枸溶性磷淤渣综合利用实验研究

Experimental study on comprehensive utilization of citric acid soluble phosphorus sludge

旨在将生产工业磷酸一铵(MAP)产生的磷淤渣中的硫、镁和磷高效分离利用,同时去除杂质离子。通过对磷淤渣进行酸浸、脱氟、冷却结晶、除杂和氨化等制备硫酸铵镁和硫基磷铵。研究表明,当酸浸液脱氟后加入氨水调节pH至0.85时,经冷却结晶硫酸铵镁的产率可达62%;在冷却结晶硫酸铵镁后的滤液中加入氨水调节pH至2.6,滤液中的杂质三氧化二铁(Fe_(2)O_(3))、氧化铝(Al_(2)O_(3))、氧化镁(MgO)质量分数分别降低至0.08%、0.58%、0.93%,向除杂后的滤液中通入氨气并控制pH=9,经浓缩、干燥可得到硫基磷铵,硫基磷铵的总氮质量分数≥16%、有效磷质量分数≥26%、总硫质量分数≥11%、水溶性磷占有效磷质量分数≥75%以上。通过这种途径实现磷淤渣的高效利用更加绿色环保。

The purpose was to efficiently separate and utilize sulfur,magnesium and phosphorus from waste phosphorus sludge produced in the production of industrial monoammonium phosphate(MAP),while removing impurity ions.Magnesium ammonium sulfate and ammonium phosphate sulfate were prepared by acid leaching,defluorination,cooling crystallization,impurity removal and ammoniation of waste phosphorus sludge.The research showed that when the acid leach solution was defluoridated and the pH was adjusted to 0.85 by adding ammonia,the yield of crystallized magnesium ammonium sulphate by cooling could reach 62%.When the pH was adjusted to 2.6 by adding ammonia to the filtrate after cooling crystallized magnesium ammonium sulphate,the mass fraction of impurities Fe_(2)O_(3),Al_(2)O_(3)and MgO in the filtrate was reduced to 0.08%,0.58% and 0.93% respectively.When ammonia was introduced into the filtrate after the removal of impurities and pH was adjusted to 9,sulfur‑based ammonium phosphate was prepared after concentration and drying,and sulfur‑based ammonium phosphate's total nitrogen content was≥16%,effective phosphorus content was≥26%,total sulfur content was≥11%,water‑soluble phosphorus percentage of effective phosphorus was≥75% or higher.In this way,the efficient utilization of waste phosphorus sludge was realized,which was more green and environmentally friendly.