| 摘要 |
PURPOSE:To prevent cracking and stripping of a coating refractory layer owing to oscillation during use of a blowing lance for refining of molten coated with refractories and to extend the service life of the lance by attaching a lumped material consisting of refractories having specific compsn. to the top end of said lance. CONSTITUTION:A coating layer 2 consisting of refractories is formed on the surface of a steel pipe lance 1 to be used in the stage of performing preliminary refining such as desiliconization, dephosphorization, desulfurization or the like of molten iron by blowing powder of carbide, lime, etc. into molten iron to prevent melting of the steel pipe lance by the molten metal and the consequent decrease in the service life thereof. The refractory cooling layer is cracked and stripped by the oscillation in the moltem metal in this case and the coating layer is eroded in short time. a lumped material 3 consisting of Al2O3-SiC-C or MgO-C refractories is attached to the top end of the lance 1 or the part slightly apart from the top end in order to prevent such erosion. The oscillation in the molten iron is thus absorbed and the cracking and stripping of the layer 2 are prevented, by which the decrease in the service life owing to the erosion of the lance is prevented. |
