how to purify graphite by hydrofluoric acid leach « BINQ ...
Graphite – Wikipedia, the free encyclopedia. Graphite is the most stable form of carbon under standard conditions. (up to seven times) to purify the concentrate, or by acid leaching (dissolving) the gangue with hydrofluoric acid (for a silicate . Leaching this concentrate with hydrochloric acid gives a 95% graphite product with a flake size ranging from 10 mesh down.