Dissolution Mechanism of Modifying Agent in Fibrotic Process of Steel Slag

The kinetic behavior of SiO2 dissolving in molten steel slag at 1773–1923 K was studied using a combination of high-temperature confocal scanning laser microscopy and a synthetic physical property tester. The experimental results showed that the change in slag electrical conductivity can characterize the homogenization process of the modifying agent in molten steel slag, and the dissolution process of the modifying agent is controlled by solute diffusion in the slag. The concentration difference between the boundary layer and the bulk of the slag is the primary driving force of the dissolution process. By increasing the reaction temperature, the SiO2 particle dissolution rate in slag can be significantly increased. Moreover, the experimental data and model calculations revealed that the SiO2 dissolution rate was the fastest when the total Fe (T.Fe) content was 14% and the acidity coefficient (Mk) was 1.5. The dissolution factors were defined to quantitatively evaluate the dissolution mechanism of particle by studying the dissolution process of slag with different components.