Manufacture of expansion graphite used for gasket, packing sheet, involves contacting sulfur trioxide gas generated from oleum and graphite followed by desorbing sulfur trioxide condensed gas from lamellar compound

摘要

Sulfur trioxide gas generated from oleum or sulfuric anhydride is contacted with graphite at normal pressure for 10 minutes to 1 day to form SO3 graphite lamellar compound. Subsequently excess SO3 condensed gas is desorbed from intercalation compound to obtain expansion graphite. Amount of oleum or sulfuric anhydride and graphite used are in weight ratio of 100:20 - 100:30.