Metabentonite and metakaolin-based geopolymers/zeolites: relation between kind of clay, calcination temperature and concentration of alkaline activator

Abstract In this paper, the composition and properties of two different activated calcinated clays were investigated under selected curing conditions. The tendency metabentonite metakaoline to form geopolymers zeolites was by FTIR spectroscopy, TGA DSC techniques, PXRD, HT-PXRD, SEM, BET-N 2 adsorption analyses. selection optimal sample compositions done on a basis preliminary results obtained from bentonite kaolin at calcination temperatures (700, 750, 800 °C) with holding time 3 h in combination NaOH concentrations (5, 10, 20 mass%). more detailed examination, samples calcined temperature °C studied. For metakaolin-based samples, dominant geopolymer formation achieved using 5 mass% NaOH. zeolite amount increased concomitantly concentration alkali activator, whereas A P determined as predominant phases. metabentonite-based 10 found be means formation. At higher alkaline activator concentrations, presence zeolitic phases faujasite gobbinsite confirmed. However, degree crystallinity significantly lower than corresponding metakaolin samples. With gradual increase concentration, specific surface area reaching value 218.95 m g −1 promising for applications. opposite effect observed result is caused changes their channel dimensions.