SOM法电解过细高钛渣制备金属钛

Preparation of Titanium by SOM Electrolytic Process from Ultrafine High Titanium Slag

摘要:

为回收利用TiCl₄生产过程中产生的过细高钛渣,在CaCl₂熔盐中以预烧成型的过细高钛渣为阴极,采用固体透氧膜法(SOM法)直接电解制备金属钛,并研究了在1100 ℃、3.5 V电压下,高钛渣阴极的电脱氧历程和杂质的去除行为。结果表明：随着电解时间延长,阴极片逐渐收缩,孔隙率下降,颗粒尺寸增大,且电解6h得到金属钛表明SOM法具有较高的电流效率。过细高钛渣电脱氧历程为：TiO₂→CaTiO₃ →Ca(Ti₂O₄)→TiO →Ti,而Al、Mn、Fe、Si等杂质通过电解得到相应单质且大部分进入CaCl₂熔盐,少量残留经稀盐酸洗涤被去除。

关键词:固体透氧膜;过细高钛渣;金属钛;电脱氧历程;杂质行为

Abstract:

In order to recycle the ultrafine high titanium slag produced in TiCl₄ production process, the titanium slag was sintered and employed as the cathode in a Solid Oxide Membrane (SOM) electrolytic process in molten CaCl2 to prepare metal Ti. The deoxidization process of the cathode and the behavior of impurities removing were studied at an electrolytic temperature of 1150 ℃with an electrolytic voltage of 3.5 V. Results showed with the increasing of electrolytic time, the size and porosity of cathode was decreased while the particle size in cathode was increased, and after 6 hours electrolyzing metal titanium was obtained which indicated the SOM process offered a high current efficiency. The deoxidization process of this electrolysis process was carried out as: TiO₂→CaTiO₃ →Ca(Ti₂O₄) → TiO→ Ti. Results also indicated the impurities which included Al, Mn, Fe, and Si were mostly reduced to corresponding elementary substance, which were moved into melting CaCl₂. A small amount of residual impurities in cathode can be removed by washing with dilute hydrochloric acid.

Key words:Solid Oxide Membrane (SOM); ultrafine high titanium slag; titanium; deoxidization process; impurities removing