Recycling silicon solar cell waste in cement-based systems

This is a study of the recycling of crystalline solar cells by incorporating them in cement matrices. The hydration process of a mixture of calcium aluminate cement (CAC) and solar photovoltaic cell waste was researched and analyzed. The nature of the hydration products of various compositions of these mixtures was evaluated at a temperature of 20 degrees C by analyzing the samples through X-ray diffraction, infrared spectroscopy and scanning electron microscopy. The total porosity and mechanical strength development of these materials were also determined. It was revealed that the presence of a solar cell residue of up to 5% in the cement matrices does not result in new hydration products that are different from those derived from the normal hydration of the CAC cement. Moreover, the material developed can be considered as an expansive cement blend because it releases H-2 at early stages. The presence of waste causes a decrease in the mechanical strength and an increase in the total porosity of this material, but it can be used for applications such as thermal insulation. (C) 2011 Elsevier B.V. All rights reserved.