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By Alan R. Buehler

In 1986, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied part of the 256,430-acre Alvord Desert and part of the 22,240-acre East Alvord Wilderness Study Area (OR-002-074 and OR-002-073A, respectively), in order to evaluate their identified mineral resources. The study areas are located in Harney and Malheur Counties, OR, about 25 mi northeast of the small village of Fields. There are no mines, prospects, or identified mineral resources inside the study areas. Basalt flows within the study areas contain chalcedony-lined vugs and banded agate which may be of interest to rock hounds. An ignimbrite flow contains perlitic material, but crystalline contaminants make it unsuitable for commercial uses. Lacustrine (lake) sediments contain diatomite and clays, and evaporite crusts contain boron too low grade to profitably mine. Small quantities of common opal and petrified wood occur which might be of possible interest to rock hounds. Some of the petrified wood is black, free of fractures, and polishes well; it may be suitable as backing material for soft, thin, and brittle gemstones, such as precious opal. The lacustrine sediments also contain black, fetid layers which have above background, but economically insignificant concentrations of zinc, cobalt, nickel, barium, iron, manganese, aluminum, and potassium. Large quantities of fine-grained dune sands within the study areas are too far from markets for economic consideration. Ephemeral streams in the study areas contain small amounts of placer gold of no economic interest. The western portions of both study areas are reported to have moderate favorability for occurrences of natural gas, and both study areas are reported to have high favorability for the occurrence of geothermal resources. As of December 1986, oil and gas leases covered 3,100 acres in the study areas.

Jan 1, 1987

By Alton B. Cook

Equipment has been designed and fabricated for study of the vaporization of oil during gas-cycling operations, A sand-packed steel tube, which can be rotated to minimize gravity drainage, is used as a model oil reservoir. A minute windowed cell at the discharge end of the tube through which the liquid-gas interface may be observed, makes possible the separate removal of produced free gas and gas-saturated oil. The operation of the model oil reservoir, and auxiliary equipment, are described by use of a schmatic flow diagram. Details of the specially designed equipment are illustrated by isometric and pictorial drawings, and a description of the experimental procedure is given.

Jan 1, 1959

By I. AITKENS

Quartz maintains a rather conspicuous position among gem stones , despite its being the commonest and, in its natural form, the most easily recognized of mineral substances . This prominence is due primarily to the extensive use of amethyst , which provides stones of the finest violet color , and also to the wide employment of yellow quartz ( citrine ) which is called topaz by jewellers and vies with the true topaz in color and brilliance . Unlike many less costly gem materials quartz is hard and durable .

Mar 1, 1932

By Lawrence W. Scott

This report presents several systems for continuously monitoring the quality of air in underground mines that are being developed by the Bureau of Mines. Underground stations measure methane, carbon monoxide and nitrogen dioxide concentrations, air velocity, and air temperature. This information is transmitted over a single telephone pair to central stations located on the surface. The central stations display alarms and the data is selectably displayed on digital panel meters.

Jan 1, 1977

By L. O. Bacon

This Bureau of Mines report summarizes the results of laboratory work in the design of instrumentation for obtaining the dynamic tensile strength of rock at minimum loading. Minimum loading is defined as the lowest tensile loading by pulse reflection to cause fracturing. The instrumentation for obtaining dynamic tensile strengths of rock cores evolved into the use of a compressed-air pellet gun to impact one end of a rock core, suspended by wires, at increasing increments of air pressure. Maximum strain was measured on most or all of the impacts, and the strain at fracture of the core was obtained by extrapolating the pellet velocity-strain curve to the pellet velocity at fracture. Stress at tensile fracture was obtained from the maximum s train, and the dynamic Young's modulus was calculated from the rod velocity by using simple rod theory.

Jan 1, 1962

By Geo S. Rice

"The most authoritative compilations on the coal resources of the British Isles are given in ""The Coal Resources of the World"" issued by the 12th International Geological Congress, 1913. The reserve, calculated to a depth of 6,000 feet, in seams containing not less than two feet of merchantable coal are as follows: Mining at present is conducted at depths from about 800 to 3500 feet. The shallower coals have largely been exhausted. The present average hoisting depth probably is about 1500 feet.The thickness of individual beds at present mined varies from about 2-1/2 feet up to 40 feet in thickness, the latter thickness being found in North Staffordshire. The coal is rarely found level, but is approximately level in some parts of Yorkshire. Anthracite is mined in limited quantities in Wales, and Wales also produces a very high grade semi-anthracite or smokeless coal, which is fa famous the world round, and is equaled only by the Pocahontas and New River coals in the United States:As concerns the methods of mining, these vary widely according to the pitch of the bed, the thickness of coal, and natural conditions, but the prevailing method is some form of longwall or semi-longwall, by which all the coal is extracted. The other principal method is a so-called pillar and, stall method, by which the coal is mined out, leaving square or rectangular pillars which are extracted on the retreat, making it virtually, a retreating longwall system. This method is applied where the roof is strong, and particularly in the thicker beds, as the longwall method is not so well adapted for mining where the thickness exceeds five or six feet, unless it is what is called a multiple seam, one in which there are partings of rock that provide material for building walls, which the roof in subsiding gradually squeezes down."

Jul 1, 1920

Vanadium, molybdenum, and a titanium-10 percent vanadium alloy were evaluated for their susceptibility to stress corrosion cracking in a number of corrodents. Tests were conducted utilizing conventional U-bend techniques with subsequent evaluation in a pneumatic constant-load apparatus. Vanadium and molybdenum were generally resistant to stress corrosion cracking in the media studied. U-bend specimens of vanadium showed evidence of stress corrosion cracking in 6 li hydrochloric and 18 li sulfuric acids; however, tensile stress specimens exposed to these solutions did not exhibit stress cracking. Similar results were obtained when U-bend specimens of molybdenum were immersed in 10 percent formic acid. Titanium-10 percent vanadium alloy was susceptible to stress corrosion cracking in 10-percent (2.85 li) hydrochloric acid solution. Heat treating the alloy greatly reduced its corrosion rate and its susceptibility to stress cor-rosion cracking in this medium.

Jan 1, 1965

By E. D. Gardner

This paper discusses prospecting for lode gold and lists the principal lags and. regulations pertaining to locating; lode claims on public lands. It is a preprint of a part of a bulletin being prepared by the United States Bureau o Mines entitled "Equipping, Developing and Operating Small Gold Mines". The increased interest in gold mining manifested during the past few years (1932-1935) bas stimulated prospecting. Many adventurers have taken to the field to search for now gold deposits. A. large percentage of them have had no previous experience in prospecting for lode gold; this paper has been written with the tope that it might assist these newcomers.

Jan 1, 1935

By R. L. Grayson, T. Simonyi, R. A. Andrel

"The purpose or this paper is to disclose analytical, statistical, and observational results relating to mineralogy and trace elements in respirable dust samples collected from two different mines in West Virginia. Samples were taken from longwall panels, and the panels operated in different coal seams, one located in the northern part or the state and the other in the southern region. Mining conditions and equipment arrangements on the panels will be described along with dust control techniques used. Results from sample analyses are summarized with emphasis on relationships between mineralogy, trace elements and mineral particle size to worker locations. Correlations are made between micro x-ray diffraction and energy dispersive x-ray analyses for sample mineralogy.IntroductionThrough the work of many researchers worldwide, the health of coal miners in modern societies is now protected from harmful exposure to respirable coal mine dust. A vast amount of research culminated in the exposure-response model of Jacobsen, et al, (l) which has been used to establish the 2 mg/m3 exposure limit in the United States. According to the model exposure to respirable dust for 35 years at this level or less could prevent the occurrence of a clinically significant case of coal workers' pneumoconiosis (CWP) in a miner. The exposure limit, of course, must be adjusted whenever greather than five percent free silica exists in the respirable dust.The Jacobsen model was built around a mean mass concentration exposure, which generally showed the highest correlation with both incidence and progression of CWP. As Morgan, et al noted, however, the quantity of respirable dust inhaled is not the only significant factor. 2) They noted that although mass of respirable dust correlates highe.st with the incidence of CWP, it is not a causal factor. Admittedly, the insidious processes causing the disease occur at the lund cell-dust particle level."

Mar 1, 1989

By A. Visnapuu

The U.S. Bureau of Mines investigated the oxidation of American Iron and Steel Institute (AISI) Type 304 stainless steel (SS) during annealing in simulated combustion products from several air-CH4 fuel ratios. Atmospheres representing air-CH4 ratios of 14:1 and 18:1 contained free 02, while atmospheres representing 10:1 air-CH, ratio did not. A Cr203 layer formed on SS samples annealed in atmospheres containing free 0, while a Cr-Fe spinel layer formed in atmospheres with no free 02. The Cr203 layer was adherent and presented a protective barrier to metal diffusion, effectively limiting oxidation of the metal substrate. The Cr-Fe spinel was not protective and allowed the diffusion of Fe through the spinel to the gas-oxide interface where it was oxidized to magnetite, which spalled from the surface. This resulted in thick scale layers on samples annealed in atmospheres containing no free 02, as compared to layers formed on samples annealed in atmospheres containing free 02. These results confirmed and explained industrial operators' observations that thick, smoky (fine spalled magnetite) scales form on SS annealed in low free-02 atmospheres, while thin protective oxide layers form on sheets in atmospheres containing free 02.

Jan 1, 2010

By Clyde L. Brown

Recent developments in portable communication equipment for use in emergency recovery work following mine fires and explosions have wade possible a convenient and dependable means of directing rescue teams working under hazardous conditions. INTRODUCTION Mine rescue and recovery operations following; fires and explosions are frequently conducted under adverse conditions that require the use of oxygen breathing apparatus by members of a 5- or 6-man team. Conventional apparatus used for this purpose for many years was equipped with an oxygen supply adequate for at least 2 hours. The design of the apparatus is such that the nose passages are closed with a clamp, and breathing is accomplished through a mouthpiece connected to the apparatus by tubes and arranged to prevent inhaling air or gases from outside sources. The use of the mouthpiece has presented difficulties in the development of telephone communication because of the wearer's inability to speak while wearing the mouthpiece. The method of conducting operations of rescue teams requires a person to direct operations at a fresh-air base as close to the rescue team as possible. At least one standby rescue team and 2 or 3 other persons assigned to various tasks are stationed at the fresh-air base. An efficient and reliable means of communication between the director of operations and the rescue team is necessary for reasonably safe and efficient work in hazardous areas.

Jan 1, 1957

By W. M. Weigel

"Sand is one of the commonest materials for industrial use, not only as a building material, but in many industrial processes. The general name applies to all grades, from the comparatively impure, unsorted product used in concrete, to especially sized products of extreme chemical purity. Various definitions have been proposed, all more or less open to objection, as they fail to cover special applications. One is: ""Sand - The fine granular material naturally or artificially produced by the disintegration or crushing of rock or slag"". This does not fit the definition of sand as understood by geologists, who consider sand only as a naturally formed product. Another is: ""Sand - The fine granular material naturally produced by the disintegration of rock"". This does not take the chemical com-position into account, and for practically all uses, except in concrete and plaster products, a material composed predominantly of silica or rather quarts is implied.Sand for special purposes usually requires different methods of preparation from those where the ordinary mixture of sizes as naturally occurring are suitable. One of the classes requiring the most uniformly sized grains is sand blast sand.Sand Blast SandThe use of the sand blast has increased rapidly during the past few years. It was formerly used almost entirely in the foundry to clean and remove inequalities from rough castings. This is still the most important application, but in addition, it is now employed for the removal of paint from old surfaces, carving and engraving on stone and marble, glass cutting, cleaning or renovating the rails of stone and brick buildings that have become discolored, preparing the surface of metals for the electrolytic bath, putting the final finish to metal surfaces, and has even been proposed as a means of channeling or cutting out blocks of stone in the quarry."

Jun 1, 1924

By David F. Smith

The American Society for Testing Materials4 has recommended that the melting temperature of potassium chromate be used-for indicating the temperature to which a coal sample should be heated in the standard method of analysis to determine its volatile matter content. The specified temperature is 950± 20° C., the melting point of potassium chromate being noted as 940° C. Le Chatelier5 originally found the melting point to be 975°; later6 he found 9400. According to Shemtschushny7 the melting point is 984°; he also found a transition at 679°. Groschuff8 found the melting point to be 971° and the transition temperature 679°. Amadori9 reports a melting point of 9.78° and a transition point of 666°. The International Critical Tables10 take the melting point as 975°, which is estimated to be correct to two significant figures. In view of the apparent uncertainty existing, it has been though worthwhile to make a careful redetermination of this datum. It is of interest not only to determine the melting point of the pure salt, but also of the commercial product, in order to test its suitability for use as a temperature indicator. The work was suggested by A. C. Fieldner, chief engineer, experiment stations division, U. S. Bureau of Mines.

Jan 1, 1929

By D. Harrington

Misuse of explosives and heedless disregard of well-known safety rules covering the use of commercial explosives cause many avoidable accidents resulting in the death or maiming of men who can ill be spared by already undermanned industry at present, and who cannot be spared by their families at any tire. Blasting accidents, when not fatal, are usually serious; the past and present needless loss of life and maiming of men from this cause are appalling and types of waste that can and should be virtually eliminated. Dead, crippled, and maimed men are distinct losses to society as well as to industry, and compensation payments for such accidents represent only a portion of the financial loss, because the value of their lost potential production can only be surmised. By their very nature, explosives are dangerous to handle, otherwise they would not perform the services for which they are used; all men on a blasting crew are subjected to the results of the carelessness of any one member, and in many instances the misuse of explosives by one person has killed scores of fellow workers. Inexperienced men should be assigned to blasting operations only under the close supervision of men well-experienced in the work and familiar with its inherent hazards. Men should be selected for blasting crews that are known to be careful, willing to follow instructions, cool-headed, and unlikely to become excited in an emergency; they should be instructed in the safe handling of explosives in accordance with the safety rules established by the explosives -manufacturing companies or the safety codes of the various industrial organizations. Unfortunately, American industry has never adopted a uniform code for the safe handling of explosives; however, many mining companies have made rules that will eliminate most unsafe practices if established safe procedure is followed carefully. The Bureau of Mines has issued numerous pamphlets giving information on the causes of accidents due to explosives in the mining industry and indicating the ways in which a good proportion of those accidents can be avoided.

Jan 1, 1943

By John L. Reuss

A laboratory study was conducted by the Bureau of Mines to investigate the technical feasibility of decomposing hydrous magnesium chlorides by using a steam pyrohydrolysis technique. This procedure consisted of injecting steam into the atmosphere of a decomposition furnace containing samples of hydrous magnesium chloride and determining the rate of hydrolysis by measuring the rate of chloride evolution. The variables investigated were temperature, amount of water vapor in the decomposition atmosphere, and hydration stage of magnesium chloride. The application of steam was shown to accelerate both the rate and completeness of magnesium chloride decomposition reactions. For example, when magnesium chloride hexahydrate is exposed to a furnace temperature of 600' C in an air atmosphere for 20 minutes, the decomposition is 37 percent. Under identical conditions in a steam atmosphere, the decomposition is in excess of 70 percent. The magnesium oxide produced by the steam pyrohydrolysis of magnesium chloride dihydrate at 800° C contained 98 percent magnesium oxide. Based on magnesium oxide composition, this is equivalent to that of burned magnesite produced at temperatures in excess of 1,300° C. To demonstrate the quality of the product on a practical basis, metal reduction tests have shown it to be equivalent to reagent-grade magnesium oxide as a carbothermic reduction feed material.

Jan 1, 1974

By Alan D. Hartman

The U.S. Bureau of Mines, under a Memorandum of Agreement with the American Society of Mechanical Engineers (ASME), established design criteria for a facility to melt residues from municipal waste combustion. This facility, which is available to potential users on a cost-sharing basis, is also applicable to a variety of inorganic waste materials from smelting or melting operations. The design consists of a mechanical feed handling system, electric arc melting furnace, fume-offgas handling system, and thermal oxidizer for final offgas treatment. Screw conveyors and a bucket elevator deliver up to 2,000 lb/h of minus I-in material to a three-phase electric arc melting furnace. This unique 800-kV?A furnace has a water-cooled shell and roof to minimize interaction of the melt with the refractory lining. The volume of the hearth below the slag taphole is approximately 1.2 st of steel. The furnace is sealed, allowing atmosphere control within the furnace and fume duct by nitrogen or inert gas injection. A jet-pulsed baghouse removes particulate from the offgas and serves as an acid gas scrubber. The clean offgas is heated to 1,800° F for 1 s in a propane-fired thermal oxidizer before being vented to the atmosphere.

Jan 1, 2010

By Marting J. Gavin

The twentieth century has often been spoken of as the age of petroleum, and from many viewpoints it can be justly considered so. Certainly the petroleum industry is one of enormous importance to this country, industrially, financially, and economically. The United States, however, at present producing over 60 per cent of the world's total output of petroleum, is not producing petroleum at a sufficient rate to provide for its own domestic, consumption. For several years this country has been importing increasing quantities of crude and partly refined oils from Mexico, and has been drawing heavily on domestic stocks of petroleum. Production in the United States is increasing, but it is not increasing at the same average rate as domestic consumption, nor is it probable that in the future domestic production will increase sufficiently to satisfy the demands of domestic consumption, but on the contrary, in the opinion of those best qualified to know, the peak in the curve of domestic production of crude petroleum will be reached in a comparatively few years, whereas the consumption of petroleum and its product will increase at a continually growing rate. This country, then, must turn, and as the increasing imports from Mexico indicate, is turning to other sources than the crude petroleum, produced in this country to make up the deficit between domestic production and domestic consumption of petroleum and its products,

Jun 1, 1920

By Thomas A. Morgan, Louis A. Panek

This report describes a method for determining the stress in rock based on a requirement for static equilibrium ; namely , that the total load on a sufficiently large area must remain constant even after a drift or stope is mined in the area . The method is based on mathematical relationships that are independent of the elastic properties of the rock and the stress distribution near the underground opening . In addition to determining the preexisting stress (before mining ) , the method described can be used to determine the change in stress due to mining .

Jan 1, 1963

By F. S. Crawford

This report deals with the effectiveness and economy of installing mine timbers treated with preservatives in long-life service locations. Early in the present century, when mine timbers and labor were plentiful, it was not general practice to install treated timbers in such places. Because national sources of good mine timber are declining steadily, the mining industry must now conserve timber. Moreover, the cost of installing and replacing mine timbers has been rising. Therefore, even the simplest of treatments can be expected to give some return on the investment when applied to timbers that are to be installed in relatively permanent locations. Better methods of treatment will produce better returns. In a service test of maple timbers treated by the hot-and cold-bath method and installed in main haulageways of the Athens mine of the Cleveland Cliffs Iron Co., Negaunee, Mich., zinc chloride-treated timbers had an average useful life of 13.3 years; borax-treated timbers, 11.2 years; and sodium fluoride-treated timbers, 7.7 years. Untreated timbers used as controls had an average useful life of 3.8 years.

Jan 1, 1950

By Thomas M. Kohler, Gerald L. Finfinger, Gregory M. Molinda

The Bureau of Mines has completed an investigation of the effectiveness of methane drainage in the Lower Sunnyside Coalbed at Kaiser Steel Corp.'s Sunnyside No. 1 Mine in Utah. Most of the previous at- tempts to drain methane gas using long horizontal holes were conducted in the Eastern Coal Province. From the high degree of success realized in these efforts and the large body of knowledge gained from associated research, it seemed natural to extend the technology to western coalfields. Previous work had indicated that properties affecting gas drainage were variable in the Sunnyside Coalbed. In an attempt to characterize these properties, four degasification holes were drilled from the out- side entries of an advancing section. The holes were drilled to lengths of 780, 1,680, 1,315, and 1,047 ft and produced initial flow rates of 50,000, 180,000, 340,000, and 240,000 f t3/d, respectively. A total of over 300 million f t3 of commercial-quality gas has been removed from the Sunnyside Coalbed. The four holes have reduced face emissions by 78 pct.

Jan 1, 1986