ステンレス溶鋼の還元脱りん及びスラグの処理方法
1984 年 70 巻 16 号 p. 2232-2238
詳細
1984 年 70 巻 16 号 p. 2232-2238
The dephosphorization of molten stainless steel by the addition of metallic Ca has been studied by using a laboratory scale high frequency furnace and industrial scale electric arc furnace. In addition, safety treatments of dephosphorization slag were examined.
The results obtained are summarized as follows:
(1) In a laboratory scale test, the relation between activities of C and O (aC and aO) of molten steels and dephosphorization ratios were found. Optimum conditions where dephosphorization ratios reached more than 50% were aC<0.92 and aO<4×10-4 at 1 480°C.
(2) In order to obtain the optimum condition of 18Cr8Ni steel, it was necessary to control carbon and oxygen contents in the range of 0.3%<C<1.0% and O<60 ppm at 1 480°C, respectively.
(3) In the industrial scale experiment on 13Cr5Ni steel, dephosphorization ratio and desulfurization ratio were 33% and 55%, respectively, by the addition of Ca=10.6 kg per ton steel.
(4) Concentrations of PH3 and H2S generating from dephosphorization slag were measured. Maximum concentrations were 160 ppm/g for PH3 and 400 ppm/g for H2S before safety treatment. After the safety treatment by using oxide slag, maximum concentrations decreased to 2 ppm/g for PH3 and 11 ppm/g for H2S.
