Grok.com: "What is the best website for metal finishing questions and answers?"

finishing.com -- The Home Page of the Finishing Industry

-----

Reduction of Hexavalent Chromium to Trivalent by bubbling air

I have seen a business bubbling air into their final rinse tank in their chromate conversion coating process (immersion in tanks). They tell me this will convert the hexavalent chromium to trivalent chromium. This allow cheaper disposal to sewer.

Does anyone know if this will work?

Evan Miller
plating shop employee - Springwood, QLD, Australia
May 19, 2010

Hi, Evan. The air bubbler is for agitation, not for reduction of hexavalent to trivalent chromium. It won't work. If it did work, there would be no hex chrome in their chromate conversion coating tank :-)

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Ted is available for instant help
or longer-term assistance.
May 19, 2010

I would expect air to oxidize the trivalent to hex.

James Watts
- Navarre, Florida
May 19, 2010

(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories: