The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
Fathi Habashi - One of the best experts on this subject based on the ideXlab platform.
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Extractive Metallurgy of rare earths
Canadian Metallurgical Quarterly, 2013Co-Authors: Fathi HabashiAbstract:AbstractA short account is given on the extraction of rare earths from monazite sand, bastnasite ore, and phosphate rock of igneous origin. This includes mineral beneficiation, leaching methods, fractional crystallisation [of historical interest], ion exchange, solvent extraction, precipitation from solution, and reduction to metals.On donne un bref compte-rendu de l’extraction des terres rares a partir de sable monazite, de minerai de bastnaesite et de roche phosphatee d’origine ignee. Ceci inclut l’enrichissement du mineral, les methodes de lixiviation, la cristallisation fractionnelle (d’interet historique), l’echange d’ion, l’extraction par solvant, la precipitation a partir de solution et la reduction en metaux.
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Extractive Metallurgy and national policy
International Journal of Network Management, 2013Co-Authors: Fathi HabashiAbstract:Hydrometallurgical technology offers a unique possibility for developing countries to exploit their mineral resources locally instead of shipping them as concentrates. Production plants may start on a small scale with small capital investment then increase productivity later when the economy permits without financial penalty. This is in contract to smelting operations which necessitates large scale production from the start with high capital investment that may not be available locally.
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Recent trends in Extractive Metallurgy
Journal of Mining and Metallurgy Section B: Metallurgy, 2009Co-Authors: Fathi HabashiAbstract:The dissolution of minerals is of importance to a number of fields of endeavour. In particular, it is the rate of dissolution that is important. Knowledge of the kinetics might allow the rate to be accelerated or retarded, depending on the field of endeavour. In understanding the mechanism of dissolution, it is the order of reaction that is of particular interest. The kinetics of dissolution of minerals are frequently found to be close to one-half order in the oxidant. The electrochemical mechanism of dissolution describes this dependence. However, a number of misunderstandings about the dissolution of minerals and the electrochemical mechanism recur, and need to be addressed. This paper addresses seven of these misunderstandings, and makes the following conclusions: (i) mechanism is not the same as chemical pathway, (ii) there is no separation of the surface into anodic sites and cathodic sites, (iii) there is no flow of electrons across the bulk of the mineral, (iv) the oxidation and reduction reactions are coupled by the transfer of electrons, not by a chemically bonded activated state, (v) polysulphides do not passivate the surface, (vi) the first step of the dissolution reaction is not by acid, and (vii) the solids do not need to be electrical conductors to dissolve by the electrochemical mechanism. ?? 2013 Elsevier B.V.
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recent trends in Extractive Metallurgy
Journal of Mining and Metallurgy Section B, 2009Co-Authors: Fathi HabashiAbstract:While pyrometallurgical processes are old technology and were the dominant and logical route used to treat sulfide concentrates they are now challenged by new hydrometallurgical processes. In these new processes there have been attempts in the past few years to avoid using autoclaves in the treatment of concentrates of zinc, copper, and nickel. The situation has been recently reversed and pressure hydroMetallurgy is being applied in many operations. An outline of these processes is given and the future trend is discussed.
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Extractive Metallurgy of aluminum
Encyclopedia of Aluminum and Its Alloys, 2003Co-Authors: Fathi HabashiAbstract:Aluminum comprises 8% of the earth’s crust and is the most abundant structural metal. Its production has surpassed that of copper and approaches that of iron. This article is a review of all aspects of the production of aluminum including: the raw materials from which it derived, production of aluminum from bauxite, electrolytic reduction of aluminum oxide, purification and refining, and environmental aspects of production processes.
C A Pickles - One of the best experts on this subject based on the ideXlab platform.
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Microwaves in Extractive Metallurgy: Part 1 – Review of fundamentals
Minerals Engineering, 2009Co-Authors: C A PicklesAbstract:Microwave radiation is a relatively new energy source, which has considerable potential for various applications in mineral processing and Extractive Metallurgy. However, the strengths of the interaction of the microwave radiation with the materials of interest are largely unknown. Additionally, in contrast to the aqueous solutions used in hydroMetallurgy, the microwave interaction with the heterogeneous solids used in pyrometallurgical processes is difficult to model from fundamentals. Since the microwave heating characteristics of most of the materials cannot be predicted, research is being performed to determine the underlying factors which govern the microwave response of ores, concentrates, reducing agents and other feedstocks used in pyrometallurgical processes. In the present research, the techniques used to measure the microwave coupling characteristics are outlined and the application of these techniques to some relevant pyrometallurgical materials is reviewed.
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microwaves in Extractive Metallurgy part 1 review of fundamentals
Minerals Engineering, 2009Co-Authors: C A PicklesAbstract:Microwave radiation is a relatively new energy source, which has considerable potential for various applications in mineral processing and Extractive Metallurgy. However, the strengths of the interaction of the microwave radiation with the materials of interest are largely unknown. Additionally, in contrast to the aqueous solutions used in hydroMetallurgy, the microwave interaction with the heterogeneous solids used in pyrometallurgical processes is difficult to model from fundamentals. Since the microwave heating characteristics of most of the materials cannot be predicted, research is being performed to determine the underlying factors which govern the microwave response of ores, concentrates, reducing agents and other feedstocks used in pyrometallurgical processes. In the present research, the techniques used to measure the microwave coupling characteristics are outlined and the application of these techniques to some relevant pyrometallurgical materials is reviewed.
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applications of microwave energy in Extractive Metallurgy a review
Cim Bulletin, 1997Co-Authors: C A PicklesAbstract:In the last few decades, microwave energy has been widely employed in food processing, rubber and plastics curing, and in ceramic sintering. Recently, the application of microwaves as an energy source in Extractive Metallurgy has received considerable attention from a number of researchers. During the period from the mid-1960s to about 1988, the majority of the research was focussed on the behaviour of materials in microwave radiation. These research activities will continue to be important, since fundamental data on the interaction of microwaves with materials are vital for the successful application of the technology. Since 1990, a number of potential applications of microwave processing have been investigated. These include: pretreatment of ores and concentrates, leaching, reduction, preheating of refractories, heating of slags and waste treatment. In this paper, the interaction of microwaves with materials of interest in Extractive Metallurgy are reviewed and potential applications are discussed.
N. Krishnamurthy - One of the best experts on this subject based on the ideXlab platform.
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Extractive Metallurgy of rare earths
International Materials Reviews, 2004Co-Authors: C K Gupta, N. KrishnamurthyAbstract:AbstractA comprehensive review is presented of the Extractive Metallurgy of rare earths. The topics covered are: world rare earth resources and production; ore processing and separation of individual rare earths; reduction, refining, and ultrapurification of rare earth elements; methods for rare earth materials analysis; and a selection of the numerous rare earth applications. World rare earth reserves are abundant and would last for well beyond the next century. However, all of the 16 naturally occurring rare earth elements are not equally distributed in the ore minerals. This, compounded with the problems specific to the isolation and recovery of each of the rare earths, sets the stage for an unequal rare earth availability. The close chemical similarity of rare earths looses its importance when divergent physical properties determine the processes for rare earth element reduction and refining. The rare earth metals, alloys, and compounds have been as pure as could be determined. Finally, the commercial...
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Extractive Metallurgy of Rare Earths - Extractive Metallurgy of rare earths
International Materials Reviews, 1992Co-Authors: C K Gupta, N. KrishnamurthyAbstract:AbstractA comprehensive review is presented of the Extractive Metallurgy of rare earths. The topics covered are: world rare earth resources and production; ore processing and separation of individual rare earths; reduction, refining, and ultrapurification of rare earth elements; methods for rare earth materials analysis; and a selection of the numerous rare earth applications. World rare earth reserves are abundant and would last for well beyond the next century. However, all of the 16 naturally occurring rare earth elements are not equally distributed in the ore minerals. This, compounded with the problems specific to the isolation and recovery of each of the rare earths, sets the stage for an unequal rare earth availability. The close chemical similarity of rare earths looses its importance when divergent physical properties determine the processes for rare earth element reduction and refining. The rare earth metals, alloys, and compounds have been as pure as could be determined. Finally, the commercial...
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Extractive Metallurgy of vanadium
1992Co-Authors: C K Gupta, N. KrishnamurthyAbstract:Foreword. Preface. History, Properties and Applications. Introduction. Discovery. Developments. Properties of Unalloyed Vanadium. Physical and Mechanical Properties of Vanadium Base Alloys. Interaction with Gases. Interaction with Molten Metals. Chemical Properties. Applications. Summary. References. 2. Sources. Introduction. Crustal Abundance. Minerals. Geochemistry. Sources and Reserves. Occurrences. Vanadium Source Utilisation Trends. Summary. References. 3. Sources Processing. Introduction. Physical Beneficiation. Aqueous Chemistry. Salt Roasting. Leaching. Solvent Extraction. Ion Exchange. Carbon Absorption and Desorption. Vanadium Precipitation. Determination of Vanadium. Uranium-Vanadium Ores. Titaniferous Magnetites. Non Titaniferous Iron Ores. Boiler Ash and Fly Ash. Spent Catalysts. Flexicoke. Vanadiferous Clays. Asphaltites of Peru. Lead Zinc Ores. Vanadiferous Shales. Phosphate Rock. Bauxite. Chromite. Ilmenite. Idaho Mudstones. Wyoming Vanadiferous Silicates. Summary. References. 4. Compounds and Alloys. Introduction. Oxides. Hydroxides. Peroxy Compounds. Vanadates. Vanadium Bronzes. Sulphates and Nitrates. Halides and Oxyhalides. Interstitial Compounds. Intermetallic Compounds. Ferrovanadium. Vanadium-Aluminium Master Alloys. Vanadium Base Alloys. Summary. References. 5. Reduction. Introduction. Thermodynamics of Reduction Processes. General Characteristics of Metallothermic Reductions. Calciothermic Reduction of Vanadium Oxides. Aluminothermic Reduction of Vanadium Oxides. Magnesiothermic Reduction of Vanadium Oxides. Magnesium Reduction of Vanadium Chlorides. Other Metallothermic Chloride Reduction Processes. Carbothermic Reduction of Vanadium Oxides. Hydrogen Reduction of Vanadium Compounds. Analytical Methods. Summary. References. 6. Refining of Vanadium. Introduction. Origin of Impurities in Vanadium. Pyrovacuum Treatments. Electrorefining. Iodide Refining. Zone Melting. Electrotransport. Analytical Methods. Gettering. Summary. References. 7. Toxicology. Introduction. Occupational Exposures. Effects on Animals and Humans. Threshold Limit Values. Vanadium Compounds Handling and Work Area Procedures. Vanadium Pollution. Summary. References. 8. A Few Minutes with Vanadium's Profile. Introduction. Occurrence. Processing. Reduction. Refining. Application. Conclusion. Subject Index.
Li Suqing - One of the best experts on this subject based on the ideXlab platform.
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review of the Extractive Metallurgy of scandium in china 1978 1991
Hydrometallurgy, 1996Co-Authors: Xu Shaoquan, Li SuqingAbstract:Abstract This article surveys the progress of the Extractive Metallurgy of scandium in China during the last two decades.
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Review of the Extractive Metallurgy of scandium in China (1978–1991)
Hydrometallurgy, 1996Co-Authors: Xu Shaoquan, Li SuqingAbstract:Abstract This article surveys the progress of the Extractive Metallurgy of scandium in China during the last two decades.
C K Gupta - One of the best experts on this subject based on the ideXlab platform.
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Extractive Metallurgy of rare earths
International Materials Reviews, 2004Co-Authors: C K Gupta, N. KrishnamurthyAbstract:AbstractA comprehensive review is presented of the Extractive Metallurgy of rare earths. The topics covered are: world rare earth resources and production; ore processing and separation of individual rare earths; reduction, refining, and ultrapurification of rare earth elements; methods for rare earth materials analysis; and a selection of the numerous rare earth applications. World rare earth reserves are abundant and would last for well beyond the next century. However, all of the 16 naturally occurring rare earth elements are not equally distributed in the ore minerals. This, compounded with the problems specific to the isolation and recovery of each of the rare earths, sets the stage for an unequal rare earth availability. The close chemical similarity of rare earths looses its importance when divergent physical properties determine the processes for rare earth element reduction and refining. The rare earth metals, alloys, and compounds have been as pure as could be determined. Finally, the commercial...
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Extractive Metallurgy of tantalum
Mineral Processing and Extractive Metallurgy Review, 2001Co-Authors: D K Bose, C K GuptaAbstract:This paper presents a brief review of Extractive Metallurgy of tantalum starting from processing of its ore to two pure intermediates K2TaF7 and Ta2O5 and their conversion to pure tantalum metal by various technically feasible processes. Though tantalum metal can be produced by several means only two processes – sodium reduction of K2TaF7 and fused salt electrolysis of K2TaF7 in the presence of oxide, have been successful on industrial scale. Besides providing salient features of these two processes, the paper presents brief accounts of studies carried out on the reduction of oxide by metallic reductants – calcium and aluminium as well as nonmetallic reductants – carbon and carbon–nitrogen. The crude metal obtained by various reduction techniques outlined are purified either by solid state pyrovacuum treatment or by melt refining in an electron beam furnace. Mechanism of refining processes taking place during these post reduction treatments are also included in the review.
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Extractive Metallurgy of beryllium
Mineral Processing and Extractive Metallurgy Review, 2001Co-Authors: C K Gupta, S SahaAbstract:Abstract A comprehensive review of the Extractive Metallurgy of beryllium is presented. Due to the strategic importance and element of secrecy surrounding the metal, any open literature on beryllium is rather limited. However, this review has been made to cover all important aspects of beryllium extraction technology namely, resources of the metal; processing of ores; reduction of fluoride and oxide to get metal and alloy; refining of the metal; post preparation processes to shape metal through powder metallurgical route and preparation of foils and ceramics. Special attention has been given to the topic of toxicology and pollution control. Recyclfng of beryllium will form the concluding section. Information on the removal of impurities during the preparation of intermediate products as well as during reduction to metal and its alloys are described with process principles. Thus this review, with the help of discussion on each unit process and at the same time emphasising on the problems faced in large sca...
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Extractive Metallurgy of niobium
1994Co-Authors: C K Gupta, A K SuriAbstract:Properties and Applications of Niobium: Introduction. Historical: Discovery, Early Developments, Recent Trends. Properties: Physical Properties, Chemical Properties, Metallurgical Properties. Applications: Niobium in Steels, Cast Irons, Niobium in Superalloys, Niobium in Zirconium Alloys, Niobium in Superconducting Alloys, Niobium in Chemical Process Industry, Niobium Compounds, Miscellaneous. Summary. Sources and Their Treatment Procedures: Introduction. Crustal Abundance. Minerals: General, Geochemistry, Niobium Mineralization. Sources and Reserves: General, Types of Sources, Reserves, Major Deposits. Ore Extraction: General, Mining, Comminution, Concentration. Major Production Practices: Pyrochlore, Niobium with Other Minerals. Summary. Chemical Processing: Introduction. Primary and Secondary Sources: General, Theoretical and Practical Aspects of Source Opening, Niobium and Tantalum Separation Processes, Primary Sources Processing, Secondary Sources Processing. Pollution Aspects in Chemical Processing. Compounds: General, Oxides, Chlorides and Fluorides, Carbides, Hydrides, Nitrides, Borides, Silicides. Summary. Reduction Processes: Introduction. Oxide Reduction Processes: General, Metallothermics, Carbothermics. Chloride Reduction Processes: General, Active Metal Reduction, Non Metal Reduction, Disproportionation and Decomposition. Fluoride Reduction Processes: General, Sodiothermic Process. Electrolytic Reduction Processes. Nitride Decomposition Process: General, Process Description. Miscellaneous Processes: Ferroniobium, Niobium Alloys, Niobium Carbide. Summary. Purification and Consolidation: Introduction: General, Impurities in Niobium. Purification Techniques: Classification of Purification Techniques, Pyrovacuum Treatment, Electrorefining, Iodide Refining, Zone Refining, Electrotransport, Chemical Gettering. Consolidation: Vacuum Sintering, Vacuum Arc Melting, Electron Beam Melting. Summary. Autobiography: Introduction. Chemistry. Mineralogy and Geology. Occurrences. Front End Processes. Back End Processes. Uses and Markets. Conclusion.
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Extractive Metallurgy of Rare Earths - Extractive Metallurgy of rare earths
International Materials Reviews, 1992Co-Authors: C K Gupta, N. KrishnamurthyAbstract:AbstractA comprehensive review is presented of the Extractive Metallurgy of rare earths. The topics covered are: world rare earth resources and production; ore processing and separation of individual rare earths; reduction, refining, and ultrapurification of rare earth elements; methods for rare earth materials analysis; and a selection of the numerous rare earth applications. World rare earth reserves are abundant and would last for well beyond the next century. However, all of the 16 naturally occurring rare earth elements are not equally distributed in the ore minerals. This, compounded with the problems specific to the isolation and recovery of each of the rare earths, sets the stage for an unequal rare earth availability. The close chemical similarity of rare earths looses its importance when divergent physical properties determine the processes for rare earth element reduction and refining. The rare earth metals, alloys, and compounds have been as pure as could be determined. Finally, the commercial...
