Preparation and Application of Polymeric Aluminum Ferric Chloride with Red Mud

The research focused on a new technology of preparing a new complex wastewater coagulant,polymeric aluminum ferric chloride(PAFC),with red mud from aluminum-making factory.Extraction efficiency of iron and aluminum oxides from red mud was affected by the liquid-solid ratio,reaction temperature and immersed time,which were 3.5∶1,80 ℃,1.5 h,respectively.According to some experiments,the optimum conditions of synthesizing PAFC were summed up,the Al/Fe molar ratio,temperature,reaction time were 1∶1,60 ℃,1.0 h,respectively.Some flocculation experiments showed that the produced complex coagulant was proven to be effective in removing turbidity,chroma and COD in wastewater.Under the conditions of PAFC 0.80 mL·L-1,sedimentation time 30 min,pH 6~7,the high efficiency of removing turbidity,chroma,COD can reach to 69 %,85 %,70 %,respectively.