Chemical Phenomena in Titanium Production. DS van Vuuren SACI January 2011

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1 Chemical Phenomena in Titanium Production DS van Vuuren SACI January 2011

2 Outline Background Routes to produce titanium Some basic physical properties Main process routes and key physical properties Conclusions Slide 2 CSIR

3 South African s Global Ti Position in 2006 South Africa World Approximate Value South Africa World Reserves 220 Mt TiO Mt TiO 2 Mineral Production 1090 kt TiO kt TiO 2 $ 175m p.a. $ 840 m.p.a. Slag Production 1090 kt TiO 2 $ 490m p.a. $ 2500 p.a. Pigment Production ~20 kt TiO kt TiO 2 $ 37m p.a. $ m.p.a. Sponge Production Nil 125 kt p.a. Ti $ 1250 m.p.a. Ingot Production Nil 145 kt p.a. Ti $ 2600 m.p.a. Mill Products Nil ~90 kt p.a. Ti $ 4500 m.p.a.

4 Approximate Physical Properties Ti & Alloys Al & Alloys Fe & Alloys Ni & Alloys Strength (MPa) 1300 max 500 max 1300 max 1400 max Density (kg/m 3 ) Normalized Strength/weight Elasticity (GPa) M.P. ( C) Rel. Corrosion Resistance Very high High Low Medium Carbon Compatibility Resistant Corrosion Bio Compatibility Excellent T Exp. Coeff. (10-6 / C) ±8.5 ±20 ±12 ±11 Conductivity (W/m C) Color Aesthetic

5 Kyushu National Museum Photo courtesy of the Kyushu National Museum

6 INCREASING COST VALUE SEPARATION PRECURSOR REDUCTANT PRODUCT TiCl 4 e - Ingot TiO 2 H 2 Al Powder M 2 TiF 6 Mg Na TiO/TiC Ca/CaH 2 TiI 4, TiBr 4 Li Sponge

7 The Race New Primary Metal Technology: Europe - Ginatta Japan Ono & Suzuki JTS USA Armstrong ADMA UK FFC Process Australia TiRO Process South Africa Peruke CSIR CHINA Rapid expansion using known technology, cheap labor and large domestic market

8 Melting & boiling points of some metals and salts (Ti M.P. = 1668 C) Element Metal Chloride Fluoride Al subl. Li Na Mg Ca Al subl. Li Na Mg Ca

9 -log(p) (Bar) Salt Vapour Pressures LiCl AlF 3 CaCl 2 2 MgCl NaCl Temperature ( C) Slide 9 CSIR

10 Hunter & Kroll processes TiCl 4 Na/Mg Hunter: Substoichiometric Kroll: Excess Mg Reaction Molten salt Hunter: Aqueous leach Kroll: Vacuum distillation Separation Mg/Na and salt Ti Sponge Slide 10 CSIR

11 Ginatta Process Carbon TiCl 4 Cl 2 Molten Electrolyte Molten Ti Solid Ti Temperature > 1670 C Electrolyte Chlorides: Only Ca & Ba Fluorides: Mg, Ca, Sr, Y Density of Ba, La & Ce too high Lining Oxides: Only Y & Sc Freeze lining Slide 11 CSIR

12 FFC and Ono & Suzuki Processes Low oxygen potential of metal of the salt cation

13 JTS Process High solubility of Ca in CaCl 2 B.P. of CaCl 2 > M.P. of Ti ρ CaCl2 < ρ Ti Slide 13 CSIR

14 Armstrong Process Na TiCl 4 Reaction Advantage of low M.P. of Na Excess Na Na, Solid NaCl & Ti Powder Na Separation NaCl and Ti Powder H 2 O NaCl/Ti Aqueous NaCl Separation Slide 14 Ti Powder CSIR

15 TiRO Process Ti Powder Separation Ti + MgCl 2 Fluidised bed Reaction TiCl 4 MgCl 2 T M.P.Mg < T reactor < T M.P.MgCl2 Leaching: Effluent, H 2 formation, recrystallization of anhydrous MgCl 2 MgCl 2.H 2 O MgO+2HCl Evaporation Large mass/energy Continuous operation under vacuum Slide 15 CSIR

16 Peruke Process HF FeO.OH Al TiF 3 FeOTiO 2 TiF 3 Production Reaction TiAlF 3 Separation AlF 3 M.P. of Al determines T Reactor Low solubility of AlF 3 in water 5.6g/lit AlF 3 does not melt: Physical separation does not work well Separation by sublimation Large mass/energy Continuous operation under vacuum (low vapour pressure) Ti Powder Slide 16 CSIR

17 Continuous metallothermic reduction in molten salt (CSIR) TiCl 4 Synthesis TiCl 4 TiCl 4 Reduction Metal/Salt Separation Ti Powder TiO 2 Feedstock Ti & Chloride salt Cl 2 Metal Mg, Na, Ca, Li Salt Salt Electrolysis M.P. of salt determines reactor temperature, construction materials & heat exchanger design. M.P. of salt and metal affects electrolyser temperature. Oxide/chloride equilibrium of salt determines salt recovery process. Slide 17 CSIR

18 Product Removal Slide 18 CSIR

19 Product Morphology

20 Conclusions The obvious: Basic physical properties of the relevant chemicals have major effects on the selection of the chemical route to produce titanium and on the associated process and equipment designs. However, there is no consensus as to what process would be better than the Kroll process and many different approaches are being pursued by different organisations around the world. Slide 20 CSIR

21 THANK YOU The support of the DST is sincerely appreciated Slide 21 CSIR

Production of Titanium Powder Directly from Titanium Ore by Preform Reduction Process (PRP)

Production of Titanium Powder Directly from Titanium Ore by Preform Reduction Process (PRP) Haiyan Zheng 1 & Toru H. Okabe 2 1: Department of Materials Engineering, Graduate School of Engineering, The