ALUMINA

摘要

A supersaturated solution of ground bauxite and caustic soda is fed to a plurality of stirrer tanks in a product cascade. Each of these stirrer tanks of the product cascade has three vertically spaced zones with differing solid contents, a central vertical shaft and at least three vertically spaced paddles carried on the shaft and each extending into a respective one of the zones. The paddles are so constructed as to differently act on the solid in dependence upon the solid contents in each zone.