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By W. A. Stickney, J. W. Town

Batch and continuous - circuit flotation , leaching , precipitation , and electrodeposition studies were made by the Bureau of Mines to determine optimum conditions for treatment of complex mercury - antimony sulfide and mercury- arsenic sulfide ores and concentrates . On the Red Devil ore sample over 95 percent of both the mercury and antimony sulfides were recovered in a flotation concentrate containing 35.6 percent mercury and 21.0 percent antimony . By selective flotation a mercury concentrate containing 71.0 percent mercury and 2.9 percent antimony was obtained with a mercury recovery of 90.4 percent . Leaching results show that , with 150 grams per liter of sodium sulfide and 50 grams per liter of sodium hydroxide , 95 to 99 percent of the mercury , antimony , and arsenic sulfides could be extracted from the concentrates treated . Sodium hydroxide reagent consumption was based on the sulfides generated in the dissolution of the sulfide minerals and on the method of metal recovery used . Selective leaching of the antimony and arsenic sulfides with potassium sulfide dissolved more than 95 percent of either of these two sulfides and 0.5 to 5 percent of the mercury sulfide present . Methods for recovering mercury and antimony from solution were electrodeposition of mercury followed by electrodeposition of antimony , aluminum precipitation of both mercury and antimony , or antimony precipitation of mercury followed by antimony electrodeposition . The method used in recovering the mercury depended on the mercury- antimony content of the solution being treated .Batch and continuous - circuit flotation , leaching , precipitation , and electrodeposition studies were made by the Bureau of Mines to determine optimum conditions for treatment of complex mercury - antimony sulfide and mercury- arsenic sulfide ores and concentrates . On the Red Devil ore sample over 95 percent of both the mercury and antimony sulfides were recovered in a flotation concentrate containing 35.6 percent mercury and 21.0 percent antimony . By selective flotation a mercury concentrate containing 71.0 percent mercury and 2.9 percent antimony was obtained with a mercury recovery of 90.4 percent . Leaching results show that , with 150 grams per liter of sodium sulfide and 50 grams per liter of sodium hydroxide , 95 to 99 percent of the mercury , antimony , and arsenic sulfides could be extracted from the concentrates treated . Sodium hydroxide reagent consumption was based on the sulfides generated in the dissolution of the sulfide minerals and on the method of metal recovery used . Selective leaching of the antimony and arsenic sulfides with potassium sulfide dissolved more than 95 percent of either of these two sulfides and 0.5 to 5 percent of the mercury sulfide present . Methods for recovering mercury and antimony from solution were electrodeposition of mercury followed by electrodeposition of antimony , aluminum precipitation of both mercury and antimony , or antimony precipitation of mercury followed by antimony electrodeposition . The method used in recovering the mercury depended on the mercury- antimony content of the solution being treated .

Jan 1, 1964

By R. S. Fowkes

The Bureau of Mines constructed a fully automated pilot plant facility to study the hydraulic transportation of solids through a lock hopper feeder system. An equation for the energy requirements to transport coarse solids hydraulically proved applicable to this system. Optimum velocities were obtained for limestone, mine refuse, and bituminous coal. The experimental data, calculations, and graphs show the effect of velocity, specific gravity, and solids concentration on head loss and power requirements. Other data were obtained and evaluated to determine the effect of particle size on head loss. Results also are given for (a) tests using friction reducing polymers; (b) tests using seven test sections of steel alloy pipe to determine their wear characteristics; (c) tests to determine spatial segregation of moving particles; and (d) tests to determine the effect of shape, size, and specific gravity on particle velocity in a horizontal pipeline. The lock hopper feeder system was found practical for continuous hydraulic transportation of the material types and size ranges tested.

Jan 1, 1969

By K. O. Bennington

Thermodynamic properties were determined by the Federal Bureau of Mines for lithium metasilicate (Li2Si03) and lithium disilicate (Li2Si205). Their enthalpies of formation were investigated by hydrofluoric acid solution calorimetry. The standard values are ?Hf°298 -393.8 ± 0.8 kcal/mole for Li2Si03, and ?Hf°298 -611.8 ± 1.0 kcal/mole for LiSi205. Enthalpy increments above 298 K were measured by copper-block drop calorimetry from 298 to 1,404 K for Li2Si03, and from 298 to 1,281 K for Li2Si205. Low-temperature heat capacities were determined adiabatically from 6 to 305 K for Li2Si205 only. The derived standard entropy is S°298 = 29.20 ± 0.10 cal/deg-mole. The various experimental data were combined with other data from the literature, and resulting properties of ?Hf°, ?Gf°, and log Kf were tabulated as a function of temperature.

Jan 1, 1976

By Lewis V. Wade

Barrett EA, Kowalski KM [1995]. Effective hazard recognition training using a latent-image, three-dimensional slide simulation exercise. Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9527. NTIS stock number: PB95-170379. Beus MJ, Orr TJ [1995]. Computer modeling and analysis of the Greens Creek mine, Admiralty Island, AK. Spokane, WA: U.S. Department of the Interior, Bureau of Mines, RI 9530.NTIS stock number: PB95-176418. [ ]

By R. Larry Grayson

Barrett EA, Kowalski KM [1995]. Effective hazard recognition training using a latent-image, three-dimensional slide simulation exercise. Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9527. NTIS stock number: PB95-170379. Beus MJ, Orr TJ [1995]. Computer modeling and analysis of the Greens Creek Mine, Admiralty Island, AK. Spokane, WA: U.S. Department of the Interior, Bureau of Mines, RI9530. NTIS stock number: PB95-176418. [ ]

By Mark I. Copeland

Bureau of Mines researchers investigated the combined effect of copper and tin additions on the mechanical properties of hot-rolled steels. Wrought steels containing 0.2 wt-pct C and up to 0.2 and 1.0 wt-pct Sn and Cu, respectively, were made and evaluated by conducting tensile and impact tests and electron-beam microprobe and electron microscopy examination. Tin additions did not significantly affect the tensile properties of steel at different copper contents in the hot-rolled condition. Tin lowered the copper content at which strengthening by copper precipitation normally starts, 0.8 wt-pct, and decreased the strength of steel aged at 1,022° F (550° C). The most adverse effect of tin was lowering the notch toughness of steels at most copper contents.

Jan 1, 1976

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 William A. Beck

Since bauxite mining began in the Irwinton District, Wilkinson County, Ga., in 1912, it has been on a small scale, as most of the deposits of high-grade ore are small. The bauxite has a high silica content, and its use has been largely limited to the chemical industry. Drilling under this project did not disclose any bauxite deposits of commercial value: However, numerous holes penetrated high-alumina clay deposits, but no attempt was made to delimit them, as the project was solely an exploration for bauxite. Bauxite was first discovered near Irwinton in 1907. The district covers virtually all of Wilkinson County and extends into the adjoining counties of Washington, Baldwin, and Twiggs. Mining was begun in 1912 by the Republic Mining & Manufacturing Co. on the Honeycutt, Parker, and Daniel properties, which are 1.5 miles from Wriley on the old Irwinton to Milledgeville Road.

Jan 1, 1949

By A. A. Bakewell

This information circular, which describes mining methods and practices at the Baguio Gold Mining Co., Philippine Islands, is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs. Since January 1952, Baguio Gold Mining Co. has operated its rehabilitated mine and mill in the Baguio district. Postwar labor and supply costs are three or four times prewar costs, whereas ore tenor and tonnage are about the same. Ore reserves remain approximately the same, but deeper and more spreadout operations add to increasing costs. Recently the company has acquired an adjoining property, which may lengthen its life substantially. Costs and general operations are more or less typical of the district, which includes three other active gold mines. Gold ore mined in the district totals approximately 4,300 tons per day.

Jan 1, 1959

By T. M. Ruff

The U.S. Bureau of Mines has developed a portable, inexpensive teleoperation system for mobile hard-rock mining equipment. The system was tested on a compact loader-trammer in a simulated stope. The teleoperation system includes radio remote control and computer-assisted navigation. A recent enhancement includes video cameras mounted on the machine to provide visual information to the operator. This system allows the operator to remain in a safe location while operating the machine from a distance, thus increasing both operator safety and mining productivity.

Jan 1, 2010

By M. R. Geer

The cleaning of fine coal, particularly for metallurgical use, is receiving greater attention. An increase in the proportion of fine coal in the run-of-mine product has been created by changes in mining practice, and a concur-rent deterioration in the quality of the fines has occurred because of more widespread full-seam mining. These two factors, augmented by the depletion of premium beds of metallurgical coal in some areas and the resulting shift to "dirtier" beds, are providing the impetus for adoption of improved cleaning techniques. For example, froth flotation, which has been used for years in a few preparation plants, now is gaining more rapidly in acceptance. Similarly, the dense-medium cyclone, which is used widely in Europe for making difficult separations, recently has been introduced to the United States. Regardless of the cleaning process employed, the finer sizes of coal can be treated with maximum effectiveness only when they are removed from the run-of-mine product and treated separately. No present process can treat the full range of sizes together with complete effectiveness. Flotation is applicable only to the coal finer than a top size ranging between 14-and 48-mesh, and cyclones require removal of all material finer than 0.5 to 0.3 mm. from the feed. Thus, the trend toward more-effective cleaning of the fine coal imposes the attendant problem of fine screening. Whereas in the past there was little need to screen finer than about l/4-in., present developments indicate that fine screening will become increasingly prevalent.

Jan 1, 1960

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 J. E. Doo1ey

To process and use the heavy ends of petroleum effectively, the development of suitable separation and characterization procedures not currently available was required. A systematic procedure was developed by the Bureau of Mines using such techniques as isothermal and molecular distillation, chemical treatment, silica-alumina gel chromatography, gel permeation chromatography, and spectrometry. Using these techniques, the Bureau achieved a detailed separation and characterization of a 370° to 535° C distillate from Gach Saran, Iran, crude oil. Such a systematic procedure and the semiquantitative data resulting therefrom should be of value in selecting feedstocks and in optimizing petroleum processing operations.

Jan 1, 1973

By Thomas J. Peters

In 1987, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied a 12,564-acre portion of the 34,795-acre Rockhouse Wilderness Study Area (CA-010-029) in order to evaluate its identified mineral resources. The study area is located in Kern and Tulare Counties, CA, about 60 air mi northeast of Bakersfield at the south end of the Sierra Nevada. A review of the geologic and mining literature, and a field examination identified a turquoise and a gold prospect in the study area, and another gold prospect and a feldspar prospect within a mile of the study area boundary. Thirty-three rock and 16 alluvial samples were taken.

Jan 1, 1988

By A. S. Swanson

In view of the necessity or increasing production of metallurgical fluorspar to satisfy wartime demands, 0, M. Bishop, former district engineer of the Bureau of Mines, L. W. Carrier and. J. S. Williams, senior geologist of the Federal Geological Survey, and E. H. Dawson, mining engineer of the War Production Board made a joint survey of the Illinois-Kentucky fluorite district in July 1942 to determine what steps should be taken to increase production. As part of their recommendations, a program for exploring the idle Klondike mine in Livingston County, Ky., was outlined. All the ore produced at the Klondike mine was mined above the 325-foot level, where some tonnage remains. Factors that influenced selection of the Klondike mine for exploration were favorable geological conditions, the state of mine development and the availability of pumping equipment and some usable mine and mill equipment. In December 1942, the Metals Reserve Co. leased the Klondike mine from the Salem Fluorspar Co.

Jan 1, 1949

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 produced 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 same type of stone. This report deals with relation¬ship 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 T. M. Garland

This report presents a Bureau of Mines assessment of crude oil and associated gas production and reserves that would result from different drilling efforts in the lower or contiguous 48 States during the 1972-85 period. The drilling effort was based upon five growth rate assumptions from the 1971 level. Additions to crude oil reserves were computed for nine cases resulting from the use of three equations for findings per foot drilled and three constant revision factors. The results indicate that the United States will not become self-sufficient in crude oil production by 1985 and also illustrate the lead time required to reverse the decline in oil production. Discussion is limited to three of the nine cases to provide high, intermediate, and low results. More emphasis is on the intermediate case because it is indicative of the most probable trends. The methodology and statistical data are included in the appendices.

Jan 1, 1974

A study was conducted by the Bureau of Mines to evaluate natural gas as an automotive fuel and to provide guidelines for optimum engine adjustments for low exhaust emissions. The study was conducted using a single-cylinder engine, a multicylinder engine, and a total of eight vehicles. Results from single-cylinder engine tests showed that the light-load, lean-limit misfire region for natural gas begins at an air-fuel ratio between 150 and 160 pct of stoichiometric. Changes in ignition timing significantly influenced emissions of nitrogen oxides and hydrocarbons, but had little effect on carbon monoxide emission. Low emissions can be achieved with current-design engines by adjustment of engine parameters, but only with heavy penalty to engine performance. Emissions from vehicles fueled with natural gas are virtually unaffected by ambient temperature change within the range 20° to 100° F. The organic emissions from engines fueled with natural gas were estimated to be 22 to 25 pct as reactive as the emissions produced using gasoline. Levels of exhaust emissions from vehicles fueled with natural gas were unchanged over 10,000 miles of normal driving.

Jan 1, 1973

By E. C. Lane

This paper on the physical and chemical properties of crude oils from California fields is one of a series of reports on the oil-producing districts of the United States. The paper includes a short discussion of results, tabular data, and individual analyses of 16 California crude oils. Analyses of other oil from California have been published in Reports of Investigations 25954/, 26085/, 28466/, and 30747/. The samples were obtained by members of the San Francisco office of the Bureau of Mines. The collecting of the samples vas facilitated by the courtesy of representatives of oil companies in California.

Jan 1, 1937

By E. C. Lane

This paper on the physical and chemical properties of crude oils from California fields is one of a series of reports on the oil-producing districts of the United States. The paper includes a short discussion of results, tabular data, and individual analyses of 16 California crude oils. Analyses of other oil from California have been published in Reports of Investigations 25954/, 26085/ 28466/, and 30747/. The samples were obtained by members of the San Francisco office of the Bureau of Mines. The collecting of the samples vas facilitated by the courtesy of representatives of oil companies in California.

Jan 1, 1937