Role of silicate phases during comminution of titania slag

Titania slag is the primary product of ilmenite smelting, and serves as a feedstock to the TiO2 pigment industry. The fine material (smaller than 106 μm in diameter) which is produced during milling of titania slag is enriched in some impurities, notably SiO2, Al2O3, K2O and CaO. Investigation of microstructures of solidified slags confirmed that these oxides partition to the silicate phases which form during final solidification. The presence of silicates on the surfaces of particles in milled slag supports the suggestion that the silicates contribute to fracture during crushing and milling. No significant macro-segregation was found in the slag ingots.