FREE ACID-REMOVING EQUIPMENT, FREE ACID-REMOVING METHOD, AND METHOD FOR MANUFACTURING MIXED NICKEL AND COBALT SULFIDE

摘要

Provided is a method, in preliminary neutralization of leach slurry generated in a hydrometallurgical process for nickel oxide ore, that is capable of promoting precipitation of iron contained in said leach slurry and limiting increases in turbidity of the overflow liquid obtained in solid-liquid separation of the leach slurry. This free acid-removing method for performing neutralization by adding a neutralizing agent to leach slurry obtained by high pressure acid leaching of nickel oxide ore and removing free acid contained in the leach slurry: uses at least two reaction tanks; adds the neutralizing agent divided between the two or more reaction tanks in multiple stages; and performs neutralization of the leach slurry continuously.