METHOD FOR NEUTRALIZING BAUXITE DISSOLUTION RESIDUAL SUBSTANCE AND METHOD FOR PRODUCING ALUMINUM HYDROXIDE

摘要

PPROBLEM TO BE SOLVED: To provide a method of neutralization which can maintain a high solid content of a bauxite dissolution residual substance slurry even after a neutralization treatment is completed, and which stabilizes pH early within a short time of the neutralization treatment. PSOLUTION: The method for neutralizing a bauxite dissolution residual substance containing a desiliconizing product 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; then gelling the mixture; and thereafter obtaining a bauxite dissolution residual substance neutralized slurry. PCOPYRIGHT: (C)2009,JPO&INPIT