EFFECT OF ORGANICS ON THE SEPARATING EFFICIENCY OF FLOCCULATES IN RED MUD SEDIMENTATION

摘要

Adding flocculates is an important method to facilitate the separation of red mud slurry in an alumina refinery, while the existence of organics will disturb their separating efficiency. The effect of seven organics (yellow humic acid, black humic acid, benzenedicarboxylic sodium, phenol, oxalic sodium, formic sodium and acetic sodium) on overflow clarity, underflow L/S and sedimentation rate in the red mud separation procedure by using three anionic flocculates such as A-600, HPAM, PAS-1 and one nonionic flocculate (PAM) had been researched in this paper. It is illustrated that different organics have distinct influences on results, but most of them significantly decrease the separating efficiency of flocculates. The optimum concentration of flocculates in liquors increases with rising organics and the negative effect of organics cannot be eliminated when its content is higher than a certain value, which is different for every organic. However, A-600 has best separating effect for all experiments while the effect of nonionic flocculate PAM is indistinctive.