Characterization of Rice Husk Ash and Its Recycling as Quartz Substitute for the Production of Ceramic Glazes

In this work a complete characterization of rice husk ash (RHA) was conducted in order to evaluate mainly the composition and the thermal reactivity in terms of crystalline phase evolution. Moreover, the screening results of the research conducted on the possibility to use RHA as silica precursor in ceramic materials, such as ceramic glazes, were reported. The selected frits were prepared in a semiindustrial furnace and the obtained glasses were investigated in comparison with the frits prepared from pure quartz. Besides, laboratory glazes were obtained and characterized following the technical rules. This work allows to confirm the possibility to use RHA as silica precursor for the development of glazes for ceramic tile. The results evidenced, however, that it is not possible for a generalized production substitution of quartz with RHA.