Expandable graphite products using high quality flaky graphite as raw material, and after special chemical process. Expandable graphite are instantaneous high temperature treatment, flake becoming to vermicular , volume expand 100~400times, this expandable graphite still keep the performance of nature graphite, and having good mold plasticity, flexible scalability and sealing ability, it is the good sealing material of graphite plates, also can be used for the metallurgical industry protection slag, flame retardant material.