Abstract: Taking Guangxi karst accumulative bauxite tailings as raw materials，a systematic study on the technical conditions for the preparation of poly aluminum ferric sulfate（PAFS） by rational acid leaching of aluminum and iron is carried out.Through the turbidity and COD removal tests，the flocculation performance of self-made PAFS and polymer aluminum sulfate（PAS) at market is compared.The results show that the PAFS has a better performance in turbidity and COD removals than PAS.Therefore，the widespread application of this technique can not only make full use of resources and promote resources recovery，but also systematically find a way to deal with the tailings.

Key words: Karst accumulative bauxite, Washed tailings, Acid leaching, Poly aluminum ferric sulfate