熔盐电解中钛离子电化学沉积行为研究  

Electrochemical Deposition of Titanium Ions in Molten Salts

作　　者：朱福兴[1,2] 邱克辉[1] 孙朝晖[2] 穆天柱[2] 邓斌[2] 

机构地区：[1]成都理工大学材料与化学化工学院,四川成都610059 [2]攀钢集团研究院有限公司,钒钛资源综合利用国家重点实验室,四川攀枝花617000

出　　处：《钢铁钒钛》2017年第4期12-18,共7页Iron Steel Vanadium Titanium

基　　金：国家重点基础研究发展规划(973计划)项目(2013CB632600)

摘　　要：对熔盐电解提钛工艺中钛离子的电化学沉积行为进行研究,首先通过调整TiCl_4和海绵钛的比例在NaClKCl熔盐中反应制备出不同电解质组分,然后在制备的电解质体系中研究钛离子的电化学沉积行为。低价钛电解质组分的XRD分析结果表明,在993 K的NaCl-KCl熔盐中,当TiCl_4与Ti摩尔比为1∶2时,反应产物主要为2价的TiCl_2,电解质形成NaCl-KCl-TiCl_2体系;当摩尔比为2∶1时,反应产物主要为2.57价的TiCl_2和K_3TiCl_6,电解质形成NaCl-KCl-TiCl_2-K_3TiCl_6体系。两种电解质体系的循环伏安研究结果表明,NaCl-KCl-TiCl_2体系中钛离子的还原历程为Ti^(2+)→Ti,主要受扩散影响,扩散系数为2.93×10^(-5)cm^2/s,而NaCl-KCl-TiCl_2-K_2TiCl_6体系中钛离子还原历程为Ti^(3+)→Ti^(2+)和Ti^(2+)→Ti两步。钛离子电化学沉积产物的SEM分析结果表明在NaCl-KCl-TiCl_2体系中,得到的钛粉产物呈现大颗粒的枝晶状,随着电流密度增大和钛离子浓度减小,钛粉产物颗粒逐步变细;而在NaCl-KCl-TiCl_2-K_2TiCl_6体系中获得产物为细颗粒的多孔状钛粉。The electrochemical deposition behaviors of titanium ions in titanium extraction by molten salts electrolysis were investigated. Different electrolytes were firstly prepared by adjusting the ratio of TiCl4 to titanium sponge in NaCI-KCI melts then the electrochemical deposition behaviors of titanium ions were an- alyzed in the obtained electrolyte systems. According to XRD of the electrolytes of low valence titanium, the main products were TiC12 and NaCl-KCl-TiCl2 electrolyte system can be formed when the mole ratio of TiC14 to Ti was 1 ： 2 at 993 K in NaCl-KCl melts,while the TiCl2 and K3TiCl6 with 2.57 of average va- lence and NaCl-KCl-TiCl2-K3TiCl6 electrolyte system were obtained when the mole ratio of TiCl4 to Ti was 2 ： 1. The results of cyclic vohammetry for the electrolyte systems mentioned above indicated that the re- duction course of titanium ions was Ti2＋→Ti in NaCl-KCl-TiCl2 influenced by diffusion with 2.93 ×10^-5 cm2/s of diffusion coefficient and it was two steps of Ti3＋→Ti2＋ and Ti2＋→Ti in NaCl-KCl-TiCl2-K2TiC16 system. The morphology of titanium powder obtained in NaCl-KCl-TiCl2 system was dendrite large parti- cles, and with increase of current density and decrease in concentration of titanium ions the particle size of products decreased. Fine and porous titanium powder was prepared in NaCl-KCI-TiCl2-K2TiCl6 melts. Key words： titanium powder, titanium sponge , TiCl4, electrolysis in molten salts, titanium ions, electro- chemical deposition, average valence

关 键 词：钛粉 海绵钛 TICL4 熔盐电解 钛离子 电化学沉积 平均价态 

分 类 号：TF823[冶金工程—有色金属冶金]