Abstract: A method for neutralizing a sulfuric acid solution containing predominantly Zn ion, comprising adding, to the sulfuric acid solution, at least one compound selected from the group of chlorine-containing compounds of Na ion, K ion, Mg ion, Ca ion, and NH.sub.4 ion in an amount at least chemically equivalent to SO.sub.4 ion contained; and then bringing the sulfuric acid solution into contact with an organic solvent composed of one or more species selected from the group of oxygen-containing organic solvents and alkylamine organic solvents to extract Zn ion from the sulfuric acid solution as a chloride complex to the organic solvent. The sulfuric acid solution after extraction of Zn ion is further treated by addition of an oxidizing agent or by an electrochemical means to convert Fe.sup.2+ into to Fe.sup.