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Ted Mooney, P.E. RET
Pine Beach, NJ
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for Metal Finishing since 1989
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How do we continuously remove titanium from an etch tank
2007
We wish to process titanium parts through an etch tank. Tank is essentially made up of sodium hydroxide,triethanolamine, diethanolamine, and sodium gluconate.
Problem is the etch tank solution has to remain under 120 ppm dissolved titanium. We are exceeding this limit after processing only
3 parts. Dumping and refilling a new tank every three parts is not practical. Does anyone know who has already solved this problem? continuous filtering?
Chem Processor - Tulsa, OK, U.S.
First of two simultaneous responses --
First, what does your vendor say? That'd be my first step.
Titanium is going to be present as some kind of anionic complex. If my vendor couldn't help, I'd look at ion exchange resins.
Dave Wichern
Consultant - The Bronx, New York
2007
Second of two simultaneous responses --
Shane,
Glad to see that you've got your question posted here! As we spoke via E-mail, filtration, chemical precipiation or ion exchange are 3 possibilities. I'll keep an eye here to see what the industry community comes up with.
Milt Stevenson, Jr.
Syracuse, New York
2007
I would query why the spec demands such a low titanium concentration.
I would be very surprised if you get a convincing answer.
Please let us know.
Geoff Smith
Hampshire, England
2007
Thank you for all your input. No solutions yet, (no pun intended) in response to previous comments, a.) Vendor can't help. Industry levels are generally 12,000ppm not 120. b.) customer query did not render any explanations as predicted other than this level was needed (engine parts?)
Shane Smith- Tulsa, OK, US
2007
Still searching for some method to remove dissolved titanium from tank to maintain.
Shane Smith- Tulsa, OK, U.S.
2007
January 2, 2008
FIRST,
Optimize your ETCH procedure (T, t, []) in order to dissolve less Ti.
SECOND,
Use a separation method (already mentionned).
- Minneapolis, MN, USA
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