mobile?Metal finishing Q&As since 1989
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Reaction of Marble to Hydrochloric Acid
Q. Hi, I would like to know if inhibited HCl solution could help to remove pink stains of Manganese carbonate from marble surfaces? Our marble material is basically dolomite. Will this solution damage our material?
Thanks!
Industrial Chemistry - Parana/Brazil
January 18, 2022
A. Hi Rafael. Step 2 is probably to research whether HCl is expected to have long-term deleterious effects on marble ... and maybe a reader can help you with that.
But step 1 in cases like this is probably some simple labs tests to see whether HCl does in fact remove those pink stains from your grade of marble, and without immediate obvious damage. Please try to give us the results of some simple lab tests before we launch flights of fancy :-)
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
January 2022
⇩ Related postings, oldest first ⇩
Q. I am a Geologist and I teach at a university in Toronto. When we did our rock ID labs the last couple of weeks I was a bit amazed because multiple of our chalk samples as well a marble samples do not fizz with HCl. The samples for each rock type came form the same sources.
Is it possible that it is the same as with dolomite, that they won't fizz due to bearing some Magnesium as well? We tried to make a powder in one small section but even that did not fizz.
I am puzzled, as were my students and the lab tech.
Thanks for your help in advance
Heidi
- Toronto, Canada
October 2, 2015
A. Only two things I can think of:
1) Blackboard chalk is calcium sulphate, not carbonate. It won't fizz.
2) There's a kind of "marble" that isn't metamorphized limestone at all, but is some form of serpentine. That's a silicate mineral and it won't fizz either.
Real limestone, calcite, marble, etc. are all CaCO3 and ought to release CO2 when exposed to HCl. Is the acid strong enough? Try 10%.
Dave Wichern
Consultant - The Bronx, New York
October 6, 2015
October 27, 2015
Q. Sorry for the delay.
We had some marble as well as some chalk samples in our collection (which we use for the rock ID classes), and these are supposedly form the same source as the others (and the look the same) and they do not fizz.
The acid in our lab is 10% HCl, so it should be fine.
I will try a bit stronger acid next time. And I also will try it with a powdered version of each.
We had some marble on a field trip this weekend, that did only fizz in powdered state. Maybe these samples are more dolomite rich and the Mg interfered with the reaction? Would that make any sense?
Thanks for your comment Dave! Any help with this is much appreciated.
Heidi
- Toronto, Canada
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