硅铁杂质对铝酸钠结晶的影响

Effects of silica and ferric oxide on crystallization of sodium aluminate

研究了SiO2和Fe2O3对铝酸钠结晶的影响,并从理论上给予了相应的解释.在其他条件不变的情况下,铝酸钠溶液中SiO2和Fe2O3浓度的提高,大大降低了铝酸钠的结晶率.当SiO2的质量浓度由0上升到20 g/L时,铝酸钠的结晶率下降了33.6%.与此同时结晶由致密变得疏松多孔;当Fe2O3的质量浓度由0上升到4 g/L时,铝酸钠的结晶率下降12.5%,结晶由致密结构经细条状逐渐变为不规则的块体.采用SEM和FTIR测试技术分析铝酸钠结晶率下降的原因是SiO2的存在改变了铝酸根离子的结构,而Fe2O3的存在增加了溶液的悬浮密度,从而使铝酸根离子不易附聚在一起,增加了铝酸钠溶液的稳定性.

The effects of silica and ferric oxide on crystallization of sodium aluminate were studied and explained theoretically in this paper. When the concentrations of silica and the ferric oxide in the sodium aluminate solution increase but other conditions remain invariable, the crystallization ratio of sodium aluminate reduces sharply, kWhen the concentration of silica increases from 0 g/L to 20g/L, the crystallization ratio of sodium aluminate drops by 33.6%, and the structure of the sodium aluminate crystal changes from compact to loose and porous. When the concentration of ferric oxide increases from 0 g/L to 4g/L, the crystallization ratio of sodium aluminate drops by 12. 5%, and the structure of the sodium aluminate crystal change from compact to leptosomatic shape and finally gradually to irregular block. By SEM and FTIR technology the reason for the dropping of the sodium aluminate crystallization ratio has been found. The existence of silica changes the structure of aluminate ion, and the existence of ferric oxide increases the suspended solid concentration in the sodium aluminate solutions. Thus the aluminate ion cant agglomerate easily and the sodium aluminate solution remains stable.