饲料级磷酸氢钙结晶过程中团聚的研究

在反应结晶过程中，一般过饱和度很大，很容易形成大量细小颗粒，这些小颗粒相互作用形成团聚体，会影响最后产品的粒度分布、纯度、晶体形貌、堆密度等参数。饲料级磷酸氢钙生产过程中极易形成团聚体，通过探索团聚体形成的pH范围，对团聚体形成的原因做了分析，并研究了中和条件对团聚形成的影响。结果表明，形成团聚体的pH范围为2.82~3.60。此外，提高反应温度、增加搅拌速度均对团聚体有减缓效果。实验最后建立了磷酸氢钙团聚尺寸模型。

Study on agglomeration in crystallization process of feed-grade calcium hydrogen phosphate

Supersaturation is generally quite large in the process of reactive crystallization，a large number of tiny particles will emerge.Agglomeration will be formed because of the interaction between these tiny particles，affecting parameters，such as crystal size distribution，purity，crystal morphology, and tap density，of final product.Agglomeration can be easily found in the preparation of feed-grade calcium hydrogen phosphate.The pH range of agglomeration formed and the forming reasons were explored and analyzed.Some neutralization conditions affecting calcium hydrogen phosphate agglomeration were studied.Results showed that agglomeration formed at pH of 2.82~3.60，and raising temperature and stirring speed will reduce agglo- meration.Finally，an agglomeration-size model was established.