A New Type of Composite Coke Prepared from Steel Slag and Mixed Coal: Preparation Process and Microstructure

Abstract

High‐reactivity coke is a kind of burden for a low‐carbon blast furnace. Herein, a new method of preparing steel slag composite coke (SCC) from steel slag and mixed coal is proposed. The effects of the raw material ratio and carbonization parameters on the compressive strength, coke reactivity index (CRI), and coke strength after reaction (CSR) are investigated, and also the phase structure and functional group are analyzed. In addition, because the main chemical composition of steel slag is CaO, the effects of the CaO component on the phase structure and functional groups are studied. The results show that with increasing steel slag ratio, the compressive strength of SCC tends to decrease. When increasing the steel slag ratio from 5% to 15%, the CRI tends to increase from 53.7% to 61.0%, and the CSR decreases from 38.6% to 6.2%. With increasing anthracite ratio, the compressive strength of SCC first increases and then decreases. With the carbonization temperature increasing, the Ca2SiO4 gradually fades away, Fe3O4 is gradually reduced to Fe, and the aromatic CC and stretching OH absorption zone is decreased. With the increasing of CaO content, Ca2Al2SiO7 tends to increase, and the intensity of the peak band (002) and peak band (100) is lowered.