PURPOSE: To migrate phosphorus to molten slag, to recover the phosphorus as a resource and to effectively utilize the phosphorus by migrating the phosphorus to the molten slag under specific conditions in a top and bottom blown metallurgical furnace, separating the phosphorus from the metal bath and migrating the phosphorus to the metal formed by a reduction treatment, then subjecting the metal to oxidation refining.

CONSTITUTION: While gaseous oxygen is top blown into the metallurgical furnace allowing top and bottom blowing of the gas, iron ore or its prereduced matter and carbonaceous material are charged into the furnace and the temp. of the molten metal is regulated within a 1360 to 1450°C. Further, the (T. Fe) concn. in the slag is adjusted within a 3 to 9% range to migrate the phosphorus into the molten slag. This molten slag is then separated from the metal bath and a reducing material is added to the molten slag and is heated to migrate the phosphorus into the formed metal. the metal formed in such a manner is subjected to oxidation refining by using basic slag to migrate the phosphorus into the slag. As a result, the phosphorus contained in the iron ore is recovered as the resource and is effectively utilized.