Desenvolvimento de vitrocerâmica a partir de reciclagem de vidros sódico-cálcicos.

Abstract

The glass-ceramics have functional properties such as chemical durability and high mechanical hardness. Based on this, the recycling of sodium-lime glass, typical of packaging, for the production of glass-ceramics can add value to this material continuously discarded in the environment. The glasses have an environmental advantage with regard to their high recycling potential, in addition to the possibility of being molded into the desired shape, which contributes to various forms of application. This work had as objectives, the development and characterization of vitroceramic tablets of considerable aesthetic appeal through the application of different heat treatments in sodium-calcium glassy residues. As well as, the obtaining of material with microhardness and impact resistance superior to the precursor glass as well as the typical glass-ceramic X-ray diffraction pattern. It was also within the scope of this research, the comparative analysis between the molds used as well as possibilities of finishing the pieces to improve the visual aspect. Eight granulometric combinations of vitreous residues and different heat treatments (800oC, 820oC and 840oC) were developed, which resulted in sintering and annealing. The tablets were characterized by X-ray dispersive energy spectroscopy (EDX), X-ray diffraction (XRD), Vickers microhardness, impact resistance and optical microscopy. As a result, the diffractograms indicated a reduction in the halo characteristic of the amorphous glassy structure and formation of crystalline phases for the amber color. The microhardness test proved the effectiveness of heat treatments to increase mechanical hardness in relation to precursor glass. Optical microscopy showed the beginning of crystallization in the microstructure of the samples. Finally, the sintering temperature of 840oC, gave the best result regarding the increase of the mechanical hardness in relation to the precursor glass. Thus, the use of glassy residues was efficient to obtain glass-ceramics, as well as the combinations of time and temperature used were satisfactory for improving mechanical properties.