Analogue iron ore sinter tablet structure using high resolution X-ray computed tomography

During iron ore sintering large structural changes occur as liquid is formed in the flame front. The transformation of the structure into the agglomerated product is important for its physical and metallurgical properties. To quantify the change in sinter structure, analogue sinter tablets were made under tightly controlled conditions in a rapid heating furnace. The effect of maximum temperature, partial pressure of oxygen and ore type was investigated using a factorial design methodology. The internal structure of these tablets was measured in three dimensions using high resolution X-ray computed tomography (4.5 μm voxel size), to determine the size, shape and connections of the pores. Most of the open pore volume was contained in a single continuous interconnected pore network. Analysis showed maximum temperature, ore type and the interaction between ore type and maximum temperature to have a statistically significant impact on tablet volume. A similar analysis showed maximum temperature, ore type and the interaction between maximum temperature and partial pressure of oxygen (pO₂) to have a statistically significant impact on total porosity. Greater melt volumes increased the size, sphericity and total volume of pores.