杂质对磷酸脲结晶的影响

采用间歇结晶法考察了杂质Al3+、Fe3+、F-、Mg2+、SO24-对磷酸脲结晶收率、析晶时间、产品粒度、晶体形态等的影响。结果表明,Al3+、Fe3+对磷酸脲结晶过程影响显著,若无晶种加入,体系降至常温仍无晶体析出;向反应体系中加入其质量1%的晶种时,随着掺杂Al3+、Fe3+质量分数的增加,磷酸脲收率逐渐下降,析晶时间显著延长,磷酸脲粒度显著减小,产品晶形不规则,晶体聚集明显,Al3+的影响比Fe3+略大;随着掺杂F-质量分数的增加,磷酸脲收率逐渐增大,析晶时间无明显变化,粒度先逐渐减小,后因小颗粒间相互嵌入聚集导致表观粒度逐渐增大,产品晶形不规则;掺杂Mg2+、SO42-后磷酸脲晶体规则,晶形仍为棱柱状,颗粒分散性好。

Effect of impurity on the crystallization of urea phosphate

The effect of such impurities as ions Al3+,Fe3+,F-,Mg2+ and SO2-4 on the crystallization yield of urea phosphate(UP),its crystallization period,product size and crystal morphology was studied by means of batch crystallization process.The results show that the dopant of Al3+,Fe3+ had significant effect on UP crystallization process,and without the crystal seed added into the reaction system,no crystals separated out when the system was cooled to normal temperature.Under the condition of 1% crystal seed added...