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Trivalent chrome

Is there any method for removing trivalent chrome from a regular chrome bath?

Michelle Amann
- Erie, Pennsylvania, USA
2002

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First of three simultaneous responses -- 2002

Michelle,

In a normal conventional chrome bath,trivalent chrome may be reduced naturally by electrolysis. Its volume is determined by the ratio between Anode area to Cathode area.Basically, Anode area equal to Cathode area (Cr+3 is consistent) Anode area greater than Cathode area (Cr+3 decreases ) Anode area less than Cathode area (Cr+3 increases ) Roughly,when ratio of cathode area and anode area is 2:1,and 3volt electrolysis is performed for 5 to 10 hours,0.5 to 1.0 g/l of Cr+3 will be produced.Vice versa,when the ratio of cathode area and anode area is 1:2.

Good Luck.

SK Cheah
- Hong Kong

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Second of three simultaneous responses --

A porous pot will do that very nicely as well as remove much of the tramp metal ions from the solution. Hard Chrome Consultants in Cleveland OH probably has the least expensive effective one.

James Watts
- Navarre, Florida
2002

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Third of three simultaneous responses -- 2002

Michelle:

Are you seriously doing chrome plating? Where did you leave your books or manuals or course notes? This question is among the first things one learns about chrome plating in any book or course. Anyway, the traditional means is to electrolyze the solution with an abnormally high anode to cathode ratio. Instead of 1:1 use 20 or 30:1 (large lead, small piece of steel). This will oxidize the ions back to hexavalent state. And before going further, go to an experienced person for more important advise like environmental concerns, waste treatment, personal exposure, etc.

Guillermo Marrufo
Monterrey, NL, Mexico