阻垢分散剂对氟硅酸钾(钠)结晶过程的影响

Effect of Scale Inhibitor-Dispersant on the Crystallization of Potassium(Sodium)Fluosilicate

在试验分析十余种阻垢分散剂及将有机膦酸和聚羧酸 (盐 )复配使用的防垢效果的基础上 ,选取效果较佳的 3种在MSMPR结晶器中研究了对Na2 SiF6 、K2 SiF6 从湿法磷酸溶液中结晶的影响。结果表明 ,所选用的阻垢分散剂均可减小晶体生长速率及平均粒径 ,但可增大晶核数密度及成核速率 ;并使晶体形态发生严重畸变 ,Na2 SiF6由八面体变为粒状及其他不规则小晶体 ,K2 SiF6 则由立方体晶体聚在一起的聚晶转为小的粒状。

The effects of 3 types of effective scale inhibitor-dispersant on the crystallization of Na 2SiF 6 and K 2SiF 6 from phosphoric acid solution are studied in a continuous MSMPR crystallizer. The results indicate that the selected scale inhibitor-dispersant can reduce the crystal growth rate and average size. At the same time can increase the population density of nuclei and nucleation rate of potassium(sodium)fluosilicate. Moreover, the crystal habit are highly modified:Na 2SiF 6 forms grain-shaped and other irregular crystals instead of hexagonal crystals, and K 2SiF 6 forms grain-shaped and small cubic crystals instead of cluster aggregated by cubic crystals.