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Art project neutralizing nitric acid with sodium bicarbonate

2006

For an Art project, I am going to do an etching with nitric acid. I am working from HOME and would really appreciate it if someone would advise me of the safe way of disposing of the acid after the etching is complete. I understand that I should put the neutralized acid into plastic containers. Is it safe after the etching is complete to RINSE with WATER and then use sodium bicarb to neutralize?

Gaili van der Klooster

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Working with nitric acid in a home environment is inherently unsafe, so neutralization is the least of your worries. If the bicarb is added very gradually, with good mixing, to a vat of already diluted acid, you should be able to avoid boiling over.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006

Actually, the safest neutralizing material is magnesium hydroxide because it reacts very slowly. You can get this over the counter (at least in the US) as "Milk of Magnesia", but the cost of using such a pure grade would be prohibitive except for the smallest of projects.

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In my case the nitric acid is being put on to a flat surface to be etched and therefore no vat is involved, in fact I will be doing it in the backyard. You make me now wonder about the safety issues even more. I did similar work in the early 1970's and just hosed the acid off when it had done it's job but now of course, other than the grass dying off, I want to neutralize it and dispose of it properly! If I do get a vat should it be made of plastic?

Gaili van der Klooster

2006

Thanks very much for the feedback Ted!

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2006

Yes, polyethylene will be completely chemical resistant. It should be fine as long as dilution or neutralization does not generate excessive heat.

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