Search Documents

By G. M. Ritcey

Purification of solutions can involve various treatment methods. In the normal sequence of metals recovery by hydrometallurgy, the ore is initially prepared for leaching by grinding to the desired optimum mesh size as dictated by the leaching parameters. Following leaching and liquids- solids separation, the resultant solution is ready for purification. The use, or introduction of solvent extraction into a plant, can be either a major or a minor part of the metal recovery process as shown by the following list where solvent extraction is normally considered: a) recovery of a metal by a simple leaching of the broken ore, e.g., copper from dump leaching where there are only the three main steps of leaching, solvent extraction, and electrowinning (1);

Jan 1, 1978

By R. S. Archibald

THE Blueberry mine is about 10 miles west of Ishpeming, Marquette County, Michigan. The property consists of about 2000 acres in sets. 3, 4 and 5, T. 47, N.R. 28W. and sets. 32, 33 and 34, T. 48, N.R. 28W., and, excepting one intervening 80-acre tract, contains the iron formation for a length of about 2 1/4 miles. The property is traversed by State Highway M-28 and is served by three railways, the Chicago & Northwestern, the Duluth, South Shore & Atlantic, and the Lake Superior & Ishpeming. The Northwestern transports the ore to a dock at Escanaba; the other railways, to Mar¬quette. Ore for Chicago goes via Escanaba and that for Lower Lake ports, as Detroit, Cleveland, and Buffalo, via Marquette.

Jan 1, 1935

By I. E. Rosenzweig

The problem considered in this paper is as follows: An arbitrary horizontally stratified area is given. The electrical properties of this area are characterized by a function p(z) (Fig. I), which shows the relationship between resistivity p of the soil and the depth z. For such general case the apparent resistivity p* will be computed, by earth-resistivity measurements carried out by any given configuration of electrodes. General solutions of this problem appear to be very important for interpretation of field results of resistivity measurements, concerning structural investigations. Such solutions have been given by many authors for the special case of a finite number of homogeneous layers (Fig. 2)lV4 as well as for the more general case of continuously ranging resistivities.5-8

Jan 1, 1940

By I. E. Rosenzweig

The problem considered in this paper is as follows: An arbitrary horizontally stratified area is given. The electrical properties of this area are characterized by a function p(z) (Fig. I), which shows the relationship between resistivity p of the soil and the depth z. For such general case the apparent resistivity p* will be computed, by earth-resistivity measurements carried out by any given configuration of electrodes. General solutions of this problem appear to be very important for interpretation of field results of resistivity measurements, concerning structural investigations. Such solutions have been given by many authors for the special case of a finite number of homogeneous layers (Fig. 2)lV4 as well as for the more general case of continuously ranging resistivities.5-8

Jan 1, 1940

By Harlowe Hardinge

THE sound made by ball, pebble and rod mills has long been used by the operator as the "telltale" of their operation. The nature of this sound depends upon local conditions and the type of mill used. By experience an operator can tell whether the mill is running properly or not. Some operators are able to detect the difference in sound much better than others and get better results running the same mill tinder the same conditions. The automatic operation of a mill using sound as the fundamental means for maintaining control presents many problems. The satisfactory solution of these problems requires, for given operating conditions, a greater average output, with improved product for subsequent processing, than can be obtained by manual control.

Jan 1, 1939

By Theodore H. Eyde

The Superior Oil Co. drilled two holes, 4720 and 5940 ft, respectively, using conventional oilfield rotary drilling equipment. The results indicated that large rotary drills can be adapted to mineral exploration purposes with few modifications. The principal advantages are: a large hole diameter, excellent samples of cuttings, a geolograph which is a constant drilling record, rapid penetration even in hard rocks, and the ability to use electric logs for measuring the properties of the rock being penetrated. The disadvantages are the high cost of mobilization, drilling, and oilfield service at remote locations. Though the oilfield sampling techniques are adequate for identifying lithology, improvements are necessary to obtain representative samples for analytical purposes. As deeper targets are explored, mineral exploration organizations will have to resort to rotary drilling.

Jan 1, 1975

By J. O. Lewis

Oil wells usually reach their maximum daily output shortly after they are completed. From that time they decline in-production, the rapidity of decline depending on the output of the wells and on other' factors governing their productivity. The production curve of a well shows the mount of oil produced per unit of time for several consecutive periods; if the conditions affecting the rate of production are not changed by outside influences, the curve will be fairly regular, and, if projected, mill furnish useful knowledge as to the future production of the well. By the aid of this knowledge the value of a property may he judged, and proper depletion and depreciation charges may be made on the books of the

Jan 2, 1918

MISCELLANEOUS U.S. 0,029,598 - Extraction of vanadium values from vanadiferous iron oxide ore. A pelletized mixture of ore, limestone and bentonite is roasted in an oxidizing atmosphere to form calcium vanadates, the calcine ground, the ground material leached with aqueous ammonium carbonate or sodium carbonate to produce a vanadium-rich solution while leaving an insoluble residue of calcium carbonate and/or calcium bicarbonate along with undissolved iron values, and the solution separated and treated for its vanadium content. This patent is a reissue of U.S. Patent No. 3,853,982, dated Dec. 10, 1974. C. B. Bare and J. W. Pasquali, assigned to Bethlehem Steel Corp. Mar. 28, 1978. 7 pp. (423-68). Filed: 3-3 1-77 (783,352).

Jan 1, 1979

By William Price

DURING the past three or four years, the fabricators of silicon-bronze alloys have endeavored to induce risers of phosphor bronze to use instead the silicon-bronze alloys, claiming that the silicon bronzes are superior to the phosphor bronzes for switches and springs, or where high fatigue resistance is desired. This paper gives the results of tests comparing several phosphor bronzes with a 3 per cent silicon bronze and a copper-nickel-tin alloy (Adnic), all processed by the Scovill Manufacturing Co. So far as the authors are aware, sheet-metal fatigue tests have not been made on any of the alloys included in this report, except on one phosphor bronze, material C, Table 1, which was tested by Townsend and Greenall1.

Jan 1, 1937

By E. A. Lucero, H. E. Robbins, T. H. Dudley

EL Salvador mine of Andes Copper Mining Co., E subsidiary of Anaconda Co., is in northern Chile about 18 miles north of Potrerillos, 7825 ft above sea level. Initial production is planned for the first half of 1959. Plant capacity will be 30,000 tpd, and there are 308,835,000 tons of proven ore reserves, averaging 1.49 pct Cu. The Inca adit is being driven as part of the mine-to-mill haulageway. Because of the overburden it is planned to mine the deposit by block caving. Ore will be dropped from upper gathering levels through ore passes to the Inca adit, through which it will be transported out of the mine to the primary crushing plant located a half mile from the portal.

Jan 3, 1958

By Waldemar Lindgren

I. Introduction............790 II. Geological Feature*:........793 The Gold-Bearing Fissure- Veins........793 Contact Melamorphic Deposits.........798 Classification According to Age........ 799 Introduction...........799 Pre-Cambrian Deposits.........800 Cretaceous Veins of the Pacific Coast...... 801 Late Cretaceous or Early Tertiary Deposits (Central Belt).. 802 Tertiary Deposits..........804 Conclusions,...........808 III. Detailed Descriptions:.........811 United Stater...811 Alaska.. ..812 Arizona,..814 California ..816 Colorado .. ..818 Idaho...823 Montana...825 Nevada...829 New Mexico,..........831 Oregon...833 South Dakota..834 Utah...836 Washington.. 837 Wyoming..838 Appalachian States..........839 British North America..........840 Mexico ....843 I. Introduction. The precious metals. gold and silver. are the basis of the monetary systems of the world. It is. therefore. natural arid inevitable that widespread interest should be manifested in their

Jan 1, 1903

By C. F. Weinaug

In recent years, several methods have been proposed for correlation of physical properties and behavior of hydrocarbon systems. These correlations were found to be unsatis. factory for predicting differential gas liberation and shrinkage data now obtained experimentally. To achieve the desired accuracy, methods were developed to adjust the correlations with two experimental pieces of data. The required data are the saturation pressure at reservoir temperature and the specific volume or density at these conditions. The saturation pressure is used to adjust the vapor-liquid equilibrium-ratio correlations. The density measurement is used to determine the apparent density of liquid methane. With these adjustments, differential gas liberation and shrinkage are predicted within the experimental error. EQUILIBRIUM RATIOS Equilibrium ratios published by the National Gas Assn. of America' were used as a basis for the calculation. The convergence pressure for the sample was determined by using a hypothetical binary system, with methane as one component and the remainder of the system lumped together to form the other component. For the critical temperature of the heavy constituent, the weight average of the critical temperatures of the ethane and heavier components was used. The correlation of pseudo-critical temperature, density and molecular weight of Matthews, Roland and Katzl was used in this calculation for the hexane and heavier fractions. Points for the critical properties of methane and the hypothetical heavy constituent were placed on a chart of the critical loci of hydrocarbon systems. A critical loci for the hypothetical binary system was drawn, and the critical pressure of this system was determined at the reservoir temperature. This critical pressure became the convergence pressure for which equilibrium ratios were read from the NGAA4 charts. The NGAA equilibrium constants for C, through C, were used for the C,; through C, fractions since they were separated on the bases of normal paraffin boiling points. The correlation of Hoffman, Crump and Hocott5 as used to estimate the equilibrium constant for the C fraction. The NGAA eauilibrium-ratio charts are based primarily on paraffin systems and have to be corrected for the presence of naphthenes and aromatics. The correlations in the literature proved too unsatisfactory for determining these corrections. EXperimental data, the saturation pressure, is used with the correlation of Soloman2 to make this adjustment. The correction factors of Soloman were cross-plotted so that the factors for ethane and heavier components were made a function of the factor for methane. a2 = 0.7927 at + 0.1646 .........(1) where a, = correction coefficient for for methane NGAA equilibrium ratio, and a2t = correction coefficient for ethane and heavier NGAA equilibrium ratios. This equation and the equation for the bubble point are solved simultaneously for the correction coefficients. The bubble-point equation is anKnXn = 1.0 . . . . (2) The equilibrium constant for the saturation pressure at reservoir temperature is used. This procedure not only corrects for the relative volatility between components, but also assures that the results will be directly related to the experimental saturation pressure. METHANE DENSITY After determining a set of equilibrium ratios, the apparent density of condensed methane at 60°F and 14.7 psia was estimated. This was found to be necessary because the correlations of Standing3 ere found to be unsatisfactory. The law of additive volumes was employed to make this calculation.

INTRODUCTION Trade financing is a particularly important component of short-term financing for a minerals company since errors, extra costs, or payment delays/defaults can easily wipe out the profit margin on a particular shipment or can cause problems when arranging purchases of e.g. reagents. It is required to make any minerals operation function and does not have to be cross-border to require proper management. Sources of working capital are as follows: 1. Extended credit terms from suppliers 2. Inventory loans from banks, finance companies 3. Accounts receivable financing or factoring 4. Credit lines or overdraft facilities from banks. TRADE CREDITS These are provided under the familiar terms "net 10 days" or payment due by the "10th day of the following month." Thirty days for payment is usual but longer periods can be negotiated with regular suppliers. Shipment may be made on open account with specified periods for settlement. In the mining industry, a custom smelter gains trade credit by paying for concentrates three months after the month of shipment. INVENTORY LOANS Various forms of inventory finance are provided via "floor-plan" or warehouse financing. A set percentage, usually 60%-80%, of a good-quality, readily saleable inventory item (e.g. bullion, concentrates, ingots) will be provided by a bank or finance company which will usually have security over these products and has a right to inspect the goods from time to time. Legal security will he achieved by warehouse receipts, floating liens, chattel mortgages, trust receipts, or through collateral management service companies. The latter certify control over stock or distribution outlets and often carry insurance against fraud. Costs range around 1.5% - 2.0% p.a. or more plus some fees to cover out-of-pockets or other costs. ACCOUNTS RECEIVABLES Accounts receivable financing is based on the company's generation of satisfactory receivables which are continuously assigned to a bank or finance company ("factoring"). Because of the risks in being able to collect receivables, such as payments to a smelter for its blister copper shipments to a refinery, this form of financing costs as much as 3% - 5% of the debt amount purchased plus an additional charge for processing paperwork. Receivables can be purchased with or without recourse and on a notification or non-notification basis to the client's customer to, respectively, pay the invoice directly to the bank or not. LETTERS OF CREDIT Letters of Credit ("L/C's") are a common feature of international trade finance whereby a bank, at the request of the buyer, issues a written undertaking to an exporter to pay a specified sum of money within a set time on presentation of previously specified documents. This undertaking means that the exporter is no longer relying on the credit standing and integrity of the foreign importer. A dispute about shipment does not otherwise affect the obligation to pay upon presentation of a "clean" set of documents. These documents include the hill of lading and other documentation, often on standard "form" bases. There are a number of conventions and techniques in L/C's such as irrevocable/revocable L/C's, time L/C's, confirmation/advising L/C's and transferable L/C's. These are tools to adjust for the varying risks that the importer will not pay. Other routes where one is comfortable with an importer include documentary sight hills (D/P hill), documentary term bills (D/A bill), and, of course, open account.

Jan 1, 1985

By K. Torssell, U. Lindborg

The kinetics of precipitation deoxidation is considered from a theoretical point of view. The size distribution and the total content of deoxidation products are estimated statistically as a function of time, taking into account Stokes and gradient collisions between the particles and separation at the top surface of the bath. The assumption is made that two particles coalesce into one larger particle as a result of a collision. General expressions are derived and calculations are carried out numerically for the case of silica particles in liquid iron. The analysis predicts a three-stage behavior for the removal of oxygen, an incubation stage, a stage of rapid separation, and a slow final stage where the content approaches the equilibrium value. The agreement with experimentally determined size distributions and deoxidation times is considered to be good. A quantitative estimation of such growth mechanisms as diffusion from the melt and redistribution of oxygen from small particles to large ones shows that these latter mechanisms cannot explain the experimentally observed gvowth of inclusions. This also indicates that collisions provide the important growth mechanism. OXIDE inclusions precipitate when a deoxidizer like silicon or aluminum is added to a steel bath. The inclusions grow and the large particles tend to separate from the bath. For each type of oxide the growth determines the sizes of the final inclusions as well as the total inclusion content of the steel. The mechanism of growth is controversial, however. It has been suggested that an inclusion grows principally by diffusion of atoms through the melt to the inclusion particle or principally by collisions and coalescence with other inclusions. Diffusion growth is always present to some extent but recent experiments and calculations by Torssell,' Kniippel et 'a1.,2 Sano et al. and Miya-shita4 indicate that collisions may be more important than previously realized. A detailed analysis has so far been lacking. The present paper is a quantitative, statistical analysis of the growth and separation of inclusions and is based on a collision theory. Nuclea-tion is not considered. The numerical estimates are based on the experimental conditions of Torssell's' investigation and comparisons are made with his observations. Torssell' studied the growth and separation of silica particles in liquid iron. Samples were taken from a 0.6 kg iron bath at various times after the addition of silicon. By a particle-counting technique developed by Bergh and Lindber~the size distribution of the inclu- sions was determined. The number of particles at the first sampling, 10 sec after silicon addition, was of the order of 3 x lo7 to 10' per cu cm, the largest particles having a radius of 2 to 4 pm. The volume fraction was 0.001 to 0.004; i.e., the dispersion was very dilute. During subsequent holding the largest particles increased their radius by a factor of 10 after about a minute, and the whole size distribution was displaced toward larger values. These results were obtained with allowance for precipitation of the equilibrium concentration of oxygen during solidification. The bath contained less than 0.01 pct of C. Figs. 1 and 2 show the typical appearance of the inclusions. Most particles are very closely spherical and appear to have been liquid or semiliquid in the melt. The observed number of inclusions, about 5x 10' per cu cm, is of the same order of magnitude as found by ~er~h.' This is a large value. It follows that the diffusion distances are very short and that the precipitation

Jan 1, 1969

By F. W. Maclennan

The following is a list of members who died in 1929. It is compiled from reports to the Secretary's office. Biographical sketches published in Mining and Metallurgy are indicated in the last two columns. Issue Containing Year of Date of Biography Election Name Death 1929 Page 1922 Adams, Waldo Peck................................ June 2 September 435 1903 Argall, Joseph.................................... Nov. 1 1894 Austin, Leonard S................................. Oct. 30 December 580 1905 Bailed, Melbourne.........................Dec. 12 May* 280 1890 Barringer, Daniel M.............................. Nov. 30 February* 119 1895 Batchelleb, HENRr R.............................. Jan. 15 March 167 BINGHAM Charles E............................. 1923 Bibkett, E. H..................................... Apr. 23 August 394 1913 Bibbell, Robert W................................. Jan. 18 April 214 1926 Blackmar, Don C.................................. June 4 March* 189 1920 Bosworth, T. O.................................... Jan. 18 April 214 1894 Boucher, Arthur S..........................Jan. 6 May 257 1927 Brandenthaler, R. R.............................. Dec. 14 January* 64 1889 Bretherton, S. E............................... Oct. 4 December 581 1911 Brunton, F. K................ .. Aug. 17 1924 Brush, Charles F................................. June 15 September 436 1925 Cameron, Frank N........................May 16 July 349 1891 Chambers, Robert E.............................. May July 348 1908 Clark, J. Murray................................. Dec. 3 August* 407 1883 Clymer, edward T............................. Oct. 13 December 579 1914 Cofpey, George T................................. May 8 July 349 1901 Cooke, L. H....................................... Aug. 23 November 537 1915 Cousins, George W........................ June 30 February* 118 1886 Cowles, A. H...................................... Aug. 13 September 436 1892 Crane, Theron I............................. Nov. 2 December 579 1921 Crowell, Samuel B................................ Dec. 9 January* 64 1907 Curtis, Bracey.................................... Jan. 31 April 215 1895 de Batz, Rene........ ............... January March* 189 1928 Dines, Tyson S.................................... March May 257 1909 Dufourco, R. G............................. January November 537 1920 Ericsson, Eric A.................................. Apr. 4 April* 231 1920 Erlenborn, Willi....................... Nov. 10 March* 189 1888 Farish, John B.................................... Nov. 14 December 580 1891 Ferguson, Vincent........................... Mar. 8 May 257 1917 Finucane, T. R.................................... Mar. 22 February* 118 1921 Foch, Ferdinand................................... Mar. 20 1885 Foucar, Edouard I....................... Jan. 3 March 167 1880 Francklyn, Charles G............................. Jan. 11 April 214 1925 Friedl, Arthur J.............................. July 9 September 435 1894 Fuller, James W. Jr............................... April 4 1876 . Goodale, Charles W.............................. April 11 May 258 1912 Graybill, John..........................Dec. 11 June* 320 1887 Gritzner, F. A.................................. Mar. 26 July 394 1906 Gunther, C. Godfrey.............................. Deo. 26 February* 118 1900 Haggen, Edward A.............................. Apr. 22 October 488 1895 Hall, Benjamin M........................Nov. 19 March* 189 1913 Harper, Walter S................................. Feb. 15 August 394 1921 Hawley, William S................................ Apr. 20 June 298 1920 Herd, Walter ... . . . ..... Aug. 23 September 435 1889 Holt, Marmadtjke B............................... Dec. 26 February* 118 1928 Husk, Albert D .... ................June 9 December 580 1920 Hutchinson, S. Pemberton......................... Feb. 16 April 214 1926 Ivanoff, Constantine L............................ Mar. 7 June 298 1914 Jaeger, Frederick..... .............July 28 October 488 1891 Jennings, Robert E.......................Oct. 30 December 580 1922 Johnson, Homar L................................. Sept. 17 October 483 1927 Johnson, Homer H................................. Mar. 21 May 257 1918 Jones, Jesse L ..... ...............Jan. 22 April 214 1892 Jones, Thomas J................................... June 18 October 488 1883 JoOet, Cavalier H................................. Mar. 29 May 258 1881 Kennedy, John S . . . . ... ..........Apr. 22 August 394 1881 Kennedy,- Hugh.................................... May 23 September 435 1895 Kebvin, James H................................... September October 488 1926 Kkom, L. J........................................ Dec. 24 January* 64 1905 La Follette, Harvey M........................... Sept. 19 November 538 1920 MacDonald, Alexander............................ May August 394 1904 Marengo, Paolo................................... May 257 1925 Maxwell, Allison R............................... May 7 November 538

Jan 1, 1930

By Carrol A. Quam

DURING the first years of operation of the titanium and iron mine of the National Lead Co. at Tahawus, New York, efforts to increase production were hampered by the increased load put on the facilities for sharpening churn-drill bits. The ore and rock are extremely hard and abrasive and it was necessary to sharpen and harden a large number of bits per day to keep the churn drills supplied. Efforts to increase the capacity of the bit shop by a two-shift operation were not wholly successful in that it was hard to train men to do a satisfactory job of sharpening and tempering the bits. The number of bits that were improperly tempered increased, thus boosting the daily requirements for bits at the drills and increasing the load on the bit-sharpening facilities.

Jan 1, 1949

By Ira B. Jorafemon

In the interesting Institute symposium of the preservation of peace by force, through mineral control, one important aspect of the question was not presented. This is the responsibility the United Nations, and particularly the United States, will incur the through limitation of the economic activities of nations that are now friendly to us, as well as of nations that are enemies or are under the control of enemies. After the war all nations, friends as well as enemies will be poor. Hunger and bankruptcy will, will like the sword of Damocles, hang over the heads of all of us on this blundering planet. When the actual fighting is over, there will be a universal attempt to squirm out from under the sword by resuming production of peacetime goods, for trade as well as immediate consumption.

Jan 1, 1944

By T. C. Wilson, Gerald Edmunds, W. M. Peirce, E. A. Anderson

Thirty-six elements have been alloyed singly with cartridge brass. Ammonia and mercury stress-cracking tests have been conducted on the as-rolled and recrystallized strip. Ultra high purity cartridge brass has also been tested. Silicon improves stress- cracking behavior. High silicon (I per cent) cartridge brass quenched from high temperature (for example, 800 C.) annealing is exceptionally resistant to ammonia stress cracking. This improvement is not lost by subsequent cold working, but is greatly reduced by subsequent low temperature annealing. Phosphorus, arsenic, barium, cerium, magnesium, tellurium, tin, beryllium, and manganese benefit stress-corrosion resistance under some circumstances, but not others. The other alloying additions tried had no large effect on stress-cracking resistance. None of the elements added accelerated stress cracking. The impurities in commercial brass are not responsible for season cracking.

Jan 1, 1945

"The Great Falls of the Missouri are situated about 12 miles below the City of Great Falls and development work for the utilization of the power which they afford is now in progress. The natural fall is about 77 feet.The development will consist of a concrete dam 1,000 feet long on the crest line, and 73 feet high. The power house will be set below the present falls near the north end and the tailrace will be cut below an island which is situated just below the falls. The maximum head will be 153 feet. The power house will contain six units of 15,000 horse power each. The construction as contemplated will comprise about 180,000 cubic yards of concrete work, using 200,000 barrels of cement."

Jan 1, 1913

By A. P. Herring, M. Hoover, D. W. Fuerstenau

The dissolution of nickel, copper, and cobalt from five different samples of well-characterized deep sea manganese nodules was measured as a function of temperature, pH, leaching time, and particle size. Nickel, copper, and cobalt extraction each respond to these variables in a different manner. The results of this investigation indicate that copper and nickel can be selectively dissolved from iron and manganese at moderately low pH, provided the reaction is given sufficient time. A high dissolution of cobalt with dilute sulfuric acid can only be achieved from nodules that have a low iron content (<5%). The most probable rate-controlling step for copper and cobalt dissolution is diffusion through the pores of the nodules, and for nickel dissolution chemical reaction appears to be rate-controlling.

Jan 1, 1974