Neutralization method and nickel oxide ore hydrometallurgical method

摘要

Provided is a method capable of improving the settleability of neutralization precipitate, generated by neutralization, and of reducing floating particles in the supernatant after solid-liquid separation, and also capable of reducing filtration load. This neutralization method is a neutralization method for generating a neutralization slurry by adding a calcium-containing neutralizing agent to a sulfuric acid acidified solution to adjust the pH, and separating the neutralization precipitate from the post-neutralization liquid. Iron oxide in an amount corresponding to 200 weight%-500 weight% of the amount of neutralization precipitate generated is added to the sulfuric acid-acidified solution that is being treated. The acidic solution is the leachate obtained by performing leaching using sulfuric acid on nickel oxide ore in a nickel oxide ore hydrometallurical method. For the iron oxide, the leaching residue generated by said leaching can be used.