新型助剂在铝酸钠溶液种分过程中的性能研究

Study on the performance of new crystal growth modifier in seeding precipitation process of sodium aluminate solution

研究了一种新型助剂在铝酸钠溶液种分过程中对溶液分解率及产物氢氧化铝附聚、二次成核的影响,对其强化铝酸钠溶液分解的机理进行了探讨,并结合XRD、SEM与激光粒度分析仪对氢氧化铝晶型、晶体形貌与粒径进行分析。平行对比试验结果表明:新型助剂可以强化分解过程,相对于空白样可提高分解率5.12%,优势明显;该助剂的使用未改变产物氢氧化铝的晶型,促进了颗粒之间的交互生长,增强了附聚能力,粗化了粒径,减少了二次成核以及提高了颗粒的抗破裂能力。新型助剂较工业结晶助剂使用后,平均粒径提高了6μm。结合种分放大试验验证,认为该新型助剂在氧化铝工业上具有很好的应用前景。

The effects of a new crystal growth modifier on the seed precipitation rate of sodium aluminate solution,agglomeration and secondary nucleation of aluminum hydroxide during the seed precipitation process were studied.The mechanism of strengthening the precipitation of sodium aluminate solution was discussed.The crystal form,crystal morphology and particle size of aluminum hydroxide were analyzed by XRD,SEM and laser particle size analyzer.The results of parallel contrast test show that the new crystal growth modifier can enhance the precipitation process,and the rate can be increased by 5.12%compared with the blank sample,which has obvious advantages.The use of the modifier does not change the crystal form of the product aluminum hydroxide,promotes the interactive growth between particles,enhances the agglomeration ability,coarsens the particle size,reduces the secondary nucleation and improves the anti-cracking ability of the particles.The average particle size of the new additive increased by 6μm compared with that of the industrial crystallization additive.It is considered that the new additive has a good application prospect in alumina industry.