Research on the preparation process of water-soluble APP from WPA and its industrialization
Water-soluble ammonium polyphosphate(APP)is a new type of fertilizer containing nitrogen and phosphorus nutrients.It has the advantages of high nutrient content,good solubility and good chelation performance with metal ions,which can increase the content of available phosphorus in soil and thus improve the effective utilization rate of phosphorus.Ammonium polyphosphate is prepared with WPA,urea and ammonia as the main raw materials.The neutralization degree of the neutralization process,the raw material ratio,reaction temperature,and reaction time of the polymerization process were studied.The optimal process conditions are as follows:The neutralization degree of MAP slurry is 0.8,the mass ratio of MAP slurry and urea is 5∶1,reaction time is 4 hours,and reaction temperature is 200℃.Under these conditions,the water-soluble ammonium polyphosphate product obtained has a phosphorus pentoxide content of 55.19%,a nitrogen content of 17.07%,an average polymerization degree of 2.04,and a solubility of 112.4 g.Industrialization research shows that compared to using industrial ammonium phosphate as raw material,the cost of water-soluble ammonium polyphosphate produced by this process can be reduced by about 20%.This process is stable,cost-effective,and has broad application prospects.
NETL
NSTL
万方数据
