高铝粉煤灰制备的高白氢氧化铝的物性分析

Analysis of physical properties of high white aluminum hydroxide prepared by high-alumina fly ash

以高铝粉煤灰烧结熟料为原料,经溶出、深度脱硅和分解(碳酸化分解或晶种分解)得到高白氢氧化铝,利用XRD、SEM和低温氮气吸附法等手段,对比了两种分解方法制得的高白氢氧化铝的物性。结果表明:种分氢氧化铝的结晶度比碳分氢氧化铝好,其晶体结构致密,晶型结构完善。氢氧化铝的等温吸附曲线属于III型,氢氧化铝以微孔为主,碳分氢氧化铝还存在一定数目的介孔和大孔。关联了碳分铝酸钠精液硅指数与高白氢氧化铝白度的关系,氢氧化铝的平均孔径和氢氧化铝吸油值的关系。

Using sintered high - alumina fly ash clinker as material, high white aluminum hydroxide was obtained after dissolution process,deep desilicationprocess and decomposition process （carbonation decomposition or seed precipitation）. Physical properties of high white aluminum hydroxide prepared bytwo decomposition methods were compared by XRD, SEM and Low -temperature nitrogen adsorption methods. Results showed that： seed precipitation alu-minum hydroxide＇s crystallinity was better than carbonation aluminum hydroxide, as well as dense crystal texture and perfect crystal structure. Aluminumhydroxide adsorption isotherm curve belonged to type ill. Aluminum hydroxide pores most belonged to mieroporous, and there were still some mesoporousand macroporeus in carbonation aluminum hydroxide. Relationships between carbonation sodium aluminate solution silicon index and high white aluminumhydrexide＇s whiteness,as well as the relationship between aluminum hydroxide＇s mean pore diameter and oil absorption value were correlated.