Effect of SO42-on product quality of water-soluble APP production
The effect of phosphoric acid with different contents of SO42-on the synthesis of APP is simulated by adding sulfuric acid.The experiment mainly included pre-neutralization reaction and polymerization reaction,and the reaction conditions are reaction temperature 120-160 ℃,slurry specific gravity≤1.75 g/mL,slurry neutralization ≤1.0(mol/mol).The volume ratio of liquid urea and ammonium phosphate slurry is 0.48:1.00,material temperature of polymerization stage is 140-250 ℃,polymerization time is 60-180 min.The results show that:With the introduction of SO42-,the total nutrient of the product decreases,when the mass fraction of SO42-＞10％,the product begins to be cloudy and the water solubility of the product becomes worse.Moreover,the content of phosphorus in polymerized states of trimerization and above decreased obviously.
SO42-water-soluble ammonium polyphosphate(APP)nutrientphosphorus form
NETL
NSTL
万方数据
