Study of Composites Based on Parkent Kaolinite Clay

Abstract

Results are provided for a study of the structure and composition of composites based on red-burning kaolinite clay and calcium carbonate heat treated at 500°C during acid activation. It is shown that during reaction with 12% H₂SO₄ there is leaching of iron and aluminum ions and formation of calcium sulfate with retention of the kaolinite structure. Introduction into the material composition of water glass leads to breakdown of the kaolinite structure that facilitates an increase in in the rate of aluminum ion extraction during subsequent acid activation. Ca²⁺- and Fe³⁺-containing components entering into the composite composition in the presence of water glass are passivated by active amorphous silica formed during reaction of water glass with air CO₂.