Synthesis and characterization of geopolymers using clay ceramic waste as source of aluminosilicate

This work deals with the valorization of clay ceramic waste as raw material for the synthesis of geopolymers. The clay ceramic waste, sodium hydroxide and sodium silicate were the independent variables of a mixture design used to define the geopolymeric system. The chemical composition, crystalline structure, particle size distribution, specific surface area, functional groups and thermal behavior of the clay ceramic waste was determined. The ceramic waste was mixed with sodium silicate and sodium hydroxide in a laboratory mixer according to the mixture design. The mixtures were poured into cylindrical molds and cured at 45 °C for 72 h. After thermal treatment, the samples were cured at room temperature for 28 and 133 days. After demolding, the compressive strength, crystalline structure, thermal behavior, and microstructure of the geopolymeric compositions was determined. At 133 days, the average compressive strength was higher than that at 28 days. As a result, geopolymers were synthetized using the waste of clay ceramic industry by alkaline activation.