Mixture Calculation of Chromium Ore Smelting Reduction Process in a Converter
The mixture calculation of producing stainless steel crude melts by chromium ore smelting reduction in a 150 t converter is carried out by use of the empirical data and the calculation method of refining plain carbon steel in a converter, according to the blowing conditions of 185 t smelting reduction converter of No.4 steelmaking shop in Chiba Works of JFE Steel. The calculation results show that the required total consumption of chrome ore, coke and limestone in the smelting reduction process is 224.942 kg, 154.9 kg and 99.223 kg, respectively, under the conditions of this calculation. The total amount of slag includes the amounts of hot metal elements oxidation into slag, lining erosion into slag and chromium ore, coke and adding flux into the slag, which is calculated respectively according to the basic raw data and the set values of process parameters. The slag component is confirmed, namely, the actual basicity w(CaO)/w(SiO2)=2.6, the percentage of CaF2 in slag is 3~4 wt%, and the calculated w(MgO)/w(Al2O3)=0.7. In the actual production, the addition of chrome ore, coke and flux is increased by 3%, 2% and 1%, respectively.