铵法处理磷石膏制硫酸钾的研究

A Study on Preparation of Potassium Sulfate from Phosphogypsum by Ammonium Bicarbonate Process

实验研究了综合利用磷石膏废渣制硫酸钾的新方法。所用原料包括农用碳酸氢铵和氯化钾， 副产氯化钾铵复合肥和碳酸钙。流程中包括硫酸铵溶液的制备、复分解制硫酸钾铵、硫酸钾产品的制备和氯化钾铵的回收四个部分。在优惠工艺条件下， 产品硫酸钾符合标准一级品要求， 其中， Ｋ２ Ｏ＞ ４５ ％ ， Ｃｌ＜ １ ．５ ％ ； Ｋ２ Ｏ 转化率＞ ７６ ％ ， 全流程 Ｋ２ Ｏ 总收率＞ ９７ ％ ， Ｎ 总收率＞９３ ％ ， 磷石膏中硫酸根转化率＞ ９３ ％ 。

A new method of preparing potassium sulfate with waste phosphogypsum has been developed. The flow sheet includes preparation of ammonium sulfate solution, potassium ammonium sulfate and potassium sulfate, and the recovery of potassium sulfate with ammonium bicarbonate and potassium chloride as the raw materials and calcium carbonate as a by product. The product of first grade, with K 2O>45% and Cl<1.5%, was obtained under the optimum conditions. The conversions of K 2O and sulfate radical were more than 76% and 93%, and the over all recoveries of K 2O and nitrogen were more than 97% and 93%, respectively.