(中南大學(xué) 冶金科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 以TiO2和Li2CO3為原料，采用固相法合成偏鈦酸型鋰吸附劑前軀體Li2TiO3，將該前軀體經(jīng)過(guò)鹽酸洗脫鋰，得到偏鈦酸型鋰吸附劑H2TiO3，其中鋰的抽出率達(dá)到98.86%，鈦幾乎不溶損。對(duì)TiO2、Li2TiO3、H2TiO3以及H2TiO3吸附鋰后的樣品進(jìn)行XRD和SEM表征。研究偏鈦酸型鋰吸附劑H2TiO3對(duì)鋰離子的吸附性能，并用偽一級(jí)動(dòng)力學(xué)方程和偽二級(jí)動(dòng)力學(xué)方程對(duì)吸附過(guò)程進(jìn)行擬合，計(jì)算相應(yīng)的速率常數(shù)。結(jié)果表明：H2TiO3對(duì)鋰離子具有較大的吸附能力，在LiOH溶液中對(duì)鋰離子的吸附容量為39.8 mg/g；吸附過(guò)程符合偽二級(jí)動(dòng)力學(xué)方程，表明吸附過(guò)程主要為化學(xué)吸附，吸附平衡數(shù)據(jù)符合Langmuir 等溫吸附方程。
關(guān)鍵字: 鋰吸附劑；Li2TiO3；吸附動(dòng)力學(xué)；偽二級(jí)動(dòng)力學(xué)
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:H2TiO3 type adsorbent was obtained by acid-modifying adsorbent precursor Li2TiO3, which was synthesized by a simple solid-phase reaction between Li2CO3 and TiO2. The extraction rate of Li+ from Li2TiO3 is 98.86%，and while almost no Ti4+ is extracted. TiO2, Li2TiO3, H2TiO3 and products of H2TiO3 adsorbing Li+ were characterized by XRD and SEM. The lithium adsorption properties were investigated by adsorption kinetics and adsorption isotherm. The kinetic data were studied by the pseudo-first-order and pseudo-second-order kinetic models. The rate constants of adsorption for these kinetic models were calculated. The results indicate that H2TiO3 type adsorbent shows superior adsorptive capacity of Li+, with the value of 39.8 mg/g in LiOH solution. The adsorption process obeys pseudo-second-order rate equation, and the process can be seen as chemical adsorption. The equilibrium data can be described well by the Langmuir isotherm equation.
Key words: lithium adsorbent；Li2TiO3；adsorption kinetics; pseudo-second-order kinetics
