Because ceramic products are difficult to be recycled with zero emission, they are buried as industrial wastes. We retrieved successfully a used product of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) as a new ceramic product. A used Y-TZP product was hydrothermally treated in an autoclave at 200°C for 66 or 162 h. The obtained powders were pulverized, press-formed and then sintered at 1450°C for 2 h. As a result, we had densely sintered recycle Y-TZP product.
