Effect of slag basicity on the interfacial wetting behavior between CA6 refractories and CaO-SiO2-MgO-Al2O3 based slag

The wettability between the slag and refractory has an important relationship with the corrosion of refractory, which can elucidate the corrosion process and reveal the corrosion mechanism. In this work, the wetting process between different basicity slag and CA6 substrate was investigated via the sessile drop method. The wetting and spread process, morphology evolution, and ion diffusion behavior were characterized and analyzed, and the interface reactions were calculated by the thermodynamic simulation software FactSage 7.1. The results show that the slag spreading process can be divided into deformation, melting, and wetting three steps. The contact angle increased with the slag basicity increased. The driving force of the higher basicity slag to penetrate CA6 refractory is weaker, and the penetration depth is smaller, so the width of the reaction layer decreased with the slag basicity increasing, indicating the CA6 refractory has a better corrosion resistance for high basicity slag. The results of the thermodynamic simulations show that the higher basicity slag can generate CA2 faster, which can inhibit the slag corrosion rapidly, leading to the increment of contact angle and weaker wetting behavior for higher basicity slag. The CA6 refractory has great potential for application in high-quality steel smelting.