Preparation of Polymeric Aluminum Ferric Chloride by Using Modified Bayer Red Mud

Using the modified Bayer red mud as raw material,a high efficient flocculant,polymeric aluminum ferric chloride(PAFC) was prepared using acid leaching process,and the optimal conditions of the acid leaching process were explored.The results show that the optimal conditions are as follows: the concentration of hydrochloric acid is 6 mol/L,the ratio of hydrochloric acid to modified Bayer red mud is 3 ∶1,the reaction temperature is 95 ℃ and the reaction time is 1.5 h.The flocculation performance of PAFC is better than that of PFS and PAC,and it has larger and dense flocs,fast settling velocity,good turbidity removal effect.This process opens a new way for comprehensive utilization of Bayer red mud,and it has good market prospects and social benefits.