Solutions for Red Mud Sedimentation & Washing in Alumina Production

In alumina production, slow red mud sedimentation, insufficient underflow density, high suspended solids in supernatant and excessive alkali loss will lead to unstable chemical costs.

We optimize both products and production processes. Customized anionic polyacrylamide with targeted molecular weight is used before leaching to improve sedimentation efficiency, increase underflow density and reduce suspended solids. Ultra-high molecular weight PH-resistant flocculants are applied after leaching to stabilize the clear liquid layer in washing tanks, enhance washing efficiency and reduce alkali loss.

Case: After implementation in a large domestic alumina plant, the clear liquid layer of sedimentation tank rose from 6 meters to 7 meters, the overall sedimentation efficiency was doubled and system capacity increased by 16%. The alkali consumption was well controlled by regulating underflow solid-liquid ratio and clear liquid height.