硫酸铝低温水解产物特性及其动力学研究

Hydrolytic kinetics and characteristics of aluminum sulfate of hydrolysis products at low temperature

以十八水硫酸铝为沉淀前驱剂,碳酸钠为沉淀剂研究硫酸铝水解动力学,并采用X射线衍射(XRD)、傅立叶变换红外光谱(FT-IR)、热重分析(TGA)和扫描电子显微镜(SEM)综合分析硫酸铝水解产物物相和形貌。结果表明,硫酸铝与碳酸钠反应过程动力学方程符合一级反应速率方程;T≤75℃硫酸铝水解产物为无定型团聚氢氧化铝;氢氧化铝生成过程为:[Al(OH2)6]3+→[Al(OH)(OH2)5]2+→[Al(OH)2(OH2)4]+→[Al(OH)3(OH2)3]。

Hydrolytic kinetics of aluminum sulfate was investigated by one-pot precipitation method using sodium carbonate and Al 2(SO 4)3·18H 2O as precipitator and precipitate precursor agents respectively.Simultaneously,the phase and morphology of the hydrolyzate of aluminum sulfate was analyzed synthetically by X-ray diffraction(XRD),fourier transform infrared spectroscopy(FT-IR),thermo gravimetric analysis(TGA)and scanning electron microscopy(SEM).The results shown that,the kinetic equation of the reaction of aluminum sulfate and sodium carbonate followed the first order reaction rate equation.Furthermore,the aggregated and amorphous aluminum hydroxide was obtained when the hydrothermal temperature was less than or equal to 75℃.The production process for aluminum hydroxide is:[Al(OH 2)6]3+→[Al(OH)(OH 2)5]2+→[Al(OH)2(OH 2)4]+→[Al(OH)3(OH 2)3].