高溶解度聚磷酸铵的合成研究及其磷氮含量分析

Study of Synthesis of High Solubility Ammonium Polyphosphate and Analysis of Its Phosphorus and Nitrogen Content

以w(P2O5)为85%的工业级热法磷酸和工业级尿素为原料,试验研究了磷酸与尿素缩合法制备高溶解度农用聚磷酸铵的工艺条件。通过试验得到的最优工艺条件:尿素与磷酸的物质的量比为0.8,聚合反应温度为145℃,反应时间为30min。在此最优工艺条件下制得的聚磷酸铵产品在100g水中的溶解量达到160g,w(P2O5)为57.7%,w(铵态氮)为19.7%,w(酰胺态氮)为1.6%,平均聚合度为2.52。

Using w(P2O5)=85%industrial-grade thermal process phosphoric acid and industrial-grade urea as raw materials,the experimental study is conducted of process conditions for preparation of high-solubility agricultural ammonium polyphosphate by condensation of phosphoric acid and urea.The optimal process conditions obtained through the experiment are that the molar ratio of urea to phosphoric acid is 0.8,the polymerization reaction temperature is 145℃,and the reaction time is 30 min.Under the optimal process conditions,the solubility of the ammonium polyphosphate product obtained in 100 g of water reaches 160 g,w(P2O5)is 57.7%,w(ammonium nitrogen)is 19.7%,and w(amide nitrogen)is 1.6%,the average degree of polymerization is 2.52.