| abstract |
[PROBLEMS] To completely separate nickel and cobalt as valuable metals and phosphorus and fluorine as impurities, and to reliably recover impurities and prevent an increase in impurity load in waste water. Provided is a method for recovering valuable metals from a lithium ion battery, that is, a waste lithium ion battery. A valuable metal-containing material obtained from a waste lithium ion battery is dissolved in an acidic solution and then separated into a leaching solution and a leaching residue, and the leaching solution obtained in the leaching step S11. The neutralization step S12 is performed by adding a neutralizing agent to separate the neutralized final solution and the neutralized starch, and the neutralized final solution obtained in the neutralizing step S12 is subjected to solvent extraction with an acidic extractant. Solvent extraction step S13 for obtaining an organic solvent and an extraction residual liquid after extraction, and back extraction for obtaining a back extract by back extracting the organic solvent after extraction obtained in the solvent extraction step S13 with a sulfuric acid solution Including step S14, each step is adjusted to a predetermined pH value range, and each step is sequentially performed. [Selection] Figure 1 |