Abstract: A melting furnace for reforming steel-making slag so as to be available, for example, to roadbed ballast by mixing steel-making dust with the slag in molten states, which is provided with a fuel oxygen burner for melting the slag and the dust, a slag charging port for charging the slag in molten state into the furnace, a dust feeder for supplying the dust into the furnace, a slag feeder for supplying the slag in powdered state into the furnace, a storage portion for storing a molten mixture of the slag and the dust in a quantity corresponding to a tilting angle of the furnace body and an outlet port for discharging the molten mixture, and is possible to dispose the slag efficiently whether the slag is in the powdered or molten state.

Abstract: A melting furnace for reforming steel-making slag so as to be available, for example, to roadbed ballast by mixing steel-making dust with the slag in molten states, which is provided with a fuel oxygen burner for melting the slag and the dust, a slag charging port for charging the slag in molten state into the furnace, a dust feeder for supplying the dust into the furnace, a slag feeder for supplying the slag in powdered state into the furnace, a storage portion for storing a molten mixture of the slag and the dust in a quantity corresponding to a tilting angle of the furnace body and an outlet port for discharging the molten mixture, and is possible to dispose the slag efficiently whether the slag is in the powdered or molten state.

Abstract: In the production of stainless steel it is aimed at to depress the highest temperature reaching during refining the molten steel with keeping the necessary tapping temperature so as to prolong the life of refractory materials of the refining furnace. After carrying out decarburization treatment under atmospheric pressure in a refining furnace by blowing an oxygen-containing gas into molten steel, further decarburization of the molten steel and reduction of chromium oxides is carried out under stirring by blowing a non-oxidizing gas under a reduced pressure, and then, reducing agent is charged into the furnace to reduce chromium oxides under keeping the reduced pressure.

Abstract: Mixed gas of nonoxidizing gas and oxygen is blown into molten chrome steel in a vessel. The molten chrome steel is stirred by the gas and is decarbonized by the oxygen in the gas while being stirred. After the carbon potential in the molten chrome steel has been lowered, the pressure inside the vessel is reduced and the nonoxidizing gas alone is blown as the gas. Bubbles of the gas blown into the molten chrome steel become large on account of reduced pressure and exhibit sufficient stirring function. Consequently, the molten chrome steel is effectively stirred and the decarbonizing reaction is prompted.