| 摘要 |
PROBLEM TO BE SOLVED: To provide a carbon material for pulling up high purity aluminum, which shows lesser oxidation loss and is capable of withstanding long-term service. SOLUTION: The production process for this carbon material comprises: blending 70 wt.% of powdery calcined coke having a 5 μm average particle size with 30 wt.% of powdery boron carbide having a 5 μm average particle size to obtain 100 wt.% of a powdery mixture; adding pitch used as a binder to the powdery mixture to subject them to hot kneading in a kneader; cooling the kneaded material and thereafter grinding the cooled material, to form a powdery material and to adjust the average particle size of the powdery material to 10 μm; forming the powdery material into a green body by hydrostatic pressing under a 150 MPa pressure; then embedding the green body in powdery coke and heating the green body to 1,000 deg.C at a 15 deg.C/hr temperature rising rate; after the heating, cooling the heated body while maintaining the non- oxidizing atmosphere; and thereafter subjecting the cooled body to heat treatment at 2,000 deg.C by using an Acheson furnace to form a carbon-boron carbide composite sintered body. |
