Influence Mechanism of Lignite and Lignite Semi-coke Addition on Drum Strength of Coke

Abstract

In order to clarify the effect of lignite and lignite semi-coke addition during coking process on the drum strength, I-type drum, thermogravimetric analyzer, SEM and XRD were used to investigate the properties of coke, such as drum strength, coking process, microstructure and crystallite structure. The result showed that because of the dramatically interaction of the volatile matter of lignite with coking coal in the initial coking stage resulting in the increase of uneven degree of macroscopic pores, the drum strength of coke decreased rapidly with the increase of lignite addition ratio. However, when the ratio of lignite semi-coke addition was less than 6%, the stacking height Lc value of coke increased and the evolution of macroscopic pores was restrained. By adding lignite semi-coke obtained from carbonization of lignite at 700°C, the drum strength of coke was improved obviously. Thus, it was promising measure to expand the application scope of lignite in the ironmaking system of blast furnace through carbonization.