Green Stoneware Containing Waste Metals

Abstract

Green stoneware tiles have been produced by the incorporation of galvanic waste to industrial compositions processed from kaolinitic clay, feldspar, quartz. Some compositions with recycled domestic glass are also prepared. The galvanic waste required a calcination step to eliminate the gas forming species prior its incorporation into industrial processes. The effective absorption of metal from the galvanic waste was attained through the formation of crystalline phases. The presence of chromite type particles in the porcelain matrix acts as “in situ” to form pigments. The crystallization process also produces a higher consume of metal cations in the surrounded area of the crystalline pigments. The followed procedure allowed to effectively immobilized up to 20 wt% metal waste in a porcelain stoneware that satisfy both the mechanical and the chemical standards required to massively commercialize such a product.