脲硫酸复肥新工艺减少氟逸出的研究

Study on Cutting down Fluorine Emission by the New Process of Urea Sulfate Compound Fertilizer

用脲硫酸代替硫酸分解磷矿生产复合肥 ,研究了反应温度、磷矿粉细度、搅拌强度、酸解剂配比 (尿素与硫酸、水的摩尔比 )对磷矿转化率和气相氟逸出率的影响。结果表明 ,酸解剂配比是影响氟逸出率的最主要因素 ,由于尿素的加入使氟逸出率较传统酸解磷矿减少 75 %以上。在酸解剂配比 3.6∶1∶1、反应温度 85℃、搅拌强度 4 0 0r/min、磷矿粉细度 12 0～ 15 0目条件下 ,磷矿初期分解率可达 90 %以上 ,气相氟逸出率可降至 3%左右 。

Urea Sulfate instead of sulfuric acid was used in decomposition of phosphorus rock in compound fertilizer production . The effects of reaction time , phosphorus rock size , stirring speed , formula ratio of acid splitting agents (molar ratio of urea to sulfuric acid and water) on the decomposition rate of phosphorus rock and fluorine emission rate were studied. The results show that the formula ratio of acid splitting agents is the major factor a ffecting fluorine emission rate, the emission of fluorine is reduced by 75% due to the addition of urea in comparison with traditional acid splitting process. When the molar ratio of urea/sulfuric acid/water is 3.6∶1∶1, the reaction temperature is 85℃, the stirring speed is 400 r/min, and the phosphorus rock size is 120～150 mesh, the decomposition rate of phosphorus rock is above 90%, the emission rate of fluorine in gas phase is decreased to 3%, and the content of fluorine in solid phase is not increased.