Lighter Structural Clay Ceramics Manufactured with Marble Cutting Dust and Paperboard Based Packaging Waste

Abstract

This work evaluates some preliminary results of adding two kinds of wastes in two characteristics clay mixtures with the aim of producing lighter structural ceramic products. The selected wastes are marble cutting dust and a packaging waste mainly composed by paperboard and polyethylene. In the case of clay mixtures, they are focused to the manufacture of both common and facing bricks. New waste based formulations are proposed on the basis of chemical and mineralogical compositions of clays and wastes and previous experiences in literature. Especial attention is paid to initial carbonate content in the selected clays, since marble waste is almost exclusively formed by calcite. Dynamic sintering tests and technological properties characterization were performed to analyse the feasibility of waste incorporation. Sintering behaviour shows a larger influence of marble dust waste and it is radically changed in the case of clay mixtures for facing products. Technology properties of unfired specimens are in general adequate for the industrial practice. Final technological properties of sintered specimens shows lower density for the new waste bearing products but not unique trends with sintering temperature for another properties as bending strength or water absorption capacity. These properties are mainly conditioned by the sintering behaviour associated to marble dust addition and, thus additional microstructure and mineralogy test would be necessary for a better knowledge of these materials and their optimised formulation.