固相法合成磁性可回收锰系离子筛及其锂吸附性能研究

Facilesynthesis of magnetically recyclable manganese ion sieve using solid state reaction method and its lithium adsorption performance

以LiOH·H2O、MnO2、Fe2O3为原料,通过固相法合成具有亚铁磁性尖晶石型Li1.33Mn1.67-xFexO4,经酸洗后制备得到磁性可回收锂离子筛。重点考察了合成过程中煅烧温度、煅烧时间及不同铁掺杂量对合成的锰系锂离子筛吸附性能及其溶损的影响。结果表明:随着煅烧温度及时间的增加,吸附容量及锰溶损均逐渐减小;铁的掺杂可以有效降低锰溶损,但随着掺杂量的增加,锂吸附容量在减小。当铁掺杂量控制在0.05,煅烧温度和时间分别为450℃、6 h时合成的离子筛锂的吸附容量为25.2 mg/g,一次吸-脱附Mn溶损降低为0.69%,且在外加磁场的作用下能实现快速回收利用。经5次循环利用后,锂的吸附容量仍保持在18.8 mg/g。

Using LiOH·H2O,MnO2 and Fe2O3 as raw materials,spinel Li1.33Mn1.67-xFexO4 with ferromagnetic properties were synthesized by the solid state reaction method,and magnetically recyclable Fe-doped lithium ion sieves were prepared after acid solution treatment.The effects of calcination temperature,calcination time and iron doping amounts on the adsorption performance and dissolution loss of as-synthesized manganese-based lithium ion sieves were systematically investigated.The results show that as the calcination temperature and time increased,both adsorption capacity and manganese dissolution loss of as-prepared lithium ion sieves gradually decreased.Iron doping could effectively reduce the manganese dissolution loss,however,the lithium adsorption capacity decreased with the iron doping amount increasing.When the calcination temperature and time were 450℃and 6 h respectively,the adsorption capacity of the as-synthesized lithium ion sieve with the iron doping amount of 0.05 was 25.2 mg/g,and the Mn dissolution loss decreased from 6.8%to 0.69%.The as-prepared lithium ion sieve could be separated and recycled under external magnetic field,and the adsorption capacity could remain 18.8 mg/g after five cycles.