Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
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for Metal Finishing since 1989
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Effective Replacement of HCl as Pickling Bath
Q. HI,
I AM USING HCL ACID WITH TITRATION OF 18 WHEN NEWLY MADE AND DISPOSE WHEN TITRATION COMES TO 8. DIP TIME - 10 MINS
AS HCL IS VERY HAZARDOUS FOR THE ENVIRONMENT. I WANT TO KNOW IF THERE IS ANY PRACTICAL REPLACEMENT OF HCL AVAILABLE. IF YES, PLEASE PROVIDE ME WITH DETAILS.
THANK YOU FOR SUPPORTING.
- ODISHA, India
August 17, 2024
Ed. note: Since 1989 this forum has enjoyed the camaraderie & warm aloha which real names & locations afford. If you're not into that spirit, those who do post with their real name may be less likely to engage with you.
A. Hi.
10 minutes sounds like an extraordinarily long pickle time for a plating shop. I don't understand the need for such extreme pickling.
Actually, HCl is the replacement for hot H2SO4 which was still quite popular when I started in the industry way back when, but which I haven't seen in use for decades now. So hot sulphuric acid is one possibility. I would suggest trying acetic acid in the lab if you must get rid of hydrochloric acid, although it would surprise me if it could replace 10 minutes in HCl :-)
I don't think I agree that, if handled properly, HCl is hazardous for the environment. In theory the waste would be neutralized, the metal precipitated out, and only salt water would remain, which covers 2/3 of the earth.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
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