冰晶石系电解质中钛的还原过程研究

Deoxidization process of Ti in Na_3AlF_6 system

本实验采用循环伏安法,对1323 K温度下冰晶石中Ti4+在石墨电极和铝阴极上的还原过程进行研究。研究发现Ti4+在石墨电极上分两步还原,两步之间的电位差约为0.5 V;而在铝阴极上是一步还原为单质钛。用Miedima模型计算了钛在铝液中的活度系数,和文献上用Guggenheim模型并结合试验数据得到的活度系数十分接近;并利用能斯特公式计算出了1323 K时钛在铝阴极上的析出电位较在石墨电极上析出时,向正方向偏移0.53 V,这可以解释为什么钛在石墨电极上是分步还原而在铝阴极上是一步还原为单质的,从而为含钛铝基合金的生产找到一些理论依据。

The Cyclic Voltammetry is used to study the deoxidize process of Ti^4＋ in Na3AlF6 melt at 1323 K. It finds that the deoxidize process of Ti^4＋ on graphite pole is two step and there is about 0.5 V gap between the two steps, The deoxidize process of Ti^4＋ on Al electrode is only one step. The activity coefficient we get with Miedima mode is close to the result of others who get the result with Guggenheim mode and experimentation. The deoxidize voltage of Ti^4＋ on Al rode, calculated with Nernst formula, is different from the one on graphite pole, and the excursion is 0.53 V. It is why the deoxidize process of Ti^4＋ is two step on graphite pole and is one step on Al pole. So it can be used for explaining something useful in theory in Al - Ti alloy production,