RUSTIC CERAMIC COVERING TILES OBTAINED BY RECYCLING OF MARBLE RESIDUES AND MSW FLY ASH

The substitution of conventional clay raw materials for some wastes, in this case, ashes from the incineration of municipal solid wastes (MSW), and other marble residues (sludge, scraps...) enriched in CaCO3 in the production of traditional ceramics, has long been recognized as leading to possible savings in costs due to the recycling of wastes as a secondary raw material. The most suitable compositions were selected regarding the production of ceramic tiles as covering for construction, as well as considering its technological and ceramic behavior. In order to evaluate the ceramic properties of these tiles, linear contraction (LC), water absorption capacity (WA) and bending strength (sigma(f)) were determined. The relation between LC values and the added residues content has been discussed. However, the increase in water absorption with the increase in the residue percentage is evident. The addition of this marble sludge gives rise to a low decrease in bending strength, which is usual when some residues are added in the production of bricks or roofing tiles. In any case, by considering the physical and mechanical properties, the tile bodies depict property values which are close to marketable ceramics.