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By Ned Baker

Details are given of a Hydride Fuel System to provide 5 kg of HZ to fuel a Caterpillar 3304 engine previously modified to operate on hydrogen fuel and intended to power an underground mining vehicle. The Fuel System was installed onto the engine and the Engine/Fuel System tested under cold start conditions and a full range of engine loads and speeds. Refueling tests were also performed. The fuel system tested will support full engine power and allow delivery of at least 3/4-power on a continuous basis, from cold start conditions.

Jan 1, 1983

By A. C. Fieldner

"Decline of the Beehive Coke OvenTwenty years ago a favorite theme of the crusader for fuel conservation was the enormous waste of valuable by-products incurred in the manufacture of blast-furnace coke in beehive ovens. Indeed, there was good reason for arousing the national conscience to this needless' loss of an irreplaceable mineral resource. In 1910, 83 per cent of the coke production was made in beehive ovens, from which surplus gas, tar, light oil, and ammonia, aggregating in value (at 1910 prices) 40 million dollars annually, were discharged into the atmosphere.In 1929, proportions were reversed and 90 per cent of the production was made in by-product ovens. The average value of by-products obtained in the production of 1 ton of coke in 1929 was $3.60, as compared with $1.16 in 1910, although the value of a ton of coke had increased only from $3.47 to $4.80. As shown in Figure 1,1 the production of by-product coke progressed rather slowly until 1915. War needs suddenly expanded the demand for coke and the by-products benzol and toluol for the manufacture of explosives. Except during the depression of 1921, this accelerating rate of production was maintained up to 1929, largely at the expense of beehive plants. The 1929 production of 60 million tons of coke will probably remain a record-breaking figure for several years. The developments which are now in progress in long-distance transmission of rural gas and in the utilization of volatile petroleum products and refinery gases for augmenting, city gas supplies may retard an other- wise accelerating demand for coke and coke-oven gas for domestic and industrial heating, Trends in Value of By-ProductsThe increasing value of by-products in comparison to the value of coke is shown in Figure 2. In 1913, the average value of by-product coke was $3.38, the value of the by-products per ton of coke was $1.41, and the cost of coal per ton of coke was $3,27, In 1929 not shown in figure) the value of the coke had risen to $4.80 per ton, the value of the by-products to $3.60, and the cost of coal per ton of coke to $5.07. The by-product values in were 155 per cent higher than in 1913, although the coke value had increased only 25 per And the cost of the coal 55 per cent. Actually the increase or the total value of coke plus by-products in this period was very little more than the increase in the coat of the coal, being 55per cent for coal and 60 per cent for coke plus by-products."

Mar 1, 1931

By L. Hoogenboom

Under contract (H0232044) to the U.S. Bureau of Mines, Mechanical Technology Incorporated made an experimental investigation of the feasibility of measuring the load in roof bolts using a magnetostrictive sensor. The program was aimed at developing an inexpensive, moderately accurate, load-sensing element suitable for permanent installation and use underground. A combination of a cylindrical load-carrying sleeve under the bolt head and 3 removable circular multipole inductive sensor around the sleeve was tested. Program tasks included: design and fabrication of several sensors; design and manufacture of a large number of experimental sleeves; definition of electronic instrumentation specifications; design and manufacture of electronic sensor readout; and evaluation and testing of many sensor-sleeve combinations. Sleeves of different materials, various lengths, diameters and areas - with and without various nickel coatings -were combined with several experimental inductive sensors that were operated over a wide range of carrier frequencies.

Jan 1, 1974

By V. F. Parry

"INTRODUCTION During the war period the Bureau of Mines expanded its investigations on western coals principally in connection with Investigations of raw material resources for western steel production. Owing to the expansion of the steel industry, there was some concern regarding the availability of suitable coking coals; end because of the potential steel shortage, the production of sponge iron, using the lower-rank fuels, was considered. Work was conducted by the Bureau of Mines on exploration projects and on testing of coals both at the Central Experiment. Station at Pittsburgh, Pa., and at the Bureau of Mines Station at Golden, Cole.The results of these investigations are being published by the Bureau in several reports of investigations and technical papers. In making this resume of coal investigations, the work done by the Bureau of Mines at Pittsburgh in the Mining and Coal Carbonization Sections will be discussed and the investigations at Golden described in greater detail.INVESTIGATIONS OF WESTERN COALSThe Mining and Coal Carbonization Sections of the Coal Division, Bureau of Mines, under the supervision of A. L. Teeny es and J. D. Davis, respec¬tively, conducted many field investigations to locate and evaluate new sources of coking coals. Drilling explorations were made in Colorado, Wyoming, Utah, New Mexico, and Washington and revealed two important new reserves of coking coal. The first one studied was the Willow Creek bed at Kemmerer, Wyo., which was reported in 1945.3/ A recoverable reserve estimated at 11,200,000 tons was blocked out, and samples of coal were extracted for coking tests. The coking properties of the coal were not quite equal to those of Sunnyside coal, but it was indicated that a 50-percent blend of the Willow Creek with Lower Sunnyside will produce a satisfactory metallurgical coke based on Columbia steel standards."

Jan 1, 1948

The Bureau of Mines analyzed the cycle of secondary gold to determine the quantity of gold not being recovered from scrap, and to identify areas for research to increase the supply of gold from scrap. Secondary gold in 1967 was estimated to be 2.4 million troy ounces; this excludes secondary gold which is recycled within consuming plants. Firms contacted included consumers using about 41 percent of the gold in 1967, And refiners that recovered about 90 percent of the secondary gold. Results of the study indicate that loss of gold is small, and refiners and consumers are accelerating programs designed to reduce recovery costs. With the increasing generation of low-grade industrial scrap, research is needed to improve present recovery techniques and to develop methods to accelerate the flow of secondary gold back to supply.

Jan 1, 1970

By Oliver Bowles

From remote antiquity stone has been employed for structural, ornamental, and memorial purposes. It was, and still is, so used because of its availability in innumerable localities and its architectural adaptability, dignity, substantiality, and durability. The principal varieties of stone used are granite, marble, limestone, sandstone, and slate. This report deals with granite. OCCURRENCE AND CHARACTER OF GRANITE Granites usually have been classed as igneous rocks derived from molten masses or magmas, but there is wide evidence that the origin of some granites may be attributed to regional metamorphism of preexisting rocks, rearrangement and recrystallization taking place without a liquid or molten stage. In any event granitization is a slow, deep-seated process.

Jan 1, 1956

By Oliver Bowles

Sandstone, a widely distributed siliceous sedimentary rock, is the third most popular building stone in the United States. It is formed by the breaking down of preexisting rocks by weathering, subsequent segregation of the detrital quartz grains into discrete deposits by the sorting action of water or wind, and finally cementation of the quartz sand into a coherent rock. The homogeneity and resistance to weathering of the resultant sandstone make it suitable for exterior construction. Its excellent wearing properties explain its popularity for flagging and stair treads. However, quarrying and dressing methods and costs are adversely affected by the abrasiveness and hardness of sandstone especially as compared to limestone.

Jan 1, 1963

By E. Chin

The only economically significant mineral exploited in Banglades - during 1981 was natural gas. Nitrogenous fertilizer production was important to the agricultural sector and was totally dependent on the natural gas for fuel and raw material. Domestic cement plants were also fu pled by natural gas. The flat river-delta terrain for most of Bangladesh makes the potential for discovering major mineral deposits poor. No large deposits of metal ores have been found and only in the small hilly southeastern section of the country is there even much chance of finding any. Heavy mineral sand deposits may eventually be exploited along the Chittagong coastline. There is a good potential for crude oil discoveries. The Bangladesh economy has been heavi¬ly subsidized by billions of dollars of foreign aid since the country's inception. A World Bank report recommended total aid needs of over $2.6 billion in fiscal year (FY) 1980-81. It received commitments for barely over one-half that amount.

Jan 1, 1983

By J. E. Murphy

The u.s. Bureau of Mines investigated electrode designs for electrowinning lead metal from a LiCl-KCl-PbCI2 electrolyte at 4500 C. The major objective of this investigation was to decrease the energy requirement for lead electrowinning. Electrolysis was performed in a bench-scale cell using several graphite electrode assemblies. Such parameters as electrode spacing, current density, and chlorine gas removal from the anode were investigated in the bench-scale tests. An optimum electrode assembly, termed the sawtooth design, was scaled up and operated at 3,000 and 4,000 A. The sawtooth electrodes operating at 3,000 A produced lead for 0.66 kW·h/kg. The electrodes were constructed by cutting large triangular grooves in the electrode surfaces. The electrodes were placed together such that the triangular peaks of one electrode projected into the triangular valleys of the other electrode. Chlorine did not build up on the anode with the sawtooth electrodes.

Jan 1, 1991

By David Bendersky

This report covers a technical and economic investigation of old electrical power systems, equipment and practices being used in the metal/non-metal raining industry. The principal sources of information were the MSHA District offices, visits to representa¬tive mines and mills, equipment manufacturers and the literature. A list of 85 mines and mills, submitted by the MSHA Districts as candidates for this study, is given and their characteristics are analysed. The electrical power systems and practices at the 10 mines and 9 mills which were visited are described. The principal areas which do not conform to standard electrical practices are discussed with emphasis on the safety aspects of these practices. The costs to update electrical power systems and practices in metal/non-metal mines and mills are given. The principal findings of the study are summarized and recommendations are submitted.

Jan 1, 1980

By George S. Rice

[This paper gives the details of tests to determine the design of stoppings capable of withstanding a pressure, applied to either side, of 50 pounds per square inch,6 as required by section 104 (a) of the Operating Regulations to Govern Coal-Mining Methods on Leased Lands on the Public Domain, issued in 1921 and quoted oil page 3. The regulations stipulated that the design for such stoppings must lie approved by the United States Bureau of Standards. The engineers of that organization felt that knowledge of the strength of such structures with respect to the effect of explosion pressure in comparison with static pressure and the strength of the walls which furnish the abutments was insufficient to justify drafting specifications; therefore, tests were needed to give information upon which a rational system of design could be based. A study was then begun; and several series of tests, made by the United States Bureau of Mines and the United States Bureau of Standards in cooperation, grave information upon which are based the detailed specifications offered in a later section. Slabs representing concrete stoppings, with and without reinforcement, were tested at the Bureau of Standards in Washington D. C.; afterwards, full-scale stoppings were tested at the Bureau of Mines Experimental mine near Pittsburgh. It was assumed that in most coal mines the strength of the floor and roof could not be relied on, but dependence must be placed upon the strength of the coal ribs. The tests developed that the maximum strength of an unreinforced concrete stopping was obtained when it acted as a flat arch buttressed against the coil ribs; but its ultimate strength depended upon the resistance to movement offered by the coal strata against which its ends were restrained or buttressed.]

Jan 1, 1931

By R. S. Dean

In addition to the normal work and that pertaining to strategic minerals, the Metallurgical Division has been made responsible for carrying on major investigations in the development of processes' for the treatment of low-grade domestic manganese ores that heretofore have failed to yield products suitable for the preparation of ferromanganese, an alloy essential to every ton of steel produced. These investigations are particularly important at this time because of their part in tucking this country self-sufficient with regard to manganese when the stock-piled ore becomes e exhausted and as foreign shipments of ferro-grade ore are cut off. The results indicate that there is a good probability of accomplishing this objective, while at the same time conservation may be promoted through the use of normally useless material from the large, low-grade ore deposits.

Jan 1, 1941

By Eugene H. Skinner

This Bureau of Mines report describes the fieldwork and subsequent analysis to determine physical properties, stress distribution, and several aspects of rock behavior as a necessary evaluation for a typical mine opening. All work was done at a test site on the 3300 level, Crescent mine, Coeur d'Alene mining district, Idaho. Free field stress beyond the influence of the opening was also determined. Conventional overcore technique with the three-component borehole deformation gage developed by the Bureau of Mines was used in three drill holes. Three field verification tests were performed using a gage newly developed by the Spokane Mining Research Center in an approach herein termed "initial deformation method." Use of this method validated that aspect of overcore theory which predicts that similar deformation effect occurs in the wall rock around the perimeter of an opening in rock under stress. Also described are all drilling procedures and performances. Physical property determinations were made on rock samples obtained from the three overcore drill holes. Twelve physical properties with a total of [532] values were obtained at various drill hole orientations and depths. Exhaustive statistical tests were utilized in the analysis of these physical properties. Further elaborated are statistical inferences based on these analyses. Extensive analysis and interpretation of Crescent mine geology are also described.

Jan 1, 1974

By J. E. Hamak

This publication contains analyses and related source data for 920 natural gas samples from 26 States and 2 foreign countries. All samples were obtained and analyzed as part of U.S. Bureau of Mines investigations of the occurrences of helium in natural gases of countries with free market economies. This survey has been conducted since 1917. The analyses published herein were made by mass spectrometer and chromatograph.

Jan 1, 1991

By Kray Luxbacher, Mario Karfakis, Erik Westman, Peter Swanson

Three-dimensional velocity tomograms were generated to image the stress redistribution around an underground coal longwall panel to produce a better understanding of the mechanisms that lead to ground failure, especially rockbursts. Mining-induced microseismic events provided passive sources for the three-dimensional velocity tomography. Surface-mounted geophones monitored microseismic activity for 18 days. Eighteen tomograms were generated and high-velocity regions correlated with high abutment stresses predicted by numerical modeling. Additionally, the high-velocity regions were observed to redistribute as the longwall face retreated, indicating that velocity tomography may be an appropriate technology for monitoring stress redistribution in underground mines.

By Damon C. Gray

This report contains a recommended program of acoustic research to be conducted by the U. S. Bureau of Mines. The program is directed toward the abatement and control of machinery noise in underground coal mining operations. The study conclusions and specific problem areas which led to the definition of the recommended program are also briefly described.

Jan 1, 1971

By Donald J. Ninteman

This Bureau of Mines publication is a literature study of the problem of spontaneous oxidation and combustion of sulfides in underground mines. It summarizes the present-day hazards, process mechanisms, and prevention and control techniques of this growing problem in underground mines. The iron sulfides generally have the greatest tendency to oxidize, particularly pyrrhotite. The presence of moisture and oxygen is essential for the oxidation reaction. Highly fractured sulfides, when found with timber or combustible refuse in slowly circulating air, pose the most serious fire hazard. Quenching with water is effective in quickly dealing with local hot spots, but ventilation at high flaw rates is the most effective and economical means for long-term prevention and control.

Jan 1, 1978

By Svend [Bue] Rondum

The final report contains a summary of the work performed under this contract, In addition to the report itself, other products were derived from this effort. Several hardware items were prototyped for use with underground belt conveyors, and a manual for installation and maintenance procedures was developed and published under separate cover. Recommendations have been included for implementation of the tools and the manual or, an industry-wide basis.

Jan 1, 1982

By Michael G. Zabetakis

Vaporization of a solvent into an airstream at temperatures above the flash point of the solvent is hazardous if vapor is liberated at a rate that is sufficient to produce a flammable mixture. In may operations, the formation of such a mixture is prevented by rapid diluton of the vapors with air. The minimum air requirements for the dilution process are determined by the composition of the lower limit mixture at the temperature and pressure of interest. Because limits of flammability cannot always be calculated with sufficient accuracy for a proposed operation, they .rust often be determined experimentally. The present Bureau of Mines investigation was prompted by an application in which the lower limits of flammability of a number of solvent mixtures were required over a range of temperatures at atmospheric pressure. These limits were to be used along with available solvent-vaporization-rate data to establish minimum airflow rates needed to prevent the formation of flammable mixtures in an industrial process. Lower limits of flammability were determined for a number of mixtures containing methyl ethyl ketone, tetrahydrofuran, toluene, ethyl alcohol, and ethyl acetate in dry air-at atmospheric pressure and temperatures between 16° and 200° C. The experimental values were found to be in good agreement at with those predicted by Le Chatelier's law; variations with temperature were in fair agreement with those predicted by a modified Burgess-Wheeler law.

Jan 1, 1962

WHY IS IT that smoke-abatement efforts do not bring more satisfactory results? The main reason is an incorrect estimate of the kind and size of the job. When an industrial community realizes that keeping the air clean is a project of similar magnitude to keeping streets clean, providing clean water, removing city waste, or guarding the moral atmosphere, then there maybe a real hope of success. We usually think of the project in too small terms. It is thought of as is the dog catcher or the boiler inspector--a matter of a man or two, a job or two, a small appropriation of variable and uncertain amount, to be abolished in a fit of economy and reestablished under pressure of a vigorous minority. Even so, it is surprising how much is obtained for the effort; but the community is rarely satisfied, for the job is bigger than it was conceived to be. Continuous, never-ceasing effort is required to clean up a smoky city. A few months of relaxation and the situation slips back some years of effort.

Jan 1, 1938