Secondary Products Obtained from Saponite-Bearing Process Water: Theoretical and Experimental Justification

Abstract

The authors provide the theoretical and experimental justification for the effective methods of modification of saponite—pillaring and thermal treatment—which ensure production of sorbents possessing high cation exchange capacity relative to cations of heavy metals. The mechanism of pillaring and thermal modification of a saponite-containing product at the temperature of 625 °C involves expansion of layers of the mineral, formation of additional acid or redox sites (pillaring) and restructuring with generation of metastable phases (thermal treatment). Modification of saponite increases static exchange capacity relative to copper cations by 2 times after pillaring and by 2.6 times after thermal treatment.