(NH_4)_2S直接沉淀法分离Li^+-Mn^(2+)中的锂和锰

The Separation of Lithium and Manganese in Li^+-Mn^(2+) System by (NH_4)_2S Direct Precipitation

以 (NH4 ) 2 S为沉淀剂 ,探讨了正尖晶石结构的 L i Mn2 O4 中锂、锰的分离和回收问题 ,重点讨论了 L i+ - Mn2 +体系的分离方法。实验以 3m ol/ L H2 SO4 溶解试样 ,以 6 % H2 O2 为还原剂将锰离子转化为 Mn2 + ,然后用 6 mol/ L NH3· H2 O调节并控制体系的 p H为 4 .2～ 6 .1,加入 1m ol/ L(NH4 ) 2 S使 Mn2 +离子沉淀完全 ,室温下过滤。分离结果表明 :硫化锰中杂质锂的摩尔百分含量为 0 .0 36 % ,滤液中杂质锰相对锂离子的摩尔百分含量为 0 .0 4 4 %。含锂的滤液和分离后的 Mn S分别以 L i2 CO3、Mn SO4 的形式回收 ,其锂、锰的一次回收率分别达到 77.89%和 97.5 6 % ,纯度分别达到 98.8%和 99.5 % ,是未来失效锂电池正极材料和锂离子筛分材料 L i Mn2 O4

Using (NH 4) 2S as precipitation agent, the methods of separation and reclamation for Lithium and Manganese in LiMn 2O 4 with spinnel structure were investigated. The separation method for Li + Mn 2+ system was discussed emphatically. In this experiment, the 3 mol/LH 2SO 4 was used to dissolve the sample. Then as reducer 6% H 2O 2 was used to transform the Mn 4+ into Mn 2+ , the 6 mol/LNH 3·H 2O was used to adjust and control the pH of system at 4.2~6.1. Finally 1 mol/L(NH 4) 2S was added to precipitate Mn 2+ completely and was filtered at room temperature. The result of separation was shown: average undesired content is 0.036% for Manganese (mol ration); 0.044% for Lithium. The filtrate containing Lithium and separated MnS were recovered in form of Li 2CO 3 and MnSO 4 respectively. The reclamation yield of Lithium and Manganese was 77.89% and 97.56%, respectively. The purity of Li 2CO 3 and MnSO 4 was achieved to 98.8% and 99.5%, respectively. It is a more reasonable method for the separation and reclamation of LiMn 2O 4 which is invalid battery and Lithium ion sieve materials.