草酸盐对水合铝硅酸钠析出行为的影响

Effect of oxalate on precipitation behavior of sodium aluminosilicate hydrate

系统研究了在145℃下不同草酸钠浓度对脱硅产物水合铝硅酸钠的粒度分布、微观结构和析出活性的影响规律.结果表明,随着铝酸钠溶液中草酸钠浓度的升高,水合铝硅酸钠的粒度逐渐细化;草酸钠增加了水合铝硅酸钠"毛线团"形晶粒的圆片状结构的厚度,并提高了其团聚程度;草酸钠不改变脱硅产物的物相组成,但使沸石含量降低,方钠石含量升高,同时降低了沸石和方钠石的结晶度,最终提高了水合铝硅酸钠的析出活性.

Efects of different concentrations of sodium oxalate on particle size distribution, microstructure and precipitation activity of sodium aluminosilicate hydrate were studied. The results showed that with increase of oxalate concentration in sodium aluminate solution, particle size of sodium aluminosilicate hydrate is gradually refined. Sodium oxalate can increase thickness of the disc structure of sodium aluminosilicate hydrate with wool - like grains and improve degree of aggregation. Sodium oxalate does not change the phase composition of desilication products, but decreases zeolite content and increases sodalite content; it also reduce crystallinity o f zeolite and sodalite, and finally increases precipitation activity of sodium aluminosilicate hydrate.