and other engineering studies for the disposal of retorted oil shale. This program was revised and published as a final document dated December 17, 1974. The document included a discussion on the peculiarity of retorted shale materials to be investigated and a discussion of the various laboratory and field tests which would need to be conducted to define their physical and chemical properties. The proposed research and development program was divided into eight work phases as follows: I - Program Development II - Exploratory Laboratory tests on old U.S.B.M., retored shale III - Laboratory tests on Pilot Plant retorted shale IV - Laboratory tests on retorted shale from Semi-Works Plant, and field and test plots and ponds. V - Field compaction tests

Jan 1, 1975

By W. E. Dennis, M. M. Fine

"INTRODUCTION During peacetime, the United States uses less than 3,000 tons of chemical-grade celestite annually. The war need, however, was estimated to exceed 15,000 tons a year.Hitherto; most of the required chemical-grade ore has been imported from England, Mexico, and other foreign countries. If foreign sources do not find it possible to meet the demand for ore of chemical grade (plus 92 percent SrSO4), it is expected that requirements could be satisfied by concentrating low-grade domestic ores. Celestite deposits on Brown, Nolan, Fisher, and Coke Counties, Texas, are considered to be possible sources of supply for this low-grade material. The Bureau of Mines explored the most important deposits to determine the grade and amount of ore available and conducted ore-dressing tests to obtain a suitable method of concentration.The exploratory work, consisting of test pitting and sampling, was carried on under the direction of W. E. Dennis, one of the authors of this paper, from October 8, 1942, to January 30, 1943. The ore dressing-tests described herein were conducted at the Bureau of Mines Laboratory at Rolla Mo.In this report, a particular deposit is referred to by the name of the landowner on whose .property the .deposit lies. The location of the deposits investigated is shown on figures 1, 2, 3, and 4.The celestite deposits were previously studied by the Bureau of Economic Geology of the University of Texas, and the results of its investigation are published in Mineral Survey Circular No. 46."

Feb 1, 1947

The panic bars (and associated linkages and electrical circuitry) that are defined in this document are a machine operator-actuated control for the emergency deenergization of the tram motors on self-propelled, electric and diesel face equipment; including haulage equipment such as shuttle cars. There are nine basic types of panic bars (and several variations) that are recommended in this document, but all of the panic bars are characteristically of the "fire door" type that is frequently encountered on outside exit doors of many public and some commercial buildings. It is also the intent of the following panic bar designs that, when emergency brakes are added to the face equipment machinery for which they are required, that they be designed and hooked up so that actuation of the panic bar will result in automatic application of the emergency brakes (immediately following the deenergization of the tram motors). The following panic bar design requirements are a restatement of the proposed requirements defined in the Federal Register, requirements cited in 'Guidelines for the Design and Installation of Devices for Deenergization of Self-Propelled Electric Face Equipment/ Automatic Emergency Brakes" by C. E. Lester and J. D. Greenhalgh of MESA, and Bendix recommendations that were formulated as a result of discussions with personnel at the various machine manufacturers and underground coal mines that we surveyed, discussions with G. L. Judy (our consultant), etc:

Jan 1, 1974

By William Y. Mo

This report presents preliminary results of a study undertaken to investigate quantitative characteristics of the demand for steel mill products and its major end-use components. The major end uses included in the study are the steel mill products used in construction, in automobiles, in producer durables, and in consumer durables. The main objectives of the research underlying this study are as follows: (1) To formulate and estimate the empirical demand relations for steel and the four major end uses in the United States; (2) to measure and calculate the responsiveness of the U.S. per capita steel consumption with respect to the changes of the steel and other nonferrous metals prices; (3) to determine and quantify the relative importance of the underlying demand explanatory factors in contributing to the average year-to-year increases (or decreases) of the U.S. per capita steel consumption; and (4) to adapt and use the estimated demand relations in making projections of the U.S. future demand for steel and the major end-use components. After extensive preliminary investigation, three versions of simple linear demand relations are selected and estimated by means of ordinary least squares (OLS) method. The annual data for the period 1947-65 are used in the estimation. Direct and cross price elasticities of demand are computed for each of major end uses. The relative importance of demand explanatory factors in contributing to the average year-to-year changes of U.S. per capita steel consumption are also calculated. For making projections, a simple autoregressive time trend model is used in estimating the future values of independent variables. Since the estimated demand relations are valid for projections only if the estimated parameters can be assumed to be unchanged in the future, and consequently, the projections derived in the study should be interpreted accordingly.

Jan 1, 1970

By John A. Breslin

This report summarizes the principal activities and significant results of the Bureau of Mines respirable dust research program since passage of the Federal Coal Mine Health and Safety Act of 1969 and the Federal Mine Safety and Health Amendments Act of 1977. This program has investigated new and improved techniques and equipment to reduce or prevent the formation of dust during the cutting cycle; to dilute, suppress, or collect airborne dust generated during mining, handling, and processing; and to improve the measurement of dust levels for evaluation of engineering controls and for enforcement of Federal dust standards. The report is intended for mining industry dust control specialists and other interested parties. It includes a brief summary of the program to date, a section on future research plans and goals, and a list of publications resulting from the Bureau's respirable dust program.

Jan 1, 1982

By R. W. Dougherty

From time to time interest has been evidenced in transporting coal with water in pipe lines. About the year 1895, United States patents broadly covering a method of pumping coal with water through pipelines were granted to W. C. Andrews. His process was used to some extent in pumping anthracite culm and waste back into the worked-out portions of the mines. About 1905, W. T. Donnely was granted patents relating to pumping anthracite silt away from the breakers. From about 1913 until 1924, a British engineer, Gilbert G. Bell, used a short pipeline to convey coal with water from barges on the Thames River to the Hammersmith Electricity Generating Station, London. Minus 5-inch coal was transferred 660 yards through an 8-inch pipe. Some trouble was experienced with fine coal, which tended to plug the line. Bell made several proposals to transport coal by pipeline overland from the Midlands to London, a distance of about 100 miles, but these were never adopted. This survey is concerned mainly with the problems presented by actual pipeline transportation of coal with water. It is assumed that the coal will have been processed to remove most of the abrasive impurities by conventional methods prior to introduction into the line, and that it has been crushed to the required top size. Dewatering at the discharge end of the line is considered part of the conventional cleaning process. There still remain many pump-performance and behavior of water-coal mixture problems that can be solved only by actual performance tests. It is recognized that the distribution of coal to other than very large users is not changed. Large storage areas would be required to supply seasonal markets. Large users, such as power plants and heavy industries, could be supplied by branch lines directly to the point of use, It is also recognized that pipe lines might not be able to carry a full range of sized coal to meet market demands in many areas.

Jan 1, 1951

By Fieldner. A. C.

"In preparing this paper, an attempt was made to obtain results of plant-scale carbonization tests on washed and unwashed coal tram to same mine. A letter. in which the following questions were asked, was sent to some 50 coke-oven superintendents and others who might be interested:“What is the influence of washing coal on:(1) The chemical and physical properties of coke, as for example, the size, the amount of breeze, the fracture, strength, cell-structure, etc.(2) The quantity and quality of gas and by-products.(3) The capacity of the ovens.(4) The composition of the coal..""Your general opinion, as well as any specific data or results of testa, on this important subject will be greatly appreciated.""Of the 45 replies received, 24 stated that they had never used washed coal; 11 had used washed coal but had no comparative data on similar coals washed and unwashed; 7 answered some of the questions based on their general experience; and 3 gave some test data on Pittsburgh bed coal from western Pennsylvania. In none of the three tests did the washed coal come from the same mine as the unwashed. The washed coals in the three tests were from the same washery - one of modern construction in which the operations are under careful technical control in order to give a uniform product containing a minimum of surface moisture. The unwashed coals which were previously used in these plants were from different nearby mines in the same coal bed, and were supplied by the same company. Obviously, no sweeping or finale conclusions can be drawn from these few tests on coal from a single washery. Therefore, the writer vas obliged to consult the literature, coal-carbonization and coal-washing engineers, and other authorities to supplement the fragmentary information gleaned from the questionnaires in order to present a picture of chat gas engineers may expect from the use of washed coal in a carbonizing plant."

May 1, 1930