To prevent the erosion refractory in the inner wall forming a circulating vessel and to enable use of high basicity flux having non-metallic inclusion absorbability in the circulating vessel by forming the composition at the part contacting with the refractory in the inner wall forming the circulating vessel to a composition containing the same components as the main components of the refractory material to the saturated solubility or higher.
The saturated flux 15 added on molten steel 2 in the circulating vessel 5 has the non-metallic inclusion absorbability in the molten steel 2 and also, since this flux has the composition containing the same components as the main components of the refractory material in the inner wall forming the circulating vessel 5 to the saturated solubility or higher, the elution of the main component in the refractory forming the inner refractory can be prevented. The flux composition existing in the outer peripheral part of the molten steel surface in the circulating vessel 5 causing to the erosion of the inner wall refractory, is made to the saturated state in the same composition as the main component of the refractory material in the inner wall refractory. On the other hand, the flux composition near along nozzle 3 is made to less than the saturated concns. in the component concns. to simultaneously restrain the erosion of the inner wall refractory and the oxidation of the molten steel surface near the long nozzle 3.
BESSHO NAGAYASU
ITOYAMA SEIJI
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