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By Lidong Teng, Seshadri Seetharaman, Aida Abbasalizadeh

0In the present paper, the feasibility of the recovery of dysprosium from spent Nd-Fe- B magnets containing approximately 9 wt% Dy was investigated by using molten salt process. The salt bath consisted of a mixture of NaCl-KCl-LiCl corresponding to the ternary eutectic composition. AlCl3 was used as a chlorinating agent in order to enable an efficient dissolution of metal in the molten salt phase in the salt bath. The metal chloride which is formed as the result of chemical reaction between the metal in magnet and AlCl3, is subsequently subjected to electrolysis in order to be deposited on the cathode. Graphite rods were dipped in the salt bath as electrodes and alumina crucibles were used as the containers for the electrolytic cells.

Jan 1, 2014

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 Tianyou Huang, Yuan Lu, Haimin Long, Jinwu Kang, Gang Nie

"The distortion of metal parts during heat treatment process is one of the main obstacles in industry to ensure high-quality work and less or no machining allowance, especially for large but thin steel castings such as heavy turbine blades. In the paper, a method is proposed to control the distortion by adjusting heat transfer coefficient of metal parts during heat treatment process. Required heat transfer coefficients can be realized by getting the metal parts into contact with various media such as water spray, insulation felt or materials with different heat conductivity. The control method based on this idea is set up and achieved. By using insulation felt and water spray to change the heat transfer coefficient during the stages of heat treatment process, the results indicate that the proper control time and vary with materials.IntroductionThe distortion of metal parts during heat treatment process is one of the main obstacles in industry to ensure high-quality work and to realize less or no machining allowance [1]. For example, the Three Gorges turbine blade’s distortion is as large as 50mm during heat treatment process. The uneven heating and cooling during heat treatment process is the main reason for distortion [2]. By adjusting heat transfer coefficient of different areas of metal parts, the heat treatment process could be controlled. The temperature variation, direct cause for distortion, could be under control. Loeser Klaus used high pressure gas to achieve uniform heat transfer during gas quenching and proposed the possibility to use ""Dynamic Quenching"" processes where the quenching severity is varied during quenching by stepwise control of either gas velocity or gas pressure [3]. Li Zhichao also suggested minimizing distortion by marking a component into several areas and imposing different heat transfer coefficients on each area [4]. Heat transfer coefficient can be controlled by getting the metal parts into contact with different media such as water spray, insulation felt, air or different heat conduction materials. In addition, the exact time to adjust the heat transfer coefficient is another factor for distortion. A method is presented in this paper by actively adjusting heat transfer coefficient for different areas of metal parts and different stages of heat treatment process to control their distortion. The corresponding experiments have been made by using different metal materials."

Jan 1, 2012

By Katsukiyo Marukawa, Mashamichi Sano, Shigeta Hara

"Various subject of studies are discussed to develop ·innovative refining processes in the 21st century for cost reduction, production of high quality steel and environmental conservation. The future refining reactor should have abilities of highly efficient mixing and separation of different phases. It is stressed ·that applications of electromagnetic and ultrasound energies, and control of flow fields rate required to create the highly efficient mixing I separation reactor.IntroductionIn recent years, it seems that the research and development in the field of steelmaking has shifted its emphasis to the solidification I ingot-making process in which continuous casting plays the leading role. From a long-range point of view, however, the need for continual development of the refining process will probably increase but is very unlikely to decrease. In order to meet such demands, it is required that problems and issues of the present process should be clearly grasped and that there must be rapid progress in process elements, such as highly efficient mixing and separation of different phases.Applications of electromagnetic and ultrasound energies and flow field control will become important options for resolving the above-mentioned problems. By efficiently and skillfully incorporating these new technologies into high-efficiency mixing/separation reactors, the innovative refining process will be established in the early 21st century."

Jan 1, 2000

By Gerardo R. F. Alvear, Alistair S. Burrows, Stanko Nikolic, James S. Edwards

"The copper ISASMELT™ process has evolved over more than a quarter of a century and can now be considered mainstream, with single furnaces producing more than 340,000 tpa of copper in matte. The next evolutionary step for the ISASMELT™ technology is to directly challenge the dominance of the Peirce-Smith converter by the implementation of a continuous copper converting process on a commercial scale. The present work describes the status of the continuous converting process – ISACONVERT™.Continuous converting has been performed successfully in pilot scale ISACONVERT™ plants, where operating results have verified the predictions of fundamental research and reinforced the underlying confidence in the design parameters. From a matte feed rate of 250 kg/hr, a calcium ferrite slag and a low-sulfur blister have been produced. Design is now complete for the first commercial application of the ISACONVERT™ process. The present paper describes the status of ISACONVERT™ by summarising results of recent pilot plant tests and describing the first commercial plant design."

Jan 1, 2009

By Eugene Jak

Copper sulphide processing technologies face increasing pressures associated with decreasing concentrate grade leading to increasing thermal inefficiency and lower productivity. Impurity concentrations are on average increasing, creating potential environmental risk and additional treatment costs. In copper flash smelters dust, partially oxidised materials and fume formed from the condensation of volatile impurities, are routinely recycled to the feed. In the converting stage the heat balance is maintained by charging anode reverts and other inert materials. In both cases, the thermal energy available from sulphide oxidation is not fully utilised or optimised. The productivities of both smelter and converter stages can be potentially increased through the addition of a high copper, low iron, low impurity precipitated copper product. Calculations are carried out for fayalite smelter and calcium ferrite converter slags using an optimised FactSage thermodynamic database. The potential for significant increases in smelter and converter productivities using existing technologies are predicted.

By Mingchun Lu, Zhijia Liu, Xueqi Zhang, Jianliang Zhang

"In order to solve the problem of shortage of scrap, especially high quality scrap, a new substitute for scrap or DRI has been developed. The decarbonization mechanism of granular pig iron has been analyzed and the technical process and decarbonized granular pig iron have been evaluated in this paper. The research result shows that this new process is superior to direct reduction process in product quality, construction investment, operation flexibility, production efficiency etc. Decarbonized granular pig iron (DGPI) not only can be used as conventional scrap but also can be charged into EAF as high purity .burden equivalent to heavy scrap:IntroductionIn the past years, with the universal application of continuos casting technique in China, the amount of scrap generated inside steelworks has been reducing continually. On the other hand, the EAF steel proportion is increasing and this gives to the obvious change in structure of steel product. At present, the requirement on both scrap quantity and scrap quality is being paid more and more attention. Because China is a country which is devoid of scrap and poor in resource (nature gas and high grade iron ore) for developing direct reduction iron (DRI) so that sponge iron can not be produced cosmically in China and has to be mainly imported. Instead of part of scrap, some cold pig iron in cold state has been charged into EAF in China. However the high carbon content in pig iron has limited its proportion in EAF metal burden. Because the price of pig iron is lower than that of imported DRI in China, the technique of granular pig iron decarboniztion is hopeful to become effective way to produce substitute for scrap or DRI."

Jan 1, 2000

By A. P. Paiva

With the aim of establishing a valuable alternative to the conventional methods, studies regarding the recovery of precious metals by solvent extraction have been increasing over the past few years. In this work, the selectivity of extraction presented by Cyanex 471X toward silver is investigated. Simulated chloride solutions considering contents of iron and copper usually present in actual leaching practice were used. The characterization of the aqueous solutions - in terms of the multiple equilibria established by the chlorocomplexes of the different metals and their relation to the total chloride concentration of the base-electrolyte - was successfully carried out by cyclic voltammetry. The results obtained support the important contribution of the electrochemical techniques for the understanding of the overall extraction phenomena.

Jan 1, 1994

By Cui Wang, Kexin Jiao, Qiuye Cai, Jianliang Zhang

Prolonging the campaign life of the blast furnace has been an important task for iron makers, and it has been studied for decades. Adding titanium-bearing materials is a generally agreed and effective technique to protect the blast furnace hearth. Titanium from titania additions in the burden or tuyere injection react with carbon and nitrogen and form scaffolds on the hearth surface to protect the hearth from subsequent erosion. In this article, the progress on blast furnace hearth protection of titania additions in Chinese steel companies and research institutions is investigated, and the difficulties in the operation and production, such as little effect after adding titaniumbearing materials and the property deterioration of liquid iron and slags, are analyzed. The future research for protection in Chinese blast furnace is proposed, and a comprehensive process which combines protection of titanium bearing materials with reasonable thermal balance and slagmaking regimes should be established.

Jan 1, 2015

By Honglei Zhang, Yue Wang, Guotao Xu, Li Liu

The influence of rich oxygen atmosphere on the properties and structure of castables used in the hot wind pipe of blast furnaces was analyzed. Results show that the cold compressive strength of castables is affected by the change of rich oxygen volume in the wind pipe, the bulk density decreases and apparent porosity of castables increases with the addition of rich oxygen in wind pipe. With the addition of rich oxygen, the velocity of heat transfer increase and result of the steel shell become over hot out of safe limit at the thin lining in hot wind pipe.

Jan 1, 2015

By T. J. A. Smith

This paper provides an overview of some of the key issues in design of smelter gas handling systems, with particular reference to smelter smelting plants. In both primary smelting and converting, gas handling and treatment systems often represent the major capital cost component. There is also ample evidence that poor system design can be a major cause of smelter down time, lost production and unforeseen high maintenance costs. The paper discusses these issues and offers guidance for improved design.

Jan 1, 1992

By Murray Hughes, Neil Brown, John Carran

"A control system architecture has been developed using the Ward-Mellor structured analysis techniques for real-time applications. This approach has produced several advantages over traditional control system implementation methods including:•,partitioning of the control system into discrete control functions.•,easy identification of the interaction between individual control functions and the rest of the system including the impact of changes at the control system boundary (i.e. additional inputs or outputs).•,simplified control software testing.•,a closed loop design, implementation and documentation process.This paper describes a generic control application in which the process specification and control system design are logically linked. Both components are used by process engineers for on-going development.IntroductionAluminium is reduced from alumina in multiple electrochemical semi-batch reactors. Raw material additions and molten metal withdrawal are made at discrete intervals ranging from seconds to days. The electrolytic reduction process is continuous, despite the semi-batch nature of the material inputs and outputs. The chemical and physical processes that occur within each reactor are complex and interdependent, therefore simple methods used for the control of many chemical processes are impractical. The process control system is required to optimise operating efficiencies within the safe operating zone.The process control of aluminium reduction cells is heavily biased towards calculation of process variables with relatively few measured sensors. Each cell is controlled independently of the other cells, although changes to process conditions and raw material . quality will affect all cells. The process responds relatively slowly and with significant time lags. Measurements and process variable calculations occur each second, however the accuracy and precision of actuator response and sensor sampling are measured 111 milliseconds. Time-based scheduling is a significant component of reduction cell control."

Jan 1, 1994

By Ryokichi Shimpo, Akio Fuwa

"The process-measurements of copper smelters in Japan were investigated for the summary of the latest technique and for the fundamental study of process control. The smelters investigated are those employing flash smelting furnace and P.S. converter, one reverberatory furnace and P.S. converter, and one continuous smelting converting furnace (M.I. process). Respective process is then considered, consisted of several reactors of different functions. The measurement methods were summarized in each reactor, including the measurement points. The methods of chemical analyses of the samples in each reactor were also investigated.IntroductionAn investigation on the process measurements, chemical analyses, and system control in copper smelters in Japan were carried out for understanding and summarizing the technique of the pyrometallurgical copper smelting operations. The typical seven processes in six copper smelters were investigated in the period from 1985 to 1987. The smelters investigated were Touyo Smelter of Sumitomo Metal Mining Co., Ltd., Kosaka Smelter of Dowa Mining Co., Ltd., Saganoseki Smelter of Nippon Mining Co., Ltd., Tamano Smelter of Hibi Kyodo Smelting Co., Ltd., Ashio Smelter of Furukawa Co., Ltd. and Naoshima Smelter of Mitsubishi Metal Co., Ltd. They include five flash smelting furnace and P.S. converter systems, one Mitsubishi continuous smelting and converting process (M.I. process), and one reverberatory furnace and P.S. converter system.The investigation was performed by making inquiries about the measurements, chemical analyses, system control, and their future prospects to the engineers in each smelter and by summarizing up in each item. The system control and future prospects were summarized in another paper titled ""Process Control Scheme of Copper Smelting Processes in Japan and Future View."

Jan 1, 1989

By R. S. Tahautdinov, A. N. Posazhennikov, V. V. Bastrygin

"The Bakal (South Ural, Russia) deposit of iron ore bearing iron carbonate (siderite) with the capacity of more than 1 billion tones belongs to the MMK. This ore cannot be fully processed via blast furnace technology because of high content of MgO. According to the investigations carried out in the USA and Japan in 1999-2004 the ITmk3 (Ironmaking Technology mark three) RHF technology is a breakthrough in Ironmaking. Four iron ore types (hematite, magnetite, high and low Al2O3/SiO2) were tested. Reduction, melting and slag removal can be achieved in just 10 min. The main objective of the investigation is to establish optimum operation conditions for the production of iron nuggets from iron carbonate bearing ore via the ITmk3 by means of the lab scale testing. Samples of iron ore and carbon reductant were chemically and physically analyzed. Green pellets were processed via a lab tube furnace to simulate RHF conditions. The nuggets and slag were chemically analyzed. This preliminary test work provides valuable information which may be used for large-scale testing in a commercially sized RHF.IntroductionThe ITmk3 process upon which this paper focuses was developed by Kobe Steel in its research facilities in 1996 [1]. After pilot testing at Kobe Steel’s Kakogava Works in 1999-2004 the pilot demonstration plant was built and operations were successfully carried out by Mesabi Nugget joint venture in 2002-2004. Steel Dynamics has committed to building the commercial plant at the Mesabi Nugget site in Hoyt Lakes (Minnesota). Only 4 iron ore types (hematite, magnetite, high Al2O3/SiO2 and low Al2O3/SiO2), as well as 4 coal types with range of volatility, ash and fixed carbon were tested. Results were consistent with nugget characteristics confirming ITmk3’s flexibility with respect to raw material inputs. At the same time, no research in the field of nugget from iron carbonate bearing ore with high content of MgO has been done. Such kind of iron ore is restricted for charging into the blast furnace due to contamination of MgO. The reason for restriction is the limitation of load of MgO in the blast furnace. If a lot of MgO enters the blast furnace, slag becomes viscous. The viscous slag is obstacle for stable operation of the blast furnace."

Jan 1, 2011

By E. V. Redin

"The Bakal (South Ural, Russia) deposit of iron ore bearing iron carbonate (siderite) with the capacity of more than 1 billion tones belongs to the MMK. This ore cannot be fully processed via blast furnace technology because of high content of MgO. According to the investigations carried out in the USA and Japan in 1999-2004 the ITmk3 (Ironmaking Technology mark three) RHF technology is a breakthrough in Ironmaking. Four iron ore types (hematite, magnetite, high and low Al2O3/SiO2) were tested. Reduction, melting and slag removal can be achieved in just 10 min. The main objective of the investigation is to establish optimum operation conditions for the production of iron nuggets from iron carbonate bearing ore via the ITmk3 by means of the lab scale testing. Green pellets were processed via a lab tube (chamber) furnace to simulate RHF conditions. This preliminary test work provides valuable information which may be used for large-scale testing in a commercially sized RHF.IntroductionThe ITmk3 process upon which this paper focuses was developed by Kobe Steel in its research facilities in 1996 [1]. After pilot testing at Kobe Steel’s Kakogava Works in 1999-2004 the pilot demonstration plant was built and operations were successfully carried out by Mesabi Nugget joint venture in 2002-2004. Steel Dynamics has committed to building the commercial plant at the Mesabi Nugget site in Hoyt Lakes (Minnesota). Only 4 iron ore types (hematite, magnetite, high Al2O3/SiO2 and low Al2O3/SiO2), as well as 4 coal types with range of volatility, ash and fixed carbon were tested. Results were consistent with nugget characteristics confirming ITmk3’s flexibility with respect to raw material inputs. At the same time, no research in the field of nugget from iron carbonate bearing ore with high content of MgO has been done. Such kind of iron ore is restricted for charging into the blast furnace due to contamination of MgO. The reason for restriction is the limitation of load of MgO in the blast furnace. If a lot of MgO enters the blast furnace, slag becomes viscous. The viscous slag is obstacle for stable operation of the blast furnace."

Jan 1, 2012

By G. Cifuentes

It's know that the cathodic purity and the electrolyte treatment is affect for the solid present in the electrolyte. Anodic slimes properties (f.e.: chemical composition, crystalline composition, sedimentation) was studied in copper electrorefining, this properties were modify through by anodic composition and current density. In this paper will be present only the preliminary anodic slimes relationship at different lead anodic composition. The anodic material was doped during the poured process with lead at different composition. It's confirm the apparition of the (Bindheimitte) SMbz07. The specific gravity of this specie is approximately 7.3 - 7.5, with this values is biggest the probability of sedimentation and smaller the slimes not sedimentabel.

Jan 1, 1999

By Erwin Flender, Preben N. Hansen, Peter R. Sahm

"Until now FDM-Techniques have been widely used for Modeling Solidification Processes in Castings. Often a rigid, regular type of enmeshment (cubes, , --) have been used. This has the advantage of low CPU-costs, but the disadvantage of a zig-zag presentation of the interface between the casting and the mold. The last point is the reason why FEM-Techniques, giving the possibility of a true presentation of the shape in the enmeshment, are increasingly used. The disadvantage is the high CPU-costs. In this paper, a technique is presented, which uses the FDM-Mesh with the zig-zag presentation of shape and ADI-Algorithms to calculate temperatures and gradients. The new idea is that the calculated parameters are not presented related to the mesh in which they are calculated, but displayed using the true shape of the casting. Such an advantage of both low CPU-costs and shape correct presentation of the calculated results are achieved. IntroductionThe main reason for using a regular type of enmeshment is that it gives the possibility, via ADI-Algorithms, of obtaining a very fast FDM-Technique. The technique presented by P.R. Sahm and P. N. Hansen (1984), and also used by E. Flender (1985), is numerically so stable that average time steps, at least 200 times larger than the limit given by the explicit FDM-Technique, can be applied. To obtain reasonably good results, average time steps in the range of 20 to 50 times the explicit limit seems to be applicable. It should be pointed out,however, that FDM-Techniques can be used on arbitrary nets, the disadvantages being the same as for the FEM-Techniques. This has, among others, been discussed by P.R. Sahm and P.N. Hansen (1984)."

Jan 1, 1986

By Reinhard F. Dobner

After a short introduction about the HK's secondary smelter process and explanations concerning the anodes produced the regulation and buffering of bleed will be described and the principles of technology for processing of bleed will be presented. Modernization aspects, especially installation equipment, and the different types of evaporators used will be described in detail. Besides, experience made with acid-resistant materials - stainless steel, enamel, plastics - will be reported. Environmental aspects such as water and air pollution will be outlined briefly and in conclusion the quality of products obtained as well as quality control will be presented.

Jan 1, 1997

By Go-Gi Lee, Jae-Young Jung, Myung-Duk Seo, Hyun-Na Bae, Seon-Hyo Kim

"Bubbles form at the anode during the electrowinning of magnesium and cause hydrodynamic acceleration and electrical field disturbance. A three-dimensional computational model was developed to investigate the effects of the geometry of the electrochemical chamber and the size distribution of bubbles on the fluid flow in the pilot plant. The results are validated by measurements of the surface characteristics of molten salt and the bubbles formed. Fluid flow at the surface was recorded with a high speed camera, and the distribution of bubble size is determined by inspecting the video images frame by frame. The measured size distribution of the bubbles is entered into the computer simulation of a multi-phase flow. A sloped roof is installed above the electrodes, to enhance the flow of the molten salt, thus resulting in higher current efficiency, lower energy consumption, and higher quality of magnesium metal.IntroductionTitanium's excellent properties of low density, high specific strength, high temperature strength, and exceptional resistance to corrosion are highly beneficial to diverse applications including aerospace, automotive, construction, and medical implants. Although the Kroll process[l] and Hunter process have been used for the extraction of titanium in the 20th century, their complicated engineering stages and high production cost, have led to further research into new processes such as FCC Cambridge, Armstrong and TiRO. Despite these intense research efforts, no process has yet been developed that is more economical than the Kroll process, by which most of the global commercial titanium is still being produced."

Jan 1, 2011

By M. Z. Mubarok

Effect of single addition of a lignin-based biopolymer additive, DP 2782, at various dosages as well as in combination with thiourea on cathode polarization during copper deposition was investigated by performing potentiodynamic and galvanostatic measurements using a potentiostat. The result of electrochemical measurements was compared with the behaviour of cathode deposition with glue and thiourea additives. Surface micro-appearance of the copper deposit after 1 h galvanostatic scan under current density of 330 A/m2 and various additive type and dosage was evaluated by scanning electron microscopy (SEM) examination. It was found that the addition of 2.5 mg/l biopolymer gave sufficiently polarizing effect of copper deposition. SEM examination of the cathode surface after galvanostatic scan revealed that the combination of the biopolymer with thiourea (2.5 and 3.5 mg/l) resulted in a compact deposit which is comparable with that resulted from the test with glue and thiourea.