Effect of Cr2O3 on properties of CaO–SiO2–FetO–MgO system and dissolution behavior of lime

The productivity of the chrome-containing semi-steel converter smelting process is directly affected by the slag-forming speed during the converter preliminary stage. The effects of Cr2O3 content on the physicochemical properties of the CaO–SiO2–FetO–MgO system, such as melting temperature, solidification behavior, mineral composition, and lime dissolution rate, were studied. The results showed that the slag was an amorphous phase at 1500 °C. When Cr2O3 was added, Ca(Fe,Mg)Si2O6 and spinel were formed in the slag. With the increase in Cr2O3 content, the amount of spinel precipitation increased, and the dendritic Fe3O4 crystal gradually changed into the granular (Fe,Mg)(Fe,Cr)2O4 crystal. As the Cr2O3 content increased from 0 to 2.91 wt.%, the melting temperature of the slag rose, and the melting range of the slag expanded slightly, but the lime dissolution rate did not change. When the Cr2O3 content further increased to 9.09 wt.%, the melting temperature continued to rise, the melting range rapidly expanded, and the lime dissolution rate decreased.