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By H. E. Powell, T. E. Hill, W. A. Calhoun

The object of this investigation was to determine the effectiveness of certain cationic flotation collectors , Ethomeens , in recovering fine particles of lead minerals from mill tailings at a grade equal , at least , to that of the mill feed ( 1.7 percent lead ) . The Ethomeens , derived from tertiary amines having one fatty alkyl group and two polyoxyethylene groups attached to the nitrogen , were evaluated by bench- scale flotation tests . The 14 Ethomeens tested consisted of four groups : Coco amine , soybean amine , tallow amine , and stearyl amine . The best results were obtained with coco amine C / 12 , soybean amine S/ 15 , tallow amine T / 12 , and stearyl amine 18/20 . From a feed containing 0.23 percent lead , rougher concentrate grades of 2.12 to 3.89 percent lead were obtained , with recoveries of 17.3 to 27.5 percent of the total lead . Some of the lead mineral particles recovered had diameters of less than 1 micron . In comparative tests , the Ethomeens , or polyethoxylated amine types of cationic surface active agents , were more selective than conventional xanthate collectors for flotation of slimed lead minerals .

Jan 1, 1964

By G. B. Botsford

In August 1943 the Bureau of Mines began an investigation of the West Portal magnetite mines, which comprise the Swayze and Turkey Hill properties. The work included (1) traversing with a dip needle to record magnetic anomalies, (2) diamond drilling, and (3) sampling old mine dumps; it was completed in April 1944. The deposit consists of two parallel veins, which strike northeast and dip southeast. They carry magnetite in gneiss and schist. The Swayze mine was discovered in 1867 and closed in 1889, while the Turkey Hill mine was opened in 1872 and closed in 1887. The dip-needle survey covered 266 acres. The diamond drilling comprised 11 holes totaling 4,910 feet from which 142 samples were taken for chemical analyses. Old mine dumps were sampled at 52 points for chemical and magnetic analyses.

Jan 1, 1948

By J. H. East

Potash is one of the essential chemicals used in fertilizing soil deficient in natural minerals . Europe uses a large tonnage of potash in the form of easily soluble salts , and this is particularly true of those countries where the natural minerals in the soil have been exhausted owing to intensive cropping of the land . The application of potash to the soil in these countries is essential if normal crops are to be obtained ; during the war , some European countries were unable to obtain sufficient potash , and productivity of the farming areas declined seriously . • The largest -known deposits of potash in the world ; with the possible. exception of Russia , occur in Germany , and the German output of processed salts constituted about 65 percent of world production prior to the war . The German potash-plant installations are large , modern , brick and steel construction and apparently built for a planned operation of many years . Two districts produced approximately 80 percent of the German potash; the Werra -Fulda district , near Vacha , had the largest production , and the Sudharz district , near Nordhausen and Sonderhausen , was second . (Fig . 1. ) Hannover and Stassfurt were two smaller producers . Potash fertilizers are rated in terms of potassium oxide (K20 ) . The usual basis for calculation of production or application of the salt is to reduce the potash content to 40 percent K₂0 .

May 1, 1947

By H. D. Jacobs

The Bureau of Mines undertook a research program to insure an adequate supply of iron raw materials for future iron and steel making needs. A sample was obtained of oxidized taconite from the western Mesabi Range in Minnesota, and the metallurgical response of the taconite to beneficiation by a process that included selective flocculation-desliming-cationic flotation was evaluated. The sample contained 35.3 pct iron and represented approximately 2 billion tons of crude material. Selective flocculation and flotation were evaluated in a pilot plant with a feed rate of 900 Ib/hr. Concentrates averaging 61.7 pet iron and 5.1 pet silica were obtained, with an accompanying iron recovery of 67.2 pet. About 83 pct of the process water requirements were reclaimed from the slime and froth tailing and then recycled.

Jan 1, 1980

By D. J. MacDonald

As part of a U.S. Bureau of Mines program seeking improvements to the Bayer process, a typical Jamaican bauxite was heated at temperatures up to 500° C in hydrogen, and its leachability under Bayer process conditions was measured and properties of its leached residue were observed. The objectives were to find ways to decrease the amount of organic carbon in bauxite or in leach liquor derived from it without impairing its leachability, and to improve the leached residue's filterability. Techniques employed included heating bauxite under pressure in an autoclave with hydrogen, and in flowing hydrogen at ambient pressure in a tube furnace. Leaching tests were done with a 600-mL stirred reactor. In some of the leaching tests, ferrous sulfate (FeS04) was introduced before leaching to produce a partially magnetic product. Results showed that exposure to hydrogen at temperatures from 160° to 360° C progressively diminished the bauxite's content of organic carbon and decreased the ratio of organic carbon to aluminum in leach liquor, an improvement that would allow a process using hydrogen-treated bauxite to be operated at a smaller recycle ratio, thereby consuming less energy and allowing greater throughput for a plant of given capacity. The bauxite's leachability was not impaired by high-temperature pretreatments, except at temperatures higher than 280° C. Pretreatments in hydrogen produced black, partially reduced bauxite which upon leaching gave a residue that was attracted to a magnetic field and was amenable to separation from green liquor by a magnetic filtration method.

Jan 1, 2010

By Floyd D. Everett

The Cougar Spar property is in southwestern Beaver County, Utah, approximately 35 miles by road northwest of Lund, a station on the mainline of the Union Pacific Railroad (fig. 1). Original fluorspar discoveries on the property were made a. short time before 1941. During 1941 lessees produced approximately 600 tons of ores averaging 40 percent CaF2. Bureau of Mines engineers examined the property in 1942 and recommended development. Work was begun in December 1942 and completed in October 1943. The area was mapped by members of the Federal Geological Survey during the project period. Development included surface trenching; drifting, and crosscutting, a short distance below the outcrop. The surface work comprised a total of 440 linear feet of bulldozer and hand trenches. A total of 550 feet of workings was driven on the 100-foot level. Samples were taken for assay from the trench exposures and from the underground workings as work progressed. Pocks in the area of the Cougar Spar property are igneous and consist mainly of fine-grained tuff and quartz monzonite porphyry. The fluorspar mineralization occurs in a northwest fault zone.

Jan 1, 1951

By A. L. Engel

This report is a compilation of the results of preliminary tests on ores containing scheelite (calcium tungstate). In most of the ores, scheelite was the only value; but several samples contained other values, such as gold, base metals, or, in one instance beryl. These investigations were made to assist the development of domestic tungsten resources by establishing satisfactory treatment methods suitable for small-scale operations. The samples were obtained through the Mining Division of the Bureau of Mines and represent, for the most part, newly discovered deposits. A previous report2/ discussed laboratory test procedures. A less detailed description of test procedures is included in the present report. As is usual in an investigation of this type, only a limited amount of work was done on most of the samples to indicate the results that could be expected from simple treatment of the particular ore. The occurrence of scheelite and the texture of the minerals present differ greatly in individual ores and must be determined and considered in establishing such details of treatment as grinding to obtain optimum liberation of the minerals, the preferred type of gravity concentration, or possible further treatment by flotation.

Jan 1, 1954

By George W. Healy

The direct retorting of zinc sulfide concentrates in the presence of lime and carbon was examined on a laboratory scale with ten-gram charges of loose mix or fifteen-gram ones of pellets. A slow stream of nitrogen swept through the furnace tube over the boat of reactants, carrying with it the zinc vapor, which condensed on a rolled-up steel sheet near the exit, permitting weight of zinc produced to be obtained after completion of a run. Variables explored were percent of theoretical reagents, temperature, and time. During the runs gas samples were analysed periodically, and the content of CO2, CO and nitrogen were obtained. The quantities of the carbon gases could be calculated because the nitogen flow rate was measured. The gases were also examined for sulfur species, but neither COS nor SO2 could be detected at maximum sensitivity. Zinc recovery increased with excess carbon and lime and with temperature. It ranged from 77% at a ten percent deficiency to 90% at a ten percent excess at 1100°C. Going to 1200°C and theoretical reagents gave 93% recovery. Increasing time from 200 minutes to 300 minutes increased zinc yield by up to 10%. Results from sphalerite and a commercial concentrate from AMAX gave generally similar results. The reaction rate of zinc sulfide as sphalerite and of calcined sphalerite indicated that the latter reacted almost twice as fast, and recovery of zinc was five percent higher. Though the retorting step using sulfide, lime, and carbon proved to be non-polluting, it was feared that on storage the calcium sulfide in the residues would decompose, giving off noxious gases. Consequently the stabilization of the residues by oxidation was essayed. Because of the presence of unreacted zinc sulfide, the first product of oxidation was S02. Reaction of CaS to CaSO4 was incomplete, going from 20% at 800°C to 90% at 1200°C. Thus the non-polluting nature of the process as a whole is in doubt, and its economics are likely to be unfavorable compared to the traditional way of calcining the concentrates, followed by retorting of the oxide with carbon.

Jan 1, 1982

By H. D. Pallister

A review of? reports and literature on the pyrite deposits at Pyriton, Ala., indicated that a large tonnage of pyrite, some of which contained a small amount of copper, had been mined and shipped to fertilizer plants throughout the South. The information contained in this literature tended to demonstrate that the ore occurred in separate lenses of greater or less extent and of varying thickness and richness in pyrite as well as in copper. The outcrop being parallel with the Atlantic Coastline Railroad and just south of it makes the deposits readily accessible for shipment. Slopes could be sunk as they were in the past in the ore body if it were of sufficient grade and thickness, and the ore could be hoisted up the slope and milled close to the slope mouth with an ample supply of water from Talladega Creek, which follows the outcrop closely.

Jan 1, 1949

By Robert E. Barieau

In the design of plants to separate helium from natural gas , it is necessary to estimate the enthalpies of the various streams at various positions in the process . This Bureau of Mines report surveys the various methods that have been used to determine enthalpies and gives information on the organizations with such capabilities . The minimum information required for developing an enthalpy diagram is presented , and the relative merits of the various methods are discussed . It is concluded that methods that require no mass flow rate or energy measurements are to be preferred .

Jan 1, 1965

By Charles B. Kenahan

Vanadium is subject to only light corrosion in phosphoric acid at temperatures up to 60° C. and has a moderate corrosion rate in this acid at 100° C. It is relatively corrosion resistant in sulfuric and hydrochloric acids up to 60° C, but corrodes rapidly at 100° C. It corrodes rapidly in dilute nitric acid at 35° C. Vanadium is almost inert in 10-percent solutions of formic, acetic, lactic, tartaric, and citric acids; in 9-percent oxalic acid it corrodes slowly up to 60° C. and rapidly at 100° C. Vanadium is resistant to corrosion in substitute ocean water, tapwater, and in 3-percent sodium chloride and 10-percent sodium hydroxide solutions. It is readily attacked, however, by 20-percent ferric chloride, 20-percent cupric chloride and 5-percent mercuric chloride solutions. Vanadium is protected by contact with magnesium, aluminum, and steel SAE 4130 in substitute ocean water, by magnesium and aluminum in 3-percent sodium chloride solution, and by magnesium in tapwater. Vanadium protects copper in substitute ocean water. When vanadium and stainless steel are coupled in sulfuric acid solutions, both metals are usually unaffected by contact, whereas the corrosion rate of titanium in sulfuric acid is greatly reduced by contact with vanadium.

Jan 1, 1962

By E. C. Perkins

Preliminary experiments are reported utilizing bacteria to leach manganese from a variety of domestic low grade manganiferous materials. In two large leaches manganese extraction ranged from 71.7 to 92.5 percent, and the products analyzed over 48 percent manganese. Nutrient requirements and leaching time experiments were made. The mechanism of leaching is not understood, but is different than the mechanism encountered in the microorganism accelerated leaching of copper in the presence of sulfide minerals.

Jan 1, 1962

By David J. Kusler

This report describes a rapid, reliable, and relatively simple method developed by the Bureau of Mines Pyrometallurgy Laboratory at Bruceton, Pa., for determining lime (calcium oxide) and magnesia (magnesium oxide) in various materials containing these constituents in greater than trace amounts. Optionally, titania (titanium dioxide) may be determined for the same sample. The accuracy of the method, suitable for most purposes, is shown by comparing the Bureau results with those obtained by accepted procedures. The method has been applied satisfactorily to the routine analysis of blast-furnace slags, for which purpose it was primarily developed, and to other calcareous compositions. In the Pyrometallurgy Laboratory it has replaced the standard methods previously used to determine lime and magnesia, and has been in general use by that laboratory for the past several years. The analysis time, generally under 3 hours, is considerably less than required by standard methods.

Jan 1, 1960

By Lloyd Williams

1. The investigation shows that the Wilder (locally known as the Bon Air No. 2) is the only known bed of commercial importance in Putnam County, although at least 5 coal horizons are known. All of the coal production now reported comes from this bed, which is found In a basin with no known coal outcrops. Further drilling in the east end of the basin should disclose the location of the eastern end of the axial trough and the lateral extent of the basin in Putnam County and adjoining areas in Cumberland County. Continuity of this deposit with that in the area in Putnam County north of Monterey is not conclusively established but may exist. 2 Known (measured plus indicated) reserves of coal, based on a minimum bed thickness of 14 inches and on 1,800 tons per acre-foot in place, are estimated at 29 million tons, as of January 1, 1953. Of this total, 28 million tons are in beds 28 inches and more thick. All born coal reserves in Putnam County me under less than 400 feet of overburden.

Jan 1, 1954

By Joan T. May

The Federal Bureau of Mines investigated the potential for recovering aluminum from copper-dump leach liquors by use of single-contact ion-exchange technology. A strongly acidic ion-exchange resin was used to extract aluminum from a typical dump leach liquor and from synthetic leach liquors. Aluminum was stripped from resin with a HS04 or NaCl solution. Bench-scale experiments indicate that a single-contact ion exchange is technically feasible, but that the process is limited by the relatively low loading capacity of the resin and the excessive amount of stripping agent required. A further limitation is that significant amounts of magnesium and iron are loaded and stripped along with the aluminum.

Jan 1, 1976

By H. G. Iverson

As a part of the program of investigation of domestic sources of manganese ore, mining engineers of the Bureau of Mines examined and sampled three properties in the vicinity of Winnemucca, Nev. As the ores were too low grade for direct production of ferromanganese, they were tested for their amenability to concentration by ore-dressing methods. Two samples of ore were procured by examining engineers of the Bureau of Mines from several outcrops in the Pollard Canyon area, Pershing County, about 30 miles southeast of Winnemucca. The manganese occurs in relatively small lenticular bodies as secondary replacement deposits in chert and quartzite. The first sample represented average run -of -mine ore as exposed in the Pollard Canyon deposits. Sample 2 was composed of hand-sorted, high-grade ore.

Jan 1, 1954

By E. J. Lintner

This paper is one of a series being prepared by the United States Bureau of Mines describing clay mining and crushing methods and costs at various operations throughout the United States. These papers are designed to disseminate technical information regarding methods used. The cost tabulations represent local operating expenditures only and not total production costs. It is recognized that publication of total production costs might, in many instances, cause embarrassment to the individual operator as well as to the industry as a whole. On the other hand, operating costs are essential to a technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations may ensue. The author wishes to acknowledge the assistance of the following persons: L. W. Camp, general manager; S. Cooper, plant superintendent; and W. R. Riel, office manager.

Jan 1, 1936

By R. J. Hundhausen

The Takilma-Waldo copper district in Josephine County, Oreg., was studied by the Bureau of Mines from September 1950 to April 1.951 and from December 1953 to April 1954. Funds for the investigation were provided by the Bureau of Mines and the California-Oregon Power Co., Medford, Oreg., on a cooperative basis. The copper mines in the district are credited with a total production of ore worth $1,700,000. Since 1933 the mines have been unproductive and, except for minor exploration, largely inactive. The history of the district indicates that the copper deposits were mined principally during periods of high metal prices.

Jan 1, 1956

By R. V. Ramani, R. Bhaskar

"The National Academy of Sciences (1) recognized the importance of studying the spatial and temporal characteristics of respirable coal mine dust atmospheres. In this paper, the progress to date of a research project on dust transportation and deposition in mine airways is presented. A mathematical model is proposed for studying the transport of dust. A source representative of dust generation in underground coal mining is defined. The influence and applicability of surface roughness, dispersivities, coagulation and reentrainment to vine dust flow arc examined. A convective-diffusion model is proposed for the transport and deposition of dust in mine airways. Using the model, the spatial and temporal characteristics can be evaluated in terms of dust concentrations in the mine atmospheres.INTRODUCTIONThe prediction of the behavior of fine particles Is Important in many fields of science and engi¬neering including physics, chemistry, mining, mineral processing, and atmospheric science. In mining from the health point of view, fine coal dust is associated with the appearance of pneumoconiosis in miners exposed to the dust. Also, in addition to being a nuisance factor obscuring visibility and general mobility of miners, it can lead to sudden catastrophic incidences of explosions. This paper outlines the progress to date of a research project on dust transportation and deposition in mine airways. A mathematical model is proposed for studying the transport of dust for the various mechanisms. The dust dispersion is defined in terms of a dispersion term determined from experimental data by Skubunov (23). Coagulation is considered as one of the mechanisms that can lead to changes in the particle size distribution. Reentrainment as a possible secondary source of dust was examined during model development but was not included in the final model."

Jan 1, 1988

By G. W. Jones

[The determination of the ignition tcqornturc ol" dict:iyl cther and othylene in air ma o;GrT;en rir..ic'r. is dcscribed In thin report J'IF.R mqdo primarily for comparison rritll sinilnr d~ton:in:~tions of ot; cr co~~o~imS-r, in the same apparatus and using the r?.:?.r.~o 1a.borntorg t cchzllique The investigation was conducted at the 2ittsbur;;h Experiment Station of the United States wcau 02 hii2cs vritEl tl~c cooperation of licrclc & Co., Inc.]

Jan 1, 1935