No registration or passwords; no pop-up ads -- just aloha, fun, & answers.
(as an eBay Partner & Amazon Affiliate earns from qualifying purchases).
Home /
T.O.C.
Fun
FAQs
Good
Books
Ref.
Libr.
Advertise
 
Help
Wanted
Current
Q&A's
Site 🔍
Search
pub  Where the
world gathers for metal finishing
Q&As since 1989



-----

Fast Disposal of Muriatic Acid -- safely and environmentally?




Q. I have roughly 30 gallons of diluted muriatic acid [affil links]. it was diluted 4:1. What would I do (fastest, safest, most environmentally friendly) to make it safe to dump on the ground or down the drain?
I have 3 mini pinschers...

Sion Sublett
- Columbus, Ohio
2007


A. Carefully neutralize with diluted caustic soda [affil links] (sodium hydroxide) to a pH near 7. The final product is sodium chloride and water (very much like sea water). Then investigate if you can dump it in your area.

Guillermo Marrufo
Monterrey, NL, Mexico


A. Adding a sodium hydroxide solution to an acid can generate significant heat. It would be safer and cheaper to use Sodium Bicarbonate ([on eBay or Amazon] ) in a vessel that is at least twice as large as the volume of liquid that you are neutralizing to allow for bubbling of the Carbon Dioxide gas that will be generated. Add the Sodium Bicarbonate slowly in a well ventilated or outside area. Continue to add the Sodium Bicarbonate slowly until the solution reaches a near neutral pH 6-7. You can then pour it down the drain assuming there is no other contaminants in the muriatic acid (hydrochloric acid). You will have metal contaminants in the muriatic acid if it ever came in contact with metal.

Mike Jackson
- Woonsocket, Rhode Island


A. Hi.

Guillermo's and Mike's suggestion are both fine for 30 gallons of diluted HCl. But be prepared: the baking soda will bubble more that you think it will even after you've been warned to expect it to bubble a lot. It will take a pretty long time, maybe a couple of hours to do 30 gallons right. After you have double-checked the pH with pH paper [affil links], you can dump it down the drain (assuming that you are not part of a regulated industry).

Neither iron/steel nor aluminum are regulated in most jurisdictions, so if those were the only metals dissolved in it, you're probably still okay. Luck & Regards,

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


Ed. note -- Readers: This is one of dozens of threads and technical articles about analysis, disposal, recycling, recovery, or extending the life of muriatic (hydrochloric) acid pickling solutions. Please search the site with an explicit search term to find info about your own situation.




(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:

 
Jobshops
Capital
Equipment
Chemicals &
Consumables
Consult'g, Train'g
& Software


About/Contact  -  Privacy Policy  -  ©1995-2024 finishing.com, Pine Beach, New Jersey, USA  -  about "affil links"