Method for purification of trivalent chromium electroplating baths
AssigneeBio-Recovery Systems, Inc.
InventorsDennis W. Darnall, Robert A. McPherson, Jorge L. Gardea-Torresdey
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Abstract
A new method for purification of trivalent chromium electroplating baths contaminated with cationic metal ions is disclosed. In this purification process, the contaminated trivalent chromium is passed at the pH level of the bath through one or more columns containing an ion-exchange resin having the picolylamine group as the functional moiety. The cationic metal ions are preferentially bound to the resin while the trivalent chromium is passed through the resin with substantially no adsorption thereby purifying the electroplating bath. This process is preferably performed simultaneously with the electroplating process.
Claims14
A method for purification of a trivalent chromium solution contaminated with cationic metal ions comprising:
- contacting said solution with a chelating ion-exchange resin having the picolylamine group as the functional moiety so that said resin has a high affinity for the contaminant cationic metal ion and substantially zero affinity for cationic trivalent chromium metal ions wherein contaminant cationic metal ions are bound by said chelating ion-exchange resin thereby purifying said solution.
Dependencies are inferred from the claim text.