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TMS 2002, 131st Annual Meeting and Exhibition
Seattle, USA, February 17-21, 2002
Cape Town, South Africa, March 11-12, 2002
This conference report covers the two mentioned conferences focussing on pyrometallurgical and extractive metallurgical aspects.
Whereas Pyrometallurgy '02 was characterised by a single session and a small number of participants, the TMS meeting was characterised (as usual) by a multitude of parallel sessions, many of them focussing on various aspects of material science. The TMS meeting is visited by many thousands of participants. Who not only attend the sessions but also the trade exhibition, which exhibits newest technology in the metals processing industry. The large scale of this conference and the many parallel sessions make it possible to attend only a fraction of what this conference has to offer (it consisted of over 220 regular sessions, each session consisting of about eight presentations; in total there were more than 1700 presentations). For this reason only two conferences will be reviewed within the TMS meeting viz. Magnesium Technology 2002 and the Third International Sulfide Smelting Symposium.
Having attended the TMS meeting for many years it was a welcome change how close Pyrometallurgy '02 came to the ideal symposium written about by Plato in his book "Symposium". The relatively small-scale organisation of this conference, together with the absence of parallel sessions, created an excellent opportunity and atmosphere to discuss the presented papers extensively. The questions and discussion after the various presentations were detailed and interesting, often discussed for considerable time from a theoretical as well as from an industrial and practical perspective, due to the diverse background of the participants and the topics covered by the presentations. It must be noted that it was a delight to be part of the discussions, be it from the floor, as session chairman from the podium or as a presenter. Pyrometallurgy '02 was what a Symposium or Conference should be like!
Whereas many of the activities at the TMS meeting are published in conference proceedings, Pyrometallurgy '02 offers each selected and presented paper the opportunity for submission to the journal Minerals Engineering for publication after peer review. This approach makes it possible for each author to further modify the papers after the valuable discussions following the presentations (essentially the first peer review). The papers, if accepted, will be published in Volume 15 Number 11, a special 'Chemical and Biological Processing' issue of Minerals Engineering.
TMS 2002, Seattle
Two conferences with an extractive metallurgical basis will be discussed here viz. Magnesium Technology 2002 and the Third International Sulfide Smelting Symposium. Small sessions on General Pyrometallurgy and General Recycling will not be discussed here. Papers of these sessions and other relevant sessions can be found in the EPD (Extraction and Processing Division) conference proceedings. Two other important sessions viz. Computational modelling of metals processing systems and the usual large session on all aspects of aluminium production are not discussed here due to the authors not being able to attend these sessions.
The reader is referred to www.tms.org for further details on the contents and conference proceedings for these events.
Magnesium Technology 2002
Magnesium Recycling and Environmental Issues
Stability of Fluorine in Molten Magnesium was studied by K. Aarstadt et al. These authors made a study on the solubility of fluorine in molten magnesium, because it is necessary to find an alternative for the use of SF6 as a cover gas to prevent oxidation and burning of magnesium. SF6 is one of the strongest greenhouse gasses known. Solubility of fluorine is measured after 5 and 25 hours, and fluorine solubility is measured with an electrochemical method. The data are however very doubtful: several analytical sessions do not show any correlation. It appears that the experimental method is not worked out, and no conclusions can be drawn. Progress towards Climate friendly Magnesium Production and Casting was discussed by S.C. Bartos. They discuss the bad environmental properties of SF6, one of the strongest greenhouse gasses known (23.900 x as strong as CO2, and with a life time 16 x that of CO2). US Environmental Protection Agency cooperates with industry and International Magnesium Association to find alternatives. Recycling of different Types of Mg-Scrap was discussed by H. Antrekowitsch et al. These authors discuss the importance of recycling of magnesium and the different methods investigated by the Department of non-ferrous metallurgy of the Leoben University. The research presented is badly founded, contains no mass balances, no investigations of grain size effects on results. The successful briquetting of magnesium chips and turnings for secondary melting and recycling was discussed by D.J. Roth et al. Briquetting is important because of safety reasons (lowering of magnesium reactive surface, reduced shipping costs, cutting fluid recovery, reduced oxidation). Loose chips are inflammable (danger). The volume reduction achieved is considerable, the recovery of cutting fluid is 25 % improved. The oxidation of briquettes is 2.5 to 4.5 times lower. Process is technically worked out, and demonstrated by a film of a working machine. Cyclone before briquetting removes all too small particles. Briquetting in general seems extremely useful. Fluxless refining of clean diecast scrap for Noranda's AJ52 High Temperature Mg-Al-Sr alloy is discussed by P. Forakis et al. Commonly used fluxes for refining of type 1 scrap (trimming material etc.) are not applicable to AJ52 because of components (Ca, Sr) in the alloy react with fluxes. Investigation of losses in fluxes (Sr, REE, Ca losses). The authors also evaluate the possible decreased of losses, and evaluation of fluxless refining. This process is under investigation. The application of Magoxide Method for cleanliness Evaluation of Magnesium alloys is discussed by B. Bronfin et al. The use of Fluoroketones in cover gasses for molten magnesium is discussed by D.S. Milbrath et al.
Various other sessions covering Mechanical Properties, Magnesium Wrought Products (Session in Memory of W.A. Barnes), Processing and R&D strategies and Corrosion and General Sessions cover more material science aspects and will not be discussed here. The interested user can purchase the proceedings that have been published for this Symposium.
Third International Sulphide Smelting Symposium
The Third International Sulphide Smelting Symposium lasted three days in which seven separate sessions were held. The session subjects ranged from Fundamentals to new projects, Smelter gas handling, new smelter projects and optimisation, operational improvements and sulphide smelting fundamentals, furnace integrity and smelting slags, Zinc, lead and PGM. The discussion below gives a short overview or just the title of various selected papers. The reader can purchase proceedings for this interesting symposium from TMS at www.tms.org.
From fundamentals to new projects
D.B. George gives an overview of "Continuous Copper Converting - A Perspective and View of the Future". H.Y. Sohn discusses "Basic Principles of Sulphide Smelting and Converting with Oxygen-Rich Gas". In this paper the influence of oxygen content on smelting and conversion is discussed. Conclusions based on interpreting phase-diagrams discussing the effects on the distribution and recovery of Cu, Ag, Ni, Co, As, Sb and Bi. The author also discuss the application of CFD models to study flash smelting. "The Kinetics of Sulfide Smelting in Mitsubishi Process" is discussed by Z. Asaki. Using Higbie's penetration theory, calculations were done about the oxidation rate of FeS in the matte by rising gas bubbles. F.R.A. Jorgensen discusses the "Ignition of Sulphide Flotation Concentrates in Flash Smelting". After reviewing the factors influencing the ignition temperature of sulphide concentrates, it was concluded that the ignition temperatures are inline with phase diagram data. M. Goto discusses "Gresik Copper Smelter and Refinery - Current Operation and Expansion Plan". "Budel Zink Sets a New Standard for NOx reduction in a Sulphuric Acid Plant" as presented by A. Berryman. J. Zhou gives "An Overview on Operation of Jinlong's Copper Flash Smelting since Start-Up".
New Smelter Projects and Optimization
"Plant Commissioning and General Operations at Port Kembla Copper" is discussed by R. West. This paper recounts experiences with the Noranda reactor, Mitsubishi and Peirce-Smith converters. C. Fountain describes in the paper "ISASMELT-Efficient &Cost Effective Smelting for MIM" the layout of the installation at Mount Isa. "The Noranda Process, the Technology of Choice for Emerging Economies in the 21st Century" is discussed by C. Harris. I.V. Kojo describes Outokumpu flash smelting technology in the paper "From Autogenous Sulfide Smelting to the Production Network - Outokumpu Flash Technology as Trendsetter in Copper Production". R.M. Parada discusses the Outokumpu flash smelter at "Chagres Smelter 1995-2000, its Modernization and Optimization". "Inco's New Anode Furnaces and Anode Casting Shop at the Copper Cliff Smelter" is described by B. Bichel, while V.K.Handa gives an "Update on Peirce-Smith Converter Operations at Sterlite Copper".
Operational Improvements and Sulphide Smelting Fundamentals I
Various topics are discussed here which include (i) Accretion and Dust Formation in Copper Smelting Thermodynamic Considerations, (ii) Sulphation of Cuprous Oxide in SO2-Rich Atmospheres, (iii) Dissolution of Particles in the Mitsubishi Smelting Furnace, (iv) Operational and Maintenance Experience from the First Full Scale Kumera Steam Dryer, (v) Optimisation of the Energy Cost at Tamano Smelter, and (vi) Development of the Toyo FSF Concentrate Burner by using Computational Fluid Dynamics.
Furnace Integrity and Smelting Slags
Topics in this session include (i) Kennecott Flash Converting Furnace: Design Improvements 2001, (ii) Improved Technology for Water-Cooled Copper Blocks (A new copper alloy, which allows for the formation of a metallic bond during casting between the pipes and the cast copper. Small differences in thermal expansion promises enhanced service life.), (iii) Current Practice in Taphole Design, (iv) Non-Isothermal Study of Refractory Dissolution by Copper Containing Calcium Ferrite Slag, (v) Slags of Suspension Smelting of Chalcopyrite Ores and Copper Matte Converting, (vi) Trends in Development of Autogenous Smelting of Sulphide Materials using Oxygen-Flame Smelting Processes.
Zinc, Lead and PGM's
This session included the following papers (i) The Behaviour of Iron as Impurity in Zinc Roasting, (ii) Agglomeration in Zinc Fluidized Bed Roasters, (iii) Improvements of Zinc Roaster Waste Heat Boiler, (iv) Technology for Processing of Lead-Bearing Materials from Copper Metallurgy at KGHM Polska Miedz, (v) ConRoast - DC Arc Smelting of Dead-Roasted Sulphide Concentrates discusses Mintek's process to treat nickel-copper and PGM sulphide concentrates (process: Remove all the sulphur by roasting, Smelt the dead-roasted concentrate in a DC arc furnace, Water-atomise the alloy, Leach the small solidified pellets, Fe in waste stream can be removed by precipitation), (vi) Online Prediction of Actual Melt Chemistry in an Ausmelt Converter using a Thermodynamic-System Identification Hybrid Modelling Technique, a joint paper between University of Stellenbosch and TU Delft (In this paper hybrid ANN-ARMAX techniques are used to predict the melt composition of an Ausmelt converter, based on (standard) process measurements. Heart of the technique is an ANN that is trained to calculate the "thermodynamic operating point" (based on the process input). The ARMAX then predicts based on historical and actual measurements the composition of the melt. Actual process data are compared with calculated predictions.), and (vii) Platinum from a Chrome Furnace - It's a Matter of Design.
Sulfide Smelting Fundamentals II
This session included the following papers (i) Thermophysicochemical Database for Batch or Continuous Processes in Nickel Smelting and Converting, (ii) Quantification of the Liquidus Surface of Some Iron Oxide Slags of Industrial Interest at Constant CO2/CO Ratio, (iii) Phase Relations and Activities in the Cu-Fe-S-As and Cu-Fe-S-Sb Systems at 1473K, (iv) Phase Equilibrium between Ni-S Melt and Slags under Controlled Partial Pressures, (v) Predicting Phase Equilibria in Oxide and Sulphide Systems, and (vi) Minor Element Distribution between Copper Matte and Re-verb Furnace Slag.
Pyrometallurgy '02, Cape Town
The first conference organised by Minerals Engineering International dealing with pyrometallurgy, was held in Cape Town, South Africa and was organised in association with the Western Cape Branch of the South African Institute of Mining and Metallurgy. The University of Queensland's Pyrometallurgical Research Centre, PYROSEARCH provided corporate sponsorship for this event.
The conference had an attendance of about 40 delegates, representing 11 different countries. The selection committee of the symposium had received over 40 papers out of which 21 were accepted for presentation. The number of papers presented was limited such that no parallel sessions had to be held. A short overview of the papers as presented in four technical sessions is given below.
The presentations in this session covered the field of slag reactions from the application of new experimental techniques to enable the determination of phase equilibria in complex ferro-alloy smelting systems as presented by Hayes et al. to the thermodynamic modelling of the FeO-TiO2-Ti2O3 system discussed by Fourie et al. Eric et al. presented the high temperature carbothermic reduction of Fe2O3-TiO2-MxOy mixtures. Banda et al. discussed the influence of slag modifiers on the selective recovery of cobalt and copper from waste smelter slags to convert old slag dumps of potentially hazardous waste into innocuous materials while at the same time extracting valuable metals to pay for this operation. An experimental study on the influence of slag basicity and the FexO content on slag foaming was presented by Stadler et al.
The papers of the environmental sessions dealt with a variety of subjects. Van Schaik et al. discussed the dynamic modelling and optimisation of the resource cycle of passenger vehicles in order to predict the amount of secondary metal available for pyrometallurgical processing over time and to emphasis the inseparable relation between (mechanical) recycling and pyrometallurgy. The critical importance of the quality control of recycling intermediate products created during physical separation, to ensure that the feed to metal producing processes permits the economic production of quality metal products was discussed by Reuter et al., based on the melting behaviour of distributed aluminium turning scraps. Abdel-latif presented two papers in this session. In the first presentation, the fundamental issues of the Enviroplas process developed at Mintek to recover zinc from metallurgical wastes were discussed. The results of a two-year research program on finding the most suitable way to recover vanadium and nickel from petroleum fly ash were presented by Abdel-latif as well.
Chryssoulis discussed the understanding of gold losses in roaster calcines in order to optimise the recovery of gold. Georgalli et al. gave a very interesting presentation on an integrated thermodynamic systems approach to the prediction of matte composition dynamics in an AusMelt converter. Kotze presented the aspects of ferronickel production from laterites and other oxidised nickel ores in a DC are furnace. Reuter et al. discussed the reaction kinetics and process simulation in submerged arc furnace for ferrochrome production, based on an extensive experimental study on chromite reduction with CO. Pistorius et al. presented a combined experimental modelling approach used for testing possible rate-determining steps during reduction of composite magnetite-coal pellets at 1300°C. Jalkanen et al. explained the simulation of the oxygen converter process using the simulator CONSIM.
In the session on furnaces, Neven discussed an experimental study for evaluation of the creation and behaviour of gas bubbles of submerged injection in an Isasmelt reactor. Jones et al. showed unique photographs of the DC arc, which were compared to models of the shape of the arc. The depression in the surface of the slag was also photographed and the results used in a model. Reynolds presented the modelling of thermal radiation of DC smelting freeboards. Eksteen discussed the challenges in the sampling and characterisation of raw materials and products of arc furnaces, whereas Frank et al. presented mass balance data reconciliation for a DC-plasma arc chromite smelting furnace to support empirical modelling.
M.A. Reuter, A. van Schaik, J. Post and J. Voncken, Delft University of Technology, The Netherlands. Email: M.A.Reuter@CITG.TUDelft.NL
Click here to view photos from this event.