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By Bradford C. Wesstrom

The extraction of metals from Copper Refinery Slimes may involve many different processes. This paper describes the use of pressure leaching for decopperizing of copper refinery slimes at the El Paso Refinery. Process equipment will be described, along with the process chemistry, unit operations and unit processes associated with the decopperizing process. Copper contained in the raw slimes ranges from 15-35%. After autoclaving less than 1 % copper remains.

Jan 1, 2000

By William H. Lesser

A recent survey of pumping plants in the anthracite region of Pennsyl¬vania showed that more than 90 percent of the pumps in use are the horizontal centrifugal types (1).2/ This report on the design and operation of centrifugal pumps should be helpful to engineers of the region who must select pumps that are best suited to particular pumping conditions in anthracite mines. Before a centrifugal mine pumping plant is designed, the special features of the pumps that may be used should be considered, especially when low repair costs and continuous operation during flood periods are prerequisites, and when acid mine water is to be pumped. Two important advantages of a centrifugal pump are that the flow is continuous and that it can be throttled without developing excessive pressure or overloading its driving unit.

Jan 1, 1950

By R. B. Lantz

Low Froude Number (Fr) theory* predicts that stably-stratified fl& around a terrain obstacle will divide into a lower layer passing essentially horizontally around the obstacle and an upper layer passing essentially over the obstacle. The prediction was formulated by Sheppard (1956) and Drazin (1961) and confirmed experimentally in the towing tank model d experiments of Hunt et a1 (1978) and the atmospheric full scale experiments of the US EPA Complex Terrain Model Development Program (1982- 1985). The US EPA Complex Terrain Dispersion Model, currently under development, employs the layering principle with the flow in each layer calculated independently by potential flow (PF) theory after the layer thicknesses are established according to a simple function of Fr, i.e., Hc /H = 1 - Fr where Hc is the dividing streamline freight and E is the obstacle height. Use of PF theory in the CTDM is attractive because numerical solutions can be obtained simply and economically, as compared to lengthy Navier-Stokes (N-S) solutions, but realism is sacrificed in creating a surface of discontinuity between the tm layers and eliminating the effects of shear and gravity in each layer.

Jan 1, 1986

By HORACE V. WlNCHELL

Location. THE St. Helens mining-district, indicated in sketch-map, Fig. 1, is chiefly in Townships 9 and 10 North, Ranges 5 and 6 East, of the Willamette meridian, in Skamania county, Wash. There is no railroad or even a wagon-road at present connecting it with any base of supplies; access is usually by wagon-road for FIG. I.-SKETCH-MAP OF THE STATE OF WASHINGTON. about 50 miles from the town of Castle Rock to Spirit lake, and from that point by pony-trail from 6 to 10 miles farther. History. Nearly 20 years ago two German farmers, totally inexperienced in prospecting, penetrated this region upon a hunting and fishing-trip. Their attention was drawn to numerous joints and crevices filled with black, glistening tourmaline, and con-

Oct 1, 1912

By J. L. Yordan

An induction time apparatus has been constructed in the present work which has a sensitivity limit of 100-150 micro-seconds. The basic unit is similar to the one used by Eigeles and Volova (1960) and Trahar (1983), but it operates with a micro-computer and has a greater sensitivity. Using this apparatus, the flotation chemistry of the quartz-amine system has been studied. It has been found that at a given dodecylamminium hydrochloride concentration, the induction time is at a minimum at approximately pH 10.5. At this pH, the collector hydrolizes to form neutral amine and the flotation recovery reaches a maximumy,suggesting that iono-molecular species are the surface-active species responsible for flotation. This finding confirms the earlier conclusions obtained using the surface tension (Somasundaran, 1976; Finch and Smith, 1973) and contact angle (Smith, 1963) techniques. The induction time measurements have also been conducted as a function of particle size, collector concentration, indifferent electrolyte concentration and temperature. The results are compared with flotation data, and the activation energies for the bubble-particle adhesion have been calculated.

Jan 1, 1986

By William M. Boorstein, Robert D. Pehlke

The rates of solution (of hydrogen in liquid pure iron and in several liquid binary iron alloys were meas-ured using a constant volume technique. The rates of absorption and desorption were found to be equal un-der all experimental conditions. increasing concen-trations of S, Si, or Te decrease the rate of hydrogen uptake but additions of Al, B, Cr, Cu, or Ni have no measurable effect up to concentrations normally en-countered in steelmaking practice. No relation ship was found between the effect of an alloying element on the equilibrium solubility of hydrogen in liquid iron and its effect on the solution rate constant. Mathe-rnatical analysis of the data indicates that under the present experimental conditions the rate of reaction of hydrogen with liquid iron is controlled by transport of gas solute atoms in the metal phase. Comparison of the present resuts with data on nitrogen taken un der similar conditions establishes that the hydrody-nurnic conditions which exist near the surface of a metal bath are best approximated mathematically by a surface renewal model for the case of rapid in-ductive stirring and by a boundary layer model for more quiescent melts. HYDROGEN has long been recognized as being a detrimental constituent in steel. If dissolved in the molten metal in excess of its solid solubility, hydro-gen can be evolved during solidification and cause bleeding or porosity in ingots and castings. In the solid metal, lesser amounts play a definite role in causing other defects such as hairline cracks, blisters, and embrittlement. For significant refinements to be made in metallurgical procedures designed to control or eliminate hydrogen from liquid iron or steel dur-ing processing, available equilibrium solubility data must be supplemented with reliable fundamental in-formation pertaining to the kinetic factors involved in the transfer of hydrogen to or from the metal. The scarcity of such information in the literature prompted the present investigation. PREVIOUS RESEARCH Whereas much of the existing data on the solution kinetics of gases such as nitrogen were obtained during the course of thermodynamic investigations, the solu-tion rate of hydrogen has been found too rapid to be accurately determined by conventional solubility meas-urement techniques. Consequently, little work on hy-drogen solution kinetics has been reported in the lit-erature. Carney, Chipman, and crant1 attempted to study the rate of solution and evolution of hydrogen from liquid iron by employing a newly devised sampling method. Although no significant quantitative data could be obtained, it was observed that the rate of solution was approximately equal to the rate of evolution of hy-drogen from the melt. Karnaukov and Morozov2 stud-ied the rate of absorption and Knuppel and Oeters3 the rate of desorption of hydrogen from molten iron by measuring pressure changes with time in a constant volume system. Karnaukov and Morozov determined the hydrogen pressures over their inductively stirred melts with the aid of a McLeod gage and therefore, were forced to work at pressures not in excess of 40 mm of Hg. Their experimental data conformed to a mathematical correlation based on diffusion control: and the rate coefficients calculated on this basis were shown to be independent of the initial absorption pres-sure. These authors reported the solution rate of hy-drogen to be eight-to-ten times higher than they had found for nitrogen in a previous study. They also re-ported that under identical conditions, hydrogen dis-solves somewhat more slowly in iron-columbium alloys than in pure iron. Knuppel and Oeters found that the desorption of hydrogen from pure iron at 1600°C was controlled in all cases investigated by diffusion in the metal bath as long as bubble formation was sup-pressed. This was substantiated by Levin, Kurochkin, and umrikhin4 who studied the kinetics of hydrogen evolution from liquid (technical) iron while applying a vacuum. Salter5 measured the rate of hydrogen ab-sorbed by iron buttons, arc-melted by direct current, as a function of hydrogen partial pressure in a hy-drogen-argon atmosphere. A carrier gas technique was used for analysis of the hydrogen absorbed. The initial rate of absorption was found to increase di-rectly with the square root of the partial pressure of hydrogen. EXPERIMENTAL METHOD Because of the rapid uptake and evolution of hydro-gen by iron-base melts, a constant volume technique was devised in order to obtain meaningful kinetic data over the entire course of the solution process. Apparatus. A schematic view of the experimental apparatus is given in Fig. 1. The hydrogen-liquid iron reaction system consisted of a gas storage bulb con-nected to a meltcontaining reaction chamber through a normally-closed solenoid valve. The gas storage bulb, an inverted 250 ml round-bottomed Pyrex flask was joined to the inlet port of the solenoid valve by a glass-to-metal seal. A more detailed illustration of the reaction chamber is shown in Fig. 2. The design of the Vycor reaction bulb was essentially that de-scribed by Weinstein and Elliott6 with the exception of a shorter, larger diameter gas inlet for this kinetic study. In position, the reaction bulb was closely by an eight-turn coil of water-cooled copper tubing which, when energized by a 400-kc oscillator, provided the inductive heating source. The walls of the bulb were maintained relatively cool by circulating cold water along their outer surface, thus preventing

Jan 1, 1970

The following is a list of members who died in 1928. 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 or Date or Biography Election Name Death 1928 Page 1914 Adams. David T.................... July 22 October 471 1905 Aguilera. Pedro................... May 3 October 469 1902 Althouse, H. W.................... NOV. 3 December 559 1920 Averill: C. C...................... July 9 October 471 1915 Baldwin, C. Kemble............... Aug. 9 October 471 1926 Barquist, Walter C............... NOV. 14 June 298 Barron,* Clarence Walker......... Oct. 2 November 511 1917 Beasley, Fred E.................... Aug. 31 October 471 1901 Belden, S. B....................... May 15 July 333 1927 Binney, Edwin, Jr.................. Dec. 29 February 96 1915 Bonsall, James Malcolm............ Feb. 12 June 284 1917 Boyle, John....................... July 12 December 561 1913 BradEn, Eugene B............. Jan. 29 March 157 1889 Bulkley, Frank.................... Mar. 25 May 240 1896 Callaghan, J. T., Jr............... Apr. 1 1892 Chalmers, George.................. Feb. 4 April 197 1898 Clark, Josiah H.................. May 7 July 333 1887 Copeland, F. K............. Nov. 10 December 561 1915 Cunningham, B. L11............... Dec. 6 August 294 1888 Dana, R. T........................ Aug. 20 December 559 1907 Dennis, Clifford G............... Dec. 28 March 1 1920 DeVenny, Thomas................ Feb. 13 April 197 1882 d'Invillier-, Edward V........... Jan. 4 March 157 1884 Duncan, M. M..................... Dec. 17 February 96 1924 Dyrssen, WaldemaR ............... Aug. 4 October 471 1906 Edmondson. H. W................ Dec. 21 February 1884 Emmerton, F. A.................. Oct. 9 June 298 1911 Eu, S. H............................ July 20 February 1917 Farrand, Ira W.................... Sept. 6 October 469 1900 Fell, E. Nelson...........•......... Mar. 25 May 231 1918 Fenton, Clarence M.............. October Junet 298 1908 Ferraris, Erminio................. Sept. 22 June 298 1914 Galloway. A. D. R............... December April 215 1924 Grant, A. W., Jr................... .4pr. 5 June 285 1917 Grant, Clifford G............... Jan. 26 January? 37 1918 Grant, Frank E.............. Jan. 14 September 417 1921 Gunderoth, C. J.................. Feb. 15 1897 Harms, Ernest..................... Aug. 12 November 512 1891 Hartrick, J. S..................... Feb. 9 June 285 1925 Hochschild, Berthold.............. Jan. 24 April 197 1917 Hutton, L. W...................... NOV. 3 January 37 1894 Jenning", S. J...................... NOV. 17 December 560 1925 Jones, J. Ravenscroft............... Jan. 29 March 157 1880 Jones, J. T......................... May 4 June 284

Jan 1, 1929

By Lloyd W. Trevoy

Commercial production of heavy minerals from plant tailings streams is undergoing study by Syncrude Canada Lrd. When tar sand from an open pit mine is processed and up- graded to synthetic crude oil, heavy minerals can be recovered from the extraction circuit and can be upgraded to provide concentrates of zircon and titanium minerals. The titanium minerals concentrate consisting of a mixture of ilmenite, leucoxene and rutile, could be utilized as recovered or could be upgraded to synthetic rutile. With the construction of further synthetic crude oil plants in Western Canada a large reserve of heavy minerals will become available for utilization.

Jan 1, 1981

By Thomas L. Ochs

The Bureau of Mines is investigating the fundamental behavior of electric arcs in electric furnace operations. The electric arc is a poorly understood phenomenon. If the arc in a steelmaking furnace can be more carefully controlled, it should be possible to increase heat transfer to the melt, reducing both electrical and acoustical noise. As a first step toward a better understanding of the are, voltage and current signals from operating furnaces were analyzed. The results of the initial analysis show that instrumentation used in monitoring and controlling furnaces, such as meters and strip-chart recorders, gives incomplete or erroneous information to the operator and therefore leads to less than optimal control. Advanced instrumentation and analysis techniques, such as the waveform analysis used in these investigations, can improve the understanding of operation and the control of electric furnaces. This report describes the instrumentation and the numerical analysis methods used and compares these methods with standard metering and recording techniques.

Jan 1, 1986

By J. J. Zaluski

The Surface Mining control and Reclamation Act (public Law 95-87) (here-inafter the "Act" or "SMCRA") passed by congress in August of 1977 represents a comprehensive federal scheme for controlling surface coal mining and the surface effects of underground mining through permitting requirements, performance guidelines, and reclamation planning. While the provisions of the Act have been the subject of numerous legal challenges and court battles over the years, it is difficult to identify a more controversial program within the Act than the provisions for designating lands as unsuitable for surface coal mining operations. The lands unsuitable designation process provides for the acceptance and review of petitions submitted by citizens or organizations seeking to have specified land areas designated unsuitable for all or certain types of surface coal mining activities. In filing these petitions, the interested parties or petitioners are required to make allegations about potential adverse impacts on people or the environment and submit evidence supporting their allegations.

Jan 1, 1992

By D. A. Reynolds, L. P. Rockenbach

"The method of analyzing light oil for benzene is fully described by Fieldner and others 4/ and Kester and Kolmes 5/. In this procedure, benzene is determined by shaking 20 cc. of the 79º to 81º C. boiling point cut from the fractionation of the refined light oil with 3 volumes of 98—percent sulfuric acid in an A. S. T. M. separator funnel of the type used for determining water in bitumi¬nous materials. After the mixture has been shaken 5 minutes it is allowed to settle at least half an hour and the acid is drawn off; the residual oil is reported as paraffins and the decrease in volume as benzene. The method has been found satisfactory for light oils from coals carbonized at 5000, 600°, and 7000 C. but does not give accurate, reproducible results for oils from the 800° C. tests.The content of benzene of the 790 to 81° C. cut is high, 90 to 95 percent, for 800° C. light oils, whereas for lower—temperature light oils it is considerably less. Benzene is the most difficult of the aromatics to sulfonate, hence the acid concentration must be maintained above 95 percent to insure complete sulfonation. Sulfuric acid (98 percent) reacts with benzene, but its reaction with paraffins at ordinary temperatures is negligible; however, more concentrated acid will attack paraffins and give erroneous yields of benzene. The reaction between benzene and sulfuric acid forms water that will dilute the acid. The effect of this dilution may be overcome by increasing the acid-to-oil ratio or increasing the strength of the acid. The latter, however, must not be used, because the stronger acid reacts with paraffins."

Mar 1, 1942

By Samuel S. Wyer

THE installation of the gas-producer power-plant in America has been so unusual that all engineers have viewed it with in¬terest; a large majority, however, regard it with a lack of con-fidence and many with positive distrust. Despite the fact that European engineers have usually been less inclined to take the initiative along experimental lines than are Americans, they have, nevertheless, developed the gas-producer plant to a very high state of efficiency to which they were forced by the neces¬sity of economy in fuel-consumption. The gas-producer power-plant is so common in Europe that engineers as well as the general public regard it with the same degree of confidence that is now universally placed in steam¬plants. Gas-engines, both small and large, are in general use there, and central stations, aggregating several thousand horse¬power, are quite numerous. The fact that gas-producer power-plants have received so little attention in America may be attributed to five conditions:-1', ignorance and prejudice; 2, newness of work; 3, in-

Mar 1, 1905

By William H. Dresher

A recent report to President Reagan from the Business-Higher Education Forum, entitled, "America's Competitive Challenge: Need for a National Response," (1) observes that in the recent past, ". . . much of that research, which is necessary for major breakthroughs and sustained productivity improvements, was redirected to short-term objectives ... At the same time, American universities, which conduct more than half of the nation's basic research, have suffered from an accumulated under-investment in facilities and equipment amounting to an estimated $1-4 billion." Also contributing to the decline in America's productivity, the report said, are "...weak technology transfers between government and industry and between universities and industry..." This report as well as other recent reports and articles have, reopened a subject which has long been debated but rarely resolved-- the interaction between the academic community and industry in the sponsorship and conduct of research. The subject is unfortunately, too often treated as a controversial issue involving ethics and the profit motive when, in fact, the two branches of society -- industry and academia -- are necessarily part of the same system. I would like to speak to you today on the subject of university-industry interactions and to some extent discuss the role of government in such interactions. Finally, I will make some remarks as to how this subject applies to the mining industry.

Jan 1, 1984

By Lorenzo Reyes-Bozo, Ronaldo Herrera-Urbina, Pablo Higueras, Alex Godoy-Faúndez

"The copper mining industry in Chile and perhaps in other countries as well is faced with the challenge to implement the best practices in order to achieve a sustainable and more environment-friendly growth. Relationships between mining industry and society have been historically complex due to its environmental impacts. Whereas the ore grade has declined continuously, this has involved an intensive energy and water consumption thus increasing operational costs at different stages of the concentration process. In the case of copper sulphide ore concentration, froth flotation is the main technology used worldwide. The amount of the different chemical reagents used in flotation plants (i.e., collectors, depressants, frothers and modifiers) affects significantly production costs and has a negative effect on the environment as well. The objective of this research work was to evaluate the use of biosolids and their main components (i.e., glucose, proteins and humic substances) as more environment-friendly flotation collectors for chalcopyrite and molybdenite. For this purpose, microflotation tests were conducted in a modified Hallimond tube. In addition, FTIR and zeta potential experiments were performed to investigate the interaction of biosolids with these sulphide minerals. Biosolids and their main components may interact through physical and chemical ways due to different affinities with such sulphide minerals as chalcopyrite, pyrite and molybdenite, which are present in copper sulphide ores. In alkaline pHs, biosolids and their main components make the zeta potential of the sulphide minerals investigated more negative. These results may provide important information concerning the behavior of the main sulphide minerals in the concentration of copper sulphide ores at industrial scale, wherein mill processes could affect their surfaces properties. Therefore, biosolids and their main components may open an opportunity to be used in copper sulphide flotation plants to partially replace conventional reagents, which are more hazardous and less environment-friendly."

Jan 1, 2014

According to the Balandin's (1) "multiplet theory of catalysis", adsorption can occur only if atoms of the reactant molecules are congruent with surface atoms of the catalyst. Such a condition calls for certain definite geometrical relationships between the reactant molecules and the atoms at the surface of the catalyst. If such a match or geometrical 'fit' is not provided, the surface reaction will not take place. An appropriate analogy to this may be the lock and key theory that enzymes should fit a substrate just as a key fits a lock. Similar geometrical considerations in adsorption studies were made in connection with the flotation of minerals. Gaudin(2) and Gaudin and Preller (3) proposed that if the dimensions of collector ions are in registry with the mineral lattice, an ordered layer of adsorbed species is formed. They explained that the structural fit is one reason for good flotation of galena with xanthate. In another study, Bachmann (4) attributed the selective flotation of KC1 from NaCl with amine to the fact that the lattice parameter of the amine collector is closer to that of KC1. Schubert(5) investigated the flotation of various nonmetallic minerals with amine and pyridine, and related the dimensions of the collector ions with the anion distances of the mineral surface. He concluded that good flotation is obtained when the tolerance is within 20%. The geometrical theory has also been used by Groszek (6) to explain the preferential adsorption of n-paraffin onto the basal plane of graphite. The geometrical theory has thus been found useful in explaining adsorptive properties of an adsorbate relative to the substrate structure. The purpose of the present work is to examine the possibilities of a geometrical fit between sodium dodecyl sulfate and Cu(OH)2 surface, and to construct a crystallographic model of the surface compound.

Jan 1, 1974

By George F. Kunz

Jan 1, 1902

By R. E. Snow

The analysis of ground water inflow and discharge from underground mines has received increased attention in recent years due to environmental issues which must be addressed under current state regulations for coal mining and processing operations. In particular, coal operators must assess the probable hydrologic consequences associated with mining activities, and must plan for mine water handling during operation and following completion of mining. The prediction of ground water inflow rates with future mine development allows preparation for potential operational problem and identification of inflow reduction methods. Similarly, evaluation of mine discharge rates is necessary to address potential long-term acid mine drainage (AND) concerns. As part of mine discharge analyses, methods. to control seepage and AMD can be considered. The objective of this paper is to discuss the practical applications of mine inflow and discharge analysis, describe the typical flow components, outline the procedures necessary to perform the analysis, and illustrate the modeling procedures and potential results of mine inflow and discharge predictions.

Jan 1, 1990

By M. Vesely

Abrasive grinding, leading to ultrafine product and "critical size" material build-up inside the mill, is proposed as the cause of high power consumption and low capacity in many fully autogenous grinding processes. Addition of steel balls (hence, semiautogenous grinding) or pebble removal and separate crushing have been used, with different efficiencies, to overcome the problem. Information and data for the conceptual analysis, basic design and operation of a pebble crusher at the Los Bronces semiautogenous grinding plant is presented along with data showing a production increase of 1000 mtpd and significant operating costs savings.

Jan 1, 1985

By J. Arzuúa, U. Castro-Filgueira, L. R. Alejano, F. Malan

"Pillar design for underground mining is typically done using empirical formulae or numerical modelling. Practical experience and recent literature, nevertheless, illustrate the shortcomings of these design approaches. Ongoing monitoring of pillars is therefore recommended to minimize the risk associated with these designs.In a mine where a large number of pillars are cut, different pillar strengths can be expected owing to variations in rock mass strength from area to area. This problem is compounded by the fact that in mining environments the pillars are not always cut according to the prescribed dimensions. Although the original design using either empirical methods or modelling may predict stable pillars, unstable pillars will be encountered in reality. Very conservative designs with large factors of safety may circumvent this problem, but this approach is uneconomical.A possible solution to localized stability problems may be to enhance the strength of a few unstable pillars. It may even be hypothesized that reinforcing a few critical pillars may prevent ‘pillar runs’ on a much larger scale. Rockbolting, strapping of pillars, and pillar shotcreting have occasionally been used in the past as possible solutions. It appears that these have not been successful in all cases and large collapses have occurred in spite of the pillar remedial work.The authors investigated the strapping of pillars by conducting laboratory tests on cabled rock specimens. The results were qualitatively compared to actual attempts of pillar reinforcement available in the literature, as well as additional observations in an old haematite roomand- pillar mine in Spain. Based on these results, the value of steel cabling and mesh wrapped around pillars to improve stability is demonstrated. Some cases where this approach will not be successful are also discussed."

Jan 1, 2017

By Raju S. Sagi

This paper deals primarily with the different types of drilling methods used by the Iron. Ore Company of Canada for sampling the soft and friable hematite-limonite (secondary) iron ore deposits found in the Scheferville area. The problems associated with drilling, sampling, sample handling and sample preparation. for chemical analysis of these ores are discussed. Systematic evaluation of the various drilling methods led to the selection of an integrated drilling system. This system consists of a rotary dual- tube - reverse-circulation drill, with tricone bit, polymer mud and mechanical sample splitter, The historic al development of this drilling system is described in detail, as are the equipment , sample flow and quality control checks carried out to obtain representative samples. This integrated drilling and sampling system has been used satisfactorily on a routine basis for determining the grade and tonnage of ore for the various deposits for the last five years (1972-76) in the Schefferville area.

Jan 1, 1977