METHOD FOR SEPARATING AND RECOVERING PHOSPHORIC ACID FROM ACETIC ACID-NITRIC ACID-PHOSPHORIC ACID TYPE MIXED ACID WASTE LIQUID

摘要

PROBLEM TO BE SOLVED: To provide a method for efficiently and selectively separating and recovering phosphoric acid from an acetic acid-nitric acid-phosphoric acid type mixed acid waste liquid. SOLUTION: The waste liquid containing acetic acid, nitric acid and phosphoric acid is mixed with an extractant solution containing trialkyl phosphate to selectively dissolve acetic acid and nitric acid in the extractant solution to extract and separate them while recovering phosphoric acid from the extraction residual liquid left by extraction. The extractant solution to be used preferably comprises a composition of (trialkyl phosphate/aromatic organic solvent)=10/90-90/10 at volume ratio. COPYRIGHT: (C)2004,JPO