聚结现象常常伴随着反应结晶过程发生,是影响产品粒度、形貌等性状的主要因素之一。围绕磷酸氢钙的聚结现象分析了聚结发生的过程步骤,并探究了工业生产中阻碍聚结现象的主要杂质元素。结果表明,以纯净稀磷酸为原料,可制得粗大、均匀、稳定性好的大颗粒磷酸氢钙产品,这种大尺寸聚结体经历了单晶团聚、小尺寸簇状晶聚结、大尺寸簇状球形晶形形成等3个关键生长步骤。结晶母液中含氟元素胶体微粒隔断聚结第二步的发生,成为阻碍聚结现象的最关键因素。探索合理利用聚结现象的工艺方法,将为饲料级磷酸氢钙工业生产中解决过滤难、干燥成本高等问题开辟新思路。

Agglomeration phenomenon often occurs in the reaction crystallization process,which is one of the main factors af-fecting the particle size,morphology and other properties of the product.Focusing on the agglomeration phenomenon of calci-um hydrogen phosphate,the process steps of agglomeration were analyzed,and the main impurities that hinder the agglomera-tion in industrial production were explored.The results showed that large,uniform and stable calcium hydrogen phosphate particles were obtained by using pure dilute phosphoric acid as raw material.The large-size aggregates undergone three key growth steps: single crystals agglomeration,small-size cluster crystals agglomeration and large-size cluster spherical crystal morphology formation.The colloidal particles containing fluorine in crystallization mother solution blocked the second step of agglomeration and became the most important factor to prevent agglomeration.Exploring the technological method of rationally utilizing the agglomeration phenomenon will open up a new way to solve the problems of difficult filtration and high drying cost in the industrial production of feed-grade calcium hydrogen phosphate.