▎ 摘　　要

NOVELTY - Producing expanded graphite, comprises (a) mixing graphite with acid to perform acid treatment, (b) introducing expansion agent including sulfur oxoacid and metal halide, and (c) expanding by applying microwaves. USE - The expanded graphite is useful in producing high purity graphene (claimed). ADVANTAGE - The method produces expanded graphite with low energy using sulfur oxoacid compound and metal halide. The expanded graphite can be expanded at high expansion rate even with low energy, and produces high purity graphene. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for producing graphene, comprising (i) preparing graphene oxide by oxidizing the expanded graphite prepared by the above method, and (ii) reducing the graphene oxide.