METHOD FOR MANUFACTURING EXPANSIVE GRAPHITE

摘要

PROBLEM TO BE SOLVED: To provide an economical method for easily manufacturing expansive graphite. SOLUTION: Oleum gas is manufactured by oxidizing sulfur for manufacturing humic sulfuric acid. SO3 gas is contacted with graphite to oxidize graphite. After the oxidized graphite is washed, it is expanded by microwave irradiation or heat treatment. Mixed acids are not used and so the mixed acid waste is not exhausted. The amount of residual sulfur in expansive graphite is largely reduced to have excellent oil absorbing property. Expansive graphite is preferably used for gaskets, packing, cushion sheets, a raw material for manufacturing thermal insulating materials and heat insulating materials, or an absorbent of volatile organic compounds(VOCs).