熔盐电解TiO2/SiO2混合物制备钛硅合金的热力学分析

以熔盐电解TiO2/SiO2混合物制备钛硅合金为研究对象,通过热力学计算,分析了TiO2/SiO2在直接电解还原过程中可能的反应路径。结果表明,TiO2和SiO2的电脱氧反应倾向于TiO2在单质Si基础上电解还原得到TiSi2,以及SiO2在单质Ti基础上得到Ti5Si3合金。中间产物CaTiO3和CaSiO3稳定,较难被还原。增大熔盐中O2-的活度有利于降低CaTiO3和CaSiO3的分解电压。CaTiO3在电脱氧后优先与Si反应生成TiSi2,CaSiO3在电脱氧后优先与Ti反应直接生成Ti5Si3。

Thermodynamic Analysis of Preparing Titanium-silicon Alloys by Electrolyzing TiO2/SiO2 Mixture in Molten Salt

In the present research, the potential reaction routes in the process of electrolyzing TiO2/SiO2 mixture have been analyzed by the thermodynamic calculations during the preparation of titanium-silicon alloys from TiO2/SiO2 in molten salt. The results suggest that the electro-deoxidization of TiO2 is preferentially reduced on the basis of silicon to form TiSi2, and the reduction of SiO2 is inclined to producing Ti5Si3 with the help of Si. The intermediates CaTiO3 and CaSiO3 are stable that are hard to be reduced. The increase in the activity of O2- in molten salt is in favor of decreasing the decomposition voltages of CaTiO3 and CaSiO3. As CaTiO3 is electrolyzed, it is easy to react with Si to form TiSi2, and CaSiO3 reacts directly with Ti to form Ti5Si3, respectively.