Cold Sintering Technology as a Friendly and Sustainable Way of Producing Ceramic Materials from Recycled Waste

This paper presents a new ceramic building material produced by the cold sintering process (CSP), as a greener and cleaner technology compared to conventional ones. The ceramic composites were made from recycled clay bricks (RCBs), a byproduct resulting from construction and demolition and waterglass (WG) as a liquid solvent, pressed at 400 MPa and sintered at a temperature of 150–200 °C. After the samples were produced, their structure and physical and mechanical properties were investigated. The internal morphology of samples shows a homogeneous structure with a low porosity (up to 3%). The compressive strength of ceramic building material produced by the CSP was up to 211 MPa, considerably higher than the reference sample whose value was 45 Mpa. This high strength is due to the internal structure of the ceramic composed of a tough amorphous phase that acts like a binder holding together the powder particles and closing most of the porosity inside the material.