The authoritative public forum
  for Metal Finishing since 1989


-----

Neutralization of fluoboric acid?

Hi!!!

I am trying to find a method/procedure to dump fluoboric acid.
What do I need to do to treat and neutralize the acid and dispose of it so it doesn't harm the environment?

I am under the impression that one could use lime to neutralize fluoboric acid, although after this has been done - is there another step before it can be dumped?

thanks for the help!!!

Adriaan Louw
chemical supplier - South Africa
November 1, 2011

That would depend on what else is in the solution and what the laws of your country are.

James Watts
- Navarre, Florida
First of two simultaneous responses -- November 2, 2011

---

Second of two simultaneous responses -- November 3, 2011

Fluoboric acid can be treated with lime, however, the breakdown of the BF4- ion is slow for the last two F- ions.

The first F- is released very quickly, and the second one in less than 30 minutes. Unfortunately, while the last two F- ions will eventually be released, the third one takes a matter of days at room temperature.

Ultimately you will be left with boric acid, or an
H2B(OH)2F- ion. If you have a boron limit, it will be very difficult to reach, except by dilution.

Lyle Kirman

Lyle Kirman
consultant - Cleveland Heights, Ohio