| 摘要 |
PURPOSE:To perform dephosphorization treatment at a low cost by subjecting molten iron to dephosphorization treatment by means of a flux consistng essentially of sodium carbonate while blowing a recarburizer directly into the molten iron from the tuyere in the lower part and ending the treatment at specific temps. CONSTITUTION:Inexpensive coke and coal powder or the like contg. a substantial amt. of sulfur are usable as the recarburizer, and these are usually blown together with a carrier gas, preferably an inert gas such as N2 or gaseous Ar into molten iron. It is preferable to blow gaseous O2 as an auxiliary oxidizer through another tuyere in order to accelerate dephsophorization reaction. Since the recarburizer is blown through the tuyere lower than the melt surface, the greater part is dissolved into the molten iron before the recarburizer arrives at the melt surface, and since it is out of contact with dephosphorization slag directly, it prevents the degradation in dephosphorization reaction efficiency. It is possible to make the dephsophorization efficiency considerably high by regulating the dephosphorization treatment end temp. at<=1,290 deg.C. |
