响应面法优化超声辅助煤矸石制备聚硅酸氯化铝及机理研究OA

Coal gangue is rich in silicon and aluminum elements and is an ideal raw material for the preparation of the flocculant polyaluminium silicate chloride(PASC).Using PASC prepared from coal gangue to treat coal slime water can achieve the purpose of using waste to treat waste.How-ever,the current process for preparing PASC from coal gangue still has the problem of a long process-ing time.In this study,coal gangue was utilized as the primary raw material for the synthesis of PASC1 via ultrasonic-assisted acid leaching.The synthesis parameters were systematically optimized using a combination of single-factor experiments and response surface methodology to determine the optimal conditions for the preparation process.Subsequent analyses of the physicochemical properties and microstructure of PASC1 revealed significant enhancements in performance metrics.Optimal con-ditions are identified as an ultrasonic temperature of 32 ℃,ultrasonic duration of 17 min,and an acid dosage of 1.42,corresponding to the mass ratio of HCl to the roasted product,with an acid leaching temperature of 45 ℃ and duration of 40 min.Under these conditions,the PASC1 achieves a turbidity removal efficiency of 99.59%in treating coal slime water.Compared to traditional acid leaching meth-ods,the optimized process not only reduces processing time but also improves the flocculation effi-cacy,evidenced by increased molecular weight and a more uniform molecular weight distribution of the flocculant.Characterization tests confirmed that PASC1 is an amorphous polymer,arising from the complexation of polysilicic acid with Al3+and its hydrolysis products.The surface of PASC1 dis-plays a distinctive structure characterized by overlapping,extended,and porous features,conducive to the flocculation mechanisms of adsorption bridging,net capturing,sweeping,and charge neutraliza-tion,facilitating the sedimentation of suspended solids and colloidal particles in coal slime water.