Transformation of LiAlSiO4 glass into bulk zeolite Li-ABW via cold sintering process and removal of heavy metal ions

We demonstrate the densification of zeolite Li-ABW using cold sintering process (CSP) of LiAlSiO 4 (LAS) glass. During CSP, LAS glass transformed into zeolite Li-ABW and densified to 96% at 180 °C under 350 MPa. A columnar structure, a typical characteristic of zeolite Li-ABW, was observed with increasing sintering time, indicating a higher crystallinity of the cold-sintered sample. In addition, longer sintering times improved the mechanical properties, yielding a maximum Vickers hardness of 4.11 ± 0.16 GPa, indentation fracture resistance of 1.32 ± 0.07 MPa·m 1/2 , biaxial flexural strength of 126.29 ± 4.01 MPa, and Young’s modulus of 78.09 ± 1.65 GPa, representing the first report of a highly dense zeolite Li-ABW. The cold-sintered zeolite Li-ABW showed removal efficiencies of over 94% for Ni 2+ , Co 2+ , and Pb 2+ from the test solution at a concentration of 0.3 mmol/L. These findings suggest CSP offers new opportunities for fabricating bulk zeolite materials for environmental purification.