Thermal loading of smectite-rich rocks: Natural processes vs. laboratory experiments

Structural changes of clay minerals were studied using XRD, TG and DTA. Two main transformation processes (illitization and kaolinization) of smectite-rich rocks followed by deterioration of physico-chemical properties were observed after heat treatment. Cation exchange capacity drops significantly with increasing temperature and so does Smicro. However, SBET values increased when heat treatment was applied.