“Microwave assisted weak alkali activation of waste glass”

Activated pharmaceutical glass waste after MW treatment.

Microwave treatment allows to reduce the curing time of activated glass waste. In literature Microwaves have been used to harden metakaolin-based geopolimers but never for curing weak alkali activated glass powders. It is generally agreed that MW heating is more efficient, prevents the formation of temperature gradients through volumetric heating of the material and, above all, requires less energy.  Pharmaceutical glass waste has been activated (2,5M NaOH alkaline solution) and microowaved after short precuring at 40°C. The solidified material obtained after MW resists boiling test (1h, distilled water at 100°C) and shows a higher compressive strength (16 MPa) than samples cured for 7 days at 40°C (10 MPa). This treatment enables to reduce normal curing time and limits energy consumption.