Solvent extraction method using two-stage extraction for separation and recovery of nickel, cobalt, and manganese

A solvent extraction method using two-stage extraction for separation and recovery of nickel, cobalt, and manganese, the method comprising:

• preparing a raw material leachate containing nickel, cobalt, and manganese;
• separating the manganese contained in the raw material leachate as a manganese sulfate aqueous solution;
• and
• separating the nickel and the cobalt contained in the raw material leachate from which the manganese is separated as a nickel sulfate aqueous solution and a cobalt sulfate aqueous solution, respectively;
• wherein three types of valuable metals comprising the nickel, the cobalt, and the manganese are individually separated and recovered, and
• wherein the separating the manganese comprises:
• adding the nickel sulfate aqueous solution to a first solvent to generate a manganese extracting solvent;
• adding the raw material leachate to the manganese extracting solvent to separate the manganese extracting solvent into a first organic phase solution containing nickel, cobalt, and manganese and a first aqueous phase solution containing nickel and cobalt;
• separating the first organic phase solution into a second organic phase solution containing manganese and a second aqueous phase solution containing nickel and cobalt;
• back-extracting the manganese remaining in the second organic phase solution to separate the second organic phase solution into a third organic phase solution not containing manganese and a third aqueous phase solution containing manganese, thereby obtaining a manganese sulfate aqueous solution from the third aqueous phase solution;
• and
• back-extracting impurities contained in the third organic phase solution to separate the third organic phase solution into a fourth organic phase solution not containing impurities and a fourth aqueous phase solution containing the impurities.