PURPOSE: To remarkably improve the thermal efficiency in refining and ingot- making processes by closely situating the refining shop and the ingot-making shop and rapidly returning the molten steel remaining in a ladle to a steelmaking furnace in the refining shop in molten state after removing molten slag remaining in the ladle at the ingot-making shop.

CONSTITUTION: The melting plant 40, with the steelmaking furnace 27, such as electric arc furnace, and the ingot-making aisle 50, which cast the ingot from the molten steel, are built closely. The molten steel and molten slag refined in the electric furnace 27 are tapped into the ladle 20 and carried to the ingot- making plant 50 through a degassing apparatus or Ar-O2 gas refining furnace, and most of the molten steel is poured into metallic molds 22, to produced steel ingot. Most of the molten slag remaining in the ladle 20 is discharged by tilting the ladle and the ladle with a little molten slag and the molten steel remaining in the bottom thereof id shifted to the adjacent melting plant 40 by exclusive cranes 31, 32, to supply the molten steel remaining in the ladle back into the electric furnace 27 in high temp. molten state. As the remaining molten steel is used in the electric furnace in molten state without forming scrap by cooling and solidifying, the thermal efficiency is remarkably improved.