| 摘要 |
PURPOSE:To improve the strength and oxidation resistance of a graphite- containing refractory composed mainly of an oxide refractory raw material and natural graphite by eliminating ultrafine oxide powder or decreasing the content of the oxide powder below an extremely low permissible level. CONSTITUTION:The objective refractory can be produced by kneading 95-50wt.% of an oxide refractory raw material (e.g. electromelted magnesia) containing 0-5% ultrafine powder having particle size of <=0.074mm, 5-50wt.% of natural graphite and, as necessary, metallic aluminum powder to prevent the oxidation of graphite, a binder (e.g. phenolic resin; the amount of additive is 1.5-3.0wt.% by outer percentage), etc., forming the obtained mixture, heating at about 200 deg.C for about 24hr, cutting to a prescribed shape with a cutter, machining with a surface grinding machine and drying in vacuum. |
