Identification of Sericite in Graphite Tailing of Heilongjiang Provice by X-ray Diffraction, Scanning Electron Microscopy and Optical Microscope

Graphite tailing is a secondary resource, and could be be recovered when the mica mineral content in tailing is higher than 10%. Graphite tailings in Heilongjiang Province contain >10% mica minerals that are 500-800 mesh. These minerals are finer than conventional mica minerals making it difficult to identify its mineral species. In order to resolve this problem, X-ray Diffraction (XRD) was used to analysis mineral composition of the graphite tailing, along with chemical analysis, Scanning Electron Microscopy-Energy-Dispersive Spectrometry (SEM-EDS) and Optical Microscopy. XRD analysis shows that mica minerals can be recovered and chemical analysis indicates that these minerals are possibly muscovite or biotite. Morphology studies indicate that mica minerals in graphite tailing and pure sericite minerals are mainly schistic and scaled, whereas pure biotite is mainly schistic. EDS analysis shows that graphite tailing contains 5%-13% SiO₂ and 4%-8% Al₂O₃. Mica mineral in graphite tailing has color similar to that of pure sericite but different from that of pure biotite, indicated by Optical Microscope. It is concluded that the mica mineral in graphite tailing is sericite of muscovite subtype. This research will provide reliable information for the subsequent mineral processing of graphite tailing and identification of sericite with similar fineness.