Modification of zeolite Na-X, sodalite and cancrinite in salt melts

Abstract

The possibility of occlusion in melts of useful components of some of the most economically advantageous materials, obtained during zeolitization of fly ash – Na-X, sodalite and cancrinite, was investigated. A very high degree of occlusion of ZnCl2 in zeolite Na-X was achieved along with complete exchange of Na extra framework cations with Zn2+. By elution, it was proved that, in the interaction of zeolite Na-X with ZnCl2 melt, occlusion takes place without destroying the zeolite aluminum-silicate framework. In a KNO3 melt, in the narrowest pore structure – the sodalite structure, occlusion does not proceed, only ion exchange occurs. Through computer modeling, the ion exchange of both the charge-balancing cations and the synthetically incorporated cation-anion pairs has been proven. The interaction of cancrinite-SO4 with a KNO3 melt results in the formation of a material with an altered cationic composition and occluded KNO3, which gradually comes out of the structure upon elution. The results obtained in the work can be a basis for the development of future applications of the modified minerals as materials with antibacterial properties (occluded ZnCl2 in the structure of zeolite Na-X) and as slow-acting fertilizers or micro-fertilizers (occluded with KNО3 cancrinite and sodalite forms).