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By J. G. Donaldson

A bench-scale method for recovering lead and zinc from slimes and mill tailings from the Tri-State District of Missouri, Oklahoma, and Kansas was developed by the Bureau of Mines. Dilute hydrochloric acid, containing sodium chloride, and chlorine gas were used to decompose the mineral constituents. Lead was electrolyzed from the pregnant acid solution, and zinc was precipitated from the depleted electrolyte by neutralization with lime. Up to 98 percent of the lead was recovered in an impure lead electro- deposit assaying approximately 85 percent lead. Zinc recoveries up to 90 percent of the total were attained in a precipitate assaying approximately 40 percent zinc.

Jan 1, 1963

By D. C. Dahlin

The Bureau of Mines has investigated podiform chromite deposits in three ultramafic bodies in the Caribou Mountain and lower Kanuti River areas of central Alaska. The investigation, reported in two parts, was done as part of the Bureau's mission to help insure an adequate supply of minerals to meet the Nation's needs. Part I describes an extensive field investigation and mineralogical studies by personnel from the Bureau's Alaska Field Operations Center. This report, part II, describes the mineralogy of 11 samples that were high-graded from surface exposures at 10 sites and presents the results of laboratory batch beneficiation tests designed to concentrate the chromite. The 11 samples, peridotites and chromitites that consisted of variable amounts of chromite or chromium-bearing spinets, olivine, and serpentine, were beneficiated by grinding and sizing, gravity concentration, and electrodynamic separation. Three high-chromium chromite concentrates, two high-iron chromite concentrates, and one high-aluminum chromite concentrate were produced. Three other concentrates were marginal, and two were submarginal. Chromium recoveries ranged from 54 to 92 pct. These results indicate that the areas may be significant chromium resources. Potential platinum association with the chromite was also investigated. Analysis of these 11 samples indicates that the areas are not good platinum resources.

Jan 1, 1983

By Michael S. Miller

The Carson-Iceberg RARE II study area, consisting o; 209,990 acres (134,983 ha), is on the crest of the Sierra Nevada in California, about 35 mi (56 km) south of Lake Tahoe. The area is divided into four parts: C4-986; C5-986; and B5-986, north and south portions. No mineral production has been recorded for the area. However, gold, silver, and tungsten resources and potential for additional resources have been estimated for the area and just north of area C4-986.

Jan 1, 1981

By Willard L. Hunter

The Bureau of Mines studied the effect of temperature upon the reduction of chromite by carbon and the relative reducibility of chromites as a function of their composition. Ferric oxide was also studied to provide comparative data. Pellets weighing approximately 1 gram and containing 70 percent ferric oxide, chromic oxide, or chromite and 30 percent graphite were subjected to closely controlled temperatures under a flow of argon for 15 minutes. The amount of CO and CO2 evolved was measured, and the reduced sample was analyzed by X-ray diffraction techniques. The reduction of Fe2O3 was studied over a temperature range of 600° to 1,400° C, while the reduction of Cr2O5 and chromite was conducted from 9000 to 1,621° C. The temperature above which appreciable reduction of Cr203 by graphite took place was 1,125° C. The temperature at which significant reduction started for three of the four chromite samples was approximately the same, indicating that there was concurrent reduction of iron and chromium oxides in the chromite mineral rather than selective reduction of iron oxides followed by reduction of chromic oxide. Rhodesian chromite appeared to dissociate at a lower temperature with concurrent reduction of iron. Based on the temperature at Which chromite was 50 percent reduced in 15 minutes, Transvaal chromite reduced most easily, followed by Mouat, then by Kampersian, and finally by Rhodesian DFC material. Statistical analysis of test results indicated that the ferric iron content of chromites affects their reduction behavior more than any other constituent.

Jan 1, 1966

By D. E. Wolfson

The Bureau of Mines carbonized 35 coal samples from Logan and Mingo Counties) W. Va., at 900° C using the Bureau of Mines-American Gas Association method, and determined yields of products and physical properties of cokes. Twenty samples represented the No.5 Block, Stockton, Chilton, Cedar Grove, Lower Cedar Grove, Alma, No. 2 Gas, and Eagle beds in Logan County, and 15 samples represented the Coalburg, Buffalo Creek, Winifrede, Cedar Grove, Lower Cedar Grove, Alma, and No.2 Gas beds in Mingo County, W. Va, Chemical analyses were determined for all coals. All coals in both counties rank as high-volatile A bituminous. Most of the coals are chemically suitable for metallurgical coals. Coals with accept-able ash and sulfur contents can be used as major constituents in coking blends with higher rank coal to yield coke with satisfactory properties for blast furnace use.

Jan 1, 1967

By Kevin Malone

Chrysotile asbestos occurs in many counties in California, and a small production had been reported at times, but development of deposits had been disappointing. A reconnaissance survey by the Bureau of Mines indicated that several deposits in the serpentine belt in Shasta, Trinity, and Siskiyou Counties might contain enough asbestos of filler grade to supply the growing demand on the west coast. Accordingly from 1956 to 1958 parts of the Mount Eddy and Shasta View deposits were investigated by trenching and diamond drilling to determine their potential. The work comprised construction of roads, bulldozer trenching, excavation of areas for diamond drilling, sampling, and upping. The trenches were excavated to expose the surface extent of some of the asbestos-bearing areas, To determine the downward continuation of asbestos-bearing sections and to secure samples for test purposes, six diamond drill holes, totaling 1,738 linear feet, were drilled in two selected areas. The trenching and core-drilling indicated that the asbestos-bearing material occurs as ribs and lenses of varying thicknesses in a broad belt of serpentine, about 600 feet wide and several miles long,

Jan 1, 1962

By M. M. Kirk

Forced-air cooling of cold-mold arc furnaces for melting zirconium and similar metals has been investigated and found to be practical from the stand-point of heat transfer. It is believed that this technique offers a significant reduction in explosion hazard from that inherent in water cooling, the current industrial practice. A copper crucible, with longitudinal, integral-type fins and with an outer jacket to confine the airstream, appears to be the best general design for air-cooled operation. Cutting the fins into short segments and bending the segments to produce a herringbone effect increased the airstream's turbulence and was found, on test, to increase the heat transfer up to 35 percent.

Jan 1, 1959

By G. T. Fisher

The U.S. Bureau of Mines conducted research on calcium ferrite slags to determine the distribution of Pb and minor elements (Ag, Cd, Zn, and Co) between Pb bullion and slag. These fundamental data are required to evaluate nonferrous smelting with calcium ferrite slags as a substitute for conventional iron silicate slags. Determinations were made in 25-cm3-capacity MgO crucibles at 1,250° C for 2 h in a CO-CO2 atmosphere with an O2 potential that would retard the formation of magnetite. Calcium ferrite slag composition variables studied were from 16 to 32 wt pct CaO in 2-pct increments and Si02 ranging from 1 to 5 wt pct in 1-pct increments with equal additions of MgO. For all compositions studied, the retention of Pb in the calcium ferrite slag was less than 1 wt pct, which compares favorably to about 6 wt pct Pb in conventional iron silicate slags used in smelting of Pb concentrates. Minor element distribution was insensitive to changes in slag composition in the range studied. However, slag composition had significant impact on the melting and fluidity of the slag.

Jan 1, 2010

By E. D. Gardner

This paper is one of a series on mining methods and costs being published by the United States Bureau of Mines. In April 19.74 the St. Joseph Lead Co., at Atlanta, Elmore County, Idaho, was mining and milling about 225 tons of gold ore daily with a total force of 150 men. The mine, which comprises the old Boise-Rochester and Monarch properties, is at an elevation of about 6,000 feet. Snow lies on the ground about 5 months each year but does net interfere greatly with local operations. However, the road to Mountain Home, the shipping point 80 miles distant, passes over a high range and usually is closed by snow from about November 15 to June 15. Heavy supplies are brought in and concentrates trucked out during the summer. In winter the district is served by a biweekly mail plane and a passenger and express plane making 4 to 6 trips weekly. Mine timber is cut locally. A plentiful supply of water is obtained from a stream brought to the property through 7,500 feet of plume.

Jan 1, 1935

By Wilber Duvall, Leonard Obert

"INTRODUCTION This report is the first of four to be presented on the microseismic method 4/ of predicting rock failure in underground mining. The application of the microseismic method to one specific case, namely, that of predicting rock bursts in deep mining, has been described in two previous reports. 5/ 6/ Since the publication of these reports 5/ 6/ the method has been extended to other fields of mining, end it is the purpose of this report (Part I) to describe the general microseismic method, giving the empirical facts upon it is based, the different testing procedures, the method of recording and analzing the data, and the interpretations that can be obtained there-from. Part II will describe a series of laboratory experiments that were performed to give information on the origin of microceismims and the microseismic properties of various rocks. Part III will cover application of the method to specific mining problems together with a brief description of a number of investigations performed during, the last three years. Part IV will describe in detail the microseicmic equipment used in the various phases of these investigations."

Feb 1, 1945

[In presenting this list of permissible explosives and blasting devices, the Bureau of Mines desires to call attention to pages 17 and 23, outlining the conditions in use under which, and only under which, the explosive or blasting device is permissible. In view of publications recounting trade practice favoring the use of a blasting device without stemming, particular emphasis is placed upon condition 4 on page 17 and condition 2 on page 23. An explosive or a blasting device enumerated in the permissible lists of thin Bureau is not permissible in use unless it is properly confined with clay or other incombustible stemming.]

Jan 1, 1941

In presenting this list of permissible explosives and blasting devices, the Bureau of Mines desires to call attention to pages 17 and 23, outlining the conditions in use under which, and only under which, the explosive or blasting device is permissible. In view of publications recounting trade practice favoring the use of a blasting device without stemming, particular emphasis is placed upon condition 4 on page 17 and condition 2 on page 23. An explosive or y blasting device enumerated in the permissible Lists of thin Bureau is not permissible in use unless it is properly confined with clay or other incombustible stemming.

Jan 1, 1941

By Richard W. Lewis, Lloyd Carpenter

The objective of the investigation was to determine spectrochemically 19 elements in the general range of 0.5 to 1,000 ppm in high - purity hafnium and its compounds . Samples were converted thermally to hafnium dioxide , mixed with buffer - carrier - internal standards , and excited by a dc arc . Spectra were recorded on photographic plates . Transmittance values were recorded densitometrically and converted to relative - intensity ratios . Four groups of standards were used to establish analytical curves from which the concentrations of impurities were obtained . Average precision of the method was 14.2 percent relative standard deviation , and relative error was 4.2 percent .

Jan 1, 1964

By John P. Gooch

The solubility of 1,1,2,2-tetrabromoethane (TBE) in water was determined from 1.0° to 97.0° C. The solubility (S) of TBE in grams of solute per 100 grams water was correlated with [S = 1,920.55 [exp (40292L7 11, T2 10 T 737.577 + 9.923962 ] where T is in degrees Kelvin. A thermodynamic analysis conducted on a system consisting of a TBE phase and a water phase in equilibrium with a vapor phase led to the calculation of the activity coefficient, vapor-liquid equilibrium distribution coefficient, relative volatility, and heat of mixing for saturated solutions of TBE in water. Data required for these calculations were the solubility of TBE in water and the vapor pressures of TBE and water as a function of temperature.

Jan 1, 1972

By Q. H. Forbes

"The high injury rand fatality rate in coal mining, as compared with other industries, has caused the mining industry to become more and more interested in accident prevention methods.The prevention of accidents in the mining industry is probably not as simple a problem as it is in other industries, but if the experience of coal mining companies who have taken up the work of accident prevention seriously during recent years means anything, there is little doubt that most mining companies car improve their accident records very materially.Such results can be obtained in practically all instances without adding to production costs. In fact, there is little doubt that a well-organized program of accident prevention Will bring about a 'material production cost reduction due to increased efficiency, lower labor turnover, fewer delays due to accidents, better satisfied workmen, and a direct saving in compensation costs as well as many other items of expense.The more closely a. person is connected with the work of accident prevention, the more he becomes a believer in the value of amity in human relationships and the more he is able to exercise a spirit of toleration, fairness, justness, and helpfulness toward the problems of others, whatever those problems may be. Human nature responds to just these expressions of good willAnother great and invaluable effect of working for safety, is the fact that it is building up in the mind an appreciation of that which is constructive and, conversely, in opposition to that which is destructive In other words; the person who is sincerely striving to prevent accidents because they are destructive, costly, tad injurious, is subconsciously training his mind to look on any proposition from a constructive point of view. Working for accident prevention and safety is about the finest social training any person can have. It does not make a Person a financial Wizard or an executive genius, but it does make for the highest type of citizenship.While humanitarian reasons alone should be sufficient to maze accident prevention work an important factor in every mining organization, there are other reasons as well, since it has been proved conclusively that there can be no efficiency and economy without safety, as somebody pays when safety is lacking. Every safety device pays dividends; every safety application evaded is an assessment and a loss. Dangerous conditions are the most expensive and extravagant conditions in or about a coal mine. The economic gains are of considerable interest to all coal mining companies and this is brought about as before stated--through decreased compensation rates, the reduction of labor turnover, etc."

Dec 1, 1930

By G. L. Oldright

This paper is the twelfth of a series on smelting in the lead blast furnace and the fifth dealing with blast-furnace gases. It was noted in Report of Investigations 2957 that the gases evolved from the top of the lead blast furnace at Tooele were similar in composition to those from the top of an iron blast furnace. It was noted in Report of Investigations 3095 that at Kellogg, where a smaller percentage of coke on charge and shorter stock column were employed, the gases evolved were much less reducing. At times there was a considerable amount of oxygen in the top gases at the second plant. More SO2 was also evolved from sulphides in the charge. Then operations were conducted as at Kellogg, the gases were alternately reducing and oxidizing. This paper deals with the gases evolved in smelting a charge containing more zinc than at either of the other two plants with about the same amount of coke as was used at Kellogg,: To compare other factors influencing the composition of the gases, it may be noted that at Tooele the approximate height of the charge column was 15 feet, at Kellogg 9 feet and at Trail 13 feet. The furnaces have about the -same cross-sectional area- tog. The furnaces at Tooele are about 6 inches wider at the tuyeres, being 54 inches wide against 48 for the other two plants. At Tooele and Kellogg the furnaces are fed at the top from bottom-dump cars. At Trail the charges are dumped from Decauville cars (bottom cars which dump when tilted), which run on tracks placed on both sides of the blast furnaces. The hoods through which the waste gases are conducted are directly above the shafts of the furnaces. The flues for removing the effluent gases lead off from under the charge floor at Tooele and Kellogg. (Charging and distribution of the feed in the furnace covered later in a rate paper of series.)

Jan 1, 1934

By James P. McGee

Use of nuclear reactors to furnish high-temperature heat is a field that has not received as much attention as propulsion and electric power production. Investigations are being conducted under a joint Atomic Energy Commission (AEC)--Bureau of Mines research program to determine the feasibility of using nuclear heat for chemical processing. A part of this process-heat-reactor program is the study of a system in [hich] helium transfers heat from 8 nuclear reactor to a chemical processing [essel]. This requires construction of (1) a nuclear reactor to operate with helium exit temperature of 2,500° F. and with pressures in the range of 250 to 500 p.s.i.g. and (2) a processing vessel (heat exchanger) to convert the enthalpy of the helium into chemical process reaction heat. Neither component exists at present, and development of each promises to be a formidable task. To aid in the study of such a system, the Bureau of Mines has designed and constructed a vessel heated by electrical induction to simulate a source of nuclear fission heat. This vessel is undergoing preliminary testing. Gasification of coal and reforming of hydrocarbons are promising uses for nuclear heat. It appears that a higher price per unit of nuclear heat can be tolerated for chemical processing than that allowable for power generation.

Jan 1, 1960

By John A. Johnson

[Tests were conducted at the Mount Weather testing adit of the Bureau of Mines4/ on the effectiveness of spraying water along the outside of the drill steel as compared with standard wet-drilling practice. The spray equipment used in the tests was designed primarily for the control, in quarries, of dust from dry drilling with solid type drill steel. EQUIPMENT Spray equipment is made in sizes to fit different drill steel but is alike in design, the only difference being in the diameter of the ring and the number of spray holes. The device is made of cast steel and has a coating of Stellite on the inside edge that comes in contact with the drill steel. It looks like a garden spray, except that the spray holes point in only one direction.]

Jan 1, 1939

By John E. Miller

A high accuracy Burnett apparatus for use at 12,000 psi and 0° to 65° C has been constructed at the Bureau of Mines Helium Research Center. The apparatus is patterned after Burnett's original apparatus, but the working pressure is much higher and elastic distortion can be essentially eliminated. An operating procedure to permit faster experimental measurements is suggested.

Jan 1, 1967

By Harold P. Rue

The problem of removing hydrogen sulphide from natural gas has become within the last few years one of major importance to the natural gas and petroleum industry. Several gas fields in the United States produce natural gas containing hydrogen sulphide, and a number of oil fields produce gas which contains hydrogen sulphide. 3 The percentage of hydrogen sulphide in natural gas produced in these fields varies from a fraction of 1 per cent to as high as 20.5 per cent by volume. Hydrogen sulphide is probably the most toxic gas associated with natural gas, and from the standpoint of health and safety it is important that the hydrogen sulphide be removed if the gas is to be used for domestic purposes. Hydrogen sulphide, besides being toxic and therefore a hazard to animal life, is under certain conditions an active corrosive agent and very destructive to equipment. The annual loss caused by the corrosive action of hydrogen sulphide on equipment amounts to hundreds of thousands, perhaps millions, of dollars. The largest percentage of natural gas produced in the United States comes from wells which also produce oil. This associated gas invariably carries with it light fractions of petroleum, which when separated from the gas, condense to the liquid form at ordinary temperatures and pressure. Commercial application is made of this natural condition, and "wet gas" is processed to obtain so-called natural gasoline by employing the principles of absorption, adsorption, or compression and subsequent expansion accompanied by cooling. In the manufacture of natural gasoline from wet gas which contains hydrogen sulphj.de, if this contaminating gas is not first removed, some of the hydrogen sulphide may oxidize to form free sulphur and water. The free sulphur will dissolve in the gasoline produced by any of the aforementioned methods and cause the product to be positive to the corrosion test and there-fore unsuitable for commercial use in that condition. The objectionable sulphur compounds can be removed by washing the gasoline with a solution of caustic soda or other chemicals, but this treatment is expensive. It is advantageous therefore to remove the hydrogen sulphide from the gas before it is processed in a natural-gasoline plant.

Jan 1, 1932