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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。
The effects of Al3 +, Fe3 +, F-, Mg2 + and SO24- on the crystallization yield of urea phosphate, crystallization time, product size and crystal morphology were investigated by batch crystallization method. The results showed that Al3 + and Fe3 + had a significant effect on the crystallization process of Urea Sulfate. When the seed crystals were added without adding seed crystals, the system did not crystallize out at room temperature. When 1% seed was added to the reaction system, with the addition of Al3 + and Fe3 + With the increase of mass fraction, the yield of urea phosphate decreased gradually, the crystallization time was significantly prolonged, the particle size of urea phosphate was significantly reduced, the crystal form of product was irregular and the crystal was obviously aggregated. The effect of Al3 + was slightly larger than that of Fe3 + , The yield of urea phosphate increased gradually, the crystallization time did not change obviously, the particle size decreased first, then the apparent particle size gradually increased due to the intercalation and aggregation of small particles, and the crystal form of the product was irregular. The Mg2 +, SO42 - Urea phosphate postcrystal rules, the crystal is still prismatic, good particle dispersion.