Impregnated graphite (also called impervious graphite) is a material that has been in industrial use for the past 60-70 years. The primary industrial use has been in the construction of chemical processing equipment where the exceptional corrosion resistance and high thermal conductivity of graphite is particularly advantageous. Typical applications include the manufacture of pharmaceuticals and phosphate fertilizer, steel pickling, processing of chlorinated organics, flue gas treatment, HCI and H2SO4 production and recovery, plus the manufacture of chemical intermediates. The impervious graphite used for the construction of graphite pressure vessels is a composite material, consisting of raw graphite that is impregnated with a resin using a tightly controlled pressure/heat cycle.