In situ observation of the crystallisation process of perovskite in titanium-bearing blast furnace slag

The crystallisation behaviour of perovskite in liquid synthesised titanium-bearing blast furnace (BF) slag (TiO2–SiO2–Al2O3–MgO–CaO) was observed in situ with a confocal scanning laser microscope (CSLM). Perovskite crystals were dendritic columnar crystals that nucleated on the crucible bottom (and wall) and grew to the centre and surface of liquid slag. The CSLM result that perovskite grew along straight lines through the successive appearances of quasi-particles on slag surface reflected the growth process of dendrites beneath the surface. The formation of perovskite required the diffusion of TiO2 and CaO to the solid interface at the dendrite tips and the rejection of SiO2, Al2O3 and MgO from the interface.