▎ 摘　　要

NOVELTY - Sagger comprises sagger main body and box cover. The top part of the sagger body is opening. The box cover is covered on the top part of the sagger body. The sagger main body comprises an outer casing wall body and outer cavity outer box wall body formed by the outer box wall is set with a gap so that the outer cavity is connected with the outside. The sagger main body is set with an inner casing. The inner casing comprises inner box wall body and inner cavity formed in box wall body. The inner cavity and the outer cavity is connected with the casket comprises a casket top. USE - The sagger is useful for preparing graphene material (claimed). DETAILED DESCRIPTION - Sagger comprises sagger main body and box cover. The top part of the sagger body is opening. The box cover is covered on the top part of the sagger body. The sagger main body comprises an outer casing wall body and outer cavity outer box wall body formed by the outer box wall is set with a gap so that the outer cavity is connected with the outside. The sagger main body is set with an inner casing. The inner casing comprises inner box wall body and inner cavity formed in box wall body. The top part of the inner casing is open. The inner cavity and the outer cavity is connected with the casket comprises a casket top and casket cover wall body. The wall body of the box cover is set in the outer cavity of the sagger main body. The height of the box cover wall is less than the height of the outer box wall body. An INDEPENDENT CLAIM is also included for preparing graphene material comprising (a) providing a graphite raw material, (b) oxidizing the graphite raw material, placing the graphite oxide in the sagger and inert atmosphere at 1000-1400 degrees C, subjecting to reduction to obtain the graphene material, where the material of saggers is high density graphite. DESCRIPTION OF DRAWING(S) - The figure shows a schematic representation of the sagger.