Simulation study on the effect of increasing pellet proportion on burden distribution in the blast furnace

Abstract

As an effective method to strengthen blast furnace (BF) smelting and to realize reduced fuel operation, high-proportion pellet charging has become an inevitable trend in the BF ironmaking. However, due to the high rolling characteristics of pellets and the low repose angle of stockline, the high-proportion pellet charge structure also brings some difficulties to the control of gas distribution and the BF operation. In order to find out the burden distribution characteristics in the BF under high pellet ratio and provide theoretical guidance for improving the operation of high pellet ratio of the BF, a mathematical model of the upper part of the bell less BF is established, and the influence of pellet ratios on the burden distribution is analyzed by a discrete element method (DEM). The results show that as the proportion of pellet increases from 10% to 50%, the width of the stockline platform decreases from 1.081 m to 0.895 m, and the stockline angle decreases from 34.00° to 31.63°. With the increase in the proportion of pellets, the porosity of the stockline decreases, and the porosity along the radial direction from the furnace wall to the center also decreases gradually.