Crude TiCl_4 purification: a review of the current state of the art and future opportunities

摘要

Raw titanium tetrachloride (TiCl_4) is produced by chlorination of titania feedstock. Prior to its utilization in the manufacture of titanium dioxide pigment or titanium metal, the TiCl_4 is purified by adding reagents that react with the impurities in the crude TiCl_4, followed by distillation of the mixture. The current state of the art in purification of crude TiC_4 was surveyed. Tests were conducted at the laboratory scale to assess the efficiency of various additives used in the purification process to minimize the vanadium content in the distillate. The effects of various reagents, namely oleic acid, sodium oleate, potassium oleate, and copper on the purification of crude TiCl_4 were compared. The purified TiCl_4 was water-clear in aspect and analysed < 2 ppm vanadium for all reagents tested. Possible reactions between the impurities in the crude TiCl_4 and the reagents are investigated thermodynamically with the FactSage program.