包覆ZrO_2锂离子筛的制备及其在盐湖卤水中的吸附性能  

Synthesis and Adsorption Properties of ZrO_2-Coated Lithium Ion-Sieve from Salt Lake Brine

作　　者：王豪 杨喜云 尹周澜[2] 曹改芳[1] 徐徽 

机构地区：[1]中南大学冶金与环境学院,长沙410083 [2]中南大学化学化工学院,长沙410083

出　　处：《无机化学学报》2017年第10期1775-1781,共7页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.51574286);中国博士后基金(No.2016M592448);中南大学博士后基金资助

摘　　要：采用水热法制备前驱体Li_(1.6)Mn_(1.6)O_4,用液相沉淀法在其表面包覆ZrO_2,再经酸洗转型为包覆ZrO_2的锂离子筛H_(1.6)Mn_(1.6)O_4。采用XRD、SEM、EDS和HRTEM对前驱体的结构、形貌和成分进行了表征。研究了ZrO_2包覆量和焙烧温度对锰溶损率和锂吸附容量的影响。结果表明:当ZrO_2包覆量为3%,焙烧温度为450℃时,在前驱体表面形成厚度约15 nm的ZrO_2包覆层,首次锰溶损率从3.14%下降到2.65%,锂离子筛在盐湖卤水中锂吸附容量保持为29.4 mg·g^(-1)。包覆ZrO_2的锂离子筛经过10次循环吸附-脱附,锰溶损率降低至0.34%,锂吸附容量保持为24.4 mg·g^(-1),高于未包覆的锂离子筛(22.9 mg·g^(-1))。包覆ZrO_2改善了锂离子筛的结构和吸附容量的循环稳定性。ZrO2-coated H1.6Mn1.6O4 was synthesized from Li1.6Mn1.6O4 precursor prepared by a hydrothermal method. The liquid precipitation process followed by acid washing was utilized to coat ZrO2 on the precursor. The structure, morphology and composition of the ZrO2-coated precursor were investigated by SEM, XRD, EDS and HRTEM analysis. The influences of coating content and roasting temperature on Mn dissolution loss ratio and Li adsorption capacity were discussed. The results indicate that a layer of ZrO2 with 15 nm in thickness is coated on the precursor when ZrO2 content is 3% and roasting temperature is 450℃. The Mn dissolution loss ratio decreases from 3.14% to 2.65% and Li adsorption capacity of the resulting ion sieve in the salt lake brine maintains 29.4 mg·g-1. After 10 cycles of adsorption and desorption, the corresponding Mn dissolution loss ratio and Li adsorption capacity is 0.34% and 24.4 mg·g-1, respectively. The adsorption capacity is higher than the bare lithium ion-sieve （22.9 mg·g-1）. The results suggest that the structure and cycle stability of H1.6Mn1.6O4 are improved by a ZrO2 coating layer.

关 键 词：锂离子筛 表面包覆 锰溶损率 锂吸附量 

分 类 号：O614.111[理学—无机化学] O647.3[理学—化学]