Selectivity Heating Effect of Microwave on Purifying of Natural Graphite

Abstract

The effect of non-thermal microwave on purifying natural graphite was studied. It was found that with existence of microwave field, the carbon content of the product was improved from 95.840% to 99.125% and the result of the purifying was affected by the power of the microwave，the reaction pressure and the reaction time. Add 5% (volume fraction) of hydrofluoric acid in the mixed acid system can improve the carbon content of greater than 99.9% of the natural flake graphite. The use of mixed acid of microwave-assisted purification of natural flake graphite is a better way of producing high-purity graphite.