JPS6442511A - Secondary combustion method in converter - Google Patents

Abstract

PURPOSE:To remarkably improve a secondary combustion ratio and to enlarge applicable range of converter operation by operating the converter while blowing powdered coal, etc., containing hydrogen at the specific concn. from a tuyere arranged at position where does not submerged into the molten steel at the time of operation. CONSTITUTION:At first, molten iron is charged into the converter 1, and at the time of refining by supplying O2 gas from a lance 5 and Ar gas from bottom blowing tuyeres 6, in the ordinary operation, gas for preventing clogging of Ar, N2, etc., is continued to blow from the tuyere 2 arranged at the non- submerged position into the molten steel 7. Further, in the peak period of decarbonization, hydrocarbon series gas of powdered coal or methane gas, etc., containing 5-25wt.% hydrogen together with the above gas of Ar, etc., for preventing the clogging are blown into the converter 1 from the tuyere 2 to sufficiently promote the secondary combustion. If necessary, the tuyere 2 is formed with an outer pipe 8 and an inner pipe 9 and at the same time of blowing the powdered coal or hydrocarbon series gas from the outer pipe 8, oxygen gas is blown from the inner pipe 9. By such a method, the secondary combustion ratio in the converter 1 can be drastically improved.