(華東理工大學(xué) 化工學(xué)院 化學(xué)工程聯(lián)合國家重點(diǎn)實(shí)驗(yàn)室，上海 200237)
摘 要: 以TiO2和LiOH·H2O為原料，經(jīng)水熱反應(yīng)、煅燒后得到納米級別鋰吸附劑前驅(qū)體Li2TiO3。用鹽酸將Li+洗脫后得到納米級別鋰吸附劑H2TiO3。通過XRD、SEM、動力學(xué)測試等手段考察煅燒溫度、煅燒時間對吸附劑的結(jié)構(gòu)和洗脫吸附性能的影響，用擬一級和擬二級動力學(xué)方程對吸附過程進(jìn)行擬合，并用Langmuir和Freundlich等溫線方程擬合吸附平衡數(shù)據(jù)。結(jié)果表明：在773 K下煅燒2 h制備的吸附劑對鋰離子吸附容量最高達(dá)到36.16 mg/g，并且具有極快的洗脫和吸附速率；洗脫5 h時，鋰洗脫率為98.8%，吸附速率常數(shù)達(dá)到0.0339 g/(mg·h)；吸附動力學(xué)符合擬二級動力學(xué)方程，吸附平衡數(shù)據(jù)符合Freundlich方程，鋰離子對鎂離子的分離因子達(dá)到154.17。
關(guān)鍵字: 納米H2TiO3；水熱法；吸附動力學(xué)；吸附速率常數(shù)；Freundlich方程
（State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China）
Abstract:Nano scale H2TiO3 adsorbent was obtained by acid-modifying adsorbent precursor Li2TiO3, which was synthesized by calcining products of hydrothermal reaction between TiO2 and LiOH·H2O. The effects of calcination time and calcination temperature on structure and ion-exchange properties were investigated via XRD, SEM and kinetic experiment. The pseudo- first and second order rate equations were used to investigate the adsorption process, and the Langmuir and Freundlich adsorption isotherm equations were fitted by the equilibrium data. The results show that the verified optimal calcination temperature and time are 773 K and 2 h, respectively. For such prepared adsorbent, the maximum adsorption capacity reaches 36.16 mg/g, the adsorption kinetic constants is 0.0339 g/(mg·h) and the extraction rate of lithium is 98.8% after 5 h. Moreover, the adsorption process obeys a pseudo-second order equation, and the equilibrium data fits well to the Freundlich model. The separation coefficient of Li+ to Mg2+ reaches 154.17.
Key words: nano scale H2TiO3; hydrothermal method; adsorption kinetics; adsorption rate constants; Freundlich equation
