An in situ spectroscopic study on decomposition of MgSiO3 during the alkali fusion process using sodium hydroxide

Abstract

The mechanism of decomposition of magnesium inosilicate (MgSiO₃) during the alkali fusion process using NaOH was investigated by Raman spectroscopy in situ and X-ray diffraction analyses. The results show that the tetrahedral silica chains within MgSiO₃ are gradually disrupted, and nesosilicate with the isolated SiO₄ tetrahedra becomes reorganized at the beginning of the alkali fusion process. In the decomposition of MgSiO₃, the two intermediates are Mg₂SiO₄ and Na₂MgSiO₄, while the final products are Mg(OH)₂ and Na₄SiO₄. It can be concluded that this decomposition did not initiate from the cation exchange reaction in the process.