Phase diagram of the system Ca�?�Ti�?�O at 1200 K

Bulletin of materials science

Sapna Gupta¹  K T Jacob¹ 

[1] Department of Materials Engineering, Indian Institute of Science, Bangalore 560 012, India$$Department of Materials Engineering, Indian Institute of Science, Bangalore 560 012, IndiaDepartment of Materials Engineering, Indian Institute of Science, Bangalore 560 012, India$$

关键词: Phase diagram;    system Caâ€�?�Tiâ€�?�O;    calciothermic reduction of TiO2;    reaction pathway.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

Phase relations in the system Caâ€�?�Tiâ€�?�O have been established by equilibration of several samples at 1200 K for prolonged periods and identification of phases in quenched samples by optical and scanning electron microscopy, XRD and EDS. Samples representing 20 compositions in the ternary system were analyzed. There was negligible solid solubility of Ca in the phases along the binary Tiâ€�?�O, and of Ti in CaO. Four ternary oxides were identified: CaTiO₃, Ca₄Ti₃O₁₀ and Ca₃Ti₂O₇ containing tetravalent titanium, and CaTi₂O₄ containing trivalent titanium. Tie-lines link calcium titanite (CaTi₂O₄) with the three calcium titanates (CaTiO₃, Ca₄Ti₃O₁₀ and Ca₃Ti₂O₇), CaO, oxygen excess TiO_{1+ð›�?} and stoichiometric TiO. Tie-lines connect CaTiO₃ with TiO_{2â€�?�ð�?��?}, Magneli phases Ti$_{n}$O$_{2nâ€�??1}$ (28 â‰�? ð‘�?? â‰�?4), Ti₃O₅, Ti₂O₃ and TiO_{1+ð›�?}. CaO was found to coexist with TiO, and Tiâ€�?�O solid solutions ð›�? and ð›�?. The phase diagram is useful for understanding the mechanisms and kinetics of direct calciothermic reduction of TiO₂ to metal and electrochemical reduction of TiO₂ using graphite anode and molten CaCl₂ electrolyte.

【 授权许可】

Unknown