X-RAY AND MAS NMR CHARACTERIZATION OF THE THERMAL TRANSFORMATION OF LI(NA)-Y ZEOLITE TO LITHIUM ALUMINOSILICATES

The high temperature thermal transformation of Li-exchanged Na/1bY zeolite has been investigated by X-ray diffraction and 29Si MAS NMR studies. At 700°C, the zeolite was transformed into an amorphous phase and upon further heating to 800°C, formation of lithium aluminosilicate with high-quartz structure, in addition to an amorphous phase, was noted. When heated above 900°C, the high-quartz structure was transformed into a β-spodumene related solid solution. X-ray and MAS NMR studies indicate the β-spodumene solid solution formed has the composition close to (Lio.23Na0.06) Al0.29Si0.71O2, which is in agreement with chemical analysis. © 1986.