COOLING METHOD OF LANCE FOR STIRRING MOLTEN METAL

PURPOSE:To extend the service life of a lance for stirring a molten metal and to reduce the cost ratio thereof in the stage of using said lance by spraying mist in the metallic pipe of the lance after the treatment thereby preventing the temp. rise of the lance. CONSTITUTION:A molten metal is stirred and refined by using a lance 3 for stirring a molten metal consisting of a metallic pipe 7 having a gas passage hole 7, and refractories 8 which cover the outside circumference of said pipe and of which the part corresponding to a slag line and the part at the bottom end are formed larger in outside diameter than the other parts. Mist is sprayed in the pipe 7 after said treatment to prevent the temp. rise of the lance 3. The mist spraying is preferably accomplished by spraying mist of about 50-100 gas- water ratio by a small diameter full cone tip to cool efficiently the pipe. The difference in thermal expansion between the refractories 8 and the pipe 7 is thus decreased and the generation of the crack and peeling in the refractories and the bend, etc. of the pipe 7 is prevented, whereby the service life of the laence 3 is extended.