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By J. B. Clemmer

Fluorspar is one of the most important nonmetallic minerals and is used extensively in the metallurgical, ceramic, cement, and chemical industries. The steel industry consumes most of it, but as the Mineral is the chief source of fluorine, it is becoming increasingly valuable to the chemical industry in the production of fluorine compounds. The development of nontoxic organic fluorides for use as refrigerants in mechanical refrigeration and air-conditioning units illustrates the increasing use of fluorspar in the chemical industry. Most domestic flurospar comes from deposits in the Illinois-Kentucky district, which centers around Rosiclare, Ill. About a dozen companies operate in the district, which comprises parts of Pope and Hardin Counties in southern Illinois and Crittenden, Livingston, and Caldrell Counties in western Kentucky. According to the latest available statistics, this district supplied 165,960 short tons of fluorspar in 1937, compared with the total domestic production of 151,230 tons. Imports totaled 37,063 tons.

Jan 1, 1939

By J. T. Dunham

The Bureau of Mines studied by dilatometry the effect of titanium on the thermal expansivity of hot-rolled zinc and Zn-l percent Cu alloy. The titanium content of the alloys was varied up to 0.3 percent. Expansion coefficients were determined from measurements made both parallel and perpendicular to the plane of the rolled sheet. Titanium reduced expansion parallel to the plane of the sheet, especially in the rolling direction, but increased expansion perpendicular to the sheet. Basal-plane pole figures showed that the degree of preferred orientation increased with the titanium content in the alloy, and that anisotropic expansion can be correlated to sheet texture.

Jan 1, 1965

By Mark Sheppard

This paper is the third of a series recording the results of tests made at various quarries throughout the United States to determine (1) the relation between the size gradation of feed to, and product from, primary crushers, (2) the particle shape of the crushed product, (3) the differences in gradation and particle shape produce- by different types of primary crushers, and (4) the differences in gradation and particle shape caused by crushing different kinds of stone. Progress reports 1 and 2 dealt with comparisons of different types of crushers crushing the seine tyre of stone. This report deals with relationship between feed and product of two different limestones, as to size distribution and particle shape, when crashed in the same crusher.

Jan 1, 1938

By John H. Hild

This is a report on work done and results obtained in a minerals exploration program conducted by the Bureau of Mines on the lead-zinc deposits in the Ross Basin-Lake Como district, San Juan County, Colo., in 1948, 1949, and 1950. Four large veins--the Seven Thirty, Red Rogers, Cashier-Shorts top-Canandaigua, and Queen Anne--and several narrow spur veins were explored at relatively shallow depths with core-drill holes. Thirty-nine holes, totaling 10,491.5 feet, were drilled, and the core samples were assayed at the Bureau of Mines station at Salt Lake City, Utah.

Jan 1, 1959

By Michael Sokaski, M. R. Geer, H. F. Yancey

This report is one of a series describing investigations by the Federal Bureau of Mines of the performance of various types of coal - cleaning equipment ; other reports in the series are listed in the bibliography . The information in these reports is useful to the coal industry and the manufacturers of coal - cleaning equipment in several ways : First , it assists the coalpreparation engineer who is planning a new plant to select the type of process best suited to the requirements by enabling him to forecast the yield and quality of clean coal obtainable with each type of equipment . Second , the information serves as a yardstick by which the performance of a plant can be judged and thus helps determine whether it is operating at satisfactory efficiency . Both these functions promote better coal - preparation practice ; that is , they help provide coal of more suitable quality for the market and likewise minimize the waste of good coal . This serves the interest of conservation with which the Bureau is vitally concerned . The present report deals with three plants using the Tromp dense - medium process , named after its inventor , K. F. Tromp , who developed the process in the Netherlands in 1936.5/ Selection of this particular dense -medium process for investigation was entirely a matter of convenience , and reports dealing with other dense -medium systems are planned for the future . Two baths are employed in one of the plants investigated . The first of these , handling 6- to 3 - inch coal , exhibited an exceptionally sharp separation between coal and impurity . This was characterized by an error area of 12 and a probable error of 0.023 . In the second bath , treating refuse from the

Jul 1, 1960

By Robert L. Jones

The Boston Consolidated mine is situated in the Bingham mining district, Salt Lake County; Utah (fig. 1). The property has had a noteworthy production of cupriferous, gold-bearing, pyritic ore in addition to lead ore. The Bureau of Mines established a diamond-drilling development project on the property in September 1943 with the primary objective of determining the continuity of a mineralized zone in the Commercial limestone below and to the northeast of the 800-foot level (fig.2). Examination of the geologic feature at the property previous to drilling indicated that the mineralized limestone horizon would continue belay the 800-foot level, but with a flatter dip than disclosed above this level. During the project period, 36 holes totaling 4,001 feet were drilled from underground stations outlining the zone below the 800-foot level (figs. 2 and 3).

Jan 1, 1949

By R. C. Hickman

Preliminary evidence indicated that the Chattanooga Shale might constitute a potential vast low-grade source of uranium. Investigation by core drilling indicated that while the Chattanooga Shale may constitute a resource for the future, the very low (0.006 percent) average uranium content is not economic when compared with the relatively higher grade western ores. A total of approximately 12,000 feet of test drilling was done in 72 drillholes, and large samples were mined for extractive and metallurgical testing. An experimental mine site was selected on the basis of the drilling project.

Jan 1, 1967

By John B. Gayle

A new, experimental coke oven was installed at the Southern Experiment Station, Tuscaloosa, Ala., in 1948. This oven, designated as the Tuscaloosa oven, features a 17-inch carbonizing chamber, globar heating elements, and silica-brick heating walls designed to simulate as closely as possible carbonizing conditions in commercial, slat-type coke ovens. Zoned heat-input arrangements maintain uniform temperatures over approximately 95 percent of the total flue area. The reasons for constructing an oven of this size, the details of the design, and the operating characteristics of the oven were given in an earlier publication.2/ This report presents the results obtained from the first series of carbonizing tests on Alabama coals with the new oven. Factors leading to the development of standardized operating and testing procedures and the results of crosscheck determinations with a commercial oven producing foundry coke are included also.

Jan 1, 1954

By P. G. Barnard

The Bureau of Mines investigated the effects of various additions of rare-earth metals or rare-earth oxides on the mechanical properties of cast and wrought plain-carbon steels. Rare-earth metals, as misch metal, were added to medium-carbon steel in amounts to 0.70 weight-percent; rare-earth oxides, as a commercial mixture, were added in amounts to 1.50 weight-percent. The melting and casting of conditioned steels were done in a vacuum-induction furnace, to avoid formation of oxides from the melting atmosphere and to pro-vide better control over chemical composition. At room temperature, data for tensile strength, yield strength, elongation, and hardness of cast and wrought steels were obtained by standard testing equipment and procedures. Impact tests were conducted on as-cast steel specimens. The greatest amount of tensile ductility and impact strength was obtained in as-cast steel with 0.50 to 0.70 weight-percent misch metal additions. No significant improvement on mechanical properties was indicated in wrought steels containing rare-earth metal additions in the range from 0.10 to 0.70 weight-percent. In general, the rare-earth oxide additions up to 1.50 weight-percent had little effect on the tensile properties of steel in the cast, wrought and annealed, or wrought and normalized condition.

Jan 1, 1967

By Kenneth J. Miller

The Federal Bureau of Mines coal-pyrite flotation process has been modi¬fied to produce a concentrated final clean coal slurry underflow that could be dewatered more effectively by filtration or centrifugation. This change was accomplished by redesigning the Bureau's two-stage flotation pilot plant facility and running the second-stage flotation step with undiluted or only partially diluted first stage coal froth concentrate. Results of the pilot plant flotation tests showed that substantial sulfur reduction could be achieved by flotation with undiluted pulp but some dilution is recommended for maximum selectivity. For example, coal-pyrite flotation in slurry of 25 percent solids yielded clean coal products analyzing as low as 0.7 percent pyritic sulfur and froth reject products containing slightly over 3.0 percent pyritic sulfur. In comparison, coal-pyrite flotation with pulp diluted to about 12.5 percent solids yielded clean coal containing as low as 0.4 percent pyritic sulfur and froth reject of 5.6 to 6.7 percent pyritic sulfur. Despite the need for some dilution, it was concluded that excellent coal-¬pyrite flotation selectivity could be achieved without diluting to 6 or 7 per¬cent solids as done in the earlier work. Thus the economics of coal-pyrite flotation would be improved by easing clean coal dewatering problems and by reducing second-stage flotation cell volume requirements.

Jan 1, 1977

By Sidney Katell

This study estimates capital investment, operating costs, and selling prices for four underground bituminous mines producing coal with annual production ranging from 1.06 to 4.99 million tons. It is assumed that the mines have a 20-year life. Wages and union welfare payments are considered as of December 6, 1974, under the Bituminous Wage Agreement of 1974, and costs for material and equipment are based on 1975 indexes. Initial capital investment ranges from $23,629,500 for the 1; 06- million-ton-per-year (MM tpy) mine to $79,907,500 for the 4.99-MM-tpy mine. Total capital investment ranges from $35,336,500 to $1 18,863,500 for the same mines. Corresponding selling prices for the coal range from $13.57 to $11.36 per ton, assuming a 15-percent discounted cash flow rate of return after Federal income taxes.

Jan 1, 1975

By L. Crocker

The Bureau of Mines investigated processes for recovering a marketable lithium product from the montmorillonite-type clays of the McDermitt caldera. The clay deposit, located on the Nevada-Oregon border, is estimated to contain over 3 million short tons of lithium. Limestone-gypsum roasting and selective chlorination proved most successful for extracting lithium from the clays; 80-pct Li recovery was achieved using either technique. With both processes, lithium silicate in the clay was converted to a water-soluble compound-either lithium sulfate or lithium chloride. The lithium was then recovered as a carbonate by water leaching the calcine, concentrating the leach solution by evaporation, and precipitating the lithium with soda ash. The operating costs for the limestone-gypsum roast process were estimated at $2.02/lb Li2C03; selective chlorination operating costs were estimated at $3.85/1b Li2C03. The current selling price of Li2C03 is about $1.50/lb. A detailed flowsheet, material balance, and process evaluation are presented for the limestone-gypsum roast process. In addition, lithium reserves and resources are discussed and the McDermitt clays are described.

Jan 1, 1988

By Manuel Gomez

Published experimental coke data from a pilot plant slot-type oven were examined by statistical regression analysis. Quantitative relationships were found to exist between the coking rate, bulk density, and fine grinding of the coal, sole-oven expansion, volatile matter, moisture, ash, and carbon con-tent of the coal and coke parameters indicative of size and strength. Regression equations developed from coke data were shown to yield computed values that were in good agreement with experimental results for 11 coke properties. Prediction equations developed were evaluated with an independent set of data. Present results indicate that the variables cited undergo much interaction and the sum of these interactions determines coke size and strength.

Jan 1, 1967

By John R. Bradley

The available supply of fuel and power is a subject of importance at all times and particularly at this time. The following brief survey of fuel and power in the United States appraises the extent of the several primary sources of energy the approximate monthly demand, 1929-40; the chief centers of production and consumption; and shifts in the principal uses from 1929 to recent years. The period covers the boom year 1929, the years of the great depression, the more normal year 1937, the recession in 1938, the year 1939, and 1940 (which was affected by armament programs). In some instances, the data for 1939 and 1940 are preliminary. The four primary sources of fuel and power are coal, petroleum, natural gas, and water power. Wood fuel, important in some regions, and foreign trade in natural gas and hydroelectricity represent a relatively small part of the energy supply and are not considered in this study. The tonnages shown are in terms of coal, based upon the calorific or B. t. u. equivalents of the several sources of power. In practice, the usable heat or energy varies according to the type of equipment available for its use. For example, the efficiency of turbine water wheels and internal-combustion engines is much higher than that of steam plants and household-heating devices.

Jan 1, 1941

By Robert E. Barieau

The following zero pressure thermodynamic properties of nitrogen gas are tabulated: [C°p, H° -o, S°], These properties are tabulated in units of joules, gram mole, degrees Kelvin and in calories, gram-mole, degrees Kelvin for every degree Kelvin from 50° to 550°. The same functions are also tabulated in units of British thermal units pound-mole, degrees Rankine for every degree Rankine from 100° to 1,000°.

Jan 1, 1967

By Franklin D. Slagle

Porosity and bulk-and sand-grain-density values were determined for 2,040 core samples of 30 formations from 47 wells in New York, Ohio, Pennsylvania, and West Virginia, and are compiled for petroleum industry use in well-log evaluation and geologic studies.

Jan 1, 1967

By Joe N. Magee

As part of the important program of promoting conservation and efficient utilization of petroleum, Bureau of Mines engineers are making studies of secondary oil-recovery projects throughout the United states and publishing reports setting forth the pertinent facts so that others may profit by the experience gained. This report presents the results of a study by engineers of the Bureau of Mines, stationed at Franklin, Pa., of secondary oil recovery in a part of the Cabin Creek field, Kanawha and Boone Counties, W. Va., where natural gas is injected into the reservoir to stimulate oil production. Most oil produced in the Appalachian region at present is obtained from stripper fields in which almost all natural energy has been dissipated. Secondary-recovery methods are used extensively in many oil-producing areas of New York, Pennsylvania, West Virginia, Ohio, and Kentucky for recovering oil not produced by primary-production methods. The part of the Cabin Creek field reported in this study is shown in figure 1 and has been designated by the operator as project 4. In 1944 the developed area of the entire field was approximately 4,200 acres, and the area of project 4 was about 600 acres. In the developed area of the project the oil reservoir is in the Berea sandstone and occurs at 2,914 to 3,410 feet.

Jan 1, 1952

By Albert W. Deurbrouck

The performance of four sand cones was evaluated by the Bureau of Mines in three preparation plants that utilized cones in various flow schemes. The cone at plant A was a simple two-product one that provided clean coal and refuse. Plant B had two cones; one cone made a primary separation and the other a secondary separation. The primary cone separated salable coal from heavy rejects. The secondary cone separated a low-ash metallurgical coal and an intermediate-ash product suitable for plant fuel or steam markets. In plant C the sand cone was equipped with a middlings draw Which continually removed an intermediate specific-gravity product below the surface of the cone. The three primary separations of raw coal effected between floats and sinks were excellent. The recovery efficiencies for the plus 1/4-inch material ranged from 99.8 to 97.6 percent, the error areas ranged from 19 to 23 square centimeters, and the probable errors in specific gravity ranged from 0.033 to 0.024. The performance data of the two secondary separations varied from excellent in plant B, where the separation was on a par with the primary separations, to somewhat inferior in plant C, where the secondary separation was effected at the middlings draw.

Jan 1, 1965

By Wilbur I. Duvall

Twelve millisecond delayed blasts in four limestone quarries in Iowa were instrumented with arrays of vertical velocity gages to determine if the direction of propagation through the rock or the method of initiation of the blast had any effect upon the level of vibration. Two gage arrays approximately 90° apart were used to test the effect of direction of propagation. The vibrations from blasts initiated by three methods were recorded. Vibration records from these tests were analyzed for peak particle velocity as a function of distance from the blast. The data are shown to fit a power Law equation. Direction of propagation is shown to affect the value of the exponent n. The effect of charge size per delay interval on the level of vibration is removed from the data by scaling the travel distance by the square root of the charge weight per delay period. The method of initiating the blasts is shown to have a strong effect upon the level of vibration and the spread in the data from one shot to another.

Jan 1, 1963

By Leonard F. Heising

Domestic production of Metallurgical-grade manganese has contributed such a small percentage of the United States industrial demands that areas known to contain large tonnages of low-grade manganese ore have been investigated by the Bureau of Mines to reduce this country's dependence on foreign ores. A major source of low-grade manganese is the Cuyuna iron range in Minnesota. The entire Cuyuna iron range is covered by an overburden of glacial drift that, in some places, reaches depths of 200 feet or more. Prospecting and exploration must be guided by geophysical methods, drilling results, or projections of exposures found in operating mines because there are no outcrops near the productive parts of the range. Past drilling for the purpose of outlining iron ore generally was confined to the highly oxidized zones. Much of the manganese with which the Bureau of Mines is concerned occurs in thin-bedded unoxidized iron formations, too low in iron content to have been of interest to those seeking commercial iron ore. The primary objective of the core-drilling reported here was to obtain cores of different classes of manganiferous rocks and to determine whether or not the samples were amenable to beneficiation.

Jan 1, 1959