This study investigates the synthesis and characterization of metakaolin-based geopolymers for the immobilization of simulated aluminum-containing radioactive liquid waste. Two kaolin precursors with different Si/Al ratios and purities were calcined between 700 °C and 900 °C. Geopolymers were prepared using a sodium silicate–NaOH activating solution (10 M NaOH) with and without sand, and cured at 60 °C. The effects of curing time and simulated liquid waste incorporation (10–40 wt%) on mechanical
