湿法磷酸生产新工艺开发研究

Development on New Process of Wet Process Phosphoric Acid Production

为提升湿法磷酸生产工艺水平,提高副产磷石膏的品质,减少湿法磷酸生产固废排放量及堆存产生的经济压力和环境风险,进行了湿法磷酸生产新工艺的开发研究。在传统湿法磷酸生产工艺中,磷矿分解和石膏结晶在同一反应槽内完成,以获得良好的石膏结晶为目的,但流程中各种杂质进入石膏相中,给石膏综合利用带来了困难。在新工艺中,磷酸分解磷矿、硫酸沉钙、石膏转晶分别在不同反应槽完成,分离出杂质含量高的酸渣,得到了高品质湿法磷酸和和高纯度的α-半水石膏。全流程磷收率>96%,产品磷酸P_(2)O_(5)质量分数为39.50%,MER值0.066;酸渣产量(每吨P_(2)O_(5))1.48 t(干基),α半水石膏产量(每吨P_(2)O_(5))3.22 t。α半水石膏质量分数≥98%,α半水石膏建材白度≥90%,石膏产品性能达高强α石膏40级,工业利用价值极高。

In order to improve the production process level of wet process phosphoric acid,improve the quality of by-product phosphogypsum,and reduce the economic pressure and environmental risk of wet process phosphoric acid production solid waste emission and storage,the new process of wet process phosphoric acid production is developed.In the traditional wet process phosphoric acid production process,phosphate ore decomposition and gypsum crystallization are completed in the same reaction tank,for the purpose of obtaining good gypsum crystallization,but various impurities in the process enter the gypsum phase,which brings difficulties to the comprehensive utilization of gypsum.In the new process,phosphoric acid decomposition of phosphate ore,sulfate calcium precipitation and gypsum transcrystal were completed in different reaction tanks,and the acid residue with high impurity content was isolated,and the high quality wet phosphoric acid and high purityαsemi-water gypsum were obtained.The phosphorus yield of the whole process is>96%,the mass fraction of phosphates P_(2)O_(5) is 39.50%,MER value 0.066;the production of acid slag(P_(2)O_(5) per ton)1.48 t(dry base)andαof semi-water gypsum(P_(2)O_(5) per ton)3.22 t.The quality score ofαsemi-water gypsum 98%,αsemi-water gypsum building materials 90%,gypsum product performance of high strengthαgypsum 40 grade,industrial utilization value is extremely high.