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By Spencer Peng, Larry Wasik, Akram Alfantazi, Michael Mahon

A dynamic simulation of a zinc tankhouse is a potential tool to improve tankhouse production and cost efficiencies. A fully dynamic simulation has potential uses in the design of new tankhouses as well as in the optimization of existing facilities. Equations from previously validated models of a single cell have been adapted to the industrial dynamic process simulation software, CADSTM Plus. Based on the inlet concentration, current density, and electrode setup, the simulation can predict many parameters, including outlet concentrations, flow rates, current efficiency and energy consumption. Multiple cells have been simulated simultaneously, allowing for an entire hypothetical tankhouse to be modeled. The simulation can be used to dynamically predict the conditions in a zinc tankhouse throughout an operation time scale. Further applications of this model include, tracking impurity buildup, modeling of recycle streams and the development of new flow regimes within the tankhouse.

Jan 1, 2012

By Vladimir Lobanov, Vladimir Skorohodov, Boris Radionov, Olga Makovskaya

"The synthetic sorbents and the activated carbons which are used for the metals extraction from weak process liquors are rather expensive. It is propose to use mineral and synthetic high-porous substances which sharply increased sorption properties by special processing. For achievement the desirable properties sorbents are impregnated by specially prepared solutions. Such solutions should contain the substances or its anionic forms which on the one hand are strong enough fixed in a supporter pores, with another are capable to form the insoluble compounds with extracting metals. Selectivity is provided by chemism of the reagent interactions with extracting metal. Due to the high concentration of a reacting ion in a sorbent phase the capacity and rate of sorption increases. Formed insoluble compound remains in a phase of the sorbent and necessity of its filtration disappears. For synthesis the sulfhydryl compounds which chemical properties allow to increase degree of extraction and capacity of the activated carbon were used. At hydrometallurgical processing of precious metals mineral raw materials the commercial solutions with the concentration of gold from 0,1 to 5 mg/dm3 are received. Commonly gold is precipitated from cyanic solutions by the zinc dust. The sorption methods are widely applicable. But the synthetic sorbents and the activated carbon using to these purposes are rather expensive. Expenses for sorbents even at its regeneration can reach 10-15 % from total expenses of gold extraction from ores. When sorbent regeneration, mostly for carbon, is not provided, this share increases to 30-40 %. Thereupon search of the sorbents combining availability, the sufficient capacity, demanded degree of extraction and the low price is actual. For the specified purpose it is offered to use the mineral and synthetic high-porous materials which sorption properties are sharply rose by special treatment. Among such substances are natural zeolites, silica gel, lignine et al. Similar treatment can improve the sorption properties of sorbents used in practice, particularly, the activated carbons. The simplest treatment of potential sorbents consists in its impregnation by specially prepared solutions. Such solutions should contain substances or its anionic forms - impregnating agents. These agents should be on the one hand strong enough fixed in a carrier pores, on the other hand are capable to form with extracting metals insoluble compounds. The more strong compounds are formed the high degree of metals extraction from solutions. The sorbents with similarly changed properties are named the impregnated sorbents."

Jan 1, 2008

By Sun Ying, Zhang Jing, Li Qiu-ju, Wang Yan-ze

Copper smelter slag was leached using sulphuric acid solutions under atmospheric conditions. Base on the composition and phase of copper slag, the effect of the concentration of sulfuric acid and leaching temperature to the leaching growth rate of Fe, Cu, Co and Ni in the copper slag were investigated in this paper. Simultaneously, the influence of sulfuric acid concentration, leaching time, leaching temperature and the amount of sulfuric acid (solid-liquid ratio) to the leaching rate of these metal elements were researched. Experimental results showed that: with the increasing temperature, the dissolution rates of the metals elements increased first and then decreased. Due to the influence of silica gel which was obtained in beginning of leaching, the higher the concentration of sulfuric acid is not conducive to dissolution of the valuable metal elements. The dissolution degree of Fe, Cu, Co and Ni were 92.83% 96.76% 93.62% and 63.41% respectively.

Jan 1, 2016

By Hiroki Kumakura, Kotaro Seki, Takashi Nagai, Masahito Abe, Daiki Noguchi

A large amount of platinum group metals (PGM) are used in automobile catalyst. It is important to recover the metals from wasted catalyst. PGM in the catalyst are supported by ceramics for four-wheel vehicle or metals such as stainless steel for two-wheel ones. The recycling process of PGM from the metal-supported catalyst has not been developed, while the process for ceramic-supported catalyst was developed, such as Rose process. We designed a noble recycling process of PGM from metal-supported catalyst using complex oxides between PbO and PGM oxide. In this study, complex oxides, PbPt2O4, PbPdO2, PbRh2O4 and so on were synthesized at about 773–973 K. And the dissolution behavior of these compounds to hydrochloric acid was investigated. PbPt2O4 and PbPdO2 were dissolved to hydrochloric acid easily, but PbRh2O4 was not.

Mar 1, 2017

By Ditze A., C. Scharf

Magnesium type 1 - scrap can be remelted without flux in the presence of different sulfur containing protective gases. Beside the draw back in the use of these gases, that either are contributing to the global warming potential (SF6) or are poisonous (S02), residues like dross and crucible sludge are produced. Dross and sludge now a days must be utilized. Partly these byproducts can be used in the aluminum industry and partly for desulphurisation of hot metal and steel. Another possibility is melting of dross and sludge with flux for the production of a secondary magnesium alloy. Then again residues are generated that must be processed. Therefore, the whole material cycle has to be considered to decide which kind of utilization practice is optimum. Based on experiments this question is discussed and the material balances for fluxfree melting, melting with flux and fluxfree melting plus other utilization of the residues are presented.

Jan 1, 2000

By Mituo Tougo, Mitsuo Tokunoh, Takayasu Kisaragi, Fuminori Chiba

We have about 200,000 tons/year of dross residue produced after the collection of aluminum from the dross generated during the aluminum remelting process. 130,000 tons of the dross residue is used as a steel deoxidant or a cement material, and the remaining 70,000 tons is abolished and buried in the ground at authorized places. The dross residue is increasing along with the increase in the aluminum production. This situation will grow more serious with a large amount of aluminum window sashes which have been mass-produced since 60's and will return before long as scraps. Our effort is being directed to the development of technologies which enable the dross residue to be recycled and reused for some purposes such as road aggregates, refractories and others, in such a way as to comply with the social requirement which gives prfority to the recycling industry, as well as to the environmental preservation.

Jan 1, 2000

By V. Bredykhin

The efficiency of scrap processing depends firstly on reliability of information about its chemical composition. The paper presents the results of the investigation and development regarding solid copper alloy scrap in the range of lump size 40÷300 mm. Nowadays the sorting of lump scrap is done by two methods: 1. Sorting according to metals and alloys is done at places of scrap generation, and further till metallurgical processing each lot has its "certificate"; 2. Hand sorting of scrap is done according to the marks on solid items in special shops using proximate analyzers or manually by experienced workers. This sorting process is labor - consuming low efficient and involves mistakes. The informational method is a promising trend in the copper scrap sorting. The method is direct, i.e. as a result of sorting the chemical composition of each scrap lump or main elements is determined, and assured data of qualitative and quantitative composition are received.

Jan 1, 2006

By Robert W. Bartlett

"Economic and other factors, mostly outside of metallurgy, that strongly influence applied research, development and especially successful commercial adoption of new processes for producing primary metals and other commodity materials are reviewed. These factors, which can be both positive and negative in their influence, are often too lightly regarded in the research planning stage. They include continuing imperatives that have long influenced new process development as well as more recent trends. Both are discussed. Nearly all new materials eventually become commodities--products made to standard specifications with no producer control over price. Success requires being a low cost producer on a world wide basis. Composites and other complex material assemblages are unlikely to escape this fate as they mature.INTRODUCTIONThe adoption of new processes, beginning with research and development, for primary metals and other commodity materials is particularly difficult because each new process must supplant an existing process that is already being used commercially. There are many requirements besides technical innovation and cost superiority that must be met by the new process. Consequently, few innovations make it all the way from the research laboratory to commercial success.This paper discusses some of the factors that influence success in developing new processes for primary metals and commodity materials, based on the authors experience as a research metallurgist and industrial research manager. It begins with some of the factors that are always present and constrain successful process research and development, and proceeds to current trends that are expected to continue long enough to influence processes in the year 2000. Many of these trends are contradictory in their effect on new process development, and the future remains uncertain.The prevailing importance of these trends will vary with the material, process concept and other factors intrinsic to each case. Nevertheless, an awareness of these influences can help to avoid some of the R&D pitfalls and dead ends. Such awareness is deemed to be a necessary condition to avoid failure when commercial adoption of a new process is the goal."

Jan 1, 1988

By Hee Dong Jang, Hong Yong Sohn, Miguel Olivas-Martinez

"Tetramethylorthosilicate (TMOS), a precursor of silica nanoparticles, is prepared from the waste silicon sludge, followed by the synthesis of silica nanoparticles from the TMOS by flame spray pyrolysis. A two-dimensional multiphase computational fluid dynamics (CFD) model for the flame spray pyrolysis process (FSP) for the synthesis of silica nanoparticles has been developed. The model incorporates the governing turbulent equations of overall continuity, momentum, energy and species mass transport to represent the gas phase and the population balance model (PBM) to account for the silica nanoparticles. The model has been validated with experimental data in terms of gas temperature and average particle size. Introduction Silica (SiO2) nanoparticles are used in various industrial applications, such as catalyst, pigments, thin film substrates, electronic and thermal insulators, and humidity sensors [1]. They are also used as additives in plastics and rubbers to improve the mechanical properties of elastomers, and in liquid systems to improve their suspension behavior. These applications rely on the particle morphology, average particle size, particle size distribution, and phase composition [2]. Silica nanoparticles can be synthesized by wet chemical processes such as sol-gel methods and high-temperature processes such as flame spray pyrolysis (FSP). The FSP process provides a unique control of particle size and crystalline structure and it can also produce high-purity, thermally stable particles continuously with minimal further treatments. The sizes of the flame- made particles range from a few to several hundred nanometers, depending on the operating conditions [1]. The synthesis of silica nanoparticles from organic compounds that contain silicon by the FSP process is of interest because it generates no harmful by-products [1, 3]. Several compounds such as tetraethylorthosilicate (TEOS) and tetramethylorthosilicate (TMOS) can be used to synthesize silica nanoparticles, but most such compounds are expensive. Thus, it is desirable to prepare the precursor compounds from waste materials. In the present study, TEOS and TMOS synthesized from silicon sludge were used as precursors of silica nanoparticles [4]."

Jan 1, 2008

By Guodong Lai, Shixing Wang, Lijuan Chu, Jinhui Peng, Zebiao Zhang

"The beneficiation of poor manganese ores containing phosphate gangue is very difficult by conventional processes, because of the similarities in the physico-chemical properties of the constituent minerals. The shaking table gravity concentration process and concentrated strong acid selective intensified leaching process were used for dephosphorisation of Yunnan manganese ore. The leaching process was effective. The effects of intensified leaching time, solid-liquid ratio and particle size were investigated. The relevant leaching factors were optimized as -0.125+0.088 mm particle size with 68% nitric acid for 24 h when using a solid-liquid ratio of 1:1 at room temperature and atmospheric pressure. Under these conditions, the P/Mn ratio was reduced from 0.0107 to 0.0056, and the grade of manganese was increased from 12.32% to 42.76%. The dissolution of manganese during leaching was negligible.IntroductionManganese and its compounds are widely used in the iron and steel industry as deoxidation and desulfurization agents and as alloying additives [1-2]. Because of the increase in demand, low grade refractory manganese ores are becoming a new source. Many Chinese manganese ores are high in phosphorus, which cannot be used directly for metallurgical purposes. This occurs because phosphorus enters into the metal phase during smelting and its presence sharply deteriorates the mechanical properties of the metal [3-4].Kanungo and Sant [3] investigated the dephosphorization of phosphorus-rich manganese ores by selective leaching with dilute hydrochloric acid. They observed that leaching with dilute hydrochloric acid (0.1-0.6M) could reduce the phosphorus contents to the specified limit of 0.12%. Ye [5] investigated dephosphorization of high-phosphorus manganese ore of the Huayuan type. Using high intensity magnetic separation, roasting and leaching with acid for dephosphorization, as used in the industry, a 40.15% manganese concentrate with a P/Mn ratio of 0.0037 was obtained. Yimin [6] investigated magnetic separation followed by inverse flotation of high-phosphorus manganese ore, and found that the P/Mn ratio could be reduced from 0.046 to 0.002."

Jan 1, 2012

By Natasa Mitevska

The distribution coefficients of Ag, As, Au, Bi, Co, Cu, Ni, Pb, Sb, Se, Te, and Zn between copper matte and slag from the reverb furnace No.2 at the Copper Smelter and Refinery, RTB BOR (Yugoslavia), are presented in this paper. The influence of the matte grade on the minor elements distribution coefficients between copper matte and slag is analyzed. The minor elements distribution in the slag phase along the slag melt depth and the furnace length is also determined.

Jan 1, 2002

By Gaifeng Xue, Lei Zhang, Xia Liu, Lina Wang, Pu Liu, Benquan Fu

"Experiments were conducted to investigate the behavior of the integrated process with a three-dimensional electrode reactor combined with Fenton process for coking wastewater treatment. Effects of initial pH value, reaction time, H20 2 dosage, Fe2+ dosage on Total organic carbon (f OC) removal rate were investigated. The kinetics of degradation of TOC from coking wastewater by three-dimensional fluid bed electrode reactor combined with Fenton process was also studied. Experimental results shows that three-dimensional fluid bed electrode reactor combined with Fenton process had better synergic effect, average 17.4% TOC removal rate was improved within an hour. It was found that TOC degradation in coking wastewater followed a pseudo-first-order reaction kinetic model. The optimum degradation efficiencies of TOC were up to 60% as pH3.4, 3.5 mM ofFe2+ andl.2-1.8ml/L H20 2 in 90min reaction period. Furthermore, the integrated process showed a rapid reaction performance at a low temperature within a short reaction time and remained high efficiencies for TOC removal. Overall, the integrated process was proved feasible for coking wastewater treatment in practical applications.IntroductionCoking wastewater is generated from coal coking, coal gas purification, and by-product recovery processes of coking, which is composed of phenolic compounds, heterocyclic compounds, polycyclic aromatic hydrocarbons, ammonia, cyanide, polycyclic nitrogen-containing aromatics, acyclic compounds, etc. Most of these constituents are refractory, poor biodegradability, toxic and carcinogenic['-31. Currently, coking wastewater is usually treated by different forms of A/O biological nitrogen removal process as the primary treatment process, but the aforementioned processes are not efficient enough to meet the requirements from the National Discharge Standard in China (GB13456-1992). According to the continuous requirement on improving environmental protection for coking industry (revised 2008), increasing wastewater utilization ratio and reducing discharge of effluent in the coke industry has to be implemented for cleaner production and sustainable development. Therefore, advanced technologies need to be developed to treat coking wastewater and reutilize the product as industrial cooling water, which would be one of the best choices to achieve zero discharge of wastewater and reduce water consumption per ton of steel [4-51 . In this study, three-dimensional fluidized bed electrode reactor combined with Fenton process was adopted to advanced treatment of coking wastewater, and the effects of operating conditions, including H2O 2 dosage, Fe2+ dosage, initial pH, and reaction time on TOC removal rate, were investigated. Meantime, study of kinetics of reaction was estimated."

Jan 1, 2013

By Brady Butler

Many high capacity metal hydrides exhibit a high degree of stability in the hydrogenated state. This stability leads to a number of significant design problems with regard to the low temperature kinetics and thermodynamics of dehydrogenation. Nanometric metal hydride materials provide a promising route for increasing the reaction kinetics while altering the thermodynamic stability of the material. The use of nanometric metal hydride materials for hydrogen storage has largely been absent because of the difficulties associated with the synthesis of these materials. In this paper, research results on the synthesis of lithium based metal hydrides by vapor phase reactions are presented. The lithium based compounds that have been made in our lab include nanosized powders of metallic Li, Li₃N, LiNH₂ and LiH. The vapor phase process has also been used to custom engineer Li-based materials with other alloying elements or doping elements. The dependence of the characteristics of these materials on synthesis process parameters is studied. The effects of nanoscaled particle sizes on the kinetics of dehydrogenation and hydrogenation reactions are also explored.

Jan 1, 2006

By Scott Shuey

The processing of post-consumer materials is an area being addressed by many industries and multiple engineering disciplines. While metal scrap and high-value uniform waste streams tend to find their way back to their respective parent processes, the more complex and low-cost ubiquitous materials, such as Polyvinalchloride (PVC) and Polytetrafluorethane (PTFE), tend to show up in many processing streams. From a metallurgical perspective, pyrometallurgical processing of a mixed metal/organic/oxide waste material allows for the recovery of thermal energy in conjunction with the recovery of metal values. The evolution of halogenic acids during elevated temperature processing can create complications with both the materials of construction of the processing equipment as well as gas stream processing. The need for dust collection coupled with a high acid content, necessitation high-volume scrubbing, increases the costs associated with gas handling. Control of the halides through entrapment as a solid in-situ during processing would simplify downstream processing. Alkali-halide complexes are being evaluated by researchers at CSM for mixed metal/polymer waste material treatment, recovering halogens as salt complexes.

Jan 1, 2006

By Yiming Rong, Gang Wang

"Water quenching is one of common heat treatment processes but with complex physical phenomenon, in which vaporizing, bubbling and convection are involved. The general simulation of liquid quenching processes is conducted by using temperature dependent value of heat transfer coefficient (HTC) obtained from experimental measurement under a strong assumption. A preliminary multiphase flow model developed by using Ansys-CFX for water quenching has been presented in this paper, which shows a distributed HTC with a time dependent feature. The conjugate heat transfer is used to describe thermal conduction in the simplified workpiece, and generation, growth and flow of bubbles are modeled by using Eulerian-Eulerian method for the gas-liquid multiphase flow. The simulation result shows the intense variation of heat exchange through the interface between workpiece and liquid, and the unsteady distribution around the solid surface.IntroductionQuenching is a rapid cooling process which makes the desired solid phase transformations happen for the certain material properties. For aluminum alloy, rapid quenching will prevent all phase transformation and generate a supersaturated single phase."

Jan 1, 2012

By A. F. Sidorov

A method of improving mineral recoveries from ores by modifying the physical and chemical properties of minerals using radioisotope radiation was tested. It was observed that irradiation modifies mineral cell sizes, changes the crystal structure of some minerals, reduces the sulfur content 1 to 1.5 % in sulfides, changes the zeta potential, alters the surface properties of mineral grains I and produces other changes. Preliminary tests indicate that accelerated electron treatment of ores in connection with mineral processing has a potential for improving mineral recoveries by flotation and by magnetic separations.

Jan 1, 1989

By Keri Ledford, Stephanie Lin, Jason Nadler

Novel processes are being developed to fabricate thin copper thermal wick samples of a targeted porous microstructure. Structures of desired porosity, thisckness and pore size and distribution are achieved by tayloring the incorporation of sacrificial polymer beads in to slurry precursors. The thickness of the final structure is dictated by precisely controllable slurry application methods, such as spin coating. Ina subsequent heat treatment, th epolymer components thermally decompose and the remaining copper particles sinter to form a reticulated foam. The resulting microstructures are characterized in terms of porosity, permeability and specific surface area.

Jan 1, 2012

By W. Marnette

Norddeutsche Affinerie is the largest West European copper producer with an annual output of more than 350,000 tonnes of refined copper, about half of which is produced from copper concentrates. However, in addition to concentrates, Norddeutsche Affinerie processes secondary raw materials and recycling materials which contain a combination of copper and lead. These materials were previously treated in blast furnaces, a technology which has meanwhile been superseded at NA by the electric furnace process, primarily owing to the necessity of complying with the increasingly stringent requirements for environmental protection.

Jan 1, 1994

By M. Rosales

Using the k-e turbulence model, a mathematical fluid dynamics simulation of the flow characteristics in a Teniente converter has been conducted. Two cases were studied: - Transversal sections in the smelting-converting zone; and - A three-dimensional simulation that includes the walls of the reactor The calculations give the velocities field, the gravity waves amplitude, the splashing behaviour, the phase distribution and the shear stress distribution. The latter helps to explain the pattern of refractory lining wear. The calculation includes the approximate shape and dimensions, and the eventual coalescence of bubbles.

Jan 1, 1999

By Beatriz Ribeiro Nogueira, Vijaya Kumar Rangari, Esperidiana A. B. Moura, Anne Chinellat, Arifa Parveen, Angel Visentim Ortiz

"Composite consisting of ethylene vinyl alcohol (EVOH) with short piassava fibers were prepared by extrusion process and their thermal and morphological behavior were investigated. The EVOH reinforced with 5 and 10 % of pi as sa va (Attaleafunifera Mart) fiber particle, based on the percentage weight ratio (wt %), untreated and treated with a commercial silane coupling agent, were prepared and the influence of fiber loading and the effect of chemical treatment on their thermal and morphological behavior were evaluated by SEM, DSC and TG analyses. Melt flow index (MFI) of the composites have been determined to evaluate the effects of fiber reinforcement on dynamic viscoelastic melt of the EVOH. In addition, piassava fibers characterization by SEM, FTIR, and organic and inorganic composition have also been carried out. The SEM results of the composites showed surface micrographs without microvoids and a good distribution, dispersion and compatibility between the fillers and the EVOH matrix. Concerning the piassava fibers characterization, the results showed that piassava has higher lignin content than cellulose and hemicelluloses, and around 0.7 % of ash with 52 % of silica (Si02). This high concentration of silica is consistent with the SEM analysis of the fiber that showed a large amount of ""silica rings"" encrusted on their surface.IntroductionLately, great worldwide interest has arisen in developing new technologies that enable the use of products with less environmental impact. Effort has been put into seeking natural modifier applications, particularly regarding the use of natural fibers. Special attention has been given to the use of natural vegetable fibers, because of the huge variety of species available. Such vegetable fibers are usually referred to as lignocellulosic materials [1]. This work evaluated the effects of piassava (Attalea funifera Mart.) fiber incorporation in an ethylene and vinyl alcohol copolymer (EVOH). The EVOH belongs to a family of copolymers with excellent gas barrier properties and resistance to organic compounds, which allow its application in different segments, from food packaging to gas tanks. However, EVOH is very sensitive to moisture, and in conditions of high humidity its gas barrier properties, thermal and mechanical properties are affected."

Jan 1, 2012