Due to increasing significance of impact of coke minerals on coke behaviour, mineral phase transformations of three industrial cokes were characterized under a range of reacting conditions including in samples after reactions with 100% CO2 up to 1500°C in a horizontal furnace. Mineral phases of the raw and the reacted cokes were characterized by using XRD (X-ray diffraction) and SEM/EDS (Scanning Electron Microscopy/Electron Dispersive Spectra). A comprehensive approach to characterize all aspects of coke minerals is presented, and accordingly minerals phases of three raw cokes were distinguished on the basis of their physical and chemical characteristics as well as their distribution behavior. At standard CSR test temperature of 1100°C, the mineral interactions were found to be sluggish such that different cokes displayed different degrees of decomposition, dissemination with carbon matrix and inclusions in pores. At a higher reaction temperature of 1500°C, the intensity of mineral reactions increased significantly resulting in severe decomposition of mineral aggregates, enhanced dissemination or increased association of fine minerals with carbon matrix as well as increased inclusions in pores. The significance and implications of mineral phase transformations on coke behaviour in an operating blast furnace are also discussed.
