(中南大學(xué) 冶金科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 采用兩步固相法制備鋰離子篩MnO2·0.5H2O，采用X射線衍射儀和相關(guān)動力學(xué)模型研究MnO2·0.5H2O的結(jié)構(gòu)及其吸附性能，探討離子篩對鹽湖鹵水中各主要金屬離子的分離特性及循環(huán)吸附性能。結(jié)果表明：溶液pH值的升高有利于離子篩對Li+的吸附，但在較強(qiáng)的堿性溶液中離子篩的溶損相應(yīng)增加；吸附數(shù)據(jù)對偽二級動力學(xué)方程和Langmuir吸附等溫方程擬合較好，相關(guān)系數(shù)分別達(dá)0.998和0.993以上；動邊界模型中各控制步驟方程的線性擬合都不夠理想；離子篩對Li+具有較好的選擇性和較優(yōu)的循環(huán)吸附性能。這表明：吸附過程為化學(xué)吸附過程，且為單層吸附；吸附過程是一個復(fù)雜過程，是多個控制步驟共同作用的結(jié)果。
關(guān)鍵字: 鋰離子篩；MnO2·0.5H2O；固相法；動力學(xué)；吸附
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract: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.
Key words: lithium ion-sieve; MnO2·0.5H2O; solid method; dynamics; adsorption
