Transform of Kaolinite in Iraqi Kaolin Clay to Halloysite by Intercalation Reaction

Abstract

The kaolinite of the Duikhala Deposite in the Iraqi Western Desert underwent intercalation with potassium acetate (KAc) and was subsequently washing with water several times. More than 70% of intercalation was achieved and checked using the X-ray diffraction (XRD) technique by observing a decrease in the peak intensity 7.2 Å and the appearance of the peak intensity at 14 Å after two days of intercalation. The surface area and cation exchange capacity were increased in the treated sample compared to the untreated one. Transmission electron microscopy images of the treated sample of kaolinite, after 35 cycles of repeated intercalation and washing, showed that the kaolinite lamellar were wrapped along the main crystal directions and transformed into the nanotube shape halloysite mineral.