| 摘要 |
PROBLEM TO BE SOLVED: To efficiently recover nitric acid as a valuable material from mixed acid waste liquid. SOLUTION: A treatment method is for a mixed acid waste liquid after acid treatment is carried out with a mixed acid containing nitric acid and hydrofluoric acid. When silicon is included in the mixed acid waste liquid, silicofluoride salt and nitric acid are generated by adding a salt of an alkali metal or alkali earth metal to the mixed acid waste liquid, and the nitric acid is separated and recovered from the mixed liquid including the silicofluoride salt and the nitric acid by means of a solid-liquid separation means. COPYRIGHT: (C)2011,JPO&INPIT
|
