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By C. Golumbic

Most early research on solvent extraction of coal has been concerned with the molecular structure of coal. Although rush work is continuing, practical aspects of the subject also are being emphasized. For example, development of the Pott-Broche extraction process resulted from the discovery of very efficient solvents for the pressure-extraction of coal. Recently, Orchin and Storch reported the use of even more efficient solvents under similar conditions. In addition to the discovery of more effective solvents, the possibility of efficient extraction at atmospheric pressure is obviously of practical interest. H. J. Rose observed that phenanthrene at its atmospheric boiling point readily dispersed 80 percent or more of Pittsburgh-bed bituminous coal. This fact served as the starting point of the present investigation, ill which determination of the chemical specificity of this solvent and the chemical nature of the resulting extracts was undertaken. This paper represents a progress report of the results obtained to date.

Jan 1, 1950

By A. W. Ambrose

"A need exists for men in oil-field production work who correspond to the mining engineer of a large mining property. Some oil companies prefer to call such an employee a resident geologist, resident engineer, or a petroleum technologist. He should perhaps be more correctly termed a petroleum production engineer. The duty of such a man is to apply his scientific and geologic training practically to oil-field development work.He should be, by education, a mining, civil, or mechanical engineer, with a knowledge of geology and chemistry. Upon completion of his education, such a man should spend several years in the oil-fields. There are two means of gaining proper experience. The first method is to work for an oil company in making a detailed study of each well, collecting data on the history and production, followed by a preparation of good records, from which well logs can be prepared. From the well logs, the geologic cross-sections, peg-models, and structure contour maps can be made. These allow a comparable, detailed study of each well, which is necessary to solve many of the problems. Along with this the engineer should visit drilling wells daily for collection of samples of formations and for a proper study of how they drill. He should form friendly relations with the drillers and production foremen. The second method of gaining proper experience is to start work as a roustabout, pumper, or on the pipe¬line gang, finally working up to a tool-dresser. After three or four years of such work, the engineer may be classed as a petroleum production engineer."

Jan 1, 1920

By John A. Johnson

Conclusions regarding the use or omission of stemming in blasting have not peen reached, pending completion of all aspects of this investigation. The results from the dust phase of this study on six classes of stemming prove that the kind of stemming affects the amount of dust produced from blasting. In previous work at the Mount Weather testing adit it was demonstrated that blasting produces the highest dust concentrations of any of the mining processes.5/ Under the conditions prevailing at the Mount Weather testing adit, the average of all rounds having a break of at least 95 percent showed that the least amount of dust was produced when no stemming was used.

Jan 1, 1940

By John A. Johnson

Conclusions regarding the use or omission of stemming in blasting have not peen reached, pending completion of all aspects of this investigation. The results from the dust phase of this study on six classes of stemming prove that the kind of stemming affects the amount of dust produced from blasting. In previous work at the Mount Weather testing adit it was demonstrated that blasting produces the highest dust concentrations of any of the mining processes.5/ Under the conditions prevailing at the Mount Weather testing adit, the average of all rounds having a break of at least 95 percent showed that the least amount of dust was produced when no stemming was used.

Jan 1, 1940

By K. E. Tame

The Bureau of Mines is studying possible modifications in conventional ore-processing methods that will confine and permit controlled disposal of radioactive liquid wastes. Stream and ground water pollution from radio-active nuclides, principally radium 226 and thorium 230, in liquid wastes from uranium mills can be minimized by reusing the waste solution within the mill. Such reuse of waste solution in an acid leach-resin-in-pulp flowsheet was investigated in the laboratory. The process consists of acid leaching for dissolution of the uranium, sand-slime separation and countercurrent decantation washing for recovery of a pregnant slime slurry, and the use of ion-exchange resin for recovery of uranium from the slurry. Reuse of clarified barren effluent for washing in the simulated mill circuit was carried through 55 cycles. Dissolution of uranium from the ore averaged 97.5 percent. Washing efficiency of 99.9 percent was attained when using 4.35 volume tons4 of combined barren effluent and makeup water per ton of ore. Absorption of uranium from the pregnant slime slurry by an ion-exchange resin averaged over 99.9 percent.

Jan 1, 1962

By J. H. Wiggins

In 1919 the United States was threatened with a shortage of gaso- line. In spite of this well-known fact, a detailed field investigation has shown that in one stage only of handling crude oil the volume of gasoline that evaporates is equal to one-thirtieth of the country's yearly gasoline production. This loss occurs during the few days that the oil is stored on the leases before being taken by the pipe line, and in 1919, in the Mid-Continent field alone, it amounted to 122,100,000 gallons. Large as it is, it is only a part of the loss on the lease. Investigation has further shown that the gasoline in crude oil evaporates from one-half to six-tenths as rapidly as the same gaso- line after being distilled and stored, all evaporative conditions being the same. Many wastes in the oil fields are called "necessary." By this is meant that the cost of preventing the waste is greater than the gain through saving. Evaporation losses have fallen heretofore in this category, but now they must be considered unnecessary. In other words, it is no longer economical for any handler of crude oil to permit losses through evaporation. In accordance with its purpose of seeking to conserve mineral resources, the Bureau of Mines investigated the loss of gasoline by evaporation in the storage and handling of petroleum. Inasmuch as most producers had not decided that their losses justified cor- rective measures and no evidence was available on the comparative losses in various stages of handling the oil, the investigation was limited to determining by experiment and observation the nature and magnitude of evaporation losses, where the greatest losses are, and the factor controlling evaporation.

Jan 1, 1922

By Bernard Porter

The densities of LiF, NaF, and KF, of binary mixtures of these alkali fluorides, and of binary mixtures of UF4, ThF4, YF3, LaF3, and CeF with each of tie alkali fluorides were measured as functions of the melt composition and temperature. Molar volumes at 1,000° C were calculated for all the mixtures. Binary systems containing LiF exhibited molar volume ideality. Binary fluoride systems containing either NaF or KF as the alkali fluoride exhibit positive deviations from molar volume additivity. However, molar volumes in the NaF-KF system are ideal.

Jan 1, 1966

By R. C. Buehl

A pyrometallurgical process for recovering manganese from open-hearth furnace slags or low-grade manganiferous iron ores is described. The slag or ore is smelted in a blast furnace to produce spiegeleisen; the speigeleisen is then blown with air in a basic converter to give an oxide slag. This slag product contains 60 to 75 percent manganous oxide and may be considered a synthetic manganese ore. In the smelting operations coke rates for five test periods ranged from 3,255 to 4,130 lb per ton of spiegeleisen. The recovery of manganese in the spiegeleisen varied from 60 to 76 percent. Recovery increased to 83 percent when the open-hearth slag feed to the blast furnace was diluted with a high-? grade iron ore sinter to facilitate smelting. In blowing the spiegeleisen a cyclic procedure was developed that gave nearly 90 percent recovery of manganese in the slag product (synthetic ore) yet prevented excessive contamination of the slag by phosphorus and iron. The overall recovery of manganese was about 75 percent when iron ore sinter was used with the open-hearth slag in the smelting step. The metal remaining after oxidizing the manganese from the spiegeleisen contained approximately 3.5 percent phosphorus. It was refined in a basic converter by blowing with air in the presence of lime" A high--grade iron and a basic phosphate slag were produced.

Jan 1, 1965

By Engelmann. William H.

In pursuit of innovative methods to improve mining productivity, the Bureau of Mines is investigating the use of inorganic salts as drilling fluid additives for penetration enhancement. Laboratory diamond drilling tests were performed on Westerly Granite with aluminum chloride solutions and on Sioux Quartzite with aluminum nitrate and aluminum, calcium, sodium, and zirconium chloride solutions as drilling fluid additives. These drilling results were compared with the average drilling performance using distilled, deionized water on Sioux Quartzite (12 replicate tests) and Westerly Granite (3 replicate tests). Maximum in-creases in penetration per given time and bit life were obtained when drilling with zero point of charge (ZPC) concentration solutions of each additive. For Sioux Quartzite, maximum increases in penetration and bit life ranged from 96 to 115 pct and 64 to 99 pct, respectively. For Westerly Granite, maximum increases in penetration of 155 and 165 pct and bit life of 109 and 136 pct were obtained at or near ZPC aluminum chloride concentrations of quartz (7.3 x 10-7 mol/L AIC13) and alkali feldspars (1.1 to 1.5 x 10-6 mol/L AIC13), respectively. This simultaneous increase in penetration per time together with extended bit life should result in increased productivity and reduced bit costs.

Jan 1, 1987

By Scott A. Stebbins

This Bureau of Mines publication presents a method for estimating capital and operating costs associated with the exploration, mining, and processing of placer deposits. To ensure representative cost estimates, operational parameters for placering equipment and basic principles of placer mining techniques are detailed.

Jan 1, 1987

By John J. Sammarco

The U.S. Bureau of Mines is conducting research into computer-assisted mining, which requires investigation of new techniques for development and application of computer-based technologies. Today's technology can require significant effort in software development, as has become evident in the early stages of this Bureau research. Technologies for software automation, such as computer-aided software engineering (CASE), are available. This report explores CASE, its general features, and its importance in software development. Information is presented to assist in selection and application of the variety of CASE tools and methods for automating various stages of software development. When evaluating CASE for use, it is important to examine tools that support an organization's existing methods of software development. Support for existing hardware platforms must also be examined. Merely selecting a "good" CASE tool does not insure success. Thorough evaluation of implementing CASE is also critical. Subjects to evaluate for CASE implementation include organization culture, support from management and end users, training resources, and pilot projects. Organizations that benefit the most from CASE evaluate CASE features with respect to their needs and they properly implement CASE.

Jan 1, 1990

By Robert S. Warfield

The Federal Bureau of mines and U.S. Geological Survey conducted exploratory investigations and geologic mapping in the Wishbone Hill district of the Matanuska coalfield almost continuously from 1942 through 1958. These investigations delineated reserves of high-volatile bituminous coal necessary to supply the rapidly expanding military and civilian requirements in the Anchorage area. This report describes the program conducted by the Bureau of Mines from 1949 through 1958, and briefly summarizes previous investigations, the results of which have already been published. The coal-bearing structure on both the north and south limbs of the prominent Wishbone Hill syncline was explored by 8,719 feet of churn drilling and 25,460 feet of diamond-core drilling. A total of 33 holes were drilled ranging in depth from 60 to 2,114 feet. To supplement the drilling operations, bulldozer and dragline trenching were undertaken at key locations; about 25,000 cubic yards of dragline trench were excavated in the vicinity of the old Premier mine.

Jan 1, 1962

By Carl F. Wingquist

In support of Bureau of Mines studies of thermal fragmentation of rock, the elastic moduli of four types of rock were measured at temperatures ranging from room temperature up to 1,500° F (1,089° K). The sonic method was employed to determine the resonant frequencies of the rock specimens and from these frequencies, the elastic moduli were calculated. Data for Young's modulus, shear modulus, and Poisson's ratio are given as a function of temperature for Dresser basalt, Reserve taconite, Jasper quartzite, and Charcoal granite. Young's modulus and the shear modulus decreased with increasing temperature up to about 1,200° F and then became relatively insensitive to temperatures from 1,200° to 1,500° F.

Jan 1, 1969

By Frank E. Cash, Roy G. Stott

This circular describes four modern change houses of the Lake Superior iron - ore district , all conceived and constructed since 1937. The oldest change house described herein was constructed and occupied in 1938 , yet it embodies the modern improvement of air - conditioning . The purpose of this report is to describe and illustrate improvements with regard to health and safety features combined in the construction , arrangement , ventilation , heating ,lighting , and other features , with the aid of photographs , sketches , and diagrams . The modern change house is a fire - resistant structure in which intermingling of men in mine clothes and men in street clothes , hazardous dust , heat and humidity , crowding , poor lighting , slippery and muddy floors , and inadequate facilities for clothes and for bathing have been largely eliminated . The miner coming off shift at a modern mine no longer faces the elements when he gets off the cage . He travels through a tunnel to the change house , where he is cooled gradually by room temperatures as he passes from the mineclothes section and shower room to the street - clothes room . He is assured of dry clothes when he is ready for them . No longer is he sent out of the change house into a muddy yard to drive away as best he can . The modern change house has an improved parking lot and graveled or concreted walkways from it to the change house entrances .

Jan 1, 1949

By L. Garner McDonald

The U.S. Bureau of Mines, under contract to the U.S. Department of Energy, investigated the erosive-wear properties of seven commercial alloys with potential applications as valves for coal-conversion plants. A dry particle, jet-erosion apparatus was used to determine the wear of seven materials: 316 and 440-C stainless steels, K-68, K-701, and K-801 cemented tungsten carbides, HC-250 white cast iron, and Haynes 6B. The alumina abrasive entrained in the nitrogen gas jet had particle sizes of 27 or 50 µm, the abrasive velocities were 55 to 170 m/s, and the particle impingement angles were 15° to 90°. The maximum specific wear for ductile materials was found to occur at impingement angles of 15° to 30°, and the minimum specific wear occurred at 60° to 90°. For the brittle materials, maximum specific wear occurred at impingement angles of 50° to 85° and minimum specific wear was at the lowest angles. As the velocity and erosive particle size increased, the specific wear increased. The specific wear was related to the velocity by the power function WocAVn, where n was 1.8 to 3.9 for ductile materials and 1.8 to 3.6 for brittle materials.

Jan 1, 2010

By R. B. Prater

The Bureau of Mines conducted research to separate the F from byproduct Zn concentrates obtained from fluorspar (CaF2) production, as part of the Bureau's effort to devise efficient, environmentally acceptable technology for recovering Zn from resources considered undesirable by Zn producers. Sulfuric acid (H2SO4) was found to be effective in F removal, while ammonium carbonate [(NH4)2C031 was not. The most important variables for reducing the necessary residence time were found to be temperature and agitation. Optimum leaching conditions were 75° C and 500 r/min for 2 h at 40 pct solids with 0.2 g acid per gram of concentrate, which resulted in a 98.3-pct F extraction. Zinc losses during F removal were in the range of 2 to 3.3 pct. Other elements such as Fe, Cd, Ca, and Cu were also partially dissolved. About 93 pct of the F was removed from the leach solution by neutralization and precipitation with calcium hydroxide [Ca(OH)2]. Additional treatment might be necessary to limit the buildup of soluble elements in the recycled leach solution.

Jan 1, 1985

By E. P. Youngman

Titanium ranks as one of the more abundant elements, is widely distributed, and occurs in concentrated form in numerous deposits. This substance was discoveres 140 years ago; but despite the efforts of metallurgists and chemists to find a place for it in industry, only within the last 10 or 15 years has the increased use of titanium pigments provided any extensive outlet for titanium ores. Even to-day titanium is confined to a few highly specialized industrial applications. The metal itself is now quoted regularly in trade journale, but scarcely yet can it be said that the production or use of the metal. has progressed very far beyond the laboratory stage. Ferroalloys containing the element were largely used for a time, especially in connection with the manufacture of Bessemer steel rails; but as American rail- ways adopted open-hearth rails in preference to Bessemer rails, the demand for the alloys in the rail manufacture gradually dwindled into insignificance. New outlets for ferrotitanium have been found in the steel industry; and the production of titanium alloys, both in the United States and in Europe, has increased in recent years. By far the largest use of titanium at the present time, however, is in pigments. The manufacture of titanium white began in Norway, but at present the United States is the leading producer. One of the two companies now operating in the United States is also the leading factor in European production. Although titanium occurs, in many minerals, the principal commercial sources are rutile (the natural oxide, Ti02) and ilmenite (iron-titanium oxide, FeO. TiO2). The latter is a coal-black mineral, but it is the one used in the manufacture of the titanium white of commerce, as well as in the manufacture of ferroalloys and arc-lamp electrodes. Rutile, the natural oxide, is not pure white and, being less common in nature, costs more; it is, therefore, reserved for use in the manufacture of titanium chemicals employed in relatively small amounts in dye works and bleacheries and for sundry minor purposes. This paper summarizes the titanium industry, with special reference to its economic aspects. It is offered as a survey of current trade literature and as a digest of material in the files of the bureau and is presented in response to numerous inquiries from prospective producers as to ways and means of exploiting deposits. (At present, much of the ilmenite consumed in this country comes from overseas, principally from British India..). A forthcoming circular, devoted to deposits of titanium-bearing ores, deals with foreign and domestic sources of supply.

Oct 1, 1930

By W. W. Adams

Because of insufficient funds for printing, the Bureau of Mines was unable to publish its annual bulletin covering accidents at metal mines in the United States for the year 1933. A brief mimeographed summary of the principal statistical data for that year was released to the public late in 1934. Since then reports for 1934 have been received from the mining companies, and in order to avoid further delay in releasing this information to the mining industry and others interested in the prevention of accidents in mining, statistics for both years are presented in this publication with a minimum of interpretation and comment. The fatal-accident rate for the metal and nonmetallic mines (excluding coal mines) of the United States was more favorable in 1933 than in any previous year since 1911, the first year for which the Bureau of Mines obtained reports from the operators. Further progress was made in 1934, when the fatality rate was even lower than that of 1933. On the other hand, the nonfatal-accident rate, which had reached its lowest level in 1932, increased in 1933 and increased further in 1934, although not to such an extent as to prevent the rate for either of those 2 years from being better than that for any year previous to r1931.

Jan 1, 1936

By N. A. C. Smith

[The beau of Mines made its first survey of motor gasolines sold throughout the United States in 1915, a second in 1917, and a third in April. 1919. These surveys shored that motor gasoline had become notably less volatile during each two-year interval. In order to ascertain whether this change was continuing, it was planned to institute semi-annual surveys, the first of which teas made in January, 1920. Contrary to expectations based on the previous surveys, the average volatility of the gasoline tested at this time was practically identical with that of the average volatility of the gasoline from the same districts in 1919. The next survey, made in July, 1920, showed a very marked decrease in volatility but as it has long been recognized that the volatility of motor gasoline manufactured for sale during the summer months is loss tan that of gasoline made and sold during the winter, part at least of the change was attributed to this factor. The average boiling point of the samples collected in the present survey is 263 degrees Fahrenheit, as compared with 264 a year ago. This shows that the average gasoline marketed at the present time is fully as volatile as that marketed a year ago. There has been, however, a noticeable change in the character of the product: the initial boiling point and 20 per cant point are lower than a year ago, whereas the 90 per cent and end-points are higher, which indicates a greater proportion of gasolines made by blending casing-head, or natural gas-gasoline, and naphtha.]

Jan 1, 1921

By D. H. Chambers, Arnold M. Lansche

Electro recovery by amalgam methods was investigated to determine the feasibility of recovering pure cadmium from cadmium sponge produced during purification of zinc electrolyte at electrolytic zinc plants . Actual material used in this work was air- oxidized cadmium sponge . An acid rinse and zinc displacement technique was developed to amalgamate this oxidized cadmium . ( In - plant use of the recovery process would probably not require this step because of the fresh state of the sponge . ) Zinc was completely removed from amalgamated sponge by selective oxidation with air . Zinc - free cadmium amalgam was circulated by an electromagnetic pump through an electrolytic cell where cadmium of 99.9+ percent purity was electrodeposited onto a rotating aluminum cathode . Polarographic methods were developed for determining cadmium and zinc in mercury and in sulfuric acid solution .

Jan 1, 1964