Application of thermal methods in the studies of potential pozzolanic reactivity of attapulgite and sepiolite

Aim of study was to verify the effect of temperature on the pozzolanic reactivity of thermally activated attapulgite and sepiolite samples. Activation temperatures were selected: 650, 700 and 750 degrees C for attapulgite and 800, 825 and 850 degrees C for sepiolite. Content of pozzolanic reactive SiO2 and Al2O3 after thermal treatment and the amount of Ca(OH)(2) consumed in the pozzolanic reaction were measured. It should be noted that a higher activation temperature improves the reactivity of attapulgite and sepiolite. The upper limit for the increase in the pozzolanic reactivity of these materials is the formation of enstatite and the deactivation of silica. In addition to reactive decomposition products, series of minerals formed in the reactions of attapulgite and sepiolite with impurities present in them are also observed.

Automated summary

The aim of the study was to investigate the impact of temperature on the pozzolanic reactivity of thermally activated attapulgite and sepiolite samples. Different activation temperatures were chosen for the two minerals. The study observed that a higher activation temperature enhances the reactivity of attapulgite and sepiolite, with the upper limit being the formation of enstatite and deactivation of silica. The reactions also resulted in the formation of various minerals due to impurities present in the minerals.