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By Fred D. Wright

A drill unit designed by Bureau of Mines engineers for testing various types of rotary bits has been in use since April 1950 at the experimental oil-shale mine near Rifle, Colo. The unit has a hydraulic drill and feed system, which provides the wide range of operating conditions necessary for adequate testing of drill bits and for obtaining data needed for the design of production scale equipment. Through the use of this unit, it has been proved that rotary drilling of vertical holes for mining the benches of the oil-shale mine is much cheaper than percussion drilling, and it is believed that in the near future the rotary drilling of horizontal blast holes in the top heading of the mine will prove equally economical.

Jan 1, 1952

By William P. Diamonds, David C. Oyler

Stimulated vertical boreholes are an effective means of removing gas from coalbeds in advance of mining. This Bureau of Mines report examines the coal mine roof damage potential of stimulation treatments. Twenty-two Government-sponsored stimulation treatments have been mined through to determine the effects on the coalbed and roof strata. Vertical fractures in the coalbed were discernible for most treatments and horizontal fractures were present for about half of the stimulations. Sand-propped vertical fractures were usually short in lateral extent. Evidence of stimulation fluid movement could generally be traced beyond the maximum extent of sand-filled fractures when fluorescent paint was added to the treatment fluids. The maximum lateral extent for a sand-filled vertical fracture was 416 ft and a paint-coated vertical fracture extended 630 ft. Horizontal fractures were generally found within bedding planes, most commonly on top of the coalbed. The maximum lateral extent for a horizontal fracture was 265 ft at a coalbed depth of 630 ft. Horizontal fractures have been found to occur as deep as 1,145 ft. Penetration of strata overlying coalbeds was observed in nearly half of the treatments intercepted. Most of these occurrences have been interpreted to be penetrations into preexisting joints. No roof falls or adverse mining conditions were encountered that could be attributed to the stimulations.

Jan 1, 1987

A revolutionary development in blasting materials has occurred in the past 5 years. Ammonium nitrate, sensitized by the addition of a few percent of No. (class) 2 diesel fuel or other suitable petroleum product, has been adopted as a low-cost, efficient blasting agent2/ by a wide variety of mining and heavy construction operations. Moreover, ready availability of the component supplies throughout the Nation and ease of their formulation into effective blasting agents have made it possible for the blaster himself to pre-pare the mixes at the site of use. Although these field-mixed products have partly or wholly displaced explosives such as dynamites in some applications, there are other blasting operations where the fuel-sensitized ammonium nitrate agents do not appear to be well adapted. Important safety characteristics are inherent in ammonium nitrate-based blasting agents prepared under competent factory control, or when field mixed under equivalent close control--as long as the hazards they present are clearly understood and respected. This publication attempts to summarize knowledge of those hazards and to incorporate practical ways to cope with them. A series of safety recommendations thus is presented. These recommendations cover the preparation, storage, transportation, and use of field-mixed ammonium nitrate blasting agents.

Jan 1, 1960

By R. L. Stein

For the past several years, the Bureau of Mines has been actively engaged in developing two new oxygen self-rescuers through research contracts with private industry. These new oxygen self-rescuers are designed to be carried by a miner while he is at work and are used during emergency escape, supplying high-purity oxygen to the user and, at the same time, absorbing carbon dioxide (C02), The first of the two new self-rescue breathing devices is a 10-minute, self-contained apparatus developed by the Mine Safety Appliance Co, Size and weight of the unit are comparable to the currently used self-rescue devices. The second device, designed and developed by Lockheed Missiles and Space Corp., is 8. 4.5-lb package which supplies 1 hour of oxygen to the miner. Both devices have a canister which contains the oxygen-producing and CO2-absorbing potassium superoxide chemical, a breathing bag, a bite-type mouthpiece, noseclip, goggles, and hoses connecting the canister and mouthpiece. When needed in an emergency, the miner removes the outer protective cover and dons the unit. For both devices oxygen is immediately available once the mouthpiece is placed in the mouth. These two new units have received prototype approval from the National Institute for Occupation and Safety Health (NIOSH) and the Mining Enforcement and Safety Administration (MESA).

Jan 1, 1976

By John W. Finch

The Secretary of the Interior acting through the Bureau of Mines and the Geological Survey is authorized by the Strategic Materials (Public No. 117 - 76th Cong., Chapter 190 1st Sess.) to make investigation concerning essential minerals of which the quantities or grades obtainable from known domestic sources are inadequate. The Bureau of Mines, in carrying out its part of this program, may investigate deposits of such minerals in whatever manner may be necessary, in order to determine (1) the extent and quality of the are, (2) the most suitable method of mining and beneficiating it, and (3) the cost at which it may be produced. The essential objective in doing these things is to determine where and how supplies of minerals and metals of which domestic production is usually inadequate might be obtained in a national emergency, even though at higher cost than usual.

Jan 1, 1939

By Stephen D. Cramer

The Bureau of Mines conducted a series of in situ linear polarization measurements in high-temperature, high-pressure hypersaline geothermal brines at the Bureau of Mines Geothermal Test Facility in the Imperial Valley of California. The measurements represented an evaluation of the linear polarization technique for obtaining instantaneous corrosion rates of materials of construction in flowing hypersaline hydrothermal fluids that rapidly form scales on exposed surfaces. A special method was devised for use with the linear polarization technique that resulted in obtaining corrosion rates for 1020 carbon steel, 316 and 430 stainless steel, titanium, various nickel-based alloys, and aluminum 6061 under strong scale-forming conditions. The measurements also provided information on scale-deposition rates in various geothermal environments. Exploratory in situ potentiostatic polarization measurements were made in the flowing brines to qualitatively determine scale-deposition effects on the electrochemical measurements.

Jan 1, 1978

By Lisa Steiner, Robin Burgess-Limerick

In 2004, there were 646 underground coal mines in the USA employing 37,445 miners. These mines reported 3556 injuries to MSHA that year - 17% were associated with bolting machines (593 injuries), 8% with continuous miners (283 injuries), and 4% each with Scoop/LHD (1 51 injuries), shuttle cars (134 injuries), and personnel transport (145 injuries). The use of the frequency of reported injuries for the prioritization of risk control strategies has limitations because of the tendency to underestimate the importance of relatively rare but high-consequence events. Injury reports also underestimate the contribution of risk factors such as whole body vibration, which have a long-term cumulative contribution to an elevated risk of injury. However, taking these limitations into consideration, the results of the injury narrative analysis suggest the following hazards as the highest priority for elimination or control: • rock falling from supported roof • inadvertent or incorrect operation of bolting controls • handling continuous miner cable • collisions while driving LHD/Scoop, shuttle cars and personnel transport • rough road while driving or traveling in LHD/Scoop, SC & PT

By D. G. RUNNER

Information Circular 6148R, " Selected Bibliography of Minerals and Their Identification ," was issued in June 1929 , revised in July 1937, and again in October 1938. The popularity of this circular , combined with the desire to make it more comprehensive , has occasioned the preparation of this compilation of references . Where possible , date of publication , publisher, current price , and number of pages are given, although prices are subject to change at intervals . The references are grouped under the following headings : minerals , gems , rocks , geology, geomorphology, engineering geology , prospecting, mining . engineering, microscopy, technical dictionaries , and miscellaneous . For ready reference, the authors ' names are arranged alphabetically under each grouping . This list is not comprehensive, but contains only those references in most common use and which are generally available in public college libraries .

Sep 1, 1949

By Richard J. Kline

This publication comprises tables listing friction loss for a flexible, spiral-reinforced circular ventilation tubing system. The tables were constructed with the following parameters: a friction factor of 62 X 10-10, 10-foot sections of tubing ranging in total length from 100 to 550 feet, air quantities ranging from 1,000 to 15,000 cfm, and one to four 90° bends in the tubing. The aim of this publication is to improve ventilation tubing analysis and to provide a method of proper fan selection.

Jan 1, 1971

By Edward F. Divers

A new nonclogging water spray system for continuous-mining machines has been developed under contract with the Bureau of Mines. This paper presents installation and operating guidelines for the system, which consists of improved and easily maintained machine-mounted hardware, including an inline Y-strainer, a hydrocyclone, a backup filter, and two quick-opening valves for flushing particulates from the strainer and hydrocyclone. Underground tests with continuous-mining machines have shown that when properly installed and maintained, the new sys tern virtually eliminates nozzle clogging and thus greatly reduces spray maintenance. The sys tern is relatively inexpensive and has been installed on typical continuous-mining machines for a total cost under $1,000.

Jan 1, 1976

By E. C. Lane

This report on properties of commercial motor fuels is the twelfth in a series made in accordance with a cooperative agreement between the Cooperative Fuel Research (C.F.R.) Committee and the Bureau of Mines of the United States Department of the Interior. The first report contained data on motor gasolines sold during the winter of 1935-36.V The -present report, covering the summer of 1941, presents analytical data for 1,857 samples, representing the products of approximately 135 companies. As in previous surveys, these companies include both large and small suppliers. In addition, the Pacific coast is represented by data averaged by the Pacific Coast Technical Group before being submitted, and these data are published exactly as they were received. Conforming to previous surveys, the data cover three groups of samples -- regular-price, premium-price, and third-grade gasolines -- and each group has been aver aged separately. The number of samples, items, and brands comprising each group, exclusive of those of the Pacific coast, are as follows: Regular price, 1,010 samples, 291 items, and 86 brands; premium price, 577 samples, 263 items, and 78 brands; third-grade gasoline, 270 samples 159 items, and 74 brands. The meanings of these terms as used in the surveys are as follows: Sample: The individual supply of gasoline obtained at the filling station and analyzed in the laboratory.

Jan 1, 1942

By D. S. Kingery

The data obtained from this study cover test areas that are gassy to ultragassy and pillared areas of different sizes and degrees of tightness. The methods of controlling ventilation, applying bleeders, and supporting bleeder entries varied in the different test areas. It was not possible to study all conditions likely to be encountered in coal mines. Undoubtedly, there are areas where bleeder entries, even though properly planned and maintained, might prove unsatisfactory. However, on the basis of this study, the following observations were made: 1. Tests showed that each bleeder system studied provided some movement of air through the pillared area; the quantities of air delivered to the pillar line, ranged from 23 to 82 percent, depending mainly on the extent to which bleeder re-turns were used as main returns from the section. 2. Pressure measurements taken across pillared areas showed maximum pressure drops ranging from 0.05 inch of water for a shallow gob to 2.69 inches for a very deep gob. The pressure differentials varied with the size and tightness of the gob but proved adequate to induce airflow across worked-out areas or through fringes of the gob to the bleeder return system.

Jan 1, 1957

By W. A. Calhoun

A method for concentration of the nickel-cobalt-bearing mineral, siegenite, from a table middling has been developed by the Bureau of Mines at Rolla, Mo. The table middling is composed of a complex series of sulfide minerals, occurring in mill operations in the southeast Missouri "lead belt." In these operations the siegenite is lost as a separate concentrate, being diverted to other products. The procedure also includes recovering commercial-grade concentrates of copper and lead. A low-grade zinc concentrate, a potential coproduct, was also made.

Jan 1, 1962

By Joseph C. Zelanko, Christopher Mark

During August, two eastern Kentucky coal miners died in a roof fall during retreat mining operations. They had just finished extracting one pillar block and were moving to the next one when the intersection they were standing in collapsed. Regrettably, this was not an isolated incident. Since the end of 2000, there have been 28 ground fall fatalities in U.S. coal mines. Of these, 10 occurred during pillar recovery operations. Although pillar recovery has been associated with about one third of recent ground fall fatalities, it accounts for only about 10% of U.S. underground coal production. Statistically, a coal miner engaged in pillar recovery is several times more likely to be killed in a ground fall than a miner on an advancing section of a longwall. Pillar recovery is dangerous because it creates an inherently unstable situation. Once the pillars are extracted, the roof is expected to cave. Safe pillar recovery does not mean preventing roof collapse, it means ensuring that it only occurs after the miners have completed their work and have left the area. Fortunately, there are a number of proven techniques that can greatty reduce the hazards of pillar recovery. These include better mine planning, improved roof support, and safer work procedures. The goal of this article is to describe the most significant "risk factors" associated with pillar recovery, and prescribe control techniques that, taken together, can reduce the overall risk to miners. The conclusions are based on extensive studies conducted by the National Institute for Occupational Safety and Health (NIOSH) and the Mine Safety and Health Administration (MSHA) that have included detailed analysis of every fatal retreat mining incident since 1992 (25 incidents resulting in 30 fatalities). Risk reduction strategies for pillar recovery can be divided into three main groups: Global Stability: Prevention of section- wide pillar failure; Local Stability: Prevention of roof falls in the working area; and Work procedures and worker location: Minimizing exposure to hazardous areas.

By R. P. Beyer

A FORTW IV computer program has been written to calculate thermodynamic properties over a desired temperature range from spectroscopic data. This program computes heat capacities, enthalpies, and entropies for monatomic, diatomic, linear, and nonlinear polyatomic gases. This research is part of the Bureau of Mines effort to provide thermodynamic data for the advancement of mineral technology.

Jan 1, 1981

By P. L. Woolf

Oil was successfully injected into the tuyeres of the Bureau of Mines experimental blast furnace. Determinations were made for the minimum oil addition necessary to permit the maximum available blast temperature of 2,250° F. and the maximum oil rates at blast temperatures of 1,900°, 2,000°, and 2,100° F. From these tests, the upper and lower levels of high-temperature heat input, which limit the smoothly operating furnace, were established. Substantial coke saving was realized with maximum oil injection. Oil-to-coke replacement ratios have been calculated for various conditions, and oil is compared with natural gas and moisture in somewhat general terms. A study of the effect of variations in slag volume and basicity on the sulfur content of the metal at high sulfur loads was made.

Jan 1, 1963

By H. L. Riley, B. W. Gandrud

"INTRODUCTION AND SUMMARYIn connection with a program of research work on coal at its Southern Experiment Station, the Bureau of Mines, in cooperation with the University of Alabama, conducts washability studies of samples of coal from coal fields in Alabama and other Southern States in which commercially important deposits of coal occur. The first such study on coal from a bed in the Arkansas field has been completed, and the results are presented in this report.One of the main objectives of a washability study is to obtain technically and commercially important data in connection with the best methods for preparing and utilizing the Nation's limited reserves of good coking coal. Such information is important from the standpoint of conservation in that it facilitates selection of preparation methods that will yield a good grade of coking coal with a minimum of losses of coal in the rejects.The coal on which this report is based was obtained by underground and tipple sampling at the quality mine of the Quality Excelsior Coal Co. about 3 miles east of Hackett, Ark. This mine operates in the Upper Hartshorne bed, which, as the main source of coal in what is known as the Hackett-Excelsior district, yields an excellent grade of low-volatile coking coal, which is marketed at steel plants in Colorado and California. Production from this bed by the major producers in the Hackett Excelsior district was at the rate of about 125,760 tons annually in 1949, according to the Keystone Coal Buyers Manual. 2/In the laboratory, the tipple sample was crushed to 6-inch top size and screened on a 2-inch round-hole screen. The 2-inch to 0 undersize, amounting to 71.4 percent of the total sample, was fractionated into a series of screen sizes and float-and-sink products to get data for determining the washability characteristics of the coal. Before the screening and float-and-sink tests were made, however, machine cuttings, which are now gobbed underground, were added to the 2-inch to 0 sample. Enough of these cuttings were added so that the resulting mixture was considered representative of what the 2-inch to 0 run-of-mine coal would be if all machine cuttings, including the part now being gobbed, were brought to the tipple as a part of the run-of-mine coal.The mixture obtained referred to in this report as the run-of-mine or raw coal."

Mar 1, 1953

By M. V. Potter

"In nearly all fields of investigation, research laboratories and routine testing laboratories encounter problems in which the primary determinations involved in the study require the measurement of mechanical vibrations or motions. These vibrations,may be of an oscillatory nature covering frequencies from a few cycles per second up to hundreds of Kilocycles per second, or they may be more or less uniform study nations occurring at rather slow rates. In electrical, or mechanical methods. In the optical case the to cause the deflection of a light beam such that the motion of the mechanican system of the beam can be determined, then by direct the by direct observation on a suitable scale or by recording it’s the electrical methods the motions can be made to changes in resistance, capacity or inductance proportion to the mechanical displacement or electromagnetic means can used to generate directly a voltage that will be porpertuial to the instantaneous vicinity of the vibrations. Other devices are used in a special instance, also but in any cause the electrical methods produce a current that is an electrical counterpart of the mechanical motion, and the motion can then be studied by direct measurements of the current or by recording the current on suitable recording meters or oscillography. Mechanical methods are used in some instance but are generally not as convenient nor as flexible as the optical and electrical methods."

Feb 1, 1943

By Jon C. Volkwein

The canopy-air curtain was originally developed by the Bureau of Mines to surround the operator of a continuous mining machine with a zone of clean air. This report describes the application and testing of a canopy-air curtain on a gathering-arm loader, as well as some of the problems associated with providing a zone of clean air to a standing, semimobile operator. The area of air-curtain coverage and effects of air velocity are discussed. In its present form, the canopy-air curtain provides a 50 percent reduction in respirable dust to the operator.

Jan 1, 1981

By S. D. Maksimovic

The Bureau of Mines identified and evaluated major sources of quartz dust during overburden drilling at a surface coal mine, The relative contribution of each source to the total dust hazard was estimated, using personal gravimetric and instantaneous dust-sampling devices. No attempt was made to determine actual dust generation rates. The major sources of dust at the drill rig during dry drilling opera-tions were the collector dump, drill shroud leakage, and drill stem seal leakage, These sources contributed 90 pct of the respirable dust and 89 pet of the respirable quartz dust generated during drilling, The collector dump cycle (21.6 pct of total drilling time) accounted for 38 pct of the respirable dust and 41 pct of the respirable quartz dust, with peak dust concentrations reaching 68 mg/m3. Shroud and drill stem leakage contributed 28 and 24 pct of the respirable dust and 32 and 16 pct of the respirable quartz dust, respectively. A dragline and second drill rig contributed the remaining 10 pct of dust and 11 pct of quartz dust. Gravimetric dust samples collected inside the drill cab and outside, near the cab door, averaged 1.65 and 1.43 mg/m3, respectively, with 6 pct respirable quartz.

Jan 1, 1985