Ceramic tiles adding waste foundry sand to different clays

Abstract

This work continues the research on recycling of waste foundry sand as aggregate in the manufacture of bricks and red clay tiles. Initially, clay with a major content of soil was used. The obtained specimens showed high porosity due to the combustion of the organic matter present. Moreover, this type of raw material has properties that vary greatly according to the extraction sites. In order to improve quality and achieve uniformity in the properties of the obtained products, samples with commercial clay in similar composition are studied in this work. The commercial clay (from Olavarría, Argentina) is composed of a mixture of mineral clays without any content of black soil. Several samples were obtained with aggregates of different percentages of foundry sand to the commercial clay, with a compaction pressure of 25 MPa. These samples were heat treated to 930°C for three hours. The characterization of raw materials and products was carried out by using different techniques: optical and scanning electron microscopies, porosity and density measurements and mechanical properties determination, among others. The results were analyzed on a comparative basis with those of samples produced from clays containing black soil. The obtained materials meet the standards required for commercial products. © 2010 WIT Press.