BOF furnace bottom management method at the time of slag coating method and slag coating implementation of the converter furnace wall

摘要

PROBLEM TO BE SOLVED: To provide a slag coating method onto the furnace wall in a converter, with which the whole surface of the furnace wall is stably and uniformly coated and the furnace service life of the converter can be extended in the converter for steelmaking, and a control method of the furnace bottom in the converter at the executing time of the slag coating, with which the rising of the furnace bottom thickness in the converter can be detected or the furnace bottom thickness in the converter can be adjusted.;SOLUTION: A lance height from the furnace bottom is controlled to 0.7 m to 3.0 m and gas flow rate is controlled to 250-600 Nm3/min so as to scatter the slag according to the repairing position in the converter and further, the scattered height and the fitted quantity to the furnace wall of the slag are controlled by adding slag solidifying agent containing MgO or CaO according to the remaining slag composition after jetting the gas. Alternatively, the back pressure of a tuyere in the gas pressure supplied in the furnace from the bottom-blown tuyere in the converter, is detected or flux is added in the molten slag left on the furnace bottom in the converter after steel tapping to apply the slag stirring with the bottom-blown tuyere and/or the top- blown lance.;COPYRIGHT: (C)2000,JPO