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By C. H. Tsau

The intermetallic compounds of Ni-25Al-xFe, x is 20-40 at.%, were prepared by arc melting and drop casting into ingots, and were rapidly solidified into ribbons by melt spinning. The microstructure evolution of these alloys with varied Fe content were examined by the x-ray diffraction, optical microscope, scanning electron microscopy and transmission electron microscopy. The results reveal that two phases, {y'} and {B} phases, are existing in the alloys with low Fe content, and the microstructure changes from the mixture of y' and {B} phases to a single 0' phase when the Fe-content reaches to 40 at.%. Also, the formation of y' phase will be suppressed by rapidly solidified process. For annealing both of the melt-spun and the cast specimens, a disorder 0 phase was revealed in both of the ribbon and the cast ingot of Ni-Al-Fe alloys with higher Fe content. In addition, increasing the increment of iron which substituting nickel in this alloys results in increasing the lattice parameter of both {y'} and{B} phases.

Jan 1, 1992

This symposium is dedicated to the lifetime achievements of Professor H.Y. Sohn. It covers the scientific fields, processing routes and investigation techniques in which Prof. Sohn has worked during his career and is based in the equally important three topical areas: Principles, Technologies, and Industrial practice. Professor Sohn was General Chair of the very first TMS Fall Extraction and Processing Symposium in 1983 in San Francisco which led to the Annual such symposia as this International symposium. Furthermore, the theme of that symposium was sulfide smelting, which is also included in this symposium. [ ] Professor Sohn was born in a beautiful dynastic capital Kaesung, Korea on August 21, 1941. He received his B.S. degree in 1962 from Seoul National University, M.Sc. in 1966 from the University of New Brunswick, Fredericton, N.B., Canada, and his Ph.D. degree in 1970 from the University of California at Berkeley all in Chemical Engineering. After working as a Research Associate at the State University of New York at Buffalo and as a Research Engineer at Du Pont?s Engineering Technology Laboratory, Dr. Sohn joined the Department of Metallurgical Engineering at the University of Utah in 1974 and currently holds the ranks of Professor of Metallurgical Engineering and Adjunct Professor of Chemical Engineering.

Jan 1, 2006

By E. Daniel Baker

"The term ""oxide disseminated gold deposits"" refers to near surface, gold-bearing veins, faults, and shear zones that typically contain appreciable amounts of oxidized ore or gossanous material, resulting from oxidation of sulphides.The concept of oxide gold deposits underwent a dramatic change after the discovery of the Carlin gold mine in north-central Nevada in the early 1960's. Now the term implies large tonnage, low-grade bulk minable deposits that are processed by milling and/or heap leach methods.Oxide gold deposits may now be classified into two types: (1) primacy ores derived directly from the effects of hydrothermal alteration on host rocks, and (2) secondary oxide ores derived from the supergene oxidizing effects of circulating post-mineral meteoric waters on gold-bearing sulphides. Each type of deposit has unique diagnostic mineralogic and metallurgical characteristics that must be addressed to achieve successful exploration strategies and viable metallurgical exploitation.The author would like to thank the management of Newmont Metallurgical Services and Newmont Mining Company for allowing presentation of this paper. Thanks are due Sevkett Acar, Donald M. Hausen, Jerry R. Odekirk, and D. Erik Spiller for their critical review of the manuscript. Also, thanks are extended to all those cited and uncited whose hard work and dedication have led to the discovery and exploitation of near-surface oxide gold deposits. Our knowledge would be greatly limited without the dedication and research of many others."

Jan 1, 1997

By F. Qian

Direct impingement of molten metal baths by a gas jet is commonly encountered in such processes as BOF and electric arc furnace steelmaking. Shape and local fluid mechanics in the impinging region is important because it determines the interaction of the metal pool with the surroundings. Goal of the present work is to characterize and understand the interfaces at the impinging region. Using a physical model consisting of water/corn oil and water/kerosene as surrogates for metal/slag, interface shapes for slag-gas, slag-metal and metal-gas are investigated. Influence of transport properties of the two liquids on the shape and flow fields are also experimentally determined under various impinging jet conditions, namely jet momentum and jet height. The viscosity of the slag layer (corn oil or kerosene) has the most significant effect on the interface shape and the induced flow fields. The interface shapes were measured both photographically and by using a surface- tracking resistance probe. The limiting condition at which the jet breaks through the corn oil or kerosene layer and reaches the water layer was determined experimentally

Jan 1, 1994

By QIE Jun-mao, DONG Fang, DENG Hao-hua

The DIL402C thermal dilatometer and STA449C thermal analyzer were employed to test the linear expansion and contraction coefficient，CP and DSC curve of 304 stainless steel. The result showed that the linear expansion coefficient range was 20.9700×10-6～21.5712×10-6 and the linear contraction coefficient range was 21.2528×10-6～21.9471×10-6.The linear expansion and contraction coefficient were higher than other steel grade，so the 304 stainless steel belonged to the crack sensitive steel. Because of the crystal phase transformation occurred during the 1000~1400 ℃,the curve of CP fluctuated obviously and the defects of casting blank occurred easily. Chosen 1414℃ as the liquidus temperature of 304 stainless steel based on the analysis results of DSC. The curve of DSC was unsmooth during 1450～1100℃，the crystal phase transformation occurs and thermal stability of slab was inferior.When the initial solidified shell formed in this temperature range,the thickness of the shell would be nonuniform and the surface defects occurred more easily.

Jan 1, 2015

By Shuichiro Okada

Various efforts to reduce energy consumption and smelting cost are made at Tamano Smelter. Production of anode copper has been increased by about 30 % and energy requirement has been decreased about 50 % respectively. Challenges toward more higher goal are being continued. Details about the following are described in this paper. 1 Waste heat recovery Steam recovery at up-take of FSFE Heat recovery from waste gas of anode furnaces 2 Application of tonnage oxygen 3 Application of pulverized carbonaceous fuels to the flash smelting furnace with furnace electrodes ( FSFE ) 4 Application of computer control system to copper smelting 5 Improvement of the fugitive gas collecting system 6 Improvement of the mechanical tuyere puncher for the converter furnace

Jan 1, 1983

By David E. Hardt

"One of the critical variables to be controlled during arc welding is the size or geometry of the weld pool. The measurement of pool geometry has become an increasingly important problem with the advance of welding automation and control, and this paper addresses that problem. The basic concept of pool size estimation via measurement of pool dynamics is presented. The theory underlying this concept is discussed and is followed by a review of the current work in this area. It is concluded that pool dynamics can be characterized by natural frequencies of oscillation, for stationary welds, and that these can be measured by appropriate signal processing performed on the arc voltage. However, it appears that only full penetration welds show a strong correlation between weld size and natural frequency. Also, the extension of these results to the realistic case of moving welds has yet to be considered in detail. Nonetheless, this method of in-process measurement for real-time weld process control is still quite attractive where applicable since it can be accomplished simply by modifying the arc current schedule and by signal processing of the arc voltage.INTRODUCTUIONThe study of welding process control has been dominated by research into methods of in processing sensing of the weld pool geometry. While it has been shown feasible to measure the topside pool geometry using video methods [1,2], the penetration or backside bead width have remained elusive quantities. This is particularly true if a topside sensor location is required.The concept of using weld pool motion as a pool geometry sensing method was proposed by Hardt et al. [3] and later demonstrated by Hardt and Zacksenhouse [5] and Richardson and Renwick [6]. The concept is based on the fluid dynamics of a pool constrained by a solid container and by significant surface tension forces (i.e. a small shallow pool, not a ""pond"" or ""lake""). Such a pool, if subjected to external forces, will exhibit a surface motion is a function of that force, the properties of the fluid, the surface tension, and the shape of the container. Thus, if this motion can be excited and measured, and the relationship to the pool geometry determined, a means of sensing pool shape will exist."

Jan 1, 1986

By B. Mishra

Calcium and lithium gallides have been synthesized by powder metallurgy techniques in the stoichiometries that can be used as reduction alloys for the Rocky Flats Plant Salt-Scrub (SS) process. The SS process is performed to recover valuable metals from salts generated in the electrorefining and the molten salt extraction processes. Combustion synthesis has been optimized for variable heating rates up to the reaction ignition temperature and for green densities of the powder compacts in terms of the ignition temperature and the exothermic heating of the product in an effort to develop LiGa and CaGaz alloys. The problems arising from the melting point and density differences of calcium, lithium and gallium have also been studied. The SS alloy compositions were produced by mixing, pressing and sintering the metal-powders. The efficiency of the intermetallic alloy, Ca-17 wt. pct. Ga, as a reductant and the effect of gallium on salt clean- up has been discussed. Measurement of actinide recovery has been studied with cerium as the surrogate for the actinide metal. The development of an alloy for SS reduces a major contaminated waste disposal problem besides recovering the valuable reactive metal.

Jan 1, 1993

By John M. Rogers

Risk management has rapidly developed to become an integrated, holistic approach that now encompasses the main risk elements such as product quality control, occupational health and safety, security, environmental liability, social issues and related management information systems. Given the obvious economic benefits, a seamless blend of risk management components has become essential to allowing organisations to sustain a competitive advantage, and is also looked upon as an important attribute in organisational growth. Juxtaposed with this management philosophy is the global trend towards outsourcing, which has seen the emergence of independent, and specialist risk management organisations. The New Millennium will undoubtedly see a shift away from "in-house" risk management practices, and consequently, the selection of a suitable risk management partner - a major vehicle for improving shareholder value - will become an important strategic management decision.

Jan 1, 1999

By M. S. Moats

The treatment of oxidized residues of zinc with high iron content continues to present a technical challenge in both the steel and zinc industries. Two main problems are commonly identified and include high treatment costs and environmental concerns about contaminated, iron-bearing residuals. A new approach to this problem is described in which selective separation of the iron and zinc into salable products may be potentially feasible. The waste material is first leached to give a solution having an approximate concentration of 110 g/l Zn, 15 g/1 Fe and 40 g/1 H2SO4 and other impurities such as Pb, Cd, Cu and Sb. A suitable organic, such as D2EHPA, is used to load the majority of the iron. The aqueous phase is then acceptable for zinc electrowinning after standard solution purification. The novel step in the flow sheet is the efficient recovery of the ferric iron from the organic solvent using a solid metal to reduce the iron to the ferrous state. The Fe+2 is easily stripped into an aqueous phase in a relatively pure form, suitable for use in water treatment. Process parameters and possible flow sheet designs are described and discussed.

Jan 1, 1995

By Joo Hyun Park, Kyu Yeol Ko

The viscosity of the CaO-SiO2-xMnO-yCaF2 slags (C/S=1.0; x=10, 40%; y=0 to 15%) was measured to clarify the effect of CaF2 on the viscous flow of molten slags at high temperatures. Furthermore, the Raman spectra of the quenched glass samples were quantitatively analyzed to investigate the structural role of CaF2 in a depolymerization of silicate networks. The critical temperature of the slags abruptly increased at 15%CaF2, which was confirmed to originate from a crystallization of cuspidine using XRD analysis. The viscosity of the slags continuously decreased by CaF2 addition in the 10%MnO system, whereas the viscosity of the 40%MnO system was not significantly affected by CaF2 addition. The effect of CaF2 on the viscosity of the slags was quantitatively analyzed using micro-Raman spectra of quenched glass samples accompanying with a concept of silicate polymerization index, Q3/Q2 ratio. A polymerization index continuously decreased with increasing content of CaF2 in the 10%MnO system, whereas it was not affected by CaF2 in the 40%MnO system. Consequently, the bulk thermophysical property of the CaO-SiO2-MnO-CaF2 slags was quantitatively correlated to the structural information.

Jan 1, 2014

By Klaus Gamweger

"This paper introduces an innovative solution to open and close the tap hole of different furnace types in the copper industry with a slide gate system. Two plates with defined drilled holes are slid against each other, which enables effective starting and stopping of the copper flow as well as throttling. Typically, the copper is poured via a tap hole into a launder system by rotating the furnace into an appropriate position. Control of the casting rate is also performed in this manner. Or, in case of stationary furnaces the tap hole is opened by oxygen lancing and closed manually with a clay- or copper-cone. These procedures show a lot of disadvantages including splashing, oxygen pick-up, and energy losses as well as a severe danger for the working staff. All these problems can be overcome with an appropriate slide gate system.IntroductionThe control of the casting rate of a copper anode furnace usually is performed by rotating the furnace into an appropriate position. This implies that the taping starts with the tap hole at a very high position. Copper splashing and an uncontrolled oxygen pick up are - with several more disadvantages - the consequences. RHI AG has developed an innovative solution for copper applications to open and close the tap hole with a slide gate system which allows also an accurate control of the flow rate. By using this system it is possible to start the casting procedure with the tap hole at the deepest position, directly above the launder. This paper presents this new slide gate system in detail and shows the advantages in production and safety issues."

Jan 1, 2012

By George J. Karcas

"Non-ferrous metals such as copper, nickel, lead, zinc and precious metals are produced via the electrorefining and electrowinning processes. Apart from controlling electro-chemical conditions for the production of these metals, there has always existed the challenge of controlling the corrosive effect of the electrolyte environment which serves as the medium for non-ferrous metal production.The practice of acid containment in electrometallurgical operations has entered the world of high technology with the advent of advanced acid resistant materials such as vinyl ester resin which is either combined with aggregate to form polymer concrete or used to line various acid containment vessels and ·surfaces. ill comparison to some Asian, European, and African copper refineries, the North and South American copper industry has recently embraced quite heavily in the use of polymer concrete electrolytic cells and process vessels, such as electrolyte storage tanks, and in the use of vinyl ester resin for corrosion protective surface sealing 'systems in lieu of epoxy, acrylic and other materials because of its combination of higher corrosion resistance and superior flexibility.Electrolytic cell construction has undergone a transformation from a multiple part configuration to a single piece moulded/cast unit. ·The one piece moulded polymer concrete cell, which has been patented by Corrosion Technology International, with the overflow, decant, inlet, fast fill and segregation systems integrally designed is now the industry standard.. The combination of a wood, steel, or concrete frame with a lining made of lead, asphalt, rubber or plastic has been historically successful in providing limited protection from chemical and mechanical attack in electrolytic cells and electrolyte storage tanks all over the world. These combinations have now become obsolete as materials such as polymer concrete provide exceptional corrosion and mechanical protection with greatly reduced maintenance requirements and improved efficiency and productivity for the tankhouse. ill addition, polymer concrete can be disposed of in a regular land fIll which is much less costly than disposing of contaminated concrete that is normally associated with conventional lined concrete cells."

Jan 1, 1997

By T. Innmi

The potential of the nickel matte anode was measured during the matte electrolysis in the commercial cell. The slime layer consists of elemental sulfur and was found to greatly influence the potential of anode. The measurements of porosity and permeability of the slime suggest that the voltage drop of the slime layer dominates the potential. Furthermore, the diffusion of the electrolyte through the slime layer is also one of the factors to determine the potential. In addition, the copper content of the nickel matte anode was found to affect the change in the anode potential during the electrolysis. The role of copper on the anodic dissolution of nickel matte is discussed in this work.

Jan 1, 1988

By Kazuteru Tozcwa

The oxidation of several sulfide minerals in aqueous ammoniacal solution is discussed thermodynamically. The region in which Cu(NH3)2 4+ is stable has been estimated as a function of pH and concentration of total ammonia, {[NH3) + [NH4)}. In ammonia leaching when copper in sulfides is assumed to be extracted in the form of Cu(NH3)2 which will be rapidly converted to cupric ammine, thermodynamic data predict that such minerals are oxidized readily in the following order, CuS, Cu2S, CuFeS2, ZnS, NiS, Ag2S. This agrees with investigations on ammonia leaching of sulfide minerals, reported previously. The leaching of copper sulfide concentrate has been examined experimentally. Copper in a copper sulfide concentrate, in which the main constituents were chalcopyrite and pyrite, was effective¬ly extracted. The copper extraction was affected by factors such as (1) agitation intensity, (2) oxygen partial pressure, (3) NH3/Cu molar ratio, (4) leaching temperature and (5) addition of ammonium sulfate. From the results obtained in this work, it is concluded that mass transfer of oxygen plays the most important role in ammonia leaching of copper sulfide minerals.

Jan 1, 1976

By M. Soltanieh

The liquidus surface? and tie-lines in the nickel-cobalt-sulphur ternary system have been determined between 1<273-1573 K. The experiments were conducted by equlibrating the liquid sulphide with the metallic alloy phase. The liquid sulphide phase was sampled and chemically analyzed. The alloy was analyzed by electrol} microprobe. Combining the present results with the.avai1abl~ literature data, the thermodynamic properties of this system were calculated.

Jan 1, 1998

By Brian R. Green

Resin-in-pulp (RIP) technology has been developed for recovery of gold. It is now time to look forward to the potential for application of the technology to other situations. Some cases have been identified and have merited preliminary testwork. Four examples, which illustrate the potential of RIP, are dealt with in this paper. These include removal of metal-cyanides from pulps, recovery of manganese that is difficult to wash from filter cakes, recovery of nickel from low grade pulps, and recovery of zinc from process residues. The discussion includes descriptions of the problems, factors that affect the choice of resin, and factors that will affect the economics of the process.

Jan 1, 1998

By R. E. Molnar

A number of flowsheets have been designed and operated, or are currently being considered, to extract copper from leach solutions having much more copper than the 4 g/L levels typically found in heap leach liquors. Dealing with these solutions has required that the envelope for ?normal? copper solvent extraction be pushed beyond the usually considered limits. Others have published information on flowsheets to recover copper from leach liquors containing over 25 g/L copper. Secondary solvent extraction circuits are often required to attain satisfactory overall recoveries. This paper reviews some of the issues faced in three pilot plant circuits that were operated by SGS Lakefield Research to produce cathode copper from solutions containing 8 to 20 g/L Cu. The primary objective was to maximize copper extraction using one solvent extraction circuit. The role of feed acidity and the disposition of impurities such as iron and chloride are considered. The challenges of running short SX piloting campaigns are discussed.

Jan 1, 2003

By Philip L. Sibrell

A new process utilizing pulsed fluidized limestone beds was tested for the remediation of acid mine drainage at the Friendship Hill National Historic Site, in southwestern Pennsylvania. A 230 liter-per-minute treatment system was constructed and operated over a fourteen-month period from June 2000 through September 2001. Over this period of time, 50,000 metric tons of limestone were used to treat 50 million liters of water. The influent water pH was 2.5 and acidity was 1000 mg/L as CaCO3. Despite the high potential for armoring at the site, effluent pH during normal plant operation ranged from 5.7 to 7.8 and averaged 6.8. As a result of the high influent acidity, sufficient CO2 was generated and recycled to provide a net alkaline discharge with about 50 mg/L as CaCO3 alkalinity. Additions of commercial CO2 increased effluent alkalinity to as high as 300 mg/L, and could be a useful process management tool for transient high flows or acidities. Metal removal rates were 95% for aluminum (60 mg/L in influent), 50 to 90% for iron (Fe), depending on the ratio of ferrous to ferric iron, which varied seasonally (200 mg/L in influent), and <10% of manganese (Mn) (10 mg/L in influent). Ferrous iron and Mn removal was incomplete because of the high pH required for precipitation of these species. Iron removal could be improved by increased aeration following neutralization, and Mn removal could be effected by a post treatment passive settling/oxidation pond. Metal hydroxide sludges were settled in settling tanks, and then hauled from the site for aesthetic purposes. Over 450 metric tons of sludge were removed from the water over the life of the project. The dried sludge was tested by the Toxicity Characteristics Leaching Protocol (TCLP) and was found to be non-hazardous. Treatment costs were $43,000 per year and $1.08 per m3, but could be decreased to $22,000 and $0.51 per m3 by decreasing labor use and by on-site sludge handling. These results confirm the utility of the new process in treatment of acid impaired waters that were previously not amenable to low cost limestone treatment.

Jan 1, 2003

By Masafumi Maeda

Our aim in this project was to develop a new copper refining technology utilizing pyrometallurgical treatment and a raw materials preparation technique. In the recycling process; raw material is not an idealized concentrate of copper sulfide but is composed of various types of scrap, industrial wastes such as sludge, ash and slag, and municipal wastes. Since we cannot expect oxidation heat in this process as in sulfide smelting, organic materials are viewed as an alternative energy source. Quality of the copper produced is targeted as 99.99% and an intermediate grade will also be marketable. To benefit the plant, rare metals and other nonferrous metals will also be recovered The overall system is described in this paper, specific topics outlined and preliminary research presented. Current Japanese technology for recycling copper based materials is briefly reviewed.

Jan 1, 1995