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Article: Dissolved aluminum in the anodizing tank.(ALUMINUM ANODIZING CLINIC)
- Article from:
- Products Finishing
- Article date:
- February 1, 2007
- Author:
CopyrightCOPYRIGHT 2007 Gardner Publications, Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Q. I know there are recommended concentration limits for dissolved aluminum in the Type II and III anodizing processes, but why is it necessary to control the aluminum in the bath? If the bath is operated outside of these limits, either higher or lower, how is the process affected?--P.H.
A. Generally speaking, the aluminum (in the form of aluminum sulfate) in the "typical" sulfuric acid electrolyte is controlled between five g/liter and 15 g/liter with around 20 g/liter being the absolute maximum for efficient operation of the bath. It is best if there is some aluminum in the bath. Too much can cause problems with the process. When making up a new bath, I usually ...