Determining the Role of Water Molecules in Sodalite Formation Using the Vapor Phase Crystallization Method

The efficiency of the vapor phase crystallization (VPC) process in zeolite formation using mixtures of a natural source (obsidian) and common waste materials (red mud and fly ash) was analyzed. The aim was to demonstrate that water molecules available during this treatment control mainly the synthesis of sodalite, regardless of the raw material used, as long as it is rich in amorphous silica and alumina pre-fused with NaOH. The data indicate that increasing the temperature to generate steam from distilled water during the VPC process results in the continuous transformation of amorphous material into sodalite and, subordinately, cancrinite. The formation of the newly formed phases was monitored by powder XRD and SEM.