摘要
锂是国家战略资源,盐湖锂镁高效分离是我国锂资源可持续发展的关键。以TiO_(2)和Li_(2)CO_(3)为原料,CoCl_(2)·6H_(2)O为掺杂剂,通过高温煅烧和离子交换制备了Co^(2+)掺杂的偏钛酸锂离子筛(Co-HTO)。以LiCl溶液为模拟盐湖卤水,研究了Co-HTO的提锂性能。研究结果表明,Co^(2+)掺杂后Li_(2)TiO_(3)的晶体结构和形貌均未发生明显变化,而比表面积和孔体积有不同程度地增加,表明Co^(2+)掺杂对偏钛酸锂离子筛的孔结构性质有一定影响。吸附结果表明,LiCl溶液pH越高,Li^(+)吸附容量越大。当pH=13时Co-HTO的吸附容量为39.7 mg/g。动力学实验结果表明Co-HTO锂离子筛吸附Li^(+)过程符合准二级动力学模型,属于化学吸附。升高温度有利于Li^(+)吸附,且吸附过程的ΔG^(Θ)为负值,ΔH^(Θ)为正值,表明Li^(+)吸附过程自发且吸热。吸附机理表明Co-HTO吸附锂离子主要通过离子交换完成。
Lithium is a national strategic resource,and the efficient separation of lithium and magnesium in Salt Lake is the key to the sustainable development of lithium resources in China.Co^(2+)Doped titanium lithium-ion sieve(Co-HTO)was prepared by high temperature calcination and ion exchange technology using TiO_(2)and Li_(2)CO_(3)as raw materials and CoCl 2·6H_(2)O as dopants.Taking LiCl solution as simulated salt lake brine,the lithium extraction performance of titanium lithium-ion sieve was studied.The results show that the crystal structure and morphology of Li_(2)TiO_(3)do not change significantly after Co^(2+)doping,but the specific surface area and pore volume increase to varying degrees,indicating that doping has a certain effect on the pore structure properties of lithium-ion sieves.The adsorption results show that the higher the pH of LiCl solution is,the larger the adsorption capacity of Li^(+)is.When pH=13,the adsorption capacity of Co-HTO is 39.7 mg/g.The kinetic experiment results show that the adsorption process of Li^(+)by titanium lithium-ion sieve conforms to the quasi-second-order kinetic model and belongs to chemisorption.The increase of temperature is conducive to the Li^(+)adsorption,and theΔGΘandΔHΘof the adsorption process are negative respectively,indicating that the Li^(+)adsorption process is spontaneous and endothermic.The adsorption mechanism of Co-HTO lithium-ion sieve is mainly accomplished by ion-exchange reaction.
作者
许乃才
郭松
史丹丹
刘静
王怡莹
边绍菊
XU Naicai;GUO Song;SHI Dandan;LIU Jing;WANG Yiying;BIAN Shaoju(School of Chemistry and Chemical Engineering,Qinghai Normal University,Qinghai Key Laboratory of Advanced Technology and Application of Environmental Functional Materials,Xining 810016,China;School of Ecology and Environmental Science,Qinghai University of Science and Technology,Xining 810016,China;Academy of Plateau Science and Sustainability,People’s Government of Qinghai Province&Beijing Normal University,Xining 810016,China)
出处
《应用化工》
北大核心
2025年第8期2061-2068,共8页
Applied Chemical Industry
基金
青海省应用基础研究(2022-ZJ-723)
中国科学院“西部之光”人才项目(1-13)
青海省“昆仑英才·科技领军人才”项目。
关键词
盐湖提锂
偏钛酸锂离子筛
机理
吸附
掺杂
lithium extraction from salt lake
titanium lithium-ion sieve
mechanism
adsorption
doping
