从废旧三元锂离子电池中回收有价金属的新工艺研究

New Process to Recover Valuable Metals from Spent Ternary Lithium-Ion Batteries

废旧三元锂离子电池经过放电、焙烧、破碎、筛分等预处理方法分离出电池活性物质、集流体与钢壳,再采用H_2SO_4-Na_2SO_3对废电池粉料(活性物质)进行浸出,浸出液调节pH至4.5,过滤以除去铁和铝,滤液再调pH至11左右,将锂和镍钴锰分离,得到的锂液经过浓缩后加入Na_2CO_3得到工业级的LiCO_3,在镍钴锰富集物中加入氨水将锰和镍钴分离,最后使用P507分离镍和钴,在相比O/A=1,平衡pH=4.5,有机相组成为25%P507+75%溶剂油,经二级逆流萃取后钴的萃取率为99.3%。使用200g/L硫酸为反萃剂,相比为5时,钴的回收率达99.21%。反萃液使用草酸铵沉钴,萃余液中的镍采用氢氧化钠沉淀,整个工艺流程中钴的回收率为91.82%,镍的回收率为91.12%。

Spent ternary lithium-ion batteries were pre-treated by discharge,roasting,crushing and sieving to separate active materials,current collectors,and battery can.Spent battery powders（active materials）were leached by H_2SO_4-Na_2SO_3.Al^（3＋） and Fe^（2＋） were removed from lixivium by adjusting pH value to 4.5.Lithium was separated from filtrate with nickel,cobalt and manganese by adjusting pH value to about 11.Industrial grade Li_2CO_3 was obtained from lithium-bearing solution by concentration and addition of Na_2CO_3.Manganese was separated from nickel,cobalt and manganese concentrates with addition of ammonia.Nickel and cobalt can be separated by solvent extraction with P507.Two-stage counter-current extraction rate of cobalt is 99.3% under the conditions including O/A=1,equilibrium pH value of 4.5,and organic phase of 25%saponified P507＋75% miscella.Cobalt stripping rate is 99.21% under O/A=5 and 200 g/L sulfuric acid.Cobalt was chemically deposited by oxalate from strip liquor.Nickel in raffinate was precipitated by sodium hydroxide.Recovery rate of cobalt and nickel in whole process is 91.82%and91.12%respectively.