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By A. C. Fieldner

In the course of its investigations on the properties of coal and in rendering fuel-inspection service to other agencies of the Government, the Bureau of Mines has accumulated a comprehensive file of coal analyses that includes data on virtually every coal field of commercial importance in the United States. As knowledge of the composition of coal is potentially valuable to every user of coal, the Bureau publishes its analytical records. Before 1921 such publications contained analyses of coal from all parts of the United States; individual analyses or average analyses of a series of shipments of coal were given with the name and location of the mine producing the coal. Beginning in 1921 the analyses were published by separate States because the quantity of data had become so great. The separate papers published to date, with Bureau of Mines Technical Paper numbers, are as follows: Alabama, 347; Arkansas, 416; Colorado, 574; Illinois, 634 and 641; Indiana, 417; Iowa, 269; Kansas, 455; Kentucky, 30S; Maryland, 465; Missouri, 366; Montana, 529; New Mexico, 569; Ohio, 344; Oklahoma, 411 ; Pennsylvania (bituminous), 590; Tennessee, 356; Utah, 345; Virginia, 365; Washington, 491 and 618 (618, published in 1941, supplements 491); West Virginia, 405 and 626; and Wyoming, 484. From time to time the various papers will be revised to include later analyses and other data. The Bureau of Mines annually receives many inquiries as to the composition of coals obtained from specific localities or, conversely, as to the localities from which a given kind of coal may be obtained. This paper presents a summary, in tabular form, of the composition of commercial coal resources of the country. Specimen analyses are given exemplifying the analysis of coal mined in each coal-producing county, or, where it was feasible, coal from each bed in each county; also, ranges of analyses, within which the composition of most of the coal represented will fall, are given where there were enough analyses to permit satisfactory determination of the ranges. In addition, the degree of metamorphism from lignite toward anthracite of much of the coal is indicated by the classification by rank. This classification reveals to more experienced users of coal some of the general properties of coal, that is, whether the flame will be long or short, whether the coal will cake in the fire, and how it is likely to behave on exposure and in storage.

Jan 1, 1942

By C. A. Herbert

In summer, when hot, moisture-laden air enters a coal mine in the region east of the Mississippi River, the moisture is likely to condense on the roof and ribs because the incoming air is cooled below its dew point upon contact with the roof, ribs, and floor of the mine passageways. When the roof and ribs become wet owing to this condensation they are said to "sweat." In many mines, as soon as this sweating begins, shale or slate roof that appears solid and strong in winter begins to cut and fall. For a long time most mining men believed (many still believe) that the roof trouble was due to this sweating. However, from observation of conditions in one mine the operators concluded that the trouble was caused by expansion and contraction of the roof due to changes of temperature. This opinion was confirmed by experiments at several mines in cooling the air as it entered the mines. Methods used in these mines for cooling the air are described in this circular. MINE A At mine A the roof gave considerable trouble in the summer, and it was observed that where a spray of water from a leaking dam kept the roof wet and at a uniform temperature no difficulty was experienced with the roof, although it had cut and fallen on either side of that point. From this fact the company officials concluded that changes of temperature in the air rather than moisture caused the trouble and that if the incoming air were cooled to approximately normal strata temperature much of the additional roof trouble experienced during the summer would be overcome.

Jan 1, 1940

By G. R. Hopkins, E. W. COCHRANE

According to reports received by the United States Bureau of Mines , Department of Commerce , as of January 1 , 1930 , there were 412 completed refineries in the United States with a daily crude oil capacity of 3,755,585 barrels . This compares with 413 refineries of 3,509,540 barrels capacity on January 1 , 1929 , which indicates that whereas the number of refineries was practically unchanged , the total capacity increased 8 per cent during the past year . Of the completed plants as of January 1 , 1930 , 358 plants , of 3,634,825 barrels total capacity , were operating and 54 , with a capacity of 130,760 barrels , were shut down . Compared with a year ago , this indicates a decline in the percentage of the total refinery capacity that is inoperative . There has been a decided decrease in the number of shut-down plants since 1924 and 1925 , when one plant in every three was inoperative . Many of the inoperative plants of 1924 and 1925 were constructed soon after the boom times of 1920. Some of these were operated for a time but were unable to show a profit during 1923 and 1924 , when an overproduction of crude petroleum was accompanied by demoralized markets for refined products . Prices for refined products improved in 1925 and 1926 , but only a comparatively few of the shut -down plants , then partly obsolete , were able to obtain or renew their crude connections and compete successfully with the larger , more firmly established refineries . After five years or more of continuous idleness , a refinery would be rendered practically useless through corrosion and obsolescence . Consequently , most plants now being carried as " shut -down " have operated intermittently since 1923 . struction . A material change occurred in 1929 in the matter of plants under con- On January 1 , 1929 , there were 14 plants under construction , with a potential capacity of 99,000 barrels per day , whereas on January 1 , 1930 , there were only eight plants of 37,200 barrels capacity being built . This decline was due to the fact that the construction program in west Texas , which was at or near its height on January 1 , 1929 , was completed prior to January 1 , 1930 .

Apr 1, 1930

By J. C. LaScola

Development of methanometers and anemometers for underground use in coal mines is reviewed. The first semicontinuous recording methanometer was developed in 1961 in West Germany. The Bureau of Mines developed an instrument using; pellesters that was a continuous recording methanometer. Expansion of freon gas created a vacuum which pulled the methane-air mixture through a tube to an electrically heated, catalyst-impregnated pellester where the mixture was burned. The National Coal Board of England developed a continuous recording methanometer based on the principle of the Davy flame safety lamp. A thermo-pile was used to sense the hurt output of the flame. Finally the Bureau of Mines improved its methanometer by eliminating the freon gas and using a diffuser head to a monitor methane-air mixtures. Development of recording anemometers proceeded from the use of a photo¬cell and light source to sense rotation of the Biram-type anemometer blades to the use of a Hall detector to sense, rotation by measurement of electromagnetic pulses.

Jan 1, 1969

By A. W. Ambrose

"Those having an intimate knowledge of the relation between production and consumption of crude oil in the United States have realized for some time that production will not be able to keep pace with consumption. The American public has had this called forcibly to its attention by the increased prices of gasoline and crude oil, and by the recent shortage of gasoline on the Pacific Coast. In substance, each year we are consuming millions of barrels of oil more than we produce, and this deficit must be made to by importations. A careful analysis of the situation makes it evident that we need every barrel of oil that can be produced.Need for the Petroleum Production Engineer.Under present production practices perhaps 80% of the oil still remains in the sand. (See Lewis, J.O., Methods for increasing the recovery from oil sands, U. S. Bureau of Mines, Bulletin 148 p. 8.) Many wells are making water, and even whole pools are being flooded. The burning of fuels under field boilers is not generally efficient, and often gas is not made to do its full duty in bringing the oil to the well.In the past the producer has had to combat these and other problems single-handed. He has been too busy to give them special attention, and he has had little competent engineering advice. Oil, gas, and water occur underground according to certain natural laws. Undoubtedly an engineer, who is familiar with production practices and understands the fundamentals of the accumulation of oil and gas, can be of service to the producer by specializing on certain problems with a view of getting mare oil from the sand. In every other enterprise of similar magnitude the engineer is regarded as a necessary unit to its operation, and he should be so in the production of oil. His field of work should extend to every phase of production in which science and engineering and geology"

Sep 1, 1920

By W. G. Sandell, L. C. Bauerle, K. C. Dean

"INTRODUCTION As a part of the wartime activities of the Bureau of Mines, metallurgical services were extended to other Government agncies engaged in purchasing and stock-piling some of the more critical and strategic materials. At the request of Dr. Alan M. Bateman, special representative of the Metals Reserve Company, metallurgical studies were made on three samples of oxide tin ore from, the States of Zacatecas and Guanajuato, Mexico. The samples were submitted for testing by A. Porraz of the Financiera Miners, S. A., institution Financiera, Edificio Guardiola, Despachos 500-507, Mexico, D. F.The samples as received were marked Nos. 1, 2, and 3 and described as follows:Sample 1. - Origin: Mining camp ""El Naranjo,"" municipality of Sombrerete, State of Zacatecas, Mexico. This sample was partly concentrated by washing and as received was all minus 10-mesh in size.Sample 2. - Origin: Deposits in Sierra. Fria and Juan Cherey, municipality, of Jerez,State of Zacatecas, Mexico. This sample represented run of-mine ore.Sample 3. - Origin: Mine ""La Frontere, "" Ranch of San Pedro del loya, State of Guanajuato, Mexico. This run-of-mine sample was low in tin content but came from a highly mineralized tin field."

Jun 1, 1947

To provide cooler air to miners working in hot areas of mines, particularly new deep hardrock mines. Approach Air supplied to hot working areas of mines is cooled by passing it through a series of water sprays. How It Works Water nozzles mounted inside a section of ventilation tubing release cooling sprays of water into the air being blown through the tube. The prototype of the water spray cooler consists of six evenly spaced water sprays located inside a 10-ft. long section of 16-inch-diameter fiberglass ventilation tubing. See diagram. This section of rigid tubing is installed into one of the positive pressure ventilation tubing lines that conduct fresh air into working stopes. The intake manifold to the six water sprays is connected to the mine?s cool water line, and the water valve on the manifold is opened. Warm ventilation air being supplied to the stope passes through the water sprays, and is cooled by the lower temperature water.

Jan 1, 1979

By Eugene T. Sheridan

The process of converting coal into coke is known as carbonization. Essentially, carbonization is destructive distillation in which the volatile matter of coal is released when coal is he ted above its decomposition temperature and passes through a plastic stage before solidifying and forming coke. The mechanics of coke formation are complex, and the specific properties of certain coals that tallow them to "cake" or form coke are still unknown. Coke is a hard, cellular, carbonaceous mass, formed by heating coal in the absence of air. It is porous, irregular in size and shape, and is similar in appearance to wood charcoal. Coke, however, is denser, more porous, and more abrasive than charcoal.

Jan 1, 1965

By Charles L. Harnes

A mineral pigment is a colored substance dug from the ground, which after treatment can be mixed with a drying oil to form a paint. Not all colored earths, however, can be made into satisfactory pigment. Much depends upon the attractiveness and uniformity of the color and the ease of purification. Mineral pigments are distinguished from chemical pigments by a difference in origin and treatment. Chemical pigments are not found ready-made in the earth but must be synthesized or otherwise obtained from other compounds or elements; for example, cadmium yellow, a chemical pigment, is precipitated from a solution of cadmium chloride, hydrochloric acid, and sodium sulfide.

Jan 1, 1942

By J. I. Paige

The effect of fluoride inclusions on the properties of titanium produced from the Bureau of Mines developed induction slag melting process is of concern to members of the titanium industry. The objective of the research was to determine the effect of CaF2 inclusions on the properties of titanium and its survival rate during melting. The data were obtained from single induction-slag-melted ingots prepared with the normal addition of 4 pct and also with 2- and 1-pct additions of CaF2 slag. The results of this effort showed that the mechanical properties of single-induction-slag-melted Ti-6Al-4V alloy exceed the minimum values specified in Aerospace Materials Specification for Titanium Alloy Bars and Forgings AMS4928H, but these materials are much more notch sensitive in fatigue than normal Ti-6A1-4V alloy titanium. First and second vacuum-arc remelts of single-induction-slag-melted ingots fragmented and increased the number of inclusions, while reductions in the amount of flux resulted in an upward trend in the spatial distance between pores in an x-y plane.

Jan 1, 1988

By Joseph M. Kurtak

The U.S Bureau of Mines conducted a five-year mineral resource assessment of the 16.6 million acre Colville Mining District in northern Alaska, which includes part of the National Petroleum Reserve in Alaska. The study was initiated at the request of the Bureau of Land Management, which administers the majority of the region. The study was done in cooperation with the Alaskan Division of Geological and Geophysical Surveys, the U. S. Geological Survey, and the University of Alaska. During fieldwork, 1593 rock, soil, and stream sediment samples were collected and four bulk samples taken for beneficiation studies. A total of 40 mineral occurrences were documented, including 27 which were previously undescribed. No mining has occurred within the district. Mississippian carbonaceous shale and siliceous mudstone contain stratiform exhalative lead-zinc-silver occurrences. Grades average 8.0% combined lead/zinc and 51 gm/mt silver. Upper Devonian to Lower Mississippian sandstones host breccia veins, containing up to 29% combined lead/zinc and 274 gm/mt silver. Mineralized quartzites of similar age have potential for disseminated-type lead-zinc deposits. Samples from Lower Cretaceous mudstone and shale beds up to 6.5 meters thick, contain as much up to 12% manganese. Upper Mississippian carbonaceous shale and limestone beds contain up to 23% phosphate. Stratiform barite deposits hosted by cherts, are up to 27 meters thick with an average specific gravity of 4.16. Vein-type fluorite occurrences are associated with Mississippian limestone. Moderate potential exists for development of zinc -lead-silver, barite, and phosphate deposits.

Jan 1, 2011

By Andrew B. Cecala

This U.S. Bureau of Mines report provides a detailed description of the Bureau-designed modified shearer clearer system. Engineering drawings are provided for all major components of this system. The modified shearer clearer system is a revised version of the original system and is intended to improve the ventilation around both cutting drums. The original shearer clearer technique was solely a dust control technique that has been effective in lowering shearer operators' dust exposures. The technique uses a series of water sprays that not only knock down a portion of the dust cloud but also act as small fans that move a substantial amount of air and keep the dust cloud from dispersing over the shearer body. The modified version is composed of two additional spray blocks for improved air movement around both cutting drums, thus lowering methane levels and the likelihood of an ignition. A laboratory study performed with the modified version in a full-scale longwall gallery resulted in a 73-pet reduction in methane concentrations at the shearer machine for both cut directions. The air-moving capabilities of the system provide more turbulence at the cutting drums and reduce methane levels.

Jan 1, 1994

By Allen L. Frank

A portable radon diffusion chamber has been tested with electrical collection of the radon daughter nuclei for enhancement of sensitivity. The detector size was small enough to be worn suspended from the belt. With a battery-supplied high voltage the sensitivity was found to be 1.43 tracks/cm2 per pCi-hr/l of ambient radon at Sot relative humidity. The track densities on the surfaces of the CR-39 plastic nuclear track detectors were found to be non-uniform, making difficult the determination of average densities with high accuracy. The fabrication of electrets for use in the detector was investigated in accordance with published techniques with negative results.

Jan 1, 1983

By Michael W. Redifer

A Fortran IV computer program was developed to calculate the composition at equilibrium of products from a set of high-temperature gas combustion reactions. The program was used to develop high-temperature equilibrium concentration profiles for various constituents as a function of temperature and oxygen concentration. The computer program was specifically applied to reactions pertaining to the corrosion of superheater tubes in pulverized coal-fired boilers; however, it is useful for any multicomponent, multireaction scheme in which equilibrium constant data can be obtained and is comprised of gaseous reactants along with finely dispersed solids or liquids. General applicability of the computer program, including its limitations, are discussed along with detailed instructions for using the program.

Jan 1, 1973

By R. G. Knickerbocker, C. T. Baroch, A. W. HACKWOOD

The difficulties inherent in the production of alumina by the formation of potassium alum and its subsequent thermal dehydration and decomposition have been overcome , to a large extent , in a process developed at the Boulder City Station of the Bureau of Mines . This process is applicable to the reserves of alunite known to occur in several Western States and , possibly , to certain clay and low-grade bauxite deposits known to exist in this country . The operations sequence of the process is shown in the flow sheet (fig . 1) . Only those steps included within the heavy line are considered in this report . Four different procedures for dehydration of alum were investigated ; ( 1 ) Spray drying , ( 2 ) rotary - kiln drying , ( 3 ) dry grinding in a thermal ball mill , and ( 4 ) dehydration in the vertical- column flash dehydrator . Based upon fuel requirements and other practical considerations , the vertical- column dehydrator , or some modification of its operating principle , offers the botter possibility for commercial use .

Feb 1, 1946

By Herbert Tomlinson

The United States Bureau of Mines has engaged in a study of the conditions under which coal mine accidents, resulting in the loss of life, limb, or time to the injured person, occur from falls of roof and coal. This publication is devoted to the results of a study conducted in the coal mines of the Book Cliffs and Wasatch Plateau coal fields of Utah. To show the necessity of this study, a statement of the fatalities that have occurred during the period 1928-1930, inclusive, in the bituminous mines of the United States and of Utah, is presented (Table 1), followed by a brief description of this Utah district, its coal beds and immediate roof, thickness of cover, dip of coal beds, methods of mining, supervision, roof testing and timbering for roof support, all of which are factors in any plan devised for preventing accidents from falls of roof and coal.

Jan 1, 1932

By G. E. McElroy

The purpose of tins paper is not to present new date on the pressure losses due to bends and chances of area in mine openings through which air flows, but rather to correlate existing data, determined mainly on small duct systems and expressed in a variety of ways, according to uniform methods that facilitate their use in pressure-loss computations. These are required in such, air-flow problems as determining the quantity that will flow through is mine openings under a certain pressure difference or, conversely, the pressure difference that will be required to maintain a certain rate of flow. Air flowing through h ducts, such as mine airways, encounters resistance to flow due to interference of the individual air streams with each other caused by the wall surfaces. The result is that part of the kinetic energy of the flowing stream is converted to heat; and constant renewal of the kinetic energy from the total energy of the flow is required to maintain it. This process manifests itself by a decrease of the total pressure (static pressure plus velocity pressure; of the air in the direction of flow; in order that flow pray occur, there must necessarily be a differences in total pressure between the two cads of the air-ay equivalent to the pressure losses occasioned by the flow, which automatically adjusts itself in magnitude to the pressure difference maintained.

Jan 1, 1932

By Forrest T. Moyer

The safety record of the metal mining and milling industries in 1965 is reviewed by the Bureau of Mines. The overall injury-frequency rate of 23.77 per million man-hours was 5 percent lower than in 1964 and was the lowest annual rate in a statistical history beginning with 1931. The injury-severity rate of 3,521 days lost per million man-hours in 1965 represented a 5-percent improvement over 1964. However, the total of 3,825 disabling work injuries comprised 61 fatal and 3,764 nonfatal injuries, one and 92 more, respectively, than in 1964. At primary nonferrous smelters, refineries, and reduction plants, the injury-frequency rate of 8.97 per million man-hours in 1965 was 13 percent lower, but the severity rate percent higher than in 1964. these plants in 1965, 4 more of 1,173 days lost per million man-hours was 17 There were 12 fatal and 971 nonfatal injuries at and 28 fewer, respectively, than in 1964.

Jan 1, 1969

By Paul W. Johnson

A computer program for calculating capital and operating costs from material and energy requirements and equipment costs for use in preparing cost estimates for metallurgical process evaluations has been written by the Bureau of Mines' College Park process evaluation group. The program permits rapid recalculation of processing costs when changes of data or equipment are desired, and produces tables of capital and operating costs suitable for publication. Equipment cost summary tables for each process section end supplemental information for input-data checking is included in the computer printout. The program is written in Fortran IV except for several subroutines which are written in machine assembly language for the IBM 7094.3 With a few modifications, the program can be used on other computers.

Jan 1, 1969

By A. Visnapuu

The Bureau of Mines has upgraded high-iron domestic chromite concentrates by a carbonyl process. The upgraded chromite concentrates show as much as 10 wt pct higher Cr203 content and up to a threefold in-crease in the Cr:Fe ratio, compared with the starting concentrates. The high-iron chromites were first reduced to convert the iron oxides to the metal, and then treated with CO at elevated pressures and low temperatures to convert part of the metallic iron fraction to iron pentacarbonyl. Carbonylation was accelerated by the addition of H2S in small quantities. The iron pentacarbonyl was extricated from the con-centrate in the pressure reactor during carbonylation by a CO sweep through a pressure-reducing valve and passed through a decomposer at atmospheric pressure to convert it back to iron metal and CO. CO pres-sure, temperature, promoter trends, and other factors enhancing iron pentacarbonyl formation are presented.

Jan 1, 1985