关键词: 煤矸石;无机絮凝剂;聚硅酸硫酸铝铁;絮凝性能;工艺优化

Abstract: Using the coal gangue of industrial solid waste as raw material,concentrated industrial sulfuric acid as leaching agent,iron and aluminum were leached from coal gangue.Polymeric aluminum ferric sulfate(PAFS)formed after through to oxidation,hydrolysis and polymerization of the leaching of valuable iron and aluminum sulfate.Sodium silicate was prepared by alkali dissolution from the acid leaching residues.Afterwards,both for conducting composite copolymer to preparation a new type of inorganic flocculant-poly aluminum ferric silica sulfate(PAFSS).The effect of the copolymerization time,copolymerization temperature,PAFS/Na2SiO3 volume ratio and the mass concentration of Na2SiO3 on preparation process of PAFSS was studied based on the single factor experiment.The conditions of prepare process of PAFSS was optimized by orthogonal experimental design.The results show that the best conditions of the copolymerization time is 15 min,copolymerization temperature is 30 ℃,and PAFS/Na2SiO3 volume ratio is 4:1 and the mass concentration of Na2SiO3 is 20％,the removing rates of turbidity to reach 99.1％.The micro-morphology and phase structure of the PAFSS can be characterized by the Fourier Transform Infrared Spectroscopy(IR),X-ray Diffraction(XRD)and Scanning Electron Microscope(SEM)and other characterized method.Phase structure analysis shows the product's structure is silicon,aluminum,and iron copolymerized amorphous polynuclearhydroxy copolymer,micro-morphology analysis suggests the product's have spherical structure and a large specific surface area.

Key words: coal gangue;inorganic flocculant;flocculant-poly aluminum ferric silica sulfate;flocculation performance;process optimization