Extractive Metallurgy of Titanium

Contents Contributors xi 1. Introduction to the development of processes for primary Ti metal production 1 Zhigang Zak Fang, Hyrum D. Lefler, F.H. Froes, and Ying Zhang References 8 Part 1 Extractive chemical metallurgy processes 11 2. A brief introduction to production of titanium dioxide and titanium tetrachloride 13 Michael L. Free 1. Background 13 2. Ore sources 13 3. Processing methods 14 References 17 3. Minerals, slags, and other feedstock for the production of titanium metal 19 Dimitrios Filippou and Guillaume Hudon 1. Introduction 19 2. Ilmenite, rutile, and other natural titanium minerals 21 3. Ilmenite smelting to titania slag 26 4. Ilmenite conversion to synthetic rutile 32 5. Titania slag upgrading to UGS 36 6. Production of titanium carbide feedstock 37 7. Conclusions 38 Acknowledgments 41 References 41 4. Chemical processes for the production of titanium tetrachloride as precursor of titanium metal 47 Guillaume Hudon and Dimitrios Filippou 1. Introduction 47 2. Titanium tetrachloride 47 3. Production of titanium tetrachloride 49 4. Titanium tetrachloride purification 55 5. Production of pure titanium dioxide 56 6. Other precursors 59 Acknowledgments 60 References 60 Part 2 Thermochemical reduction of TiCl4 63 5. Fundamentals of thermochemical reduction of TiCl4 65 Toru H. Okabe and Osamu Takeda 1. Historical developments in titanium metal production 65 2. Kroll process 66 3. Hunter process 71 4. Fundamentals of titanium reduction process 75 5. Electrochemical reactions during thermochemical reduction 78 6. Reduction mechanism of TiCl4 during the Kroll process 81 7. Past research for new titanium production processes 83 8. Summary 90 References 92 6. The Kroll process and production of titanium sponge 97 Matthew R. Earlam 1. Introduction 97 2. Source of ore 99 3. Production of TiCl4 100 4. Purification of TiCl4 101 5. The Hunter process 102 6. Armstrong process 103 7. Kroll process 103 8. Magnesium reduced acid leach (MRAL) (no longer practiced) 104 9. Vacuum distillation process TOHO timet 107 10. Preparation for melting 110 References 111 7. A modified Kroll process via production of TiH2 - thermochemical reductions of TiCl4 using hydrogen and Mg 113 Mykhailo Matviychuk, Andrey Klevtsov, and Vladimir S. Moxson 1. Introduction 113 2. Process description 114 3. Experimental results 120 4. Role of hydrogen for ADMA process 122 References 127 Further reading 128 Part 3 Thermochemical reduction of TiO2 129 8. Metallothermic reduction of TiO2 131 Toru H. Okabe 1. Introduction 131 2. Studies on reduction of titanium oxide before 2000 134 3. Studies on reduction of titanium oxide after 2000 143 4. Future prospects of metallothermic reduction processes for direct production of titanium from oxides 155 5. Summary 159 References 160 9. Hydrogen assisted magnesiothermic reduction (HAMR) of TiO2 to produce titanium metal powder 165 Yang Xia, Hyrum D. Lefler, Ying Zhang, Pei Sun, and Zhigang Zak Fang 1. Introduction 165 2. Fundamentals of the HAMR process 167 3. HAMR process description 172 4. HAMR product characterization 173 5. Summary 176 Acknowledgments 176 References 177 10. Deoxygenation of Ti metal 181 Ying Zhang, Zhigang Zak Fang, Pei Sun, Yang Xia, Hyrum D. Lefler, and Shili Zheng 1. Introduction 181 2. Thermodynamic properties of the TieO solid solutions 182 3. Methods of deoxygenation 186 4. Concluding remarks 206 A. Appendix 207 Acknowledgments 220 References 220 Part 4 Electrochemical reduction of TiO2 and TiOC 225 11. Invention and fundamentals of the FFC Cambridge Process 227 George Z. Chen and Derek J. Fray 1. Background: how the concept of electro-deoxidation came about 227 2. Understanding of electro-deoxidation: interactions of the oxide cathode with molten salts 230 3. Understanding of electro-deoxidation: metal/insulator/electrolyte 3PI models 235 4. Understanding of electro-deoxidation: the metal-to-oxide molar volume ratio 236 5.