溶胶-凝胶法制备的偏钛酸型锂离子吸附剂模拟从盐湖卤水中吸附Li+研究

Simulative adsorption of Li+ from the saline lake brine by the H2TiO3-lithium adsorbent synthesized by the sol-gel process

摘要:

本文以钛酸丁酯和乙酸锂为钛源和锂源，采用溶胶-凝胶法制备了钛酸锂（Li2TiO3）纳米粒子，用盐酸对其进行处理得到偏钛酸型锂离子吸附剂（钛锂离子筛）。配制了盐湖卤水模拟液，在吸附之前向模拟液中加入氢氧化钠除去Mg2+和Ca2+，并用所制备的吸附剂进行了模拟从盐湖卤水中吸附锂离子的研究。结果表明偏钛酸型锂离子吸附剂对锂离子的吸附容量为8.25 mg·g-1，Li+的分配系数(Kd)为24.54 mL·g-1，其数值远大于Na+ (0.52 mL·g-1)和K+ (0.97 mL·g-1)的分配系数。Li+对Na+的分离因素()为47.2，Li+对K+的分离因素()为25.3，表明所制备的吸附剂对Li+具有很好的选择吸附性。

Abstract:

The Li2TiO3 nanoparticles were prepared by the sol-gel process by employing lithium acetate and tetrabutyl titanate as lithium and titanium sources, respectively, followed by modification with hydrochloric acid to obtain H2TiO3-lithium adsorbent (titanium lithium ionic sieve). Simulation of the saline lake brine was prepared, followed by adding sodium hydroxide to the prepared solution before adsorption to remove Mg2+ as well as Ca2+. Simulative adsorption of Li+ by the obtained adsorbent from the saline lake brine was carried out. The results indicate that the adsorption capacity of H2TiO3-lithium adsorbent for Li+ is 8.25 mg·g-1, and the partition coefficient (Kd) of Li+ is calculated to be 24.54 mL·g-1, which is much larger than that of Na+ (0.52 mL·g-1) and K+ (0.97 mL·g-1). Li+ to Na+ separation factor () is 47.2, and Li+ to K+ separation factor () is 25.3, indicating that the synthesized adsorbent has an excellent selective adsorption performance to Li+