[en] The identification of corrosive agents and corrosion mechanisms is necessary to increase the furnaces campaign. Silica refractories installed in 'Santa Marina' glass furnace crown were studied. X-ray fluorescence technique was used to determine the corrosive agents diffusion, which are present in the furnace atmosphere, leading to the formation of low melting temperature phases, causing the matrix glassing. Another interesting aspect was observed in the iron oxide/refractories color relation, according to its deepness. Hg porosimetry and X-ray Diffraction were also used to evaluate the microstructural variation and phase changes. (author)