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.

SHUBHAM
- ODISHA, India
August 17, 2024

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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_yosem
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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