Understanding of the thermophysical properties of porous sinter is especially important for operation optimization and energy saving in integrated steel mills. Under this prospect

nondestructive X-ray microtomography was applied to characterize the pore structure and the simulations for estimating the sinter effective thermal conductivity were performed. Three sinter cakes produced from pilot-scale sinter pot tests under three hydrated lime addition levels were scanned with resolution ratio of 40 μm. The reconstructed sinter cakes have various complex pore distributions

leading to remarkable anisotropic thermal conductivities and complicated temperature field. The pores smaller than 300 μm dominate the number frequency in sinter cake (around 45%-50%)

while a small amount of pores larger than 1 mm account for around 95% of the total pore volume

which determines the thermal behavior greatly. The estimated effective thermal conductivities of three samples are 0.645

0.682

and 0.784 W·m-1·K-1

corresponding to the porosity of 53.8%

53.1% and 49.7% respectively. Comparing these values with values of similar iron agglomerates in the literature

some empirical correlations and analytical models

the results proved that CT-simulation is a valid approach for capturing the peculiar details of the real sinter porous structure

thus to predict thermal behavior with higher accuracy than the simplified geometric models.