Addition of cement kiln dust in ceramic wall tile bodies

The volume of wastes generated from heavy industries, such as cement and steel industries, is increasing, and the cost of landfill disposal grows daily. Economical and eco-friendly areas of recycle are being developed to stop the growth of these waste products. Cement kiln dust (CKD) is a waste product in the cement industry. It contains very fine grains like cement in addition to finer particles of lime, silica, alumina and iron. These particles contain high concentrations of sulphates and alkalis. The aim was to study the effects of using CKD as an alternative source of CaO in ceramic wall tile production. Ceramic tiles compositions in different ratios were prepared with CKD (15 mass% max) rather than calcite. All shaped samples were sintered at 1150 °C. Optical dilatometer was used to evaluate sintering behaviour. Physical properties, such as linear firing shrinkage, bulk density, flexural strength and water absorption, were also measured. The bodies containing CKD showed a decrease in moisture expansion and were whiter than the body of a standard composition. This study showed that CKD is an effective CaO source in ceramic tile production.