湿法磷酸中脱除重金属的工艺研究

Study on the Process of Heavy Metal Removal from Wet Process Phosphoric Acid

介绍了一种H2S循环脱湿法磷酸重金属的新工艺,通过对比分析了H2S循环脱湿法磷酸重金属新工艺与传统Na2S溶液脱重金属工艺的脱除效率、工艺安全性、循环经济性以及技术经济性,结论如下:H2S循环脱湿法磷酸重金属新工艺可以实现脱As后折85%H3PO4中As指标降至0.5mg/kg;本工艺拥有较高的工艺安全性、循环经济性、技术经济性,可使原料Na2S和NaOH的消耗量优化倍数达到了117、5.8倍,S元素的总利用率为94.5%,H2S循环脱重金属新工艺的尾气量由传统工艺的10 400 m3/kg(以As计)减至4 800 m3/kg(以As计)。

A new process of H2S cyclic wet process phosphoric acidheavy metal removalis introduced.The removal efficiency, process safety, cyclic and technical economy of the new process of H2S cyclic wet process phosphoric acidheavy metal removal and the traditional process of Na2S solution heavy metal removal are compared and analyzed.The conclusions are as follows: The new process can reduce As index to 0.5mg/kg as in H3PO4by 85% after As removal.This process enjoys high process safety, cyclic&technical economy, which can make the consumption optimization of raw materials Na2S and NaOH reach 117 and 5.8 times respectively, and the total utilization rate of S element is 94.5%.The exhaust volume of the new process is reduced from 10,400 m~3/kg(As) in the traditional process to 4 800 m~3/kg(As) in the new one.