Fig. 10 shows the powder XRD patterns of the
wasteform before and after leach test. From the results, it was
noticed that the wasteform is stable ever after one month continuous
exposure with water. However, the crystallinity of the
wasteform after the test was affected as it can be seen from the Xray
diffraction pattern (Fig. 10b). Thus, the preliminary results on
the phase stability towards ionic substitution, thermal stability and
chemical durability study indicate that langbeinite structure could