二水磷酸铁间歇及连续结晶过程研究

Intermittent and Continuous Crystallization Processes of FePO_(4)·2H_(2)O

开展了控制结晶合成FePO_(4)·2H_(2)O的工作,重点研究了全间歇、半间歇、半连续、全连续结晶四种结晶方式对产品Fe/P、粒度和形貌的影响规律。结果表明,全间歇或半间歇结晶得到亚稳态晶型FePO_(4)·2H_(2)O,属单斜晶系,产品的Fe/P存在批次间差异性,而粒度和形貌基本稳定。另外,半连续或全连续结晶过程存在转晶现象,最终得到热力学稳定构型FePO_(4)·2H_(2)O,属正交晶系,批次间产品Fe/P、粒度和形貌具有一致性。

The crystallization of iron phosphate dihydrate was carried out,and the effects of four kinds of crystallization methods of intermittent crystallization,semi-intermittent crystallization,semi-continuous crystallization and continuous crystallization on Fe/P,crystal size and morphology of the product were comprehensively investigated.Results indicate that metastable monoclinic FePO_(4)·2H_(2)O is obtained via intermittent crystallization or semi intermittent crystallization.It shows the difference between batch products,though the crystal size and morphology are basically consistent.Besides,the thermodynamically stable orthogonal FePO_(4)·2H_(2)O is obtained in the process of semi continuous crystallization and continuous crystallization through polymorph transformation.It shows the similar Fe/P,crystal size and morphology between batch products.