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By Wilbert J. Huff

This is the sixth of a series of annual reports describing the work of the? Explosives Division, Bureau of Mines, United States Department of the Interior.3/ It deals particularly with the activities of the division from July 1, 1940, to June 30, 1941. The studies outlined in this and preceding reports of the series have been conducted under the direction of the author and the respective unit leaders, to whom specific credit is given.

Jan 1, 1942

PRODUCTION of cesium, cesium salts, and rubidium salts in the United States declined somewhat from 1961 levels; rubidium production was virtually unchanged. Imports of pollucite declined because consumption was supplied partially out of inventory. Domestic Production.-About 50 tons of pollucite was reported mined at the Tin Mountain mine in the Black Hills of South Dakota. The Dow Chemical Co., Midland, Mich., MSA Research Corp., Callery, Pa., and Penn Rare Metals, Inc., Revere, Pa., produced a total of 159 pounds of cesium. Rubidium production remained essentially the same as in 1961. Shipments of the two metals by these companies and by American Potash & Chemical Corp., Trona, Calif., totaled 279 pounds. Production of cesium and rubidium salts by American Potash & Chemical Corp., Penn Rare Metals, Inc., and Rocky Mountain Research, Inc., Denver, Colo., declined substantially during 1962.

Jan 1, 1963

By H. P. Greenwald, Irving Hartman, H. C. Howarth

"INTRODUCTION A report of tests of seven small pillars formed from the Pittsburgh coal bed in the Experimental coal mine was given in Technical Paper 605 5/ Five additional pillars were tested between July 1939 and. October 1940. The data obtained, in the later tests permit an extension of the conclusions reached in Technical Paper 605, which appears to be important enough to the mining industry to justify a progress report that will explain briefly what it is and how it was obtained. Full detail of the tests will appear in a second technical paper, preparation of which is deferred so that results of pillar tests now under way my be included.DESCRIPTION OF TESTSExcept for minor improvements in operating details, the five additional tests were made as described in Technical Paper 605, pages 2 to 7. Briefly, the desired pillar was formed from the coal bed, by excavating a passage around it (no explosives were used), and enough material was removed from above to permit installation of the assembly used for applying pressure. Each pillar was tested resting on its original fireclay floor, which was restrained from lateral flow by a ring of concrete. Vertical and lateral movement of the pillars in two directions as measured carefully in all tests."

Jun 1, 1941

Severe whipping of shuttle car trailing cables occurs when the car stops suddenly or reverses direction. This causes cable damage, and can seriously injure personnel near the cable. FMC has contracted with the U.S. Bureau of Mines to design, build and demonstrate a reel control system that will significantly reduce or eliminate whipping. II. CONCLUSIONS Results of engineering effort show that the following conditions are primarily responsible for the whipping problem. Causes may exist individually, or in combination.

Jan 1, 1972

The principle activities of the Explosives Research Laboratory from July 1, 1961 to June 30, 1962, are described briefly in part 1. Part 2 gives short abstracts of publications that appeared during fiscal year 1962; in general, the research reported in these publications antedates the report period. Part 3 gives the results of an investigation which, although too limited to warrant separate publication, merits presentation in some detail because of current interest in ammonium nitrate-fuel oil compositions.

Jan 1, 1964

By S. J. Davenport

The increased consumption and importation of fluorspar and cryolite (1)3/ in recent years, and especially the addition of fluorine compounds to drinking water in the United States, have aroused renewed interest in the properties of such compounds and possible health hazards incident to their use. It has been suggested that the issuance of a revision and elaboration of Information Circular 7311, The Hazards of Hydrogen Fluoride Poisoning in the Mineral and Allied Industries, which hay been out of print for some time, would be opportune. Fluorine minerals have been known since the Middle Ages. Fluorine was isolated in 1886 by Moisson (2).

Jan 1, 1954

By J. W. Paul

The United States Bureau of Mines has made a study of roof control in 68 mines operating in the Pittsburgh coal bed in Pennsylvania, West Virginia, and Ohio. In making these studies, much information was also obtained on various exact methods of development and pillar extraction as practiced by this large group of mines. It is proposed in this paper to describe these methods, by which this group of mines in 1931, a year of reduced industrial activity, produced 28,123,000 tons of bituminous coal - 7.4 percent of the national production for the same year and an amount equal to the combined production of the coal mired in the States of Alabama, Colorado, New Mexico, Utah, and Wyoming. The results of these studies, insofar as they pertain to the prevention of injuries from falls of roof, have been published by the Bureau of Mines. In this paper only a few mines typical of each system will be described; however, should the reader be interested in other details with respect to these mines, he may refer to the following publications: T.P. 522, 1932, 43 pp. Falls of roof and coal in mines operating in the Pittsburgh coal bed in Marion and Monongalia Counties, W. Va., by J. W. Paul and J. N. Geyer.- A study of nine mines in these two counties of northern West Virginia.

Jan 1, 1935

Sixteen papers concerned with the technology and utilization of low-rank fossil fuels are presented as the proceedings of the 1973 lignite symposium. This symposium, the seventh in a series of biennial meetings, was cosponsored by the Bureau of Mines and the University of North Dakota.

Jan 1, 1974

By G. N. Schrauzer

Work has been carried out in the development and testing of carbon monoxide (CO) detection devices which use silica-gel impregnated with metal salts. If carbon monoxide is present, the ?detection gel? (the treated silica-gel) changes from a yellow to a blue-green or blue color. The detection gel "regenerates", i.e., returns to its original yellow color, within 4-24 hours after removal from air containing CO. The detection gel exhibits a threshold of CO response which can be adjusted over a wide range of CO concentrations, typically from 50-500 ppm in air. The preparation of detection gel using salts of palladium, molybdenum and copper is described. Also reported are the results of testing the detection gel&apos;s response to carbon monoxide under varying conditions of temperature and humidity and in the presence of some potentially interfering gases. Low levels of hydrogen sulfide (~ 5 ppm)1 nitrogen dioxide (< 7 ppm), and acetylene (> 200 ppm) were found to affect the detection gel. Temperature and humidity were also found to affect the detection gel&apos;s response. Increasing temperature shortens the gel?s response time while increasing the humidity delays the gel?s response and alters the threshold of the gel. A brief discussion of the further research and development necessary to stabilize the detection gel?s desirable characteristics is included. Descriptions of testing equipment and procedures are covered in detail.

Jan 1, 1978

By Roy C. Bartholomae, Jeffrey Shawn Peterson

1. INTRODUCTION In the early 1980s, the U.S. Department of the Interior’s Bureau of Mines Pittsburgh Research Center required that a large reverberation acoustic facility be constructed. This facility was designed to determine the sound power level emissions of mining equipment, especially continuous miners and jumbo drills. A contract for a conceptual design of a reverberation chamber was awarded to Wyle Laboratories of Huntsville, AL, which had extensive experience in the design, construction, and accreditation of acoustical reverberation chambers. The following standards were referenced as guidelines for the design of the chamber: ANSI S1.31-1980, “Precision Methods for the Determination of Sound Power Levels of Broadband Noise Sources in Reverberation Rooms” and ANSI S1.32-1980: “Precision Methods for the Determination of Sound Power Levels of Discrete-Frequency and Narrowband Noise Sources in Reverberation Rooms.” Specific requested criteria included that the room be large enough to accommodate typically large mining equipment and that there be adequate acoustical modal density in the frequency range of interest. It was also required that the room dimensions would support broadband acoustical measurements down to the 100 Hz third octave band. With the closing of the Bureau of Mines in 1996, this reverberation chamber lay dormant for a number of years. However, this facility is now part of the National Institute for Occupational Safety and Health’s (NIOSH’s) Pittsburgh Research Laboratory (PRL). One of NIOSH’s missions is to decrease noise induced hearing loss among the nation’s mineworkers. To this end, PRL researchers are refurbishing and instrumenting this reverberation chamber to facilitate assessment of the various engineering controls being developed to decrease the sound power level emissions of mining equipment. Early on, this work has sought to bring the chamber up to the level of ISO 3743-21 standard for engineering grade measurements for broad-band noise, with a longer range goal of improving the lab to meet the requirements of ISO 37412standard for broadband precision grade measurements. 2. DESIGN OF THE REVERBERATION CHAMBER The nominal room dimensions are 18.3 meters long by 10.3 meters wide with a height of 6.7 meters. The chamber volume is 1,286 cubic meters. These dimensions are important, as few reverberation facilities are large enough to test typically huge mining equipment. The floor is poured concrete with a sealer to make it acoustically reflective. The walls are built of hollow concrete block, 16 inches long x 8 inches high by 12inches thick. Each block has two hollow cores. The hollow block cores were completely filled with concrete with horizontal and vertical steel reinforcing bars 16 inches on center. This was done to supply a

By John C. Nigro

This Bureau of Mines report summarizes the performance characteristics of a 30-day around-the-clock gasification-pelletizing test conducted in October and November of 1980 with North Dakota Indianhead lignite. Gasification was conducted in a commercial-size, 6.5-it-diam, Single-stage, fixed-bed, atmospheric pressure producer with a rated capacity of about 30 million Btu/hr. Iron oxide pellets made from a commercial hematite concentrate were fired with the low-Btu gas in a 2.8-ft-diam by 35-ft-long pilot plant rotary kiln at a rate of 900 lb of pellets per hour. Gasifier operations at fuel feed rates up to 3 tons of lignite per hour and hematite pellet induration with raw 160-Btu/std ft3 lignite gas are described.

Jan 1, 1982

By N. R. Dixon

This report summarizes all work performed under U.S. Bureau of Mines Contract No. J0395028, "Noise Control of Rubber-Tired Front-End Loaders Used in Surface Mining. " Two loaders, a Caterpillar 988 and an International H-400B, were chosen for this program, and the noise sources and acoustic paths that contribute to the operator&apos;s noise exposure were identified. Retrofit noise control treatments were designed and installed on these loaders, and noise reductions of more than 10 dBA at the operator position were achieved on both machines. The retrofit packages are low cost and have been field tested in two mines for more than two years. The results of the program were communicated to the mining industry through a series of noise control workshops and a field manual. The workshops were given in nine states across the U.S. and more than 440 manuals were distributed An audio/visual slide presentation was also developed which the program.

Jan 1, 1983

To reduce the exposure of mining machine operators to respirable dust. Approach: A protective curtain of filtered air is blown down around the operator&apos;s head, from a manifold mounted on the machine canopy. How It Works: Mine air is drawn into the system through a filter which removes respirable dust. The filtered air enters a centrifugal blower which pushes it through a flexible hose to a manifold mounted on the canopy above the operator. Air leaves the manifold through a perforated plate and flows down around the operator&apos;s head. A photograph of an installed system can be seen in Figure 1. The second photograph, Figure 2, shows the sys-tem components. An important advantage of this dust protection system is that it is not worn or carried, or in any way connected to the operator. It is therefore not uncomfortable, encumbering, or

Jan 1, 1976

By Fred E. Fiedler

A demonstration project investigated the feasibility and effectiveness of two management interventions, Management Training and Organization Development, for improving productivity and safety in metal/non-metal mines. The management training intervention was conducted at Texasgulf Company&apos;s trona mine, using three nearby trona mines as controls. The Organization Development intervention took place in Hecla Mining Company&apos;s Lucky Friday mine, using the highly similar Star Mine as control. The two management interventions seemed about equally effective in reducing accidents and injuries, as well as MSHA citations, and the management intervention at the Texasgulf mine also appeared to have led to substantial improvement in mine productivity.

Jan 1, 1983

By Martin H. Stanczyk

Bench scale, laboratory batch attrition grinding tests were made of a coarse commercial kaolin in a stainless steel, 5-inch-diameter attrition grinding machine to study the effect of a number of basic operating variables on particle size reduction and electric energy consumption. The results of the investigation showed that the more important operating variables influencing the efficiency of kaolin comminution and energy consumption requirements were type, size, and shape of grinding media, grinding media to clay weight ratio, peripheral rotor speed, clay slip pulp density, degree of pulp dispersion, and the angular arrangement of the rotor and stator bars. The tests also indicated that variables having less influence on grinding efficiency and energy consumption were pulp temperature, design of rotor cage, rotor clearance, rotor-stator bar interval, addition agents, pulp level, degree of pulp aeration, and chamber liners. The research showed that grinding media had the greatest influence on abrasion of machine parts and that spherical-shaped grinding media were superior to sharp angular or long bladed media with respect to media degradation, machine abrasion as well as grinding efficiency.

Jan 1, 1968

By E. J. Gleim

The importance of "good voltage,? especially for direct-current systems in coal mines, is not always fully appreciated. From the practical 4 aspect there are three viewpoints from which low voltage may be considered, namely: (a) its effect upon operation of electrical equipment, (b) its effect upon cost of maintenance and power, and (c) its effect upon safety in the mine. The design of electrical motor-driven equipment usually is based upon a given or assumed constant value for the voltage of the system; consequently, when there is an appreciable drop below this value, unsatisfactory operation is likely to follow. In the case of shaker conveyors, for example, one manufacturer has pointed out that these conveyors must be operated at a certain definite speed if maximum output is to be secured. As shunt motors are used in the conveyor drives, either a rise or fall in voltage will produce corresponding changes in speed and thus seriously affect the efficiency of the conveyor. The introduction of automatic control for mine equipment has been greatly retarded because the relays, contactors, and other special devices required have failed to function properly when attempt was made to operate them on systems subject to variable and low-voltage conditions.

Jan 1, 1937

By Choon Kooi Quan

Water availability is essential for mining and minerals processing. To provide government and industry with recent data for water use planning and management, the Bureau of Mines canvassed a number of U.S. producers of nonfuel minerals to determine their water use in 1984. Data were analyzed and compared with previously published data in order to examine historical trends in water utilization in the nonfuel minerals industry and to estimate water requirements in the year 2000. Total water use in the domestic nonfuel minerals industry during 1984 was estimated at 2,267 billion gal, of which 571 billion gal was new water and 1,696 billion gal recirculated water. The largest users of water were the phosphate rock, iron ore, copper, sand and gravel, and crushed stone industries, together accounting for almost 90% of total used. More than one-half of all water was used in Florida, Michigan, and Minnesota. In the year 2000, total water use will amount to an estimated 2,679 billion gal, of which 810 billion gal will be new water and 1,869 billion gal recirculated water. Most of this water would be used in producing the foregoing suite of minerals,

Jan 1, 1988

By Paul C. McWilliams

The U.S. Bureau of Mines has, primarily through its contract program, used large-scale centrifuges to determine design criteria for tailing embankments. The centrifuge runs were made at two installations, the University of Cambridge, Cambridge, England and Sandia National Laboratories, Albuquerque, NM. The major problems considered were as follows: slope stability of embankments, modeling erosion and seepage, use of the phreatic surface level to ascertain the validity of centrifuge modeling, and the effects of compaction and weathering on a tailings embankment. This report summarizes the results of the four test series conducted at University of Cambridge and Sandia National Laboratories. A review of prior centrifuge applications to mining problems is included. Consideration is given to future centrifuge application to mining problems in both soil and rock mechanics.

Jan 1, 1989

By Kenneth M. Maas

The Bureau of Mines inventoried all lands in Alaska to determine the availability of land for oil, gas, and coal leasing. Acreage for onshore oil, gas, and coal basins was digitized as was land ownership data. Regulatory policy concerning oil, gas, and coal leasing for various government agencies and private concerns was determined. Oil and gas basins underlie 79.4 million acres of Alaska&apos;s 378 million acre landbase. Federal agencies manage 44 million of these acres. The Bureau of Land Management is the lead agency for most oil and gas leasing on Federal lands. Lands have to be specifically opened for oil and gas leasing to be available. The state of Alaska manages 21.1 million acres underlain by these basins. More than 80 percent of this acreage is available for resource development. Native corporations manage the remaining 14.3 million acres of favorable oil and gas land. Coal basins underlie nearly 51 million acres of Alaska. Of this land, 26.4 million acres are under Federal jurisdiction. The state manages 17.3 million acres of land underlain by coal basins. Nearly 7.3 million acres of favorable coal lands are managed by Native corporations.

Jan 1, 1991

By Laird Crocker

A goal of the Federal Bureau of Mines is to minimize the undersirable environmental conflicts and impacts associated with mineral processing operations. To help reach this goal the Bureau operated a citrate-process pilot plant for the removal of sulfur dioxide from lead smelter sintering machine waste gases to test the process. The process uses a carboxylate solution such as citric acid to absorb sulfur dioxide from waste gases. The absorbed sulfur dioxide is subsequently reacted with hydrogen sulfide to precipitate sulfur and regenerate the solution for recycle. Nominal capacity of the pilot plant was 1,000 scfm of 0.5 vol-pct sulfur dioxide gas. The pilot plant was operated for over 5,400 hr and produced about 55 net tons of sulfur. The operation demonstrated that (1) 99 pct of the sulfur dioxide could be removed from lead smelter sintering machining waste gases containing from 0.1 to 0.6 vol-pct sulfur dioxide, (2) sulfur precipitation and solution regeneration with hydrogen sulfide in conventional stirred vessels was readily controlled, (3) precipitated sulfur could be continuously recovered as a 99.S-pct-pure product by flotation and melting, and (4) 78 dry-vol-pct hydrogen sulfide gas could be produced from pilot-plant product sulfur, natural gas, and steam.

Jan 1, 1979