PURPOSE: To establish the optimum Ti source blowing technique for effectively preventing local damage of the furnace bottom while suppressing the production of a compound such as TiC in the case of protecting the furnace bottom surface by blowing Ti source from tuyeres.

CONSTITUTION: In the case of protecting the furnace bottom by blowing the Ti source when the rising of center temp. at the furnace bottom in the blast furnace is observed, while executing iron tapping from two pieces of the iron tapping holes positioned at the angle of within 90° in the circular direction, the Ti source is blown from the tuyeres provided in the range of 180 ±30° in the circular direction to the center angle of these two pieces of the iron tapping holes.