铝及铝合金化学抛光磷酸废液制备磷酸二氢铵研究

提出了以铝及铝合金化学抛光磷酸废液为研究对象有效回收磷资源制备工业级磷酸二氢铵（MAP）的工艺方法。实验结果表明,将原废液稀释至质量浓度为95 g/L,反应温度为80 ℃,氨水中和除杂终点pH为4左右,除杂反应时间为1 h,将过滤液用氨水二次调节pH至7~8后蒸发浓缩,浓缩液加入纯度较高的磷酸废液回调pH至4~5,冷却结晶后85 ℃烘干得到MAP产品,产品经主含量、XRD分析,结果显示各项指标均符合HG/T 4133—2010《工业磷酸二氢铵》一级产品标准的要求。

Study on preparation of ammonium dihydrogen phosphate from phosphoric acid waste solution of chemical polishing of aluminum and aluminum alloy

A methodology for producing industrial grade ammonium dihydrogen phosphate（MAP） through effective recycle of phosphorus from phosphoric acid waste solution of chemical polishing of aluminum and aluminum alloy was proposed.The ex-perimental results showed that when the concentration of original waste solution was diluted to 95 g/L,the reaction tempera-ture was 80 ℃,the pH of the end point of neutralization and impurity removal was about 4,the impurity removal reaction time was 1 h,the pH of the filter liquid was adjusted to 7~8 by ammonia,and then evaporated and concentrated,the concentrated liquid was added with high purity phosphoric acid waste liquid to adjust the pH to 4~5,the MAP products were cooled,crys-tallized and dried at 85 ℃.Through the analysis of main content and XRD,the result showed that all indexes met the first-grade product standard of HG/T 4133—2010,Industrial Ammonium Dihydrogen Phosphate.