Either carbon tetrachloride, or carbon disulphide. Can't remember which, but
it dissolves carbon. It's been about 35 years since I needed this
information.

The fire fighting technique for a fire in a vat of carbon disulphide is
really unique. I'll leave everyone to guess. You can also ask me......

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"HeyBub" wrote in message
...

Carbon is slightly soluble in liquid iron - that's how they make steel -
and, according to my CRC Handbook, virtually nothing else.

Inasmuch as there is no viable chemical solution to your problem, you'll
have to rely on a mechanical solution, i.e., scrubbing or removing the top
layer of the fireplace bricks.

You might consider wallpapering over the ugly-looking black stuff.