Production of highly reactive cokes by adding alkali metals and alkaline earth metals and their effect mechanism

The influence of alkali metals and alkaline earth metals on coke reactivity and coke microstructure was studied by the mechanical mixing method to produce metallurgical cokes with high reactivity. The Gasification kinetics of coke samples was further studied to clarify the catalytic mechanism of alkali metals and alkaline earth metals on cokes, which provided a basis and guidance for the production of hydrogen-rich blast furnace charge. The chemical reactivity index of cokes increased significantly after adding alkali metals or alkaline earth metals. Meanwhile, CaO had little effect on the structural strength of cokes, while the structural strength of cokes added with K2CO3 and Na2CO3 decreased. The microstructure analysis of different coke samples showed that cokes produced new pores after adding alkali metals or alkaline earth metals, with increased contact area and decreased disorder of cokes. These were the main reasons for the increased reactivity index of cokes. The addition of alkali metals or alkaline earth metals increased the positive reaction rate constant and the effective diffusion coefficient inside cokes by analyzing the kinetic behavior of cokes after adding alkali metals or alkaline earth metals. Furthermore, it reduced gasification reaction resistance and internal-diffusion mass transfer resistance.