고체연료의 측정된 연소율과 소결광 내 Calcium-Ferrite 형성량을 이용한 수치모델링을 통한 소결 공정의 동역학적 평가

Abstract

In general, the sintered ores were generated by mixing raw materials such as iron ore, CaCO3 and solid fuels. The forming fraction of CaO based liquidus phases was dependent on the mixing ratio of raw materials and temperature. In order to improve the quality of sintered ore, it is very important to control the temperature distribution of the sintering process. However, the controlling temperature for sintering the iron ore is not simple because the complex reactions among the combustion of cokes, the decomposition of CaCO3, the melting of CaFe2O4 and slag occurred immediately. The controlling temperature in the sintering process can be conducted by simulation of the complex reactions. In this study, the formation fraction of CaO based liquidus phases was investigated by changing sinter basicity at ~1423 K. In the experiment, when the temperature increased from room temperature to target temperature, the atmosphere was controlled by the N2 gas. After reaching target temperature, atmosphere was changed to dried air gas and then combustion of solid fuels has been carried out for 2 hours. The samples were evaluated using EPMA and image analysis. Furthermore, we measured the combustion rate of solid fuels which is one of the factors to determine the temperature of the sintering process. In the experiment, when the temperature increased from room temperature to target temperature, the atmosphere was controlled by the (N2) gas. After reaching target temperature, atmosphere was changed to dried air gas and then combustion of solid fuels has been carried out for 2 hours. The numerical model of the sintering process was developed by 4th Runge-Kutta method using combustion rate of solid fuels which is obtained from the experiment. The distribution of temperature was simulated by the developed model.