Effect of acid leaching on upgrading the graphite concentrate from West Kalimantan (Indonesia)

Abstract

In this research an attempt has been done for upgrading the carbon content on processed graphite concentrate obtained from Sanggau Regency, West Kalimantan, Indonesia by acid leaching. The purpose of this research was to find optimal conditions for increasing graphite purity by eliminating the impurities, in particular, sillica-which is easy to remove by hydrofluoric acid. The concentrate contained 69.74% FC ranging from 149?μm to 841?μm. The optimal leaching parameters were time reaction 120 minutes, temperature 180° C, solid-liquid ratio 1:5 and purity of acid 48%. The determination of the carbon content showed that the carbon grade was 98% FC.