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By Hillary W. Clair

An equation is derived for the rate of reaction of a sphere of metal oxide in a restricted enclosure through which a reducing gas is flowing . The equation takes into consideration the reaction rate coefficient , transport through the gas and through the porous shell of reduced oxide , the rate of gas flow , and the volume of the enclosure . The equation serves as a model for predicting the course of reduction of a particle of metal oxide in a shaft furnace .

Jan 1, 1964

By David Schlain

The galvanic corrosion properties of titanium and zirconium were investigated by the Bureau of Mines. The dissimilar metals involved in these experiments included magnesium, magnesium alloy FS1, aluminum alloys, zinc, steel, tin, lead, copper, Monel, nickel, and several stainless steels. Couples were immersed in synthetic ocean water, tap water, 5-percent ammonium sulfate solution, 5-1/2-percent sodium chloride solution, sodium hydroxide solution, 0.1 N hydrochloric acid, and various concentrations of sulfuric acid.

Jan 1, 1956

By C. E. Hennig

On January 1, 1959, the United States had 313 petroleum refineries with a total installed crude-oil throughput capacity of 9,819,846 barrels per day, according to the Bureau of Mines annual survey. Compared with a year ago, this represents a net decreased of five in the number of slants mild a net increase in capacity of 412,139 barrels per day. The continued increase in total capacity and decrease in number of plants raised the average capacity of a refinery to a new high of 31,373 barrels per day. During 1958 total capacity increased in every refining district except the Louisiana Gulf district, which showed a 2-percent decrease due mainly to the retirement of the American Oil Company's plant at Destrehan, La. The largest increase, 14 percent, occurred in the Texas Inland district followed by a 12-percent increase in the Arkansas-Louisiana Inland district. At the beginning of 1959 the industry was building facilities that would add 108,400 barrels per day to crude-oil capacity. It also had under construction a capacity of 226,100 barrels per day as replacement. On January 1, 1959, no new refineries were under construction.

Jan 1, 1959

By Edward M. Kawenski

Tests were made in the Bureau of Mines Experimental Coal Mine on stop-pings similar to those used in operating coal mines to obtain information on air leakage through the face and the rupture strength of a stopping subjected to a pressure differential. Block stoppings were made from cinder, slag, and gravel aggregates with and without mortared joints and coatings. Sheet stop-pings were uncoated brattice cloth and nylon or brattice cloth and expanded metal-lath coated with asphalt, latex, mortar, or rigid urethane foam. Limited data were obtained on air through stoppings subjected to simulated roof convergence and to shock forces created by the firing of an adjacent charge of explosive. The pressure differential required to rupture stoppings was determined. shows that coating the face of a stopping effectively reduces ail: leakage. Block stoppings, particularly those with mortared joints, are most resistant to pressure and shock forces than are sheet stop-pings. Where ground movement is a factor, sheet stoppings leak less air than block stoppings.

Jan 1, 1965

By William H. Pomroy, Annie M. Carigiet

This U.S. Bureau of Mines publication is an analysis of underground coal mine fire incidents occurring in the United States during the 15years from 1978 through 1992. The fire data used in this analysis were obtained from U.S. Mine Safety and Health Administration mine fire investigation reports. Fires were analyzed by year, State, coalbed thickness, mine size, mining method, ignition source, burning substance, location, equipment involved, detection method, time of day, time of year, number of injuries and fatalities, method of extinguishment, and evacuation measures taken. In all, 164 fires are included in this report, or an average of 10.8 fires per year. The most fires occurred in West Virginia, Kentucky, and Pennsylvania, respectively. However, the fire incidence rates for these States, expressed as the number of fires per million tons of coal mined, were the lowest, second lowest, and fourth lowest of all underground coal producing States. The most common ignition source was electricity; the most common burning substance was coal; the most frequent fire location was the belt entry; the most common equipment involved in fires was the conveyor belt; and the most common extinguishing agent was water.

Jan 1, 1995

By Robert L. Crosby

The Bureau of Mines investigated the substitution of cement copper powder for commercial copper powder in an Fe-7 pct Cu-l pct C powder metallurgy alloy. Copper powders from six different commercial cementation operations were separately upgraded by screening and hydrogen reduction. They were then mixed with commercial iron and graphite powders to form the Fe-7 pct Cu-l pct C alloy. Various chemical and physical properties were determined on the upgraded cement copper and the alloy powders. Mechanical, physical, and chemical properties were determined on green and sintered specimens made from the alloy powders. Mean tensile and bending strength of sintered specimens were significantly lower than the means from specimens made from commercial metal powders. The lower strengths are apparently related to poor sinterability.

Jan 1, 1970

By Noel N. Moebs

Studies by the Bureau of Mines have identified geologic structures in mine roof rock that contribute to many roof falls in Appalachian coal mines. These structures, including paleochannels, scours, pinchouts, slickensides, clay veins, crevasse splays, and joints, can often be identified during, and sometimes before, mine development. Mine projections can be revised to reduce the adverse effects of discontinuitites in roof structure; large roof areas of laminated sandstone or incompetent strata generally can be delineated or inferred from exploratory drill hole data, and the need for supplementary support can be anticipated. Accurate descriptions of roof geology also provide some indication of optimum length and type of roof bolts that should be installed.

Jan 1, 1981

By C. B. Strachan

The Mascot concentrator treats 1,900 tons of zinc ore per day by gravity concentration and flotation. During the year 1929 the heads averaged 2.90 per cent zinc, and the recovery was 90.15 per cent; the concentrates produced contained 60.19 per cent zinc. ACKNOWLEDGMENT Acknowledgment is made to M. H. Newman, geologist, Robert Ammon, chief metallurgist, D. B. Grove, mill superintendent, and W. A. Calhoun, metallurgical clerk for assistance in the preparation of this paper.

Jan 1, 1930

By Michael S. Miller

In 1985, at the request of the Bureau of Land Management, the Bureau of Mines studied a 50,57U-acre portion of the 90,345-acre Twin Peaks Wilderness Study Area (CA-020-619A) in order to evaluate its identified resources. The area studied is located about 45 miles northeast of Susanville, CA, in Lassen County, CA, and Washoe County, NV. The area is underlain by Tertiary volcanic, volcaniclastic, and intrusive rocks. Quaternary stream, lake, and landslide deposits overlie the older rock. There are no mines or mining claims in the study area. One mineral resource, pozzolan, was identified. Mining claims, inactive in 1985, have been staked adjacent to or near the northwest corner of, and also southeast of, the study area. Examination and sampling of 17 mineralized sites, delineated mostly by prior geochemical surveys, showed at least 30 million tons of subeconomic pozzolan resources and small or low-grade occurrences of gold, silver, copper, lead, zinc, nickel, molybdenum, zeolites and clay.

Jan 1, 1986

By Jerome J. Hoeppner, Walter W. Fowkes

The Federal Bureau of Mines has determined the distribution of forms of sulfur for several lignites and gasification chars and noted the changes induced by the gasification process . A method was adopted for quantitatively determining sulfide sulfur that was found to be present in the chars , although absent in the lignites . Changes in the behavior and distribution of sulfur forms were further investigated concerning the ashing of lignites and chars under standard conditions , as well as at various temperatures , and the determination of volatile matter applied to both chars and lignites . The authors concluded that the first and greatest change in the form of sulfur present in natural lignite , upon heat treatment , resulted from the reduction of pyritic and sulfate sulfur to sulfide . Organically - bound sulfur originally present is less reactive , but largely disappears on strong ignition . An appreciable part of the sulfur content of natural lignite is fixed in the char as sulfide and in the ash as water - soluble sulfate and will affect the summation of constituents , to a greater or lesser degree , in reporting the ultimate analysis of a lignite or char .

Jul 1, 1960

By Paul Zinner

An exhaustive program of geologic studies and mapping has been conducted by the Geological Survey in the Iron River district of Michigan since May 1943. Means of contributing to the success of these studies were sought by the Bureau of Mines, and eventually a program involving geophysical studies and core-drilling was undertaken in the area. All of the work was done either to develop data that would contribute directly to geologic studies or to investigate geophysical methods that might be used as a primary means for the discovery of minable iron ore.

Jan 1, 1949

By C. H. Elder

Two degasification test boreholes were drilled to depths of 1,238 and 1,212 feet on Bureau of Mines property at Bruceton, Pa., as part of the Bureau's long-range coal degasification program. The holes provided detailed geologic information and geologic sections, which were correlated with regional stratigraphic cross sections prepared by the Pennsylvania Geological Survey. Gas content determinations and coal analyses were made on the Upper Freeport, Middle Kittanning, Clarion, Brookville, and Mercer coalbeds; gas content of the coalbeds ranged from 53 to 165 cubic feet per ton. Formation pressure and gas flow tests were conducted on selected coalbed intervals in borehole 1; formation pressures ranged from 292 to 473 psig. The middle Kittanning coalbed was hydraulically stimulated using very heavy gelled water, but gas production remained low because gel residue and formation water inhibited the flow of gas. Gas contents in the Clarion, Upper Brookville, and Mercer coalbeds were anomalously low owing to the proximity of porous sand-stones which act as reservoirs for gas migrating from coalbeds.

Jan 1, 1977

By George Saliba

This report disucsses the formulation of a mathematical model for the steering of a conveyor belt by a flat return idler and a troughed idler under various loading conditions. Significant parameters associated with belt training are identified. The generation of a skewed flat return idler model in terms of a steering force and self-aligning torque is presented. Development of the mathematical model for the flat return steering idler is illustrated for the case of no circumferential slip occurring and for the assumption of a bidirectional slip mechanism. Experimental results supporting the theoretical analysis is presented.

Jan 1, 1977

By A. D. Bauer

For several years the Bureau of Mines has conducted surveys to determine the changes in motor gasoline being sold throughout the United States. The present survey shows that far the districts in which samples were collected, the average gasoline is becoming more volatile instead of less so, as is sometimes supposed. This year's gasoline is much more volatile than that sold two years ago, and it has a somewhat better distillation range than last summer's samples. A comparison of the average figures for several years, shows that motor gasoline is also becoming more uniform in character. The large seasonal change is disappearing, but ?winter gasoline', still has a lower initial boiling point than "scanner gasoline". This difference in volatility is made intentionally to facilitate starting the motor in cold weather. The end point shown in the present survey is slightly lower either than that of last winter or of the summer of 1921.

Jan 1, 1922

By E. R. Palowitch

A centrifugal float-and-sink test procedure has been developed by the Bureau of Mines to reduce the time for the gravimetric separation of coals finer than l4-mesh from as long as 24 hours to less than 1 hour. Comparative tests indicated that centrifuging a minus 14-mesh Pittsburgh-bed coal for 20 minutes at 1,500 revolutions per minute produced results that compared favorably with static float-and-sink test results. Standard deviations of the mean recovery and ash content of the float obtained centrifugally ranged from 1.31 and 0.04 percent, respectively, at 1.30 specific gravity to 0.21 and 0.05 percent, respectively, at 1.60 specific gravity. As in static separations, retreatment of the products separated at low specific gravities was required.

Jan 1, 1961

By R. W. METCALF, A. G. Charles, F. M. SHORE

To furnish the information frequently requested by producers and suppliers as to the fuel requirements of the Federal Government , the Bureau of Mines , with the cooperation of the consuming departments and establishments , has collected the data herein , showing the Government's fuel consumption during the fiscal year ended June 30 , 1930. The following tables show the quantities and kinds of fuels consumed by the Federal Government in each of its departments and their principal branches , in each State , and in Alaska , Hawaii , Panama Canal Zone , Porto Rico , and the Virgin Islands . The separate departments and establishments were asked to supply information for each Federal building or other plant and , as to vessel fuel , the amount loaded at each port of supply . Fuels consumed in internal combustion engines are not included . The report does not include fuels used by Post Offices of the fourth class , since their fuels are not purchased by the Federal Government but are covered by an allowance in each case for light and heat . In some cases the data supplied represent receipts , which are approximately equivalent to consumption . The present study is believed to be the first effort to bring together the data representing the Government's requirements for the various fuels which it consumes . Figures showing the coal consumed by the Federal Government were gathered for the year 1922. These data are shown in an article by O. P. Hood and R. H. Kudlich of the Bureau of Mines , contributed as a chapter to " Industrial Coal ; Purchase , Delivery and Storage , " published by the American Engineering Council . The figures of coal consumption presented herewith are approximately comparable with those published for 1922 , a relatively small difference being due to the fact that the 1922 figures include the Philippine Islands and all other territory in which any coal was consumed by the Government . At the present time , the only data on Government fuel consumption that are published regularly are those compiled by E. B. Swanson , chief economist of the petroleum economics division of the Bureau of Mines . These are published annually by the Bureau of Mines in " Sources and Distribution of Major Petroleum Products , Atlantic Coast States , " and by the bureau in cooperation with the American Petroleum Institute in the annual " National Survey of Fuel Oil Distribution . " It is believed that the data herewith will prove of interest and value to the fuel industries as well as to Government consumers and that it will also afford a basis for measuring future trends in the use of the various fuels by the Federal Government . Figures showing the quantities of the various kinds of fuels consumed by each of the executive departments and independent establishments , are given in Table 1. It should be noted that when one organization procures and delivers fuel to be consumed by other branches

Apr 1, 1932

This report discusses the nonfuel critical minerals position of the United States-both current and future (to the year 2000). We have assumed that there will be no major global disturbances-military, political, or economic-during the rest of this century. However, international relationships, strategies, and conditions that affect the supply of minerals are very tenuous, normal trading patterns can be easily upset, and national and ideological objectives can and do interfere with "normal" free market conditions. For example, the Department of Defense has reported that the Soviet Union is engaged in a strategy designed to reduce the availability of strategic minerals, through either physical disruption, market manipulation, or domination of producing or neighboring states. Although such a strategy poses serious concerns for the United States and the free world, the impacts of disruptions are not covered in this publication. Historical Perspective The modern industrial economy of the United States is founded on the production and use of minerals.* Two hundred years ago our forebears began taming a raw continent, developing a base for agriculture and a rudimentary minerals producing system. In the 19th century, with the aid of imported labor and capital, the development of America's vast natural resources was undertaken, and the transition from an agricultural to industrial society was underway. By the century's close, the United States had emerged as a great industrial power, partly through the development of such mineral resources as iron in Minnesota and coal in Pennsylvania.

Jan 1, 1983

By Michael R. Kennedy

This report describes the demonstration of longwall mining in a seam dipping 27 to 34'. Equipment was selected on the basis of capability, compatibility, and co t. Snowmass, Bureau of Mines, consultants and manufacturers were involved in the selection process. The equipment arrived in early 1981, prior to completion of development for the first panel; therefore, the equipment was operated on the surface for training. The surface training paid off with a fast, efficient installation and start-up of the face. The longwall equipment operated very well on the steep pitch with an average equipment downtime of 21.9[9]. Coal handling outby the face was a problem which caused an additional downtime of 19.5%. Development for the panels proved to be the major problem in the economics of longwall mining on a steeply dipping seam. During the first 9 months of operation the longwall averaged 71.9 TPMS and development averaged 0.6 TPMS for an overall average of 14.1 TPMS. Had mining continued, timing of development would have been another major problem. Monitoring of subsidence, pillar stability and shield loading was done in connection with mining, but little useful information was gained from the monitoring.

Jan 1, 1987

By E. Morrice

This report of the Federal Bureau of Mines presents a laboratory procedure, with the requisite equipment, for electrowinning ingot (liquid) cerium metal from a fused-fluoride bath, the metal purity being about 99.9 percent. Physicochemical studies, including bath properties and electrochemistry, are included, with a speculative model of the mechanisms involved. An historical review of the methods used for electrowinning misch metals and yttrim-group metals, as well as individual rare-earth metals, is presented. The electrolytic preparation of metal from fused salt and nonaqueous media is summarized, along with the unsuccessful attempts at depositing the metals from aqueous solutions.

Jan 1, 1961

By R. D. Leitch

Tests have recently been conducted by the Bureau of wines on the ignition hazard of exposing heated filaments of electric mine lam bulbs in an explosive mixture of methane and air. This investigation was undertaken in order to settle a question that had arisen in connection with the safety of miners? electric lamps. For several years, in view of former studies made by the Bureau and reported in Bulletin 524, the fact that the heated filaments of even low voltage, lour candlepower bulbs constitute a danger was generally accepted by the Bureau's engineers. These early tests, as well as subsequent tests, were conducted with Pittsburgh natural was as the testing medium.

Jan 1, 1925