Pyrite cinders are the solid waste in the production of sulfuric acid.Using pyrite cinders to prepare high efficient flocculants is an important way because of its comprehensive utilization,which can eliminate the hazards of cinders and realize the resource generation.Polymeric aluminum ferric sulfate chloride (PAFSC) as a novel inorganic composite coagulant,was prepared by using pyrite cinders.A mixed acid (hydrochloric acid and sulfuric acid) was used to acidulate leach pyrite cinders,and then the pickle liquor was manufactured to synthesize PAFSC via hydrolization and polymerization.The results of an experimental study,using PAFSC as a composite coagulation reagent to treat wastewater,were presented.The structure and morphology of PAFSC were investigated by using some conventional methods,and were characterized by means of scanning electron microscopy (SEM),and X-ray diffraction (XRD),Fourier transform infrared spectrophotometer (FTIR).The evaluation of treatment efficiency of the coagulation-flocculation performance was brought about by measuring the reduction of turbidity and chemical oxygen demand (COD).In addition,the parameters affecting coagulation-flocculation performance,such as the coagulant dosage and wastewater initial pH,were also examined.PAFSC shows a superior coagulation-flocculation performance with the maximum COD removal efficiency of 82.4% and the residual turbidity efficiency of 99% at the coagulant dosage of 45 mg/L.Compared with polymeric ferric sulfate (PFS),the synthesized PAFSC has better coagulation-flocculation performance.