Process for neutralizing bauxite dissolution residual substance and process for producing aluminum hydroxide

Abstract

A process for neutralization is provided which can maintain a high solid content of a bauxite dissolution residual substance slurry even after a neutralization treatment is completed and the stabilize pH within a short time of the neutralization treatment. Such a process for neutralizing a bauxite dissolution residual substance containing a desiliconizing product which is generated in the production process of aluminum hydroxide using Bayer process, includes: mixing a bauxite dissolution residual substance or a bauxite dissolution residual substance slurry with sulfuric acid in an amount ranging from 0.6 to 1.2 equivalence to the total amount of sodium contained in the bauxite dissolution residual substance or a bauxite dissolution residual substance slurry, such that the solid content after mixing becomes 400 to 700 g/l to gelate the mixture, and thereafter obtaining a bauxite dissolution residual substance neutralized slurry.

Dependencies are inferred from the claim text.