添加剂对铝酸钠溶液晶种分解过程附聚及二次成核的影响

Effects of additives on agglomeration and secondary nucleation in seed precipitation in sodium aluminate solution

研究了添加剂I3、I32和I33对铝酸钠溶液分解过程附聚和二次成核的影响,探讨了其作用机理,并利用电子显微镜(SEM)对产品的结晶形貌进行了观察.结果表明,添加剂的应用促进了不同颗粒间附聚的进行,提高了附聚颗粒的临界半径,并有效抑制了二次成核的发生.添加剂I33在40ml·L-1时,附聚产物小于30μm的细粒子个数分数降低26.1%,平均粒度增加21.08μm(相对空白样).晶体形貌分析表明,添加剂促进了晶体间的交互生长.

In order to stabilize the particle size of Al（OH）3 production in sodium aluminate solution, a systematic study of the effects and mechanism of additives on agglomeration and nucleation in seed precipitation was made. The result indicated that some appropriate additive at certain concentration could significantly decrease the fine particle content, enhance the agglomeration process, and effectively restrain the secondary nucleation process. For instance, additive I33 at 40 ml·L^-1 decreased the content of particles less than 30 μm by 26.1% and increases the mean particle size by 21.08μm. The crystal morphology showed that the additives could accelerate the inter-growth of crystals.