论文部分内容阅读
以湿法磷酸、尿素为原料制备工业级磷酸脲,再以工业级磷酸脲与聚磷酸铵晶种在一定氨及二氧化碳压力下制备高聚合度聚磷酸铵。工业级磷酸脲制备条件为:尿素与磷酸摩尔比1.05、反应温度80℃、反应时间1.0 h及冷却结晶时间2.0 h;聚磷酸铵制备适宜工艺条件为:氨气分压90 kPa、二氧化碳分压40 kPa、反应温度280℃、反应时间2.0 h,所制得聚磷酸铵的平均聚合度大于220。
The industrial phosphoric acid urea was prepared from wet-process phosphoric acid and urea, and the industrial-grade urea phosphate and ammonium polyphosphate seeds were used to prepare ammonium polyphosphate with high degree of polymerization under a certain ammonia and carbon dioxide pressure. The preparation conditions of the industrial grade urea phosphate are as follows: the molar ratio of urea to phosphoric acid is 1.05, the reaction temperature is 80 ℃, the reaction time is 1.0 h and the cooling crystallization time is 2.0 h. The suitable technological conditions for ammonium polyphosphate preparation are as follows: ammonia partial pressure 90 kPa, carbon dioxide partial pressure 40 kPa, the reaction temperature 280 ℃, the reaction time 2.0 h, the average degree of polymerization of ammonium polyphosphate obtained is greater than 220.