磷酸二氢钾的制备工艺

综述了生产磷酸二氢钾的各种方法,认为以磷酸与氯化钾为原料和以碳酸氢铵、磷酸、氯化钾为原料生产磷酸二氢钾工艺路线在工业上是有利的。两条路线均存在原料易得、操作简便、收率≥95%、成本低、副产品能全部回收、无环境污染等优点。以磷酸与氯化钾为原料路线,需采用能避免腐蚀、利于氯化氢排出的专用设备,但所得KH2PO4质量好,w(KH2PO4)≥98%,w(Cl-)≤0 2%。以碳酸氢铵、磷酸、氯化钾为原料路线,设备简单、投资少,但KH2PO4质量分数一次性仅达92%～98%,质量较差。

Technologies for Preparation of Potassium Dihydrogen Phosphate

The paper reviews the preparation of potassium dihydrogen phosphate.Both the method from hydro-phosphoric acid and potassium chloride and the method from ammonium bicarbonate,hydro-phosphoric acid and potassium chloride are considered to be more beneficial in industry.The materials which these methods use are easily obtained and the operation is simple.No wastes occur during operation and the by-products are all recoverable.The yield rate of product is over 95% and the cost of the product is lower than others.The first method requires a special equipment to avoid erosion and to expel hydrochloride smoothly.The content of the product obtained is over 98% and the Cl~- less than 0.2%.The second method is of the features of simple equipment and small cost,but the content of its product can only be up to 92%-98%.