失效锂离子电池焙烧及其有价金属浸出

Leaching of Valuable Metals from Calcined Spent Lithium-ion Batteries

研究了失效锂离子电池焙烧物料中有价金属的浸出行为.首先以LiCoO2,Co3O4为实验原料,与Na2SO4,K2SO4,(NH4)2SO4和浓硫酸调成浆料,在不同温度下焙烧转化,然后用热水浸出.在不同条件下,LiCoO2焙烧转化物料在水中的溶解率为56.4%～100%,Co3O4焙烧转化物料的溶解率达97.2%～100%.经测定,烘焙后LiCoO2或Co3O4转化为M2Co(SO4)2·nH2O(M=Na,K,NH4+),易溶于水.在此基础上,将失效锂离子电池与Na2SO4和浓硫酸的浆料在400℃下进行焙烧,再用70℃热水浸出焙烧产物.结果表明,Li,Co元素均可完全浸出,Cu,Al浸出率亦在99%以上.

Leaching behavior of valuable metal elements in roasted spent lithium-ion batteries was investigated.The pulp of LiCoO2 or Co3O4 mixed with concentrated sulfuric acid and one of sodium sulfate,potassium sulfate and ammonium sulfate was heated in the temperature range from 150 ℃ to 300 ℃.The cobalt-containing transformation products were then subject to dissolution in hot water.The dissolution rate of transformation products of LiCoO2-containing pulp was 56.4%～100%,and that of Co3O4-containing pulp 97.2%～100%.M2Co（SO4）2·nH2O（M=Na,K,NH4＋） phases formed in the transformation products with sodium sulfate,which were easily dissolved in hot water.Moreover,the mixture of roasted residue of spent lithium-ion batteries with concentrated sulfuric acid and sodium sulfate was heated at 400℃.All of the Li and Co elements in the mixture were leached out in hot water at 70℃,and the leaching rates of Cu and Al were greater than 99%.