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By T. Takasu

Overall productivity in copper refining is currently determined by the electrorefining process. Previous research showed that forced convection of the electrolyte improves the morphology of the copper deposit on the cathode and suppresses passivation of the anode. In this paper, electrorefining experiments under forced convection were carried out in the presence of As, Sb and Bi impurities, both in electrolyte and in the anode, to determine the effect of the impurities on the electrorefining process. The concentrations of the impurities in the deposit increased with increasing current density without forced convection. An increase in the fluid velocity suppressed the increase in impurity concentration. These concentrations were high, especially in the initial stage of deposition without forced convection, corresponding to a decrease in the cathode potential measured during that period. This indicates that the enrichment of impurities was induced electrochemically. The reason for the decrease in cathode potential was the low concentration of copper ions on the electrode surface because of ion consumption by the electrolysis. The forced convection of the electrolyte enhanced the ionic mass transfer and thus suppressed the polarization and deposition of the impurities. The fluid motion was shown to be effective in achieving electrolysis under high current density conditions.

Jan 1, 1999

By Chu Yong Cheng

Synergists can be used in solvent extraction to improve the selectivity of extractants for metals. Research work carried out by the SX group at the AJ Parker Cooperative Research Centre for Hydrometallurgy / CSIRO Minerals has shown that the pH isotherm of nickel with Versatic 10 was significantly lowered by the addition of the synergist Acorga CLX50. The paper discusses how this synergistic shift can be used to alleviate a gypsum formation problem at Bulong nickel laterite operation in Western Australia. Metal pH isotherms were obtained with Versatic 10 and synergist CLX50 using synthetic leach solutions. In terms of pH50, the extraction order of the metals with 0.5 M Versatic 10 alone was Cu > Zn > Ni > Co > Mn > Ca > Mg, whilst the extraction order with Versatic 10 and 20% by volume CLX50 was Cu > Ni Zn > Co > Mn > Ca > Mg with the pH50 (Mn-Co) significantlyincreased. This is significant because the isotherms of valuable metals Ni, Cu, Co and Zn shift more towards low pH than those of the waste metals Mn, Mg and Ca, resulting in a possible good separation of Ni, Cu, Co and Zn from Mn, Mg and Ca. The use of intermediate precipitation, solids/liquid separation and re-leach in the three Western Australian nickel plants make these processes complicated and costly in capital and operation. The research work carried by the SX groupat the AJ Parker Centre has led to the development of direct SX (DSX) processes to recover nickel and cobalt from leach solutions using synergistic organic systems. Semi-continuous tests with a BHP Billiton pilot plant leach solution showed that Ni and Co together with Zn and Cu were separated from the major impurities, Mn, Mg, Ca, and Cl, in the first SX circuit. The co-extracted impurities were easily scrubbed. After stripping, Ni and Co together with Zn and Cu were concentrated, resulting in a much smaller second SX circuit in the down stream processes.

Jan 1, 2003

By M. D. Street

Lead and zinc production commenced in 1966 at Brunswick Smelting using the Imperial Smelting Process. In 1972 the blast furnace was modified to produce lead bullion only which was refined to corroding grade lead using conventional kettle refining techniques. Since 1972 consumption of lead concentrate and production of refined lead has doubled and this paper describes changes to operating and maintenance techniques which have contributed to this improvement. Reference is also made to improved environmental, health and hygiene practices at the smelter.

Jan 1, 1983

By Theo Lehner

"During my first contact with industrial metallurgy as a summer vacation worker at the Steelplant at Luleå, Sweden, I came during a visit to MEFOS into contact with works of Prof. Worner caried out during the piloting of the Worcra continuous steelmaking process. These tests are still today remarkable as an innovative step in the art of metalmaking. By that they involved the necessary ingredients for the development of our art: seeing, knowing and doing. Industrial injection as applied during slag fuming will be discussed below.Phenomena of injection metallurgyPhenomenon according to Collins dictionary is"" anything that can be perceived as an occurrence or facts by the senses"". To open the senses for the interesting phenomena in pyrometallurgy must be the main task of any educator. The investigations by Engh et al. around the mixing phenomena of the WORCRA process are an early example of combining senses with knowledge. To see what you model must be a crucial part in any development. This can also involve to see and control that one is subject to the same conditions as in published models. Below the need ""to see"" will be illustrated by some recent investigations around slag fuming. In the literature various models for reactions occuring during the fuming of slags are presented. Two recent models hint ·ata) the occurrence and importance of iron for the fuming processb) the occurrence and importance of lead droplets during respectively."

Jan 1, 1996

By Chang Wei, Zhigan Deng, Jiqiang Liao, Minting Li, Hongsheng Xu, Yan Song, Cunxiong Li, Xingbin Li

"Abstract: Direct ?otation of oxidized zinc-lead ore is characterized by recovery of zinc and lead only around 55% and 50%, respectively. Mineralogical analysis shows that the sample used in the present study is a carbonate hosted zinc-lead ore, with a zinc and lead carbonate content that accounts for 80.14% and 75.63% of the total minerals, respectively. The carbonate hosted zinc-lead ore was hydrothermally sulfidized with elemental sufur and the experimental data indicated that under the conditions employed up to 75% zinc and 82% lead sulfidation extent were achieved. As a result of pre-sulfidation followed by flotation, the recoveries of zinc and lead into flotation concentrate were over 90%. A flotation concentrate was obtained with 52% Zn and 37% Pb from the materials which was treated by sulfidation.IntroductionSulfide ores are the primary source of zinc and lead, and they are becoming depleted; thus, metallurgical investigators are interested in using abundant oxidized zinc-lead ore reserves. The high-grade zinc-lead oxidized ore, which normally has a zinc content higher than 15%, can be disposed of by acid leaching and electrolysis. However, the low-grade ore, which has a zinc content lower than 10%, is difficult to smelt with pyrometallurgy and hydrometallurgy, and the processes are very complicated and expensive in terms of production flow and energy consumption. Therefore, making the low-grade oxidized zinc-lead ore more beneficial has become more important in recent years. Flotation is the most common process, and the primary method of recovering zinc and lead from sulfide or oxide minerals. It is well known that there is a difference between sulfurized and oxidized minerals regarding their separation by flotation. Flotation of zinc and lead oxidized minerals is extremely complex because of the similarities in the physicochemical and surface chemistry of the constituent minerals. There are no known direct-acting collectors capable of producing single metal concentrates [1-3]."

Jan 1, 2012

By H. Y. Cho

LS-Nikko Copper Inc, has been operating its Onsan copper smelter since 1979. The smelter began its operation with a designed capacity of 80,000 tpa of copper from concentrates and its smelting capacity was increased to 140,000 tpa of copper by modifying the existing line in 1988. The Mitsubishi Continuous Smelting and Converting Process has been operating since 1998 at the initial capacity of 160,000 tpa of copper. In 2002, the smelting capacity of the Onsan smelter has been increased to 426,000 tpa of copper from concentrate. Now the Onsan smelter has plans to increase its smelting capacity to 500,000 tpa of copper from concentrates by 2010. During the expansion work, the modernization of facilities will be accompanied by an increase in smelting capacity, via the Outokumpu process. This paper reviews the brief history of smelting capacity increase in Onsan smelter and its Outokumpu process modernization plans.

Jan 1, 2006

By Juha Järvi

Outokumpu Zinc Oy has two separate roasting lines with fluidized bed furnaces and waste heat boilers for calcine collection and heat recovery. During the last 30 years, zinc production in Kokkola plant has increased continuously and at the same time the raw materials have changed. Therefore, the waste heat boiler has been under continuous research and development. The waste heat boiler plays a significant role in the process and consequently the reliability and efficiency of the device is important for the effectiveness of the entire process. Many changes have been made to the boiler in the last decades. New radiation tube screens, tube bundles, and baffle-plate constructions have been added to the boiler and also rapping systems for the dust have been developed. The latest improvement to the boilers was a baffle wall, located in the middle of the radiation section roof in the first boiler, and baffle plates in the lower part of the convection section in the second boiler. The new boiler design and optimization were carried out using physical water and air-dust modeling as well as computational fluid dynamics. The modeling work agrees well with experiences in practice. The latest developments have increased the operating hours per year and the effectiveness of the waste heat boiler.

Jan 1, 2002

By G. Archer

ASARCO, a large and diverse producer of nonferrous metals, is involved primarily in the smelting and refining of lead and copper. Lead-antimony alloys, antimony trioxide, bismuth, cadmium oxide, selenium, tellurium, silver and gold are among products which result from processing by-products of smelting and refining. The complex mixture of concentrates at some smelters and the high impurity loads at some refineries result in various drosses, sludges, dusts and slags. In this paper, the complex interplant and intraplant transfer of by-products is addressed. These by-products result in an exchange of metals between the lead circuit and the copper circuit. Examples of the transfer of by-products and the prospects for the recycle of valuable products from wastes generated by customers and unrelated processors are also discussed.

Jan 1, 1992

By Courtney A. Young

All cyanide species are considered toxic and can be found predominantly in industrial effluents generated by metallurgical operations. For example, cyanide's strong affinity for metals makes it favorable as an agent for metal finishing and treatment and as a lixivant for metal leaching, particularly gold. These technologies are environmentally sound but require safeguards to prevent water contamination. Various methods of cyanide remediation by separation and destruction are available, but certain methods are more effective than others depending on the cyanide species being remediated. Photolytic destruction is regarded as the one technique that is independent of the cyanide species involved. The destruction of various cyanide species by several photolytic techniques has been investigated for the past few years. A literature survey suggests heterogeneous photocatalysis with anatase (TiO,) should behave similarly to homogeneous photolysis with hydrogen peroxide (H,O,) since proposed reaction mechanisms for both processes involve hydroxyl radicals. However, experimental evidence on a suite of cyanide species suggests otherwise. A new mechanism for the photocatalytic destruction of cyanides, especially SAD species, is therefore proposed.

Jan 1, 1998

By Vince Newberry

Alcan Rolled Products at Oswego, New York, commissioned Recycle II during May of 1995. Recycle II is an advanced technology UBC recycling facility designed to meet the most stringent environmental standards enforced to date in the United States, particularly with respect to NO, and particulate emissions. This paper addresses the exacting requirements and strategies of Alcan's Recycle II project andThorpe Technologies' design considerations and solutions for the supply of environmentally favorable melting furnace and delacquering systems. The furnaces are equipped with low NOx regenerative burners and furnace pressure and hearth gas flow controls designed specifically for processing the hearth gases through baghouses. The delacquering system is a new generation Apros concurrent flow unit designed for low NOx emissions.

Jan 1, 1995

By Y. Waseda, S. V. Gnyloskurenko

"Present paper reviews the various processes for making of metallic foams. These methods are classified in accordance with the state of initial metals - liquid, powdered and ionized. Liquid metal can be foamed by direct inputting of gas into melt, using gas releasing foaming agents or producing supersaturated metal-gas solutions. This group also includes methods creating voids in the melt. Powder route is based on using powdered matrix metal with foamable precursor materials. Finally Deposition techniques allows making highly porous metallic structures using ionized metal.Experimental study presented shows importance of wettability in bubble formation at gas blowing into melt simulation liquid (water) through holes. Good wettability of injection holes by water ensures formation of bubbles with smaller sizes that effect to the final foam structure.IntroductionOne of the objectives of future production technology is to make of lightweight constructional materials while achieving improved property and good economy as well.The most perspective lightweight materials are cellular or foamed materials that are Wide8pread. in nature and have a growing interest in industry and everyday life.Even metals and metallic alloys can be produced as cellular solids or metal foams beside of the traditional engineering materials such as polymers, ceramics or glass. Recent developments in metal foams, especially aluminium, have produced a new class of lightweight materials."

Jan 1, 2000

By E. S. Peterson

The selective separations of trace metals- and organics from water are processes of importance to industry. The application of a new metals capture technology coupled with polymer membrane technology has proven to be one avenue to accomplish such selective separations. The polymers used in these studies are polyphosphazenes. Polyphosphazene polymers consist of an alternating backbone of nitrogen and phosphorus atoms. The polymers have high thermal and chemical stabilities. Experiments at the Idaho National Engineering Laboratory demonstrate that polyphosphazene membranes coupled with Chromato Chem,"Chelation Chromatography" process are capable of removing both chlorinated hydrocarbons and metal ions from process streams. These results point to a wide range of potential industrial and environmental applications for such systems. Data will be presented which show the efficiency and selectivity of separations, postulated separation mechanisms, and the initial designs of industrial demonstration units which are currently under construction. Parts of this work have been performed under a Cooperative Research and Development Agreement (CRADA) between ChromatoChem, Inc. and Idaho National Engineering Laboratory (INEL). The work at INEL was been sponsored by the United States Department of Energy's Office of Industrial Technologies

Jan 1, 1995

By Hongfa Hu, Stavros A. Argyropoulos

"This paper describes a mathematical model which simulates numerically reaction driven fluid flow phenomena. The driving force of this reaction is an exothermic heat of mixing. In addition, the model predicts the heat and mass transfer phenomena where both heat source and heat sink co-exist in close proximity. The heat source is generated by an exothermic reaction. The heat sink is formed by a moving boundary such as the melting of a solid. This type of phenomena occur quite often in various metal processing operations in which exothermic additions are immersed in liquid metals. The model is based on the SIMPLER algorithm and uses an enthalpy method to predict the fluid flow, temperature, and concentration fields. The results indicate that the exothermic mixing reaction was responsible for an abrupt rise in temperature around the moving boundary. The intensity of this reaction was also found to be responsible for the enhanced convection of fluid and the acceleration of the moving boundary. The modelling results were also verified by experimental work which included velocity and temperature measurements in a low temperature physical model. IntroductionAlloying additions are used extensively in the treatment of liquid metals during metallurgical processes. The alloying additions introduced into liquid metals can be classified into various classes, each of which follows its own route[l]. As a major group, the exothermic additions follow two different steps during their assimilation into liquid metals. In the first step, upon immersion, a metal shell solidifies around such additions, and then melts back. At this point, the second step commences. During this second step, due to the mixing of the addition with a liquid metal, an exothermic reaction occurs, which liberates large amounts of heat, resulting in an enhanced convection in the liquid metal surrounding the addition."

Jan 1, 1994

By N. V. Sujathkumar, I. Vasudhevan, R. Santhakumar

"Freshwater ornamental fish culture is gaining importance in India and cheaper and nutrient rich live foods such as infusorians, daphnids, copepods and tubifecids are needed urgently. In this regard, adequate research has been conducted to produce such live feeds through recycling of agriculture and animal wastes. By this venture, besides generation of additional income, environment is also kept clean. In order to popularise the technologies relating to production of live foods from wastes and generate employment opportunities, training programmes were conducted for 100 Self Help Group women belonging to Thoothukudi district. The topics of the training included, breeding of ornamental fishes by utilizing the building material wastes, production of live foods through recycling of agricultural and animal wastes. A study on feed back was conducted with 100 respondents represented from different villages. The variables such as socio economic status, economic motivation, usefulness of training and constraints were included in this study. The impact assessment of this training of rural women indicated that 79 percent respondents were in favour of using the training for self employment by utilizing different kinds of wastes. Similar training programmes have also been planned in other parts of Tamilnadu. Introduction Ornamental fish culture is one of the most appropriate sectors to provide opportunities of employment to uplift the status of rural women. To ensure women utilize their full potential in useful and profital activities like freshwater ornamental fish culture, it is necessary to provide training and support for rural women which will ultimately lead to empowerment. Self Help Group Women are being trained routinely in India on the production of live foods for ornamental fish culture through recycling of agricultural and animal wastes. In this regard, training programmes were organized for the Self Help Group Women on freshwater ornamental fish culture. Which is gaining much importance in India. Cheaper and nutrient rich live foods such as infusorians, daphnids, copepods and tubifecids are needed urgently. The techniques of live feed production through recycling of agricultural and animal wastes would not only generate additional income by would also keep the environment clean."

Jan 1, 2008

By F. A. Steward

Copper is one of the trace minerals essential to life. It is added, usually in the form of copper sulfate, to virtually all formulated feedstuffs and to dietary supplements fed to animals on forage. Over the past five years, an improved inorganic copper source trademarked Micronutrients TBCC™, has been developed, tested and commercially introduced. TBCC is a crystalline form of basic copper chloride. Synthesis is accomplished in a continuous neutralization I crystallization process. In current commercial production, the primary sources of copper currently used as feedstocks are the etching solutions used to manufacture electronic printed wiring boards. These solutions have traditionally been managed as hazardous wastes, but their use to manufacture TBCC™ exempts them from regulation as wastes under the "Use/Reuse" provisions of RCRA. Research conducted over five years at multiple universities has shown that animals are healthier when fed this source of copper and that vitamin losses in feed are reduced by its use.

Jan 1, 2000

By Andrew Shabalin, Vladimir Skorohodov, Svetlana Babaeva, ?lga Makovskaya

"At processing of some kinds of wastes (electronic scrap, secondary materials, spent nuclear fuel) in nitric acid solutions, and also in technology of silver refining, the significant amounts of palladium and platinum passes into a solution. The ion-exchange concentration of palladium and platinum in nitric acid solutions (5-500/dm3) are investigated. More than 30 various classes of ionites are tested. The most chemically resistance resins at the given conditions are identified. It is shown, that the maximum sorptive capacity to studied metals at high acidity the complexing, synthetic and inorganic sorbents possess. To definition of platinum metals sorption optimum conditions the kinetics is studied, isotherms of a sorption at various parameters from nitrate solutions are obtained. The conditions of the platinum and a palladium desorption from the pregnant sorbents and its regeneration with the subsequent reuse of materials were defined. The raw materials containing precious metals have very diverse composition and physical properties. Commonly the materials are processed by hydrometallurgical way. If gold or PGMs there are in raw materials to its opening hydrochloric acid solutions are applied. As an oxidizer nitric acid, hydrogen peroxide, gaseous chlorine, etc are used. Nevertheless, at processing of argentiferous materials and preliminary treatment of a waste including the spent nuclear fuel, nitric acid solutions are often used and the specified metals in some extent pass into solution [1]. Therefore selective extraction of PGMs from nitrate solutions is an actual problem. In the present work the ion-exchange concentrations of palladium and platinum in nitric acid solutions (5-500 g/dm3) are investigated. At the testing more than 30 various classes of ionites the most chemically resistance resins at the given conditions are identified. These resins are synthesized on the base of polyacrylate, styrene-divinylbenzene and vinylpyridine. For a selection of the most effective resin among what are made in Russia and overseas, a number of ionites with various functional groups were studied. Influence of functional groups type on a PGM sorption is shown for extraction of a palladium as an example (table 1). The presented data shows, that palladium concentration in a phase of ionites depends on sorbent type. If the increasing of solution acidity essentially reduces palladium sorption by sulfonic cation-exchange resins (KU-2×8) than its sorption by strongly basic anionites is approximately equal. Intermediate position is occupied by complexing sorbents. The latter (AN-31, SN-3, ANKB-35, Lewatit TP 207, Purolite S 930) are the most effective for extraction of PGMs from nitrate solutions from the point of view of capacity value. According to [2], solution behavior of Pt (II) and Pd (II) are similar. As is known from coordination chemistry, ligand environment of the metal ions substantially impacts to character of electronic spectra. The figure 1 shows the results of measurements of optical density of platinum bearing solutions with various concentration of nitric acid at ?=400 nanometers"

Jan 1, 2008

By R. M. G. S. Berezowsky

Treatment of Hudson Bay Mining and Smelting Co. Ltd. (HBM&S) zinc concentrate in the Sherritt zinc pressure leach process produces a residue containing elemental sulphur, residual sulphides, precipitated iron species, si1ver and gold. Flotation of the residue recovers most of the elemental sulphur and residual sulphides to the concentrate, leaving iron oxides and bask sulphates in the tailings. The tailings also contain most of the sflver and some gold. Direct cyantde leaching of the oxide tailings (220 g/t Ag, 1.4 g/t Au) was capable of leaching most of the gold, but only a minor portion of the silver. This paper reports testwork, conducted by Sherritt on behalf of HBM&S, to define a process for a high recovery of the precious metals from the oxide tailings. A si1ver enhancement treatment, consisting basically of digestion of the residue with lime at 90°C to render the silver amenable to enhanced recovery by subsequent cyanidation, was selected as the most promising approach. Batch silver enhancement and cyanidation tests showed that treatment of the oxide residue with 80 kg/t CaO at 90°C for 1 to 2 h increased the silver extractability in subsequent cyanidation from <20% to 96%. A 96 h continuous miniplant test (1 kg/h solids feed rate), of a circuit including a silver enhancement treatment step followed by conventional cyanidation and carbon in pulp silver and gold recovery, confirmed metal recoveries to the carbon of 90% Au and 96% Ag. Reagent consumption rates were 1ess than 100 ?kg/t CaO and 5 kg/t NaCN.

Jan 1, 1990

By Zhenyang Wang, Yiran LIU, Xiangdong Xing, Jianliang Zhang, Zhengjian Liu

Basic characteristics of marine placer were systematically studied by chemical analyze, scanning electron microscope and X-ray diffraction in this paper. It could be found that the marine placer mainly consists of titanomagnetite and titanohematite. A series of experiments were performed to investigate reduction-magnetic separation for Fe and Ti from the marine placer. Effects of reduction temperature, reduction time, carbon ratio, magnetic density, and grinding fineness on the reduction-magnetic separation process were investigated. And the optimal process parameters were obtained as follows: the reduction temperature 1300, the reduction time 30 min, the carbon ratio 1.1, the magnetic density 50mT, and the grinding fineness of 0.074μm 86.34%. Under such conditions, the metallization rate, iron grade of magnetic substance and iron recovery reached to 94.23%, 97.19% and 90.28% respectively, and the titanium grade in non-magnetic substance and recovery of was 57.94% and 87.22% respectively. The effective separation of iron and titanium could be achieved in reduction-magnetic separation process.

Jan 1, 2015

By S. S. Ryu, J. C. Kim, H. Lee, Y. D. Kim, I. H. Moon

"Recently, W-Cu alloy becomes one of the very important candidate materials for heat sink and packaging in the field of microelectronics due to its good thermal properties. The metal injection molding of W-Cu powder can satisfy the requirement for mass production of complex shaped parts in microelectronic devices. In the present study, the application of MIM process to the nanostructured W-Cu powder prepared by mechanical alloying was investigated. The multi-component binder system of 45PW+ l 5BW+ 30PE+ I OSA was proven to be suitable one for the MIM of the W-Cu composite powders by adopting the debinding cycles of multi-stage in N2 and H2 atmospheres. Other process conditions for the MIM of the nanostructured W-Cu composite powder were also studied. The MIM debinding part of W-30wt.%Cu was sintered to the relative density of more than 96% by sintering at 1200 °C for !hour in H2 atmosphere. Such an improvement of sinterability was attributed to the intrinsic homogenous and fine mixing state of W-Cu phases in nanostructured W-Cu composite powders, and also partly to the effect of the activated sintering by the presence of impurity introduced during the extensive milling.IntroductionW-Cu alloys have been widely used for heavy duty electrical contacts and arcing resistance electrode(1-2). Recently there has been a growing interest in this W-Cu alloy because of its superior thermal managing properties and its high micro wave absorption capacity(3). Such W-Cu alloy parts are conventionally fabricated either by the Cu infiltration sintering technique or by hot pressing of W-Cu powder mixtures. However, these conventional PM techniques are hardly applicable for mass production of small size parts with a complicated shape such as the parts required for microelectronic devices. The metal injection molding(MIM) technique is potentially applicable for the mass production of small and complicatedly shaped parts compared with other PIM forming techniques."

Jan 1, 1998

By Basak Anameric

Pig iron nugget process was developed by Kobe Steel as an environmentally friendlier, economical alternative to traditional blast furnace process. The process aimed to produce highly metallized, slag free pig iron nuggets throughout a single stage heat treatment, utilizing coal as a reducing ? carburizing agent. The objective of this work was to determine whether the pig iron nuggets produced at the laboratory conditions had comparable physical and chemical properties with the blast furnace pig iron. The physical and chemical properties of the pig iron nuggets were determined utilizing x-ray fluorescence spectroscopy, x-ray diffraction, optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and apparent density measurements. The pig iron nuggets had similar chemical composition and apparent density values (6.7 ? 7 g/cm3) with blast furnace pig iron and they had microstructures similar to low carbon white cast iron. These properties make them a competitive alternative to blast furnace pig iron.

Jan 1, 2006