TiO_2真空碳热反应及可溶性TiO阳极电解过程研究

Extraction of Ti by a Combination of Vacuum Carbothermal Reduction and Electrolysis with Soluble TiO

通过对TiO_2碳热还原进行热力学计算,得出真空碳热还原技术能降低反应温度。采用X射线衍射以及电阻测量装置考察了TiO_2真空碳热还原过程,并将最终还原产物制备成可溶性TiO阳极进行电解。结果表明:在还原温度为1200℃,还原时间2 h,TiO_2与碳摩尔比为1:3的条件下,可以得到电阻率较低(小于0.03Ω·m)的低价氧化钛。整个还原过程TiO_2遵循逐级还原理论,反应产物会经历TiO_2→Ti_6O_(11)→Ti_4O_7→Ti_3O_5→Ti_2O_3→TiO的还原过程。最终将还原产物TiO与C混合制备成阳极,石墨为阴极时,850℃在CaCl_2-KCl熔盐体系中电解2 h后可生成TiC;相同实验条件下,TiO与C按配比压制成阳极,铁为阴极,中间以泡沫陶瓷材料相隔,产物则为金属钛及钛铁合金。

The two-step extraction of Ti from TiO2. First, vacuumcarbothermal reduction turned TiO2 into soluble Ti- oxides. Next, TiC was produced in the electrolysis with an anode made of carbon and conductive soluble Ti-oxides. The impact of the reduction conditions, including the reduction temperature and time, molar ratio of TiO2/C and pressure, on the stoichiometry of the reduced products was calculated in thermodynamics and investigated with X-ray diffraction. The calculated results show that reduced at 200℃ for 2 h and with a TiO2/C molar ratio of 1：3,TIO2 turned into soluble Ti- oxides with a resistivity less than 0.03μm in the sequence of TiO2→Ti6O11→Ti4O7→Ti3O5→Ti2O3→TiO. The TiC was produced in electrolysis for 2 h at 850%,in the electrolyte of molten CaC12-KClsolution,with anode made of C and the conductive Ti-oxides, and the cathode of graphite. The Fe-cathode and anode of C and Ti-oxides, separated by foamed ceramics, produced Ti and TiFe alloy under the same reaction conditions.