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By Wantae Kim

In order to establish the optimized recovery process for heavy minerals from Korean beach sand, we investigated the several physical separation methods such as gravity and magnetic separation followed by mineralogical characterization. There was clear relationship between the particle size and heavy mineral content that heavy minerals were mostly concentrated in the particles below 100mesh. Gravity separation using the spiral and shaking table separators made it possible to concentrate heavy minerals by rejecting the light and coarse particles consist mainly of quartz and other non-valuable minerals. The high-intensity magnetic roll separator and subsequent induced magnetic separator were applied to fractionate magnetic particles according to their magnetic susceptibility. The content of TiO2 of high susceptible ilmenite-rich fraction was 43.98wt.% while those of ZrO2 of non-magnetic and magnetic residue were 6.78wt.% and 3.11wt.%, respectively.

Jan 1, 2006

By P. Hanniala, J. Sulanto

"The requirement for the reduction of sulphur dioxide emissions from copper smelters is becoming more and more important. Therefore, the most important question in smelting technology will be how to produce even, high strength SO2 gas in smelter and how to combine smelting and converting. The best sorution in certain cases is to eliminate converters totally.Outokumpu is already responding to this challenge. As a result of extensive research work, Outokumpu Oy has developed the Flash Smelting Process for direct smelting of blister copper from concentrates in one step.The newest process development is the Kennecott-Outokumpu Flash Converting process, where solidified copper matte is converted into blister copper. The production of low volume high SO2 content gases, separation of smelting and converting operations to allow increased on-line availability, and simplified process control are the major benefits of the process which translates to reduced smelter capital and operating costs.Also, it has been studied the use of the same Outokumpu furnace for smelting and converting alternately when the production capacity is low.In this paper, the developments and improvements of the Outokumpu Process are described from the operation and investment cost standpoints"

Jan 1, 1988

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 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 George R. St. Pierre

A method for the quantitative description of activity interactions between solutes in a metallic solvent which is consistent with stalistical thermodynamic principles is presented. The chemical potential of a solute in an alloy is derived from the weighted mean of its values in the individual solvent components, µi = S?jµi(i). The weighting factors, ?j, are obtained from the distribution functions. The resulting equation contains far fewer adjustable parameters than the Epsilon Formalism and because of its correct functional form it provides an improved fit to the available data on a variety of alloy systems containing oxygen, carbon, sulfur, nitrogen, and hydrogen. For a binary metallic solvent ( A, B ) containing a solute (i), it is shown that

Jan 1, 1995

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 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 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 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 Jeong-Soo Sohn

Physical treatment and chemical treatment of spent lithium-ion battery were studied in our research team. Especially we developed two types of acidic leaching for crushed powders containing LiCoO2 of spent lithium ion battery. One of them is sulfuric acid leaching with H2O2 as a reducing agent. The leaching rates of cobalt, lithium and the other metals were above 99 % at the condition of 2 M H2SO4, 10 vol. % H2O2, 75 °C, 300 rpm agitation speed, 250 g/5L solid liquid ratio and 75 minutes reaction time. And the other leaching process is the oxalic acid leaching. In this process more than 99% of Li and less than 1% of Co were dissolved at the condition of 3M oxalic acid, 80°C reaction temperature, 300rpm agitation speed, 50g/L initial solid/liquid ratio and 90min extraction time. Each process has its advantage and disadvantage. In sulfuric acid leaching, leaching reagent is very cheap and cobalt could be recovered into cobalt hydroxide. On the other hand, oxalic acid is more expensive than sulfuric acid but lithium could be dissolved selectively. Also cobalt could be recovered into cobalt oxalate and it could be changed into cobalt oxide after heat treatment. In order to select the effective recycling process, recovery rate and purity of cobalt hydroxide and cobalt oxalate were compared and it was investigated which process was more environment-friendly and economical.

Jan 1, 2006

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 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 Kazuya Kitatani, Gen Sasaki, Naoto Ohta, Hideharu Fukunaga, Makoto Yoshida, Jin Pan, Kenya Nagahisa, Toshihiro Ishikawa

"A sintered SiC (Tyranno-SA) fiber-reinforced MAS glass matrix composite was fabricated by using a slurry infiltration method and hot-pressing. The microstructure and mechanical properties were investigated: To prepare the preform, the MAS glass slurry including a dispersing agent was infiltrated into a bundle of the fibers. The preform was then hot-pressed under the conditions of 1473 K, 30 MPa, 3.6 ksec. A unidirectionally-reinforced oxide matrix composite with 50% Vf. of the fiber and a density of 2.84 g/cm3 was obtained. As the mechanical properties at room temperature, the three-point flexural strength- and quasi-static adsorbed energy were 500 MPa arid 6,000 J/m2, respectively. Without graphite or an h-BN pre-coating on the surface of the fiber, pull-out and bridging of the fibers from the matrix was found, and this leads to a high value of the adsorbed energy. By TEM observation, nano-scale crystalline products were found between the fibers and the glass matrix. The push-out test reveals that this layer causes the appropriate debonding of the interface during the fracture process of the composite.Introduction It is known that the CFCCs (continuous-fiber-reinforced ceramic matrix composites) are characterized by their non-linear fracture behavior, which is' hardly found in monolithic ceramic materials. It is inevitable for the CFCCs to exhibit a large fracture toughness so 'that debonding of the fiber/matrix interface; pull-out and bridging of the fibers then' occurs during the fracture process. This series of fracture behavior is known as the so-called ""the mechanism of toughening of the CFCCs"". Thus, different from the MMCs in which strong interfacial bonding is necessary, the interfacial strength of the CFCCs has to be controlled. As techniques for controlling the interfacial strength, it is also known that both a CVD-graphite coating and an h-BN coating are effective to induce the mechanism of toughening[1,2]. In the case, of the Si-C-O or Si-Ti-C-O fibers/glass or crystalline oxide matrix composites, it is reported that the formation of the in-situ graphite layer, which is also effective to increase the fracture toughness of the CFCCs, is often found during the fabrication process such as hot-pressing. The lower the crystallinity of the Si-C-O fibers, the higher is the tendency to form the in-situ graphite layer as found by the chemical reaction between the fibers and the glass matrices[3-12]. On the-other hand crystallized stoichiometric 'SiC fibers are attractive for high temperature service because of the higher phase stability compared to the Si¬C-O or Si-Ti-C-O fibers. However, in the previous, studies, the mechanical properties and the interfacial chemical reaction of the crystallized SiC fibers / glass matrix Composites have still been unknown. In this study, a polycrystalline 'sintered SiC fiber-reinforced MAS glass composite was fabricated. The mechanical properties and microstructure were then investigated. The slurry infiltration technique followed by hot-pressing was used to prepare the composites. The formation of the in-situ graphite layer and the relationship between microstructure and mechanical properties at room temperature were examined by the TEM observation of the fiber/matrix interface."

Jan 1, 2000

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 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 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 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 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 A. H. -J. Siegmund

Since the last survey of lead smelters in 1987, the lead industry has experienced many changes. Technological innovations, in combination with a dramatic shift in the market structure as well as more stringent government regulations, caused major upheavals in many different areas. Therefore, a new survey was performed to review the progress in the technology of lead recovery over the least decade. The newly conducted survey reflects all current phases of the world's primary lead production, from charge preparation to refined metal shipment. It was prepared by sending questionnaires to individual companies, and the detailed statistical data of this survey are presented. In considering the data developed from the survey, it should be recognized that the primary lead industry is at a crossroad where novel technologies will gradually substitute the sinter machine - blast furnace operation in the new millennium.

Jan 1, 2000

By Henry Hu, Alfred Yu

"A numerical model has been developed to simulate heat and mass transfer phenomena occurring during a novel magnesium reduction process-the vertical retort technology. The model was based on the control - volume finite difference approach. Simulations were run to determine the effect of various processing parameters on magnesium reduction cycle time. The model predicted temperature distributions, heating curves, recovery ratio of magnesium, and total process times. The predictions were used to optimize the magnesium reduction process including dimensions of the retort, geometries of the reactant compounds, and productivities. The results indicate that the implementation of the optimized processing parameters significantly decreases the reduction time, and consequently increases the production rate as well as lowers the energy consumption.IntroductionMagnesium consumption has been growing considerably in the past decade [1]. Of the total magnesium production, 30% is produced by the thermal reduction (Pidgeon) process, and it is anticipated to be still the main technology for producing magnesium in future [2]. One of the advantages of the Pidgeon process is that it is capable of producing high purity magnesium demanded by both the automotive and aerospace industries. However, the inefficiency of heat and mass transfer taking place in the horizontal Pidgeon reduction process results in low productivity, high energy consumption, labor-intensive operation, large floor space and high capital investment. This limits the production scale of a horizontal Pidgeon reduction process [3].Vertical reduction processTo overcome the shortcomings of the horizontal magnesium reduction process, a novel vertical magnesium reduction process [3] for large-scale production has been developed, in which heat and mass transfer in the retort is enhanced. The new process shortens reduction time, reduces energy consumption and increases productivity. The vertical reduction system is comprised of a vertically-placed retort, a heating furnace and a vacuum system. A section of the vertical retort is illustrated in Figure 1. Since the retort is set vertically, instead of horizontally, the entire procedure of loading the reactants material in the new process is different from the one for the horizontal reduction process."

Jan 1, 2001