In this work, glassy layers of three commercial mold fluxes were obtained by quenching from 1300°C. These layers were characterized by XRD, Raman and XPS spectroscopy. The viscosity of these materials, measured between 1250-1350°C, were associated with a polymerization index of the silicate networks determined by the deconvolution of the Raman peak between 800-1200 cm-1. The higher content of sodium (Na) and fluorine (F), forming Si-O-Me links (Me = F, Na) it is associated to a lower activation energy of viscous flow. From the analysis of XPS spectra it is proposed that, in addition to Si-O-Na, other species such as Si-O-Ca-F are formed.
