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By George T. Motock

The author prepared the following report as the result of a trip to Germany in the summer of 1945 for the Technical Industrial Intelligence Commitee Subcommittee on Metals and Minerals. The purpose of this committee, which functions under the Joint Intelligence Committee of the Joint Chiefs of Staff of the United States Armed Forces and of which the Bureau of Mines

Jan 1, 1946

By C. Melvin Lepper

The Bureau of Mines has developed an improved earth resistivity field system which employs a novel technique for obtaining null measurements. The instrument is designed to operate reliably in high-noise environments such as those found in the vicinity of operating mines. The system consists of a low-frequency transmitter, a sensitive receiver and an external battery pack, each in its own case to provide protection from the elements. The receiver and transmitter units have self-contained recharge-able batteries to supply power to the circuitry and separate built-in battery chargers that operate on standard 115 Vac power. The system is portable and simple to operate. Measurement accuracy, reliability, and dynamic range are superior to most commercially available equipment even though less time and effort is required to make null readings. Unlike some commercial systems, long integration times are not required to enhance signal-to-noise ratio in areas of high background noise.

Jan 1, 1974

By H. A. Watson

Fluorine-containing polymers are comparatively new materials that exhibit very desirable characteristics not usually found in non-fluorine containing polymers. Among these characteristics are heat and flame resistance, desirable electrical properties, and chemical inertness. Polytetrafluoroethylene and polymonochlorotrifluoroethylene are examples of such polymers commercially available. In practical applications it is reasonable to expect thermal position of these materials if they are subject to high enough temperatures. The temperatures at which thermal decomposition takes place and the nature of the gaseous products of decomposition are considered pertinent data in intelligent use of these materials. The purpose of the tests discussed herein was to determine: (1) The temperatures at which gases were produced when small specimens of the two polymers were located and (2) determine the identity of the major constituents of gaseous products.

Jan 1, 1950

By P. L. Swanson

Over a recent 20-month observation period, the U.S. Bureau of Mines obtained seismogram records from a single vertical-component, short-period seismometer installed at the surface of a metal mine in northern Idaho. The seismic events were analyzed for local (Richter) magnitude (M), time of occurrence, location, and relation to rock bursting and production blasting. Approximately 150 seismic events with -0.5 = M = 2.9 were located within the mine, yielding a b value (slope of the logarithm of the number of events with magnitude greater than M versus M) of 0.5. Event locations were constrained using a dense underground array of high-frequency accelerometers. Twenty of the surface-recorded events, with 0.5 = M = 2.9, were associated with rock bursts that produced damage requiring at least 1/2 day of cleanup and/or repair. Other possibly hazardous rock bursts, with magnitudes as small as -1.1, were numerous but were not associated with significant structural damage. Approximately 60 pct of the seismic events with M > -0.5 and 75 pct of damaging rock bursts occurred within 45 min of blasting. Estimates of characteristic rupture dimensions for rock bursts with -1.1 = M = 2.9, based on a conventional dislocation shear-slip model of failure, range from 3 to 300 m.

Jan 1, 2010

By Mary S. Esfandiary

This is a revision of a directory of coal research organizations throughout the world that was first published in 1961 as Bureau of Mines Information Circular 8008. Because of the wide acceptance of the first edition, a revision which would supply up-to-date information on coal research and which would facilitate communication among organizations of similar interest seemed important. This compilation includes the names and activities of organizations of various types-government, university, private, and industry. The areas of investigation that each organization is engaged in are indicated in broad terms: Analysis and constitution, mining and geology, preparation, briquetting, combustion, high-and low-temperature carbonization, gasification, conversion to solid and liquid fuels, and health and safety. Publications issued by and describing the work of each organization are cited; almost all of the organizations also publish results of their investigations in the technical press. Selected technical and trade publications that publish information on the science and technology of coal and are not published directly by any of the organizations listed are cited in the pages following the list of organizations in each country. Information that would improve coverage and accuracy of the next revision of the publication will be welcomed by the Bureau of Mines.

Jan 1, 1966

By Edward F. Fries

The U.S. Bureau of Mines is conducting research that will lead to computer-assisted mining equipment. This research will facilitate improvements in safety by relocating workers from dangerous areas and will increase production by providing more accurate control with less downtime of equipment. A Bureau-developed microcomputer network enhances this research by permitting a group of diverse computers to interact with a mining machine as well as with each other over a common data link. The network is composed of specially integrated off-the-shelf hardware and industry-standard operating system and programming languages. Using the network, researchers can conduct various experiments with the mining machine using a diverse group of sensors, computers, and micro controllers. This report gives a brief background on the Bureau's work in computer-assisted mining, followed by discussions on the network hardware and architecture and the network packets, and an analysis of network operation.

Jan 1, 1992

By Frank A. Peters

The Bayer process treating Jamaican bauxite was evaluated from an economic standpoint, using standard estimating methods and published data, to present a reference point for cost estimates for nonbauxite alumina processes. The estimated operating cost for a plant producing 1,000 tons of alumina a day is $47.96 per ton of alumina when charging $8 per ton for bauxite and $2.30 per hour for direct labor. The estimated fixed capital cost is $46 million.

Jan 1, 1966

By R. S. Fowkes

Jetstream pressure distributions and coal cutting rates were determined for a number of nozzles and under different operating conditions. The jetstrearn pressure distribution data were fitted to an assumed curvilinear equation by the utilization of a numerical least-squares technique with the aid of a digital computer. Subsequent manipulation of the approximation equation showed that the total force of the jetstream, rather than its maximum pressure or total kinetic energy per unit Lime, was the most significant quantity affecting the coal cutting rate. A shorter method for assessing the ability of a nozzle to cut coal was found.

Jan 1, 1968

In October, the Aluminum Company of America restarted the fourth of seven pot-lines at its Point Comfort, Tex. primary aluminum smelter. The price of primary aluminum ingot, as quoted by American Metal Market, was increased from a range of 60.5 to 63.0 cents per pound at the end of September to a range of 66.0 to 66.5 cents per pound at the end of October. BERYLLIUM On October 15, Brush Wellman, Inc., of Cleveland, one of two U.S. producers of primary beryllium products, announced a planned $6 million expansion of its extraction plant at Delta, Utah, increasing the plant?s capacity to extract beryllium from bertrandite ore by 25%. Another $5 million will be spent on two mine expansion programs in Jaub and Millard Counties, Utah. Other mineral claims and 1 eases he 1 d by The Anaconda Company will be taken over by Brush Wellman through lease or purchase. This expansion, when completed in 1981, will decrease U.S. dependence on imported beryl ore.

Jan 1, 1979

By Arnis Mangolds

A study of the technical and economic feasibility of using a unique undercut and fill system developed by USBM engineers to mine steeply pitching coal is discussed. A brief resource assessment has indicated that significant reserves exist in most coal regions to justify the development of a safe and economical method of extracting steeply pitching coal. The undercut and fill system combines hydraulic coal cutting with unassisted gravity fluming of the coal slurry. Mining occurs across strike and the extended entry is backfilled to provide uniform strata control and an impermeable water and air barrier. Subsequent mining occurs beneath the previously filled stope such that the roof consists of a solid, controlled back. In addition to providing positive roof and hanging-wall support, the backfill system eliminates subsidence potential, post-mining drainage, and the danger of spontaneous combustion from naturally drafting air currents. A unique through-flowing ventilation system permits passage of return air through the production face via ducting located at the backfill-coal junction. This provides a constant supply of fresh air at the face, eliminates the need for brattice cloths, and provides an additional escapeway for the miners. The preliminary estimates indicate a production rate in the neighborhood of 31.9 tons/ manshift. Capital costs are approximately $3.17/raw ton over a 20-year life with an initial investment per annual ton of $48.29. Total cash-costs for labor, supplies, power and benefits range in the vicinity of $19.59 for a 704,460 ton/year mine, or a total cost of $22.76/ton. These costs do not include federal and local taxes or post-of-money; however, the cost of coal is well within the area selling price.

Jan 1, 1981

By Frank L. Hess

In the first cart of that little space of time that we have designated as the nineteenth century, chemistry had reached a wonderful stride. Viewed from the present heights attained by the efforts of innumerable chemists with perfected apparatus, mire reagents, air under pressure, water, gas, and electricity conducted to the desk, and. numberless other helps, it seems marvelous that chemists of that day obtained such results. In 1820, about half of the elements had. been discovered; of these discoveries, Swedes had made 15 or more, about once-third of the elements then known and nearly half of those discovered after 1700.

Jan 1, 1939

By E. D. Gardner

The Bureau of nines, in cooperation with the mining companies of the Southwest, is conducting an investigating to ascertain the safest and most economical explosives to use in metal mines, and to ascertain the best methods of blasting under various conditions. A part of this investigation has been a study of drilling and blasting drift rounds in metal mines. This paper covers one phase of work on drift rounds and discusses the methods of loading the individual holes of the rounds. The blasting tests, on which this paper is based, were made at the Copper queen Branch of the Phelps Dodge Corporation at Bisbee, Arizona.

Jan 1, 1927

By R. K. Koch

The Bureau of Mines developed a zircon sand molding process for static casting of small titanium or zirconium shapes. Castings with unfinished weights up to 3.5 kg (7.7 lb) were produced in an inductoslag furnace and castings up to 7 kg (15.4 lb) were poured in a consumable electrode skull-casting furnace. Molds and cores were made by ram-molding, foundry-grade zircon sand (AFS gfn 93 to 95) bonded by grade D waterglass and tempered with water. Molds and cores were cured either at 250° C (482° F) or 900° C (1,652° F). Castings from the higher temperature molds broke cleanly from the sand while the lower temperature molds produced castings that had to be cleaned by sand-blasting. However, low-temperature cured molds and cores have a number of advantages as follows: (1) A faster, less energy-consuming curing cycle is used; (2) expended cores are water soluble which greatly facilitates core removal; and (3) enough of the binder in crushed expended molds is reactivated by temper water so that the molding mix can be reused five times without any fresh binder additions and up to twenty times without exceeding a total cumulative binder addition of 52 ml/kg dry sand. Crushed used molds that had been cured at 900° C had no detectable binding strength when mixed only with temper water. A large number of oxide and silicate mold washes were studied for improved casting integrity. The most effective wash found for zirconium or titanium casting was monoclinic zirconia (325 mesh).

Jan 1, 1977

By W. P. Yant

[At the majority of mines where flame safety lamps are used either as working lights or as a means of detecting gas, no check it made on this condition of the various parts of the lamp and their assembly other than a visual ink inspection. Although this inspection should be made carefully in view of tae serious consequence that may follow Vie use of a faulty lama, In many instances the inspection is of a perfunctory nature. The Bureau of Mines has therefore designed a small box or gallery for testing lamps for defects and improper assembly before they are taken into the mine. The test simulates the condition when a lamp is extinguished by its introduction into an explosive mixture and the operator attempts to relight the wick while the lamp contains the explosive mixture. This test is more rigorous than merely subjecting a lighted lamp to an explosive methane-air mixture. In the latter test the products of combustion tend to blanket the propagation of flame from within the lamp to the exterior, especially if there are defects at the top of the gauzes. Moreover, when the lighted lamp is subjected to an explosive methane-air mixture the methane builds up slowly within the lamp until the lower inflammable limit is attained, whereupon a feeble explosion occurs within. If the nonlighted lamps is first filled with the methane-air mixture that gives the maximum violence and is than ignited, the dampening effect of products of combustion is obviated and the strain on defects is]

Jan 1, 1930

By J. R. Thoenen

In Progress Report 1,4/ a number of facto mere demonstrated and conclusions drawn from experimental tests and records made during commercial blasting operations at a number of quarries. For example, the tests showed (1) that vibrations received on outcrops were of comparatively

Jan 1, 1938

By C. M. McKinney

The Bureau of Mines analyzed 626 crude oils from 546 oilfields in the United States that produced 2,500 BOPD or more during at least 1 of the last 3 years. Included also are crude oil analyses from eight fields that produced less but which were located in areas having few or no fields that produced 2,500 BOPD. The tables show the geographical and geological source, general characteristics. and determined and computed analytical data for each sample. The analyses were made according to the Bureau of Mines routine method and are directly comparable to other previously published analyses.

Jan 1, 1966

By Albert L. Toenges, Louis A. Turnbull, Henry E. Dekay, James N. Scudder

A preliminary survey of coke and steel plants conducted by the Bureau of Mines in cooperation with the Office of Solid Fuels Coordinator and under the auspices of the Coke Production Committee indicated that a very appreciable increase in pig-iron production would be obtained if pres- ent blast furnaces were supplied with a more uniform coke. Control of the sulfur and ash content of coal used for making coke is an important factor in producing uniform coke and thus increasing blast- furnace efficiency. In some mines producing metallurgical coal, the analysis of the coal bed shows a wide range of sulfur and ash content. To obtain production of coal with minimum deviation in sulfur content sampling, grading, selective mining, blending, and surface preparation are practiced at some mines with satisfactory results. The mines selected for this study have developed these methods and are successfully producing coal of uniform sulfur and ash content. The systems employed at different mines vary according to the physical character- istics of the coal bed, the manner of occurrence of impuritites in the coal, the development plan and mining system, surface preparation and the acceptable impurity content of the prepared coal. The ash content of the coal can be controlled by face preparation and in the cleaning plant. The introduction of some method or practice at other mines might make possible the use of coal for inetallurgical purposes that otherwise could not be used for making coke because of the wide variation of sulfur and ash content.

Dec 1, 1943

By B. J. Moore

This publication contains routine analyses and related source data for 528 natural gas samples from 21 States collected during calendar year 1965 as part of a continuous survey of the United States for occurrences of helium in natural gas. This survey has been conducted by the' Bureau of Mines since 1917. The analysis published herein were made by mass spectrometer and a special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4863 and 576.4

Jan 1, 1966

By B. J. Moore

This publication contains routine analyses and related source data for 528 natural gas samples from 21 States collected during calendar year 1965 as part of a continuous survey of the United States for occurrences of helium in natural gas. This survey has been conducted by the Bureau of Mines since 1917. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4863 and 576.4

Jan 1, 1966

By John Campbell, Miller. W. E., G. W. Jones

"INTRODUCTION Because of its interest in accident prevention, the Federal Bureau of Mines has cooperated with city officials and utilities in investigating the causes of explosions in sewers, manholes, and other underground spaces and has aided in the development of means to prevent such explosions. For several years this Bureau has cooperated with the Boston Edison Co. and the Boston Consolidated Gas Co. of Boston, Mass.,for the purpose of detecting and eliminating combustible and physiologically harmful gases in manholes in Boston and vicinity.These investigations 5/ have shown that combustible gases from the usual sources — leakage from gas—distributing systems and underground tanks and gasoline wastes — can be located and the dangerous conditions remedied by a well—planned, adequately supervised, systematic, and continuous manhole survey. However, other types of gas contamination, termed ""soil"" gases, are present in manholes at times and are more difficult to eliminate because they have no fixed origin and because seasonal and barometric chances affect their production and passage into the manhole. Soil gases usually are abnormally high in carbon dioxide and low in oxygen and contain varying amounts of methane. They are especially dangerous to men entering manholes because they lack sufficient oxygen to support life."

Feb 1, 1940