电化学还原TiO_2制备金属钛及反应过程的研究

Process of Reduction of TiO_2 Using Electrodeoxidation

采用熔盐电解法,在900℃熔盐CaCl2中以烧结TiO2为阴极,石墨棒为阳极制备出了金属钛。研究了不同温度下烧结阴极的形貌及其对电解反应的影响。结果表明:600℃下烧结4h的阴极具有良好电化学反应性能;电解过程中脱氧速度不均匀;TiO2电极的还原是由外向内,由高价向低价再到金属分步进行的;电解还原过程电流效率低约为15%。阴极的孔隙大小和颗粒尺寸会影响电极的反应速度。

The method of electro-deoxidation was used to reduce solid TiO2 to titanium in CaCl2 melt at 900℃.The sintered TiO2 samples acted as the cathode, while graphite as the anode. It was found that the sintering temperature of the oxide cathode and the duration of electrolysis affected forming of the products. The results show that the electrochemical activation of the cathode can be enhanced aider sintering at 600℃ for 4 h. The rate of electro-deoxidation for TiO2 varied during electrolysis. The electrochemical deoxidation of TiO2 in the molten salt was conducted step by step from outside of cathode to its inside and from high valence oxide to low valence oxide until to metal. The efficiency of electro-deoxidation is 15%. The speed of electrode reaction is affected by the sizes of pore and grain of cathode.