PURPOSE: To extend the life of the bottom of an electric furnace and to improve the operating efficiency of the furnace by charging earthy graphite as a recarburizer into the furnace to form the recarburizer layer on the furnace bottom and executing the recarburization melting of scrap on said layer thereby protecting the furnace bottom.
CONSTITUTION: The earthy graphite having a suitable grain size is charged into a 3-phase AC arc furnace 1 and the granular recarburizer layer 3 having about 200mm layer thickness is formed on the furnace bottom 2. The scrap is then charged to the upper part thereof and electricity is conducted to a 3-phase AC electrode 5 to melt the scrap, thus forming a molten iron 4 on the layer 3. The molten iron 4 has specific gravity larger than the specific gravity of the earthy graphite 3 but the intrusion of the molten iron into the gaps among the recarburizer particles is prevented by surface tension, by which the recarburization effect is progressed through the contact surface with the earthy graphite 3. The floating of the earthy graphite 3 is obviated. The erosion of the brick of the furnace bottom 2 by the molten iron 4 is thus prevented, by which the life is extended and the operating efficiency of the furnace 1 is improved.
UMEZAWA KAZUMASA
MIMURA MITSUTOSHI
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