Effects of Minerals and Carbon Structures on the Dissolution of Coke in Liquid Iron

The effects of coke mineralogy and carbon structures on coke dissolution in liquid iron were studied at 1 500°C. Coke mineralogy was studied by measuring the dissolution of three cokes, with three different mineralogies, in liquid iron. To allow the change in carbon structures in the coke during dissolution to be determined, samples were quenched and characterised. The dissolution of coke analogue samples were also studied, which contained the ash from the cokes. The three cokes were found to have distinctly different dissolution rates. The dissolution of the three coke analogue samples was found to closely replicate the dissolution of the three cokes. By using the coke analogue, carbon structure, porosity and particle size were largely eliminated as variables. Therefore, it was likely that the differences in coke minerals between the three cokes were predominantly responsible for the dissolution rates of the samples. The differences in carbon structure between the cokes likely had little effect on the dissolution of coke in liquid iron. To help understand this, Raman spectroscopy of quenched samples was used to assess the changes in carbon structures in the coke samples during dissolution. The cokes became more graphitic with time at 1 500°C. Further, though the coke started off with different carbon structures, the cokes assessed tended to a similar value dominated by the temperature effect on graphitisation.