In this study, soda-lime silica waste glass was used as partial and total replacement for feldspar in porcelain. The prepared samples from feldspar, quartz, kaolin and different percentages of waste glass by powder technology technique were sintered at 1,100 ºC and 1,200 ºC. The tests measured for samples involves mechanical, physical and thermal properties. A results of these tests indicated an increasing and decreasing in the samples properties with increasing of waste glass additive, and that continues to 75% waste glass of feldspar. While X-ray diffraction analysis indicated a presence of tridymite phase SiO₂, mullite phase 2SiO₂.3Al₂O₃ and anorthite phase CaAl₂Si₂O₈ in the sample contained 100% waste glass of feldspar and fired at 1,200 ºC. This study showed possibility of replacement of feldspar used in porcelain industry by waste glass as flux, and a percent of waste glass additive, which gives the best properties of porcelain samples, is 75% wt. of feldspar.

Keywords: soda-lime silica waste glass, porcelain, feldspar, fracture strength, kaolin