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By Jian Wang, Hongyang Cao, Binxiu Wu, Junhong Li, Jimin Wang

"The enrichment and separation of scattered metal indium component in the pressure leaching solution with sulfuric acid from vacuum furnace germanium slag were studied by iron substitute and P204 extraction, which is supplied by shaoguan smelter. The experimental results show that the extracting power of P204 for indium from pressure leach solution is powerful. The optimal technological condition were the ratio of P204 and sulphonating serosene 3:7, phase ratio 1:3, solution pH 1.2, and extracting 5 minute. The enrichment indium solution of 21.7 g/L In at 95.2% recovery ratio was obtained by three-stage counter flow extraction and four- stage counter flow stripping.IntroductionScattered metals, such as Indium and germanium, were inriched as intermediate product or by-product during the metallurgy process of other non-ferrous metals, such as lead, zinc, copper and tin. For example, the indium and germanium were inriched in vacuum furnace germanium slag, which is the by-product of zinc vacuum distillation operation from hard zinc. It is difficult to recovery the indium from the vacuum furnace germanium slag, because the indium content is low, and the chemical composition and phase compositon were complex.Recovery indium from bearing indium zinc slag was researched extensively, such as pressure acid leaching, high temperature evaporation, solvent extraction method[l-7], acid leaching method has the advantages of high leaching rate, which can be separated hydrochloric acid, sulfuric acid and silicon fluoride acid systems. Solvent extraction method has the advantages of low production cost, fast reaction speed, high enrichment ratio, and simple operation."

Jan 1, 2013

By B. Wan

The process of synthesizing silica nanopowder by the gas phase thermal oxidation of tetraethylorthosilicate (TEOS) in a diffusion flame reactor was simulated using a commercial computational fluid dynamic (CFD) code. The fuel combustion process and silica particle formation and growth in the flame are modeled. The temperature, velocity and particle size distribution (PSD) fields inside the reactor are computed. Chemical reaction rate and population balance model (PBM) were used to calculate the particle formation and growth and PSD.

Jan 1, 2006

By Yuuki Yoshida

Electrolytic manganese dioxide, EMD, is the positive electrode material of primary batteries and the raw material of LMC used as the positive mass of lithium ion batteries and is currently produced by anodic deposition on and harvesting from a titanium anode in acidic manganese sulfate solutions prepared by dissolving high purity of manganese sulfate into sulfuric acid solutions. This paper presents an alternative method of EMD production using a novel anode, Mn2O3 coated titanium, at lower operating temperature than the current process to explore a possibility of manganese recovery from zinc electrowinning solutions. The Mn2O3/ Ti anode prepared by thermal decomposition of a precursor solution containing Mn (II) showed the anodic deposition of MnO2 by constant current electrolysis and the current efficiency was 95% in maximum, while the current efficiency and the crystallographic structure of deposited MnO2 depended on the current density, the electrolysis time, the bath temperature, and the concentration of Mn(II). The deposited MnO2 was successfully harvested from the anode and the recovery rate was 98%.

By J. H. Huang

In this investigation, the selective precipitation of cobalt and molybdenum from Co-Mo aqueous solutions was studied in order to recover efficiently valuable elements from industrial effluents generated from a novel electrodeposition of nanocrystalline Co-based alloys process and reduce the effluent impact on environment. It was found that the behavior of cobalt in aqueous solutions was substantially affected by the presence of molybdenum. When adding 11.6 to 46.6g/L molybdenum to a 50g/L cobalt solution, the co-precipitation of molybdenum and cobalt started to occur at pH value of 3-4. However, without the presence of molybdenum, cobalt could only be precipitated out of the solution at about pH 6. Most of the molybdenum was found in the solid phase when the solution pH reached 5. After further increasing pH to greater than 7, the molybdenum dissolved back into the solution. Cobalt kept precipitating as the pH increased. When the pH was greater than 7, most of the cobalt was present in the solid phase. The chemical and physical characteristics of the precipitated materials were investigated by SEM, XRD, AAS and EDX. It was revealed that the precipitate was initially present as cobalt molybdate oxide hydrate and subsequently transformed as sodium cobalt molybdenum oxide. With further increasing the solution pH, the precipitate was transformed into cobalt hydroxide. Further investigation implied that most of molybdenum was chemically tied to the precipitate produced at the low pH, yet at the same time, physically entrapped at the high pH. The paper also presents the influence of reaction temperature and time on the precipitation process and kinetics.

Jan 1, 2003

By Akira Yazawa

To realize highly efficient process in extractive metallurgy, continuous operation nearly in equilibrium is preferable, but most metallurgical processes consist of plural steps with different chemical potentials. Traditional two-step process of sintering followed by reduction is continuous in each step, but is heterogeneous reaction system far from equilibrium, and the chemical potentials are varied considerably along the distance the charge travels in a reactor. This route will become old-fasioned in next century due to the various inherent problems caused especially by sintering process. To establish reasonable new smelting processes, the important tasks of the metallurgists are how to introduce feed and reacting gas in the reactor, and also how to overcome the difference in chemical potential in the reactor system. Based on the ways to solve theses tasks, recent proposals of new smelting process for copper and lead are classified and discussed with the help of sulfur-oxygen potential diagram. On such potential diagram, each equilibrium step in continuous smelting is expressed at a fixed point, and two reactors with different chemical potentials must be connected by continuous molten flow through launder or partition wall. In the latter case, the reactor is apparently single, but some technical problems must be overcome. While, in a batch smelting like converter, potential variation is successively realized along a path on chemical potential diagram with the time elapsed. To establish immediate equilibrium, continuous steady flow of reactants into well mixed reactor is indispensable. In modern smelting process, the ore is mostly supplied in the form of powder which have huge surface area and fluid character, and consequently injection process must be very attractive. Several examples are discussed for both of copper and lead smelting, and promising future technologies are suggested.

Jan 1, 1988

By P. T. Velu

Light weight aluminum alloys are the major construction materials for a number of structures in automobile and aerospace industries. Higher cost of production is the key impediment which restricts the usage of these alloys. A new electrochemical process route for the low cost production of aluminum alloys is being investigated, in which alloying elements are obtained from the dissolved compound. In the present investigation, solubility of lithium compound has been determined by measuring the EMF, when it is dissolved in the electrolyte. The solubility of Li2CO3 increased with temperature from 2.95 wt pct at 1063 K to 7.57 wt pct at 1093 K. Activities of the compound in the electrolyte were deduced using Temkin's ideal solution approach.

Jan 1, 1995

By Bora Derin, Sertac Yazici, M. Seref Sonmez

"In this study, the recycling conditions of waste liquor obtained after the production of tungsten boride powder from calcium tungstate by self-propagating high temperature synthesis (SHS) and the following hydrochloric acid leaching were investigated in detail. Environmentally unfriendly and extremely acidic (pH~ -0.3) liquor consisting of calcium, magnesium, and boron ions was treated with 1 M sodium carbonate solution to precipitate magnesium carbonate and calcium carbonate phases. The obtained amorphous precipitates were heated up to the temperature of 400°C for re-crystallization. As a result, MgO, CaC03 and CaMg(C03)z phases were obtained, while sodium, boron, chlorine ions were remain in the solution. The present study is still in progress.IntroductionSelf-propagating high temperature synthesis (SHS) is one of the techniques used in the production of a variety of advanced ceramics, inter-metallic, organic and inorganic compounds, oxygen free single crystals, and polymers [ 1, 2]. The reaction becomes selfsustaining and propagates in the reactant mixture, after initiation in SHS process. SHS products may contain the mixture of several unwanted compounds and elements. Therefore following acidic leaching process may be needed to purify the target product. In the previous study, calcium tungstate (Ca W04), magnesium (Mg) and boric acid (B20 3) mixture were reacted to produce tungsten boride powder by SHS process according to the Reaction 1. Then, magnesium and calcium containing byproducts (i.e. MgO, Mg3B206 and Ca3B206) found in the SHS product were leached out by using concentrated hydrochloric acid (HCl) solution to obtain pure tungsten boride powder [3].Ca W04 + 0.5B203 + 4.5Mg = WB + 4.5Mg0 + Cao (1)After the leaching, filtrate solution consisting of different amounts of magnesium, calcium, and boron requires additional treatment for the environmentally acceptable disposal.Several works were carried out about magnesium precipitation conditions and kinetics from brines. Rabadzhieva et al. investigated the precipitation of Mg(OH)z from brines by using NaOH as well as caustic soda [ 4]. Turek ve Gnot investigated the precipitation efficiency of Mg(OH)z for the temperature range between 10-40°C, while the reaction was kinetically experimented by Alamdiri et al [5, 6]. Homogeneous precipitation of nesquehonite (MgC03.3H20) by the reaction of MgCli with (NH4)2C03 in supersaturated solutions and factors that influence the precipitation of MgC03.3H20, such as reaction temperature, initial concentration, stirring speed, titration speed, equilibration time, have been studied by Wang et al [7]. The precipitation of Mg(OH)z by calcium hydroxide from aqueous solutions was studied by Baird et al. [8]. Stratful et al. focused on conditions influencing the precipitation of magnesium ammonium phosphate from wastewaters [9]. 1031"

Jan 1, 2011

By Matthew Tunnicliffe, Akram Alfantazi, Paul Nesbitt, Farzad Mohammadi

"Lead and its alloys are proper candidates for anodes in electrowinning processes mainly because they are insoluble in the leach solutions and relatively cheap. However, the annual cost of corrosion problems associated with these anodes is millions of dollars. In this study lead-silver and lead-calcium anodes were tested under typical nickel electrowinning conditions and the effect of chloride on the corrosion performance of the anode materials was investigated. Corrosion rates of the anodes were calculated using the discharge plateau (reduction of lead dioxide to lead sulfate) after galvanostatic experiments. It was found that lead calcium anodes have the highest corrosion rate both in the presence and absence of chloride. Surface morphology of the electrodes was studied using SEM and the corrosion products were characterized using XRD.IntroductionLead (Pb) is usually the preferred material for commercial anodes since it is insoluble in the leach solution and the costs are manageable. One advantage of using an insoluble material as an anode is the higher purity of the cathodic deposits and better quality of the end product. During nickel electrowinning, metallic nickel is deposited on the cathode while oxygen evolution reaction (OER) takes place on the anode. In practice, relatively high potentials are necessary for the reaction to proceed at the desired rate because of the high overpotential of OER on lead. Lead anodes get oxidized in typical electrowinning conditions and usually have two to three years of lifetime. Although the price of each anode is insignificant, the overall cost of corrosion of these anodes is considerable, which is due to the large number of anodes used in a plant, typically two to three thousand. Therefore, corrosion is a significant problem associated with lead anodes in commercial nickel electrowinning plants and industries show interest in addressing this problem. Corrosion of lead electrodes in acidic environments has been previously the subject of many research studies [I-7]. It has been reported that, during the anodic polarization of lead, several phases may be present on the surface, depending on the potential range that is being studied [8]. Lander showed that lead is oxidized at potentials higher than 0.252 YsHE with tetragonal lead monoxide being the main reaction product [9]. At 0.666 YsHE lead can transform to lead dioxide; however, it is not stable and transforms to lead sulfate and lead oxide. At potentials higher than 1.684 YsHE, lead dioxide is eventually a stable phase and forms a protective layer on the surface [I 0, 11]. Under conditions of a typical nickel electrowinning plant, usually a 200 A/m2 current density is passed through the electrodes."

Jan 1, 2012

By Dhanesh Chandra

In this symposium, research in the area of energy conversion is presented. This symposium has special significance, as we honor three prominent scientists from hydrogen storage research and development field. In this symposium, the majority of papers presented by international scientists and engineers are in the area of hydrogen storage. Other energy conversion papers include magnetic materials, superconductors, and thermal energy storage materials. Recent developments in light-weight high gravimetric hydrogen density hydrides have led to potential use of hydrides for onboard automobile and other applications. This, of course, is significant from environmental concerns of CO2 and other emissions from the current use of carbon based fuels in automobiles. Thus, it is becoming increasingly important to switch to cleaner alternative fuels such as hydrogen [1]. The Challenge of Vehicular Hydrogen Storage as potential hydrogen energy carriers for vehicular applications, with a driving range of approximately 300 miles, require ~5-13 kg of hydrogen stored on-board. In the United States, Centers of Excellence have been established in metal hydrides, chemical hydrides, and carbon-based materials, and abundant scientific and industrial research is being carried on metal hydrides; only some of the current research from the Centers will be reported here. The European commission, Japan Institutions, and others also have numerous hydrogen storage programs in progress. Several international collaborations have also begun between IEA and IPHE scientists to accelerate the progress of development of practical hydrides. A summary of the abstracts is included in this overview.

Jan 1, 2006

By J. M. Tourre

1995 have seen a continuation of a positive trend in the Rare Earth industry The availability of a greater diversity of Raw Material has brought additional flexibility to the Producers permitting better economics China remains the major raw material source; Chinese concentrate producers have increased capacity in 1995 (Baotou, Sichuan, etc) China's role in the Rare Earth industry will continue to evolve; the acquisition of a majority equity position by San Huan/CNNC will have a significant impact on both the Rare Earth and Magnet markets Chinese producers are increasing the quality of their products and realize their true values Chinese market, itself, is also changing as the internal needs for separated rare earth's grow Already already producer of Lamps, Loudspeakers, Magnets, and TV tubes, China is in an unique position where the potential of its internal market might be more promising than the prospects outside China 1995 has also seen the application market become more diverse and complex. There are new applications growing at a very strong pace (such as battery alloy), applications that are now penetrating their target markets with significantly increased growth rates (such as bonded NdFeB), and some applications that became more complex requiring much more sophisticated products (such as catalysis). Rare Earth producers have to spend significant ressources in order to monitor the market trends in order to predict the demand and then adjust their raw material mix. Even though there is a greater diversity of raw material available, there is still some Rare Earth elements that are in excess, while other are just in balance. As a consequence rare earth producers invest heavily in R&D in order to develop new applications for these excess elements.

Jan 1, 1997

By J. Y. Aubut

The modernization of the CCR Refinery to permanent cathode technology is presently underway. The 360,000 mt/y refinery is being retrofitted to accept the Kidd process. Part of this modernization includes the installation of Kidd stripping machines, and the total replacement of the materials handling equipment. It also involves the reinforcement of building structures to accept the new equipment and the ability to operate in different modes. The future equipment will interface with some existing apparatus, which is being retained for future operations. The whole operation will be automated and will allow product traceability for quality purposes. This retrofit poses important challenges given the size and scope of the modernization project and because it is being undertaken concurrently with normal plant operations.

Jan 1, 1999

By Kaixi Jiang, Bangsheng Zhang, Lei Zhang, Haibei Wang, Xiaoping Zou

"China plays an important role in the global molybdenum industry; in fact, both China's molybdenum mine and smelter production ranked first in the world. The characteristics of China's molybdenum resources are quite complex, and moly-nickel ores with carbon, coppermoly ores and wulfenite can be only found in China. This paper firstly introduces China's molybdenum resource/ reserve situation. Secondly, the status of molybdenum smelting technologies, especially roasting by rotary kilns and multiple-hearth furnaces, are discussed. The practices and the development of some new technologies, such as pressure leaching, solvent extraction, ion exchange, carbon adsorption for moly-nickel ores and low grade molybdenite concentrates, are also introduced.IntroductionMolybdenum is widely used in special steels, aviation, alloys, chemistry, electronic and medical industries because of its excellent physical and chemical characters [1,2].In nature, molybdenum exists mainly as molybdenite associated with copper ore which are the main material for smelting. About 99% of molybdenum is produced from molybdenite. In addition, wulfenite, molybdenum oxide ore and graphite shale containing Mo-Ni have also industrial value to extract molybdenum and other metals such as Ni, Re, Pb and Zn. The reserves of molybdenum in China are about 8.4 million tons metal; China is ranked as the second largest source in the world. The output in China is more than 40 kt in 2010. Ferromolybdenum is the main product and then ammonium molybdate. The consumption in China is about 20 kt and the rest is exported to overseas.The first molybdenum smelter in China was built in 1963. Today the main producers include Jinduicheng Moly Company, Luanchuan Moly Company and Jiangxi Copper Group Company. Technologies and equipment have changed greatly. Roasting and multi-hearth furnaces are widely used. Several new processes were developed such as pressure leaching, solvent extraction, ion exchange and carbon absorption [3-8]."

Jan 1, 2012

By J. M. Floyd

"Top submerged lance furnace developments started in CSIRO in the early 1970s and was given the name Sirosmelt. In the early work the technology was developed for tin smelting and processing tin slags but once a small pilot plant was established other slag processing applications were soon recognised and evaluated for various copper, nickel, zinc and cobalt-containing slags. The process was tried for copper smelting and converting, which was proven in the small pilot plant in 1978. In the same year the first commercial application of the technology was established for the recovery of tin from slags at Associated Tin Smelters, Sydney. Work on lead smelting was initiated by the CSIRO team in the late 1970s and laboratory work led to pilot plant trials by Mount Isa Mines.In the second decade of the technology the focus of development became commercial acceptance of the technology through marketing, development and application by Ausmelt and Mount Isa Mines; the former commercialising and developing the technology for a wide range of applications, while the latter concentrated on its own commercial needs of copper and lead smelting. This decade saw a number of commercial plants built in Australia, with considerable interest becoming evident from other parts of the world. Towards the end of this decade Mount Isa also entered into the business of marketing of the technology through rights dating to the joint work with CSIRO in the late 1970s.So far, after five years, the third decade of the technology has been characterised by diversification of applications of the technology to areas outside the non-ferrous and precious metals production industry. The waste processing and recycle industry and the iron and steel industry have recognised that the top submerged lancing system is a new type of reactor with many significant features which provide new opportunities for processing a range of materials under good environmental controls in a cost effective manner.I hope this audience will excuse my boldness in talking about the third decade of the technology when we are only half way through! I am aiming in this paper to not only talk about the past, but to try illustrate the future directions which I envision."

Jan 1, 1996

By W. P. lmrie

The recent years have seen many copper smelting operations become uneconomic due to a combination of low metal prices, high energy and labor costs, environmental requirements and high investment costs for modernization or replacement. Since a copper commodity requirement remains, the industry will recover, but many operations will need to determine which processes can offer the best prospect for economic operation and readiness for reliable investment and implementation. Corporate investment decisions involve the judgment of many factors in addition to topical technical aspects. Consideration of plant management and operational aspects are thus included. Taking account of such proven processes as conventional, flash and continuous smelting, plus modified conventional and new unproven processes, this paper gives a systematic approach to aid optimum choice for a modernization or grassroots investment. Actual achievements in energy form alternates, conservation and cost effectiveness are highlighted, and areas of remaining potential for energy saving are discussed.

Jan 1, 1983

By Andrey Tarasov, Erki Unn, Valery Paretsky

"The stability of the markets of energy resources and labor in countries of the Baltic Sea Region including Estonia is determined to a significant degree by the use of combustible shales as fuel and their distillation resulting in generation of up to 70% of non-recyclable waste. The objective of this business plan is to substantiate the investments for establishment of a new facility in Estonia for waste-less and environmentally safe processing of fossil minerals and man-made products generated in the shale industry, as well as other hazardous wastes. The proposed facility will use a basically new waste processing technology developed in Russia - i.e., processing in sparged molten slag This technology eliminates any release of harmful pollutants to the environment and a facility using this technology does not require, therefore, any sanitary protection zone.IntroductionIn the Baltic region, and first of all in Estonia and some other European territories, there are large natural deposits of combustible shale, which due to the lack of other own resources of energy and hydrocarbons for the chemical industry is burned and distilled with low technical and economic efficiency generating large amounts of toxic and highly toxic wastes and intermediate products. Currently, the penalties for disposal of such wastes have grown to such an extent that shale burning and distillation might become unprofitable. This might result in suspension of the given operations, which in turn will affect in an adverse way the markets of energy resources and labor market in those countries. Furthermore, in addition to the “shale problem”, Estonia, similarly to most member countries of the European Union, faces the challange of environmentally safe processing of highly toxic wastes, such as municipal solid wastes, oilpolluted materials, medical wastes and infected materials, spent rubber tires, etc. These wastes are at present stored or processed with release of a significant quantities of extremely toxic cancerogenic substances (dioxins, furans) or collected and exported for treatment at an extremely high cost and with a loss of valuable components contained in these types of waste and often with return of supper toxic processing products."

Jan 1, 2008

By R. M. Nadkarni

This paper examines the broad' economic parameters of copper smelting by conventional and new smelting technology. Location, transportation of products to market and pollution control options are discussed.

Jan 1, 1983

By K. Olsen

As aluminum alloy usage in automobiles grows, there are increasing demands on recycling processes and facilities to deal with mixed alloy automotive aluminum scrap. These processes and facilities strive to produce near virgin aluminum stock, which can be relatively costly and difficult. One alternative is to use physical processing methods to upgrade the scrap properties instead of chemically refining the scrap. The Impulse Atomization Process (LAP, patent pending) is a new process for making metallic and ceramic powders. It can produce fine homogeneous microstructures in scrap aluminum alloys due to high undercooling and rapid solidification. The particles have a very narrow size distribution and are in a convenient form for consolidation. This paper compares and contrasts the microstructural features of Impulse Atomized. and quenched Impulse Atomized powders,' for both AL6061 and a scrap aluminum alloy composition.

Jan 1, 1995

By Joseph Sofra

It has become increasingly evident that sustainable metals production in the 21st century requires producers to balance the needs of cost effective, high value production with that of responsible plant operation. This is becoming more difficult as lower grade and more complex feed materials, including recycled scrap and residues, are being processed to reduce production costs and decrease exposure to primary metal market fluctuations. One particular facet of the metals industry facing these challenges in the 21st century are copper producers, The recent steady decline in the copper price has seen the industry cut expenditure, tighten control on income streams and focus on high returns on capital investment. For these reasons copper producers are looking towards flexible technologies that can deliver high value products, with minimal environmental impact at low capital and low sustainable operating costs. Ausmelt's Top Submerged Lancing (TSL) technology for copper production is a low cost, proven technology for the processing of both primary and secondary copper materials. Both the smelting and converting operations introduce significant advantages in environmental performance, improved process efficiencies and high rates of metal recovery, Ausmelt has made significant gains in the past 4 years in establishing a strong market position for its copper technology, New installations in China, South Africa and India as well as existing operations in Zimbabwe and China have demonstrated its effectiveness. This paper reviews the application of Ausmelt Technology for both smelting and converting of primary and secondary sources, It discusses Ausmelt's design and implementation philosophy, and how this philosophy meshes with the needs of the end user.

Jan 1, 2003

By Shengqin Zhang, Jagannath Pal, Yousef Mohassab, Hong Yong Sohn, Mohamed Elzohiery

The kinetics of magnetite reduction with mixtures of hydrogen and CO of various compositions has been investigated as part of the development of a flash ironmaking process at the University of Utah. This new process bypasses the cokemaking and pelletization or sintering steps required for the blast furnace. The particle kinetics were studied using magnetite concentrate particles of different sizes. Reduction degree of 60% was achieved in a few seconds in at 1350 oC using CO reductant alone and over 90% when H2 + CO gas mixture was used. The effects of reductant partial pressures, temperature, and particle size on the reduction kinetics were studied.

Jan 1, 2016

By Q. G. Liu

New solid-state electrochemical sensors 1;.1sing Li2SO4-Ag2SO4 electrolytes have been developed to measure SO2 and/or SO3 in gas mixtures. Silver embedded in part of the electrolyte is used as the reference electrode. Although single-phase electrolyte sensors yield accurate results for one to two days, a two-phase electrolyte cell exhibits excellent long-term chemical stability. For example, stable and accurate potent iometric responses have been obtained over a six mo.nth period. The. advantages of the two-phase electrolyte ( 23 mol% Ay 2SO4 ) cell include excellent mechanical strength on temperature cycling and an insensitivity to compositional variations in the electrolyte and to temperature fluctuations. Experimental tests have shown excell.ent results in SO2-air. mixtures with the SO2 concentration ranging from 3 to 10,000 ppm (vol). However, the SO2 concentration range was limited by a lack of standard gas mixtures, and our sensor cells can be used to measure S02 concentrations significantly less than or larger than our experimental range. Results also indicate that the presence of significant concentrations of CO2 and H2O in the gas mixture has no effect on the sensor response. Thus the two-phase electrolyte ( 23 mol% Ag2S04) sensor has exceptional selectivity, reliability and long-term chemical and mechanical stability.

Jan 1, 1985