To provide a method for purifying a solution, which purifies a waste treatment liquid for a chemical conversion film with the use of trivalent chromium by effectively removing impure metal ion components such as a zinc ion, a ferrous ion, a copper ion and a nickel ion from the waste treatment liquid for the chemical conversion film with the use of trivalent chromium, without removing a trivalent chromium ion, a cobalt ion and the like which are necessary metal ion components, and extends the life of the waste treatment liquid of the chemical conversion film.
The method for purifying the trivalent-chromium-containing waste treatment liquid for the chemical conversion film includes: a step (a) of bringing the waste treatment liquid for the chemical conversion film of trivalent chromium in contact with a chelate resin having an amino phosphate group; and a step (b) of making the chelate resin selectively absorb at least one type of a metal ion selected from among a zinc ion, a ferrous ion, a copper ion and a nickel ion in the waste treatment liquid for the chemical conversion film of trivalent chromium and remove it therefrom.
| JP2003320293 | COATING PRETREATMENT APPARATUS |
| JPS61177379 | EXTENSION OF EFFECT LIFE OF CHROMIUM PHOSPHATE COATING BATH |
| WO/1996/001914 | PROCESS FOR FORMING A PHOSPHATE CONVERSION COATING |
OBA NAOKI
SUZUKI CHIKA
| JP2006137987A | 2006-06-01 | |||
| JP2007152188A | 2007-06-21 | |||
| JPH0532714A | 1993-02-09 | |||
| JPH04228599A | 1992-08-18 | |||
| JP2003507160A | 2003-02-25 |
Nobuo Ogawa
Atsushi Hakoda
Kenji Asai
Koji Hirayama
Hironobu Hattori
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