Modification of the microstructures of CaO-SiO2-Al2O3-MgO slags using various minor elements

CaO-SiO -Al O -MgO (CSAM) system is a fundamental and significant system in geology, metallurgy and the glass industry. Herein, we firstly investigated the roles of minor elements on the microstructures of this system. By Raman spectra and deconvolutions, we found that the presence of B O induced an increase of the degree of polymerization (DOP) of the networks. On the contrary, the existence of Na O, K O and MnO had an opposite effect, i.e., the average number of bridging oxygen per Si atom decreased by 0.20, 0.07 and 0.11, respectively, with ~5 wt% of additions. Moreover, two particular minor elements, CaF and CaS, resulted in a decrease of the DOP. Furthermore, the macroproperties of this CSAM system with various minor elements were connected to the present microstructural analysis and thus the micro-macro relationship was deeply discussed, based on which we elucidated the clues for modifying this system in different levels using these minor elements.