added 0–15 wt.% eggshell powder to 70 wt.% red plastic clay, 15 wt.% commercial quartz and 0–15 wt.% calcareous materials to produce ceramic wall tiles.
Freire and Holanda added 0–15 wt.% eggshell powder to 70 wt.% red plastic clay, 15 wt.%commercial quartz and 0–15 wt.% calcareous materials to produce ceramic wall tiles.