Production Process Optimization of Mongolian Iron Ore Pellets for Baogang Group

Baogang Group imported large quantities of Mongolian iron ore to solve the shortage of ironmaking raw materials. But the basic parameters of Mongolian iron ore in pellets production are deficient. In this paper, orthogonal experimental method was used in the optimization of roasting production process of Mongolian iron ore pellets. The results show that when the content of Mongolian iron ore is 55%, the factors affecting the expansion rate of pellets in order of decrease is bentonite proportion, roasting temperature, roasting time and preheating temperature. For pellets containing 55% Mongolian iron ore, the optimum roasting schemes are as follows: bentonite proportion at 3.3%, roasting temperature at 700°C, roasting time at 14 minutes and preheating temperature at 1280°C. Under this roasting scheme, the expansion rate of pellets is 13.41%, and the compression strength reaches 2275N, which meets the technological requires of large blast furnace. The main phase of the Mongolian iron ore pellets is hematite, with a porosity of 25%-30%. And the content of gangue and liquid phase is relatively low, which is beneficial to the reduction process of pellets in blast furnace.