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By B. R. Eichbaum, J. E. Murphy, J. A. Eisele

The US Bureau of Mines demonstrated ferric chloride leaching of galena concentrate on a continuous bench scale basis. Leaching was performed at 95°C (200°F) and with a contact time of 15 minutes. The ferric chloride leaching solution was continuously fed to a leaching tank at a constant rate for periods up to 45 hours. In each test, a constant redox potential was maintained in the slurry exiting the leaching tank by controlling the concentrate feed rate. In the 45 hour test, lead extraction exceeded 99.5%, and the lead chloride produced was 99.97% pure.

Jan 1, 1986

By L. M. Kaas

Maintenance costs comprise a large portion of total operating cost, 30% to 60% of the operating cost dollar not being unusual. Thus even a relatively small percentage reduction in this cost would represent a sizable increase to mining profitability. Mine and mill maintenance management is a complex problem. An effective maintenance manager must study the experiences of the past and make decisions based on that experience. Data Processing equipment-more specifically, the computer-can be an effective and economical tool to simplify the job of maintenance record-keeping and to aid in the formulation of many accurate and timely management reports. These reports will enable improved control to be established over day-to-day practices; permit comparisons of unit and component performance; spotlight inefficient maintenance practices; and further, better, more efficient cost control. The net result can be increased profits through reduction of operating costs.

Jan 12, 1967

By R. W. Smith, Z. Sadowski

The stabilities of finely divided mineral suspensions were determined as functions of pH and concentrations of polyethylene oxide, sodium ligninsulfonate, sodium dodecybulfate, and sodium oleate. In addition, the electrokinetic potentials of the minerals were determined under identical pH and additive concentration conditions. Flocculation or dispersion of the suspensions is discussed in terms of both the amount and manner of adsorption at the appropriate solid-liquid interface as it is influenced by additive concentration and pH.

Jan 1, 1986

By John A. Church

The operations of the Tombstone Mill and Mining Company, in Arizona, have been extensive and interesting; and I will eudeavor to describe what is novel in their work, without attempting to go over the well-known facts of silver milling, concentration and smelting which are the general branches of their business. Their mines are at Tombstone, and their mills at Charleston, ten miles distant. The ore has been mined only above water-level, and at first was

Jan 1, 1887

By Cyril Stanley Smith

BETA brass (consisting of approximately equal atomic proportions of copper and zinc) exists as a random solid solution at high temperatures, but at low temperatures [ ] an ordered structure is stable, with the copper and zinc atoms occupying alternate sites on the body-centered-cubic lattice. On cooling, ordering commences at a temperature of 450° to 490°C., depending on the composition. The degree of ordering progressively increases at lower temperatures until it becomes virtually complete at about 100°C. The electrical resistivity of the alloy illustrates the changes clearly (Fig. I). This type of reaction has been a favored subject for study by physicists. An [ ] excellent summary of the theory is to be found in a paper by F. C. Nix and W. Shockley.1 All published data on electrical conductivity, specific heat and other properties agree in indicating that the ordering reaction in beta brass takes place so rapidly that it cannot be prevented or even retarded by quenching. With most ordered alloys, cold-working induces disorder and

Jan 1, 1942

With over one year experience, Western Deep Levels Ltd., reports satisfactory operation with new features of its 200,000 ton per month gold reduction plant. Western Deep is Anglo American group's newest gold mine. It is situated 43 miles west of Johannesburg on the West Wits Line and will ultimately be extracting ore from a depth of 13,000 ft. Although the plant was put in production in March 1962, after a three month break-in period, construction of the fifth milling section was not completed until last month.

Jan 7, 1963

Elected Died 1895 *ABBOTT, AI ATTHUR 1908 1882 *ABBOTT, ARTHUR V 1906 1903 * ADAMS, CHARLES C. 1905 1884 *ADDY, MATTHEW 1896 1889 * AKERS, WILLIAMS 1906 1894 *ALLEN R B 1896 1905 * ALLEN, R. SCOTT 1906 1874 *AMIOT, H 1892 1886 *AMSLER, CARL 1894 1895 *ÅNGSTROM, CARL 1901 1900 * ARLETT, GEORGE H 1906 1895 *ARMSTRONG, JOHN F 1898 1882 *ARNOLDS, HUGO 1886 1875 *ASHBURNER, CHARLES A 1889 1872 *ASIIBURNER, WILLIAM 1887 1883 *ATKINS, C M , JR 1885 1905 * AUDTIN, PETER T 1907 1897 *AYERS, WILLIAM 1898 1885 *BABCOCK, GEO H 1893 1884 *BAILEY, EDWARD 1889 1880 *BAILEY, JACKSON 1887 1900 *BALLOU, FRANKLIN 1903

Jan 1, 1910

US underground mine production of nonfuel minerals was 153 million tons of crude ore in 1971, according to a recent US Bureau of Mines report compiled by Dravo Corp. Underground capacity includes all nonfuel mineral commodities and is distributed into three general categories: (1) metallic ores; (2) nonmetallic ores; and (3) construction materials, such as clay, sandstone, and limestone. All three categories are produced by a combination of open-pit and underground methods. While US underground mining represents only 5.9% of total domestic capacity, it is significant in the types of products produced. Domestic supplies of potash, trona, A lead, zinc, sulfur, and fluorspar are almost exclusively recovered from underground mines, as well as a significant portion of the gold, silver, molybdenum, and salt supply.

Jan 7, 1975

This brief resume of the events transpiring in Mexico, culled from the daily New York newspapers since the last Bulletin went to press, does not show any degree of improvement in the situation. MEXICO SEEKS TO AVOID BLAME FOR BANDIT RAIDS All foreign passengers leaving Nogales for Mexico on the Southern Pacific or Mexico Railroad. whose business would take them through territory occupied by the Yaqui Indians or Mexican bandits were requested by Mexican Consul Emilio Tamez to sign a statement that they relieve the Mexican government of responsi-bility for anything which might happen to them while in that part of Mexico. The Mexican consul stated, says the N. Y. Tribune, that this was by order of Mexican Ambassador Ignacio Bon ill as, at Washington. When the State Department was advised of this activity Secretary Phillips, in a message to the consulate at Tampico, according to the N. Y. Tribune, asserted that "compliance with the waiver requirement will not interfere with the relation existing between the United States and its citizens and that Americans so complying will in no way lose the protection of this government."

Jan 11, 1919

By B. Van Voorhis

Successive changes have been made in stoping methods at the Magma mine. Factors that have made these changes advisable are: vein width, heavy and swelling wall rock, abnormal rock temperatures, ventilation, labor costs, timber costs, mining speed, and labor-saving mechanical developments. Additional localized conditions, such as low angle post-mineral faulting and selective mining, have also made changes necessary. A stoping method with enough flexibility to meet most of these conditions has been in use for the past ten years. The Magma Copper Co. was organized by the late William Boyce Thompson in 1910 and acquired by purchase and location several groups of contiguous claims, among them the Silver Queen property. The Hub and Irene claims acquired in this purchase cover the apex of the vein, and all stoping done up to 1920 was from these two claims

Aug 1, 1956

By Terry G. Richard, Sunder H. Advani

A sequence of 250 unconfined compression tests were completed on a common marine shale indicative of the overburden strata of east- central Ohio. The samples were of a light gray clay shale of Pennsylvanian age. The shales considered are obvious layered materials with distinct bedding planes. For this reason there is sufficient evidence to consider this material as anisotropic in nature. With a properly chosen reference coordinate system this anisotropy can be reduced to a layered orthotropic characterization. This implies that the mechanical properties can be specified with regard to principal material directions. With this nature in mind a systematic study of the combined influences of strain rate and moisture conditioning was initiated. Of particular interest is the variations in unconfined ultimate compressive strength with variations in the controlled parameters of strain rate, moisture conditioning level and direction of testing. Results of this particular phase of the program are presented.

Jan 1, 1982

By Jerry L. Taylor

Utah Power & Light Company is an electric utility serving approximately 1.8 million people in Utah, Idaho, and waning. In order to supply coal to fuel power plants, Utah Power & Light awns three mines in central Utah. Planning for these mines is aided by a computer program developed by the staff mining engineers. This program, when supplied with the pertinent seam and mining configuration data, calculates the time to mine each section. This allows the planning engineer to estimate accurately the time required to extract pillar sections or develop longwall panels. The program's greatest benefit, however, is its ability to allow the engineer to examine quickly, different combinations of possible mine layouts to determine the most efficient plan. Computer aided mine planning has been used at Utah Power & Light Company since 1979, and has significantly improved the accuracy and quality of mine planning.

Jan 1, 1983

By Kenneth E. Kulp, Theodore Botinelly, George J. Neuerburg

Distribution of hypogene iron oxides may be useful in prospecting the Montezuma district, central Colorado, for certain metals, some of which have not been mined or sought in the district. The depletion of accessory magnetite in fresh rocks of the Montezuma stock identifies sources of ore minerals for the pneumatolytic metals, locates probable areas of possible contact-pneumatolytic deposits, and, in the altered rocks of the stock, identifies rock through which hydrothermal ore fluids have passed. Specularite veins are located in structures through which pneumatolytic ore fluids have passed and thus indicate optimal areas for prospecting. The presence of unusual amounts of vicarious metals such as bismuth, mercury, tin, and tungsten serves to identify magnetite and specularite that were involved in the pnematolytic ore process.

Jan 1, 1972

By Edwin B. Johnson

The success of self-fluxed sinter in enhancing the operation of the blast furnace during the past few years has reasonably led to the assumption that the use of self-fluxed pellets might result in even greater furnace efficiencies. A great share of development work in agglomeration has been directed towards techniques related to the production of self-fluxed pellets, but no appreciable tonnage of self-fluxed pellets had been produced on a commercial scale until this past year when The Cleveland-Cliffs Iron Co. produced 35,000 tons of such pellets by the grate kiln system at the Republic mine during the period May 21-June 5, 1962.

Jan 3, 1963

By Frank Schrader

J. DANA SPERR, Jerome, Ariz. (communication to the Secretary*).¬Very little accurate information has been published about this district. Most of the geological data appearing in the technical press are based on "careful observations" made from an auto stage and a casual glance through the U. S. Geological Survey Bulletins, No. 340 of 1908 or No. 397 of 1909, both by F. C. Schrader. Mr. Schrader's report is still the best publication on the district. A really careful study of this report will uncover only a very few statements which have since proven questionable. This is a remarkable record when it is considered that only a short time was spent by Mr. Schrader in the field and that there was very little development work done at that time. The mining world and especially Mohave County, Ariz., will feel a sense of gratitude to Mr. Schrader for revising his early report. on this

Jan 3, 1917

By John K. Dienes

The permeability of sands and soils seems to be adequately de- scribed by Darcy's law, but the permeability of rocks is complicated by a number of factors related to the probability of crack intersections. During the last few years we have developed a statistical theory of fragmentation which has been successful in explaining the observed behavior of rocks. In this paper, a theory of permeability is developed which draws on the concepts employed in previous work. The permeability involves three factors, the average fluid flux per crack, the number of cracks per unit area, and the fraction of cracks that are not isolated. Probabilistic ideas are used in connection with the hydrodynamic theory of flow through a single crack to develop an integral expression for permeability. The result has the form of Darcy's law for anistropic media. Although the current work is motivated by the need to develop optimized oil-shale retorts, we believe that the theory can be applied to a variety of other problems.

Jan 1, 1982

By Andrew Roy

The Mahoning Valley coal region lies on the extreme northern outcrop of the Ohio coal-field, and all the mines, with one exception, are opened on the lower coal of the series, No. 1 of the Ohio Geological Survey. The coal ranges from an inch to five, six, and sometimes seven feet thickness, the workable height being between two and a half and six feet. There are two varieties of coal, known in market as "Briar Hill coal " and " Mineral Ridge coal;" both varieties are drawn from the same seam. The Briar Hill coal is generally called block coal, and is the kind so largely used in a raw state in smelting iron. It possesses a laminated structure, easily splitting into horizontal sheets, but is very difficult to break in the opposite direction. The faces of the layers are often covered with a soft, dead, carbonaceous material, like charcoal, and the whole seam throughout is marked by alternate layers of dead and bright-looking coal. In the act of combustion the coal neither swells nor changes form, the masses retaining their shapes until they fall to ashes in the furnace. The Mineral Ridge variety is much softer, and is also shorter in the grain than the Briar Hill kind, and it contains a good deal of

By K. V. S. Sastry, S. C. Panigraphy, D. W. Fuerstenau

The batch balling behavior of hematite, magnetite and limestone was found to depend markedly on the grinding method used for feed preparation. Wet ground materials require higher moisture for balling than do dry ground materials. Further, as the fineness of the wet-ground material is increased, the overall rate of agglomeration decreases, whereas the opposite is true for dry-ground materials. In contrast, the resulting pellet size distributions are not affected by the nature of the feed material preparation. These differences and similarities in the agglomeration behavior between wet and dry ground materials may result from the hydrophilic/hydrophobic nature of the surfaces, the formation of pre-agglomerates during dry comminution, and possible variations in the packing density of particles in the agglomerates.

Jan 1, 1978

By R. Hogg, F. F. Aplan, P. B. Bradley

The mineralogy of the solids contained in the black-water effluent from coal preparation plants has been investigated. Samples were obtained from 13 locations, representing major coal seam in the Appalachian, mid-continent, and western regions of the United States. On the average, the samples were found to contain 60% carbonaceous material with the balance as mineral matter. The mineral fractions from all of the samples from the eastern half of the United States were found to be remarkably similar, consisting of over 50% illitic clays; about 10-15% each of kaolinite, calcite, and quartz; and lesser amounts of chlorite and pyrite. The western samples were somewhat different, generally containing significant quantities of montmorillonite clay. Flotation may be wed to recover additional clean coal contained in the black-water discharge.

Jan 1, 1981

By W. M. Morris

THE volumetric behavior of isobutane at temperatures below its critical temperature has been studied by several investigators. Seibert and Burrell1 measured the vapor pressure of isobutane from the ice point to the critical temperature. Dana and co-workers2 determined among other thermodynamic quantities the density of the saturated liquid and the saturated gas and the vapor pressure from approximately 0° to 130° F. Sage and Lacey3 studied a number of the thermodynamic properties of this hydrocarbon from 70° to 250° F. The specific volume in the gas and liquid region was determined at pressures up to 3000 lb. per sq. in. ? throughout this temperature interval. In addition, the vapor pressures were measured at 30° intervals. These data taken together serve to establish the thermodynamic behavior of isobutane at temperatures between 0° and 250° F. with reasonable accuracy. However, apparently there are no data available at the higher temperatures. For this reason an investigation of the volumetric behavior of isobutane at temperatures between 100° and 460° F. was carried out with apparatus that has been described in another paper (A.I.M.E. Tech. Pub. 1127).

Jan 1, 1939