Behavior of Ironmaking Slag Permeation to Carbonaceous Material Layer

Abstract

To investigate the slag permeation to packed bed of carbonaceous materials, the measurement of molten slag’s densities, surface tensions and dynamic contact angle on carbonaceous materials at relatively low temperatures (from 1 673 to 1 773 K) are carried out by applying the sessile droplet method. The interfacial compositions of slags and carbonaceous materials were examined by SEM/EDX. SiC at carbonaceous material surface was not observed. The variation of measured density, contact angle and surface tension with time were found to be almost negligible with given slag composition and at given temperature. It is reported that carbonaceous material wettability at the temperature of more than 1 873 K was strongly dependent on the slag composition as well as carbon properties. The almost constant contact angel with time in this study can be attributed to the negligible formation of SiC at carbonaceous material surface.
The slag permeation model has been developed along with the measurement of physical properties. The maximum retention height of liquid layer on the sphere packing layer is expressed by H_C=A/L_C+L_C/2, where A is constant and H_C and L_C are the dimensionless slag layer retention height and the dimensionless sphere's diameter, respectively. Slag layer retention height on the carbonaceous material packing layer is evaluated using the measured physical properties. The proposed characteristic length λ (=√(−γ_L cos θ/ρℊ)) in the model can be used to characterize the slag permeation behaviour.