成胶条件对硫酸铝法制备拟薄水铝石性能的影响

考察了硫酸铝法制备拟薄水铝石成胶过程中pH、温度以及反应物浓度等因素对拟薄水铝石性能的影响。结果表明,不同的成胶条件对产物的物性影响较大,pH的大小决定产物的晶型,在pH为6.5～8.5可得到较纯净的拟薄水铝石,高pH下的产物是三水铝石,低pH(pH6.0)得到结晶度很低的无定形水合氧化铝;提高成胶温度,产物的比表面积以及孔容都会有明显的提高;在考察的浓度范围,改变浓度对产物的晶型影响不大,但比表面积、孔容以及平均孔径均会有所下降。在合适的成胶条件下可制得纯净的拟薄水铝石,可在一定的范围通过调节试验参数控制拟薄水铝石的堆积密度、比表面积、孔容和孔径等物化性能。

Influence of precipitation condition on properties of pseudo-boehmite prepared by aluminum sulfate method

Effects of precipitation condition （ neutralization of NaAI02 solution by Al2 （ SO4 ）3 ） , i. e. , pH,temperature and reactant concentration, on properties of pseudo-boehmite were investigated. It was shown that precipitation condition had much influence on properties of pseudo-boehmite. Pure pseudo-boehmite was obtained at pH of 6.5 - 8.5, with formation of gibbsite under higher pH and amorphous hydrated aluminum hydroxide with low crystallinity under lower pH （ 〈 6.0）. Surface area and pore volume increased with temperature. Reactant concentration had little influence on crystallinity of the products, but surface area, pore volume and pore diameter declined with reactant concentration. A variety of pseudo-boehmite with different bulk density, pore volume, surface area and pore diameter could be prepared by adjusting the parameters.