Abstract:Satisfactory results are obtained when the mid-Qian sedimentary diasporic bauxite is subjected to Bayer digestion at 245~280℃with the addition of certain amount of lime. The conditions influencing the digestion process, according to their importance, are as follows: temperature, caustic soda concentration of starting liquor, residence time and burden molar ratio, etc. Conditions for both traditional and tube digestions have been determined. Adding excessive lime and adopting single-stream tube digestion technology are of great advantage for retarding velocity of scale growth on the surface of heat exchangers and for treating and utilizing red mud etc. in the meanwhile.

Key words: bauxite　lime　tube digestion　scale