The effects of phosphoric acid and pyrolysis temperature to the formation of flaky graphite from lignite

Abstract

The flaky graphites were prepared from lignite. The effects of phosphoric acid ratios and pyrolysis temperatures on flake formation were studied by SEM, TEM and XRD. The results showed that the flaky graphite occurred at a pyrolysis temperature of 600°C with a 1.0:1.0 ratio of carbon to phosphoric acid. The flaky formation was almost completed by pyrolysis at 800°C and with a 1:2.0 ratio of carbon to phosphoric acid. The flaky graphite had a thickness and lateral dimension of about 50 nm and 2μm. © 2011 Academic Journals.