Production of ammonium phosphates and product thereof

摘要: Ammonium phosphate solutions free of precipitates are prepared from wet-process phosphoric acid containing incidental metallic impurities such as iron, aluminum and magnesium by concentration the to an anhydrous state formation acyclic polyphosphoric acids therein which prevent precipitation upon neutralization. The is heated a temperature greater than 120° C. at atmospheric or subatmospheric pressures while removing volatile thereafter neutralized with ammonia. neutralization step can be performed elevated temperatures ammonia cooled ambient temperatures. resulting ammonium diluted water obtain solution clear precipitates.