CaO-CaF2系フラックスを用いた含クロム溶銑の脱りんの最適フラックス組成と酸化条件
1992 年 78 巻 6 号 p. 878-885
詳細
1992 年 78 巻 6 号 p. 878-885
Removal of phosphorous from chromium-containing hot metal by using CaO-CaF2-based fluxes was investigated at 1480 ± 20°C. Experiments were carried out using a 300 kg induction furnace in which the fluxes were injected into the metal by using a gas mixture of O2 + Ar. Experimental results showed that the optimum ratios of CaO/CaF2 and O2/(CaO + CaF2) for dephosphorization were approximately 1/1 and 40 Nl/kg, respectively. Under these conditions, about 50 per cent of phosphorous was removed by using 70 kg/ton of the flux from the metal containing 6 mass% of carbon and 28 29 mass% of chromium. The contents of Cr2O3 of the slag after the treatment were as low as 12 mass%. When the ratio of O2/(CaO + CaF2) was increased to more than 40 Nl/kg, the loss of chromium by oxidation was increased without any favorable effect on the degree of dephosphorization. In addition, when chromium contents are more than 17 mass%, the observed value of LP( (mass% P)/[mass% P]) was good agreement with the calculated one on the assumption that the oxygen potential is determined by the reaction of CaO·Cr2O3 formation.
