多孔陶瓷基锂离子吸附剂的制备及性能研究

Preparation and adsorption performance of porous ceramic-based lithium ion adsorbent

采用溶胶-凝胶法在不同条件下制备Li_4Ti_5O_(12),通过XRD分析寻找出制备Li_4Ti_5O_(12)的理想条件.将高岭土、滑石粉、氧化铝和碳粉制备的多孔陶瓷在前驱体溶胶中进行浸渍负载,经干燥、煅烧制备得到多孔陶瓷基Li_4Ti_5O_(12),进行酸改性得到锂离子吸附剂,测定其对Li^+的吸附容量.实验结果表明,在一定范围内提高煅烧温度和增加保温时间有利于Li_4Ti_5O_(12)的生成,在750~800℃下保温5~8h得到的产品结晶度好、晶相纯度高.洗脱率和吸附容量随着煅烧温度和保温时间的增加而增加,在800℃下保温5h得到的样品经过酸洗后洗脱率为51.7%,对Li^+的吸附容量为12.2mg Li+/g Li_4Ti_5O_(12).

Li4Ti5O12 was synthesized by the sol-gel process under different conditions, and the as-pre- pared products were characterized by XRD in order to find out the ideal condition of preparing Li4Ti5O12. The precursor sol was loaded on porous ceramics synthesized from kaolin, talcum powder, a- lumina and carbon powder, and then Li4Ti5O12 based on porous ceramics was prepared after drying and calcination. Subsequently, porous ceramic-based lithiumion adsorbent was obtained by modification with hydrochloric acid, and then adsorptive capacity of the obtained product was measured. The results indi- cate that increasing calcination temperature and holding time is beneficial to the formation of Li4Ti5O12. The products with good crystallinity and purified crystal phase are obtained after a calcination at 750- 800℃ for 5 - 8 h. The extraction rate of Li＋ from Li4Ti5O12 and the adsorptive capacity are increased with the increment of calcination temperature and holding time. The Li＋ drawn out ratio of the products calcined at 800 ℃ for 5 h is 51.7%, and the adsorptive capacity reaches 12.2 mg Li＋/g Li4Ti5O12.