湿法磷酸装置扩能技改

Capacity Expansion Revamp for A Wet Phosphoric Acid Plant

利用絮凝剂的凝聚作用 ,在湿法磷酸装置中增设絮凝系统 ,把絮凝剂加入磷酸料浆中 ,使磷石膏结晶聚凝、长大 ,大大提高了真空过滤机的过滤能力 ;并辅以对硫酸加料方式的改进 ,在磷酸反应槽低位真空冷却移走料浆热量的流程中 ,硫酸加料采用多点雾化的方法 ,以消除局部过饱和 ;对稀酸 (过滤级磷酸 )贮槽底部的淤浆用于生产MAP。达到了装置能力从 30 0kt/a提高至 4 0 0kt/a(P2 O5计 ) ,其特点是投资少、扩能措施简便 ,经济效益显著。

Flocculating system is added in the wet phosphoric acid plant to utilize the flocculating effect of the flocculant, which is added in the phosphoric acid slurry to facilitate the crystallization, coagulation and growth of ardealite and the filtering capacity of the vacuum filter is significantly increased; with the improvement of sulfuric acid feeding method, multipoint spraying of sulfuric acid is used in the flow of slurry heat transfer by the coarse vacuum cooler at the phosphoric acid reactor so as to eliminate local supersaturation; slurry at the bottom of diluted acid (filtration grade phosphoric acid) storage tank is used for production of MAP. The plant capacity is updated from 300 kt/a to 400 kt/a (as P_2O_5), which features less investment, easy measures for capacity expansion and significant economic benefit.