And the higher feed molar ratio zone, NH?4HCO?3/YCl?3 larger than 3, is the probable crystallization zone, fish scales bright slice praseodymium carbonate crystal can be obtained by aging a long time.

• 在高配比区域(NH4HCO3/PrCl3的摩尔比大于3)为碳酸镨的可结晶区域,延长陈化时间可以得到鱼鳞片状的亮晶产物;