Elaboration of geopolymer binder from pharmaceutical glass waste and optimization of its synthesis parameters

Abstract

The objective of this study is to manufacture a new geopolymer binder from pharmaceutical glass waste as a main raw material. The geopolymer synthesis followed a chemical procedure whereby the effect of several parameters, namely, the glass particle size, the concentration of the alkaline solution and the cure temperature were optimized. Several techniques were used to characterize the raw material and the obtained geopolymers: X-ray diffraction, X-ray fluorescence, Fourier-transform infrared, scanning electron microscopy and thermo-gravimetric analysis. The compressive strength of the produced geopolymers was determined by mechanical tests. The results show that the pharmaceutical glass waste produces geopolymer binder of high mechanical performance. Contrary to metakaolin-based geopolymers, no sodium silicate is required for the setting and hardening of this geopolymer type. The thermal activation by increasing the cure temperature improves the geopolymerization kinetics and leads to a high compressive strength, which exceeds 60 MPa for 60 °C and NaOH alkaline solution molarity of 8 M.