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

摘要

PROBLEM TO BE SOLVED: To provide a method for recovering nitric acid from an acetic acid-nitric acid-phosphoric acid type mixed waste liquid with high efficiency at a low cost by a simple distillation operation.;SOLUTION: The method for recovering nitric acid from the acetic acid-nitric acid-phosphoric acid type mixed waste liquid includes a first distillation process for distilling off a mixed acid liquid, which contains acetic acid and nitric acid by distilling the waste liquid containing acetic acid, nitric acid and phosphoric acid and a second distillation process for dissolving at least one kind of a metal salt, which is selected from the group consisting of cesium nitrate and magnesium fluoride, to the distillate solution and distilling the distillate solution to distill off acetic acid to obtain the mixed acid liquid increased in the compositional ratio of nitric acid as a distillation residue.;COPYRIGHT: (C)2008,JPO&INPIT