研究锂电池浸出液中钴、镍、锂的P507萃取分离方法,通过直接采用草酸反萃富钴有机相得到草酸钴产品.实验对含有53.8 g/L 钴的料液进行萃取.研究结果表明最佳萃取条件如下:有机相组成(体积分数)为25%P507+5%TBP+70%磺化煤油,萃取剂皂化率为70%,水相初始pH为3.5,常温下萃取10 min,有机相与水相的相比ψ(O)/ψ(A)为1.5:1.0,通过3级错流萃取,钴的萃取率达99.5%,锂和镍的萃取率仅为4.9%和3.1%:P507萃取分离钴、镍、锂过程的焓变分别为: -2.043,-0.812和1.586 kJ/mol;直接使用草酸反萃富钴有机相,得到分相良好的油一水一固3相,最优反萃工艺为:0.03 g草酸/mL富钴萃取剂,温度为40℃,ψ(O)/ψ(A)=1.0:2.5,钴的反萃率达99.5%,反萃后的萃取剂和水相均可再生循环利用.%The extraction and separation of Co, Ni and Li from Li-ion batteries powders leaching solution was carried out using P507, and cobalt oxalate was directly prepared by stripping with oxalic acid. The initial concentration of cobalt in feed solution was 53.8 g/L. The results show that the optimal extraction condition is as follows: organic phase composition of 25％ P507+5％ TBP+70％ sulfonated kerosene; saponification rate is 70％, ambient temperature equilibration time is 10 min, phase ratio Ψ(O)/Ψ(A) is 1.5:1.0 and aqueous phase pH is 3.5. In this condition, 99.5％ of Co in the solution is extracted by three-stages extraction, while the extraction efficiency of Li and Ni is only 4.9％ and 3.1％,respectively. The enthalpy of P507 extraction Co, Ni and Li is determined as -2.043, -0.812 and 1.586 kJ/mol,respectively. Oil, water and solid with good three-phase are separated by oxalic acid stripping. The optimum back extraction process is as follows: at 40 ℃, 0.03 g oxalic acid/mL co-rich extractant, andΨ(O)/Ψ(A) is 1.0:2.5. The stripping efficiency of Co reaches 99.5％. The extractant and aqueous can be recycled after stripping.
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