摘要
采用两步固相法制备锂离子筛MnO2.0.5H2O,采用X射线衍射仪和相关动力学模型研究MnO2.0.5H2O的结构及其吸附性能,探讨离子筛对盐湖卤水中各主要金属离子的分离特性及循环吸附性能。结果表明:溶液pH值的升高有利于离子筛对Li+的吸附,但在较强的碱性溶液中离子筛的溶损相应增加;吸附数据对伪二级动力学方程和Langmuir吸附等温方程拟合较好,相关系数分别达0.998和0.993以上;动边界模型中各控制步骤方程的线性拟合都不够理想;离子筛对Li+具有较好的选择性和较优的循环吸附性能。这表明:吸附过程为化学吸附过程,且为单层吸附;吸附过程是一个复杂过程,是多个控制步骤共同作用的结果。
The lithium ion-sieve MnO2 ·0.5H2O was prepared by two-step solid phase and its adsorption properties were investigated by XRD and all sorts of relevant dynamic models.The separation characteristics of the lithium ion-sieve for the main metal ions in Salt Lake and circulation adsorption performance were also studied.The results show that the rise of pH is in favour of the adsorption of lithium ion-sieve,but in strong alkali solution the dissolution loss of the lithium ion-sieve also increases accordingly.The adsorption data fit better for the pseudo-second-order rate equation and Langmuir adsorption isotherm equation,and the correlation coefficients reach above 0.998 and 0.993,respectively.The performance of dynamic boundary models is not satisfactory.The lithium ion-sieve has good selectivity for lithium and circulation adsorption performance is very good.This suggests that the adsorption process is chemical adsorption with a single layer and a complicated process with some control steps.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2012年第11期3135-3143,共9页
The Chinese Journal of Nonferrous Metals
基金
国家"十一五"科技支撑计划项目(2008BAB35B04)
中央专项中南大学前沿研究计划重点项目(2010QZZD003)
