PRODUCTION OF CERAMIC

PROBLEM TO BE SOLVED: To produce a ceramic product which is safe and physically stable and from which any heavy metal or the like, is not eluted by melting ash in a waste material, crystallizing the molten ash to form a crystallized material, mixing the crystallized material, a plastic raw material and a nonplastic raw material together in a specified mixing ratio, forming the resulting mixture into a formed body, drying the formed body and firing the dried body at a specified temperature. SOLUTION: The ash in a waste material is fused at 1,300-1,500 deg.C then cooled to form a glassy material, and the glassy material is reheated to almost completely crystallize the glassy material thereby obtaining a crystallized material containing at least either anorthite crystals or β-wollastonite crystals. The 40-70 wt.% of the crystallized material, 10-50 wt.% of a plastic raw material for providing plasticity and viscosity and the remainder of a nonplastic raw material for adjusting mechanical strength, rigidity and toughness are ground and mixed, then an adequate amount of water is added to the resulting mixture to knead the mixture, and the kneaded mixture is formed, dried and fired at 1,000-1,200 deg.C to produce a ceramic product. Wherein as the plastic raw material, a clay mineral such as kibushi clay (produced in Japan) is used and as the nonplastic raw material, a rock mineral such as feldspar is used.