Synthesis of Li^+ adsorbent(H_2TiO_3) and its adsorption properties  

锂离子吸附剂(H_2TiO_3)的合成及吸附性能(英文)

作　　者：石西昌[1] 张志兵[1] 周定方[1] 张丽芬[1] 陈白珍[1] 余亮良[1] 

机构地区：[1]中南大学冶金科学与工程学院,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2013年第1期253-259,共7页中国有色金属学报（英文版）

基　　金：Project(2008BAB35B04) supported by the National Key Technologies R&D Program of China;Project(2010QZZD003) supported by Central South University Advanced Research Program,China

摘　　要：H2TiO3 was obtained from the acid-modified adsorbent precursor Li2TiO3,which was synthesized by a solid-phase reaction between TiO2 and Li2CO3.The extraction ratio of Li＋ from Li2TiO3 was 98.86%,almost with no Ti4＋ extracted.The effects of lithium titanium ratio,calcining temperature and time were investigated on the synthesis of Li2TiO3.Li2TiO3,H2TiO3 and the adsorbed Li＋ adsorbent were characterized by XRD and SEM.The lithium adsorption properties were investigated by the adsorption kinetics and adsorption isotherm.The results indicate that H2TiO3 has an excellent adsorptive capacity for Li＋.Two simplified kinetic models including the pseudo-first-order and pseudo-second-order equations were selected to follow the adsorption processes.The rate constants of adsorption for these kinetic models were calculated.The results show that the adsorption process can be described by the pseudo-second-order equation,and the process is proved to be a chemical adsorption.The adsorption process that H2TiO3 adsorbs Li＋ in LiCl solution well fits the Langmuir equation with monolayer adsorption.选取TiO2为钛源、Li2CO3为锂源,采用高温固相法合成锂吸附剂前躯体Li2TiO3,并探讨锂钛比、焙烧温度、焙烧时间等因素对合成Li2TiO3性质的影响。将Li2TiO3用一定浓度的盐酸酸洗脱锂后制得偏钛酸型锂吸附剂H2TiO3,酸洗过程中锂的抽出率达到98.86%,而离子筛中的钛溶损却很小。采用XRD和SEM等分析手段对TiO2、Li2TiO3和H2TiO3及其吸附锂后的样品进行表征。最后应用伪一级和伪二级动力学方程对H2TiO3的吸附性能进行研究,并对吸附过程进行拟合从而计算相应的速率常数。结果表明:H2TiO3对锂离子具有较大的吸附能力,吸附过程符合伪二级动力学方程,表明吸附过程主要为化学吸附;在LiCl溶液中的吸附平衡数据符合Langmuir等温吸附方程,表明吸附过程为单层吸附。

关 键 词：Li＋ adsorbent Li2TiO3 adsorption property kinetic models monolayer adsorption TIO2 Li2CO3 

分 类 号：O647.3[理学—物理化学] TQ424[理学—化学]