ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis and properties of CaAl-layered double hydroxides of hydrocalumite-type

Viktor Tóth, Mónika Sipiczki, Attila Pallagi, Ákos Kukovecz, Zoltán Kónya, Pál Sipos, and István Pálinkó

Department of Organic Chemistry, University of Szeged, Dóm tér 8, H-6720, Szeged, Hungary

E-mail: palinko@chem.u-szeged.hu

Abstract: CaAl-layered double hydroxides (CaAl-LDHs) with various carbonate ion contents are essentially formed in Bayer liquors during the causticisation step in alumina production. Under well-defined conditions hemicarbonate is formed, which is beneficial in the process of retrieving both Al(OH) ₄ ⁻ and OH⁻ ions. In the current work, Ca₂Al-LDHs with various carbonate contents were prepared by the co-precipitation procedure and the products were dried in different ways. Structural information was obtained by a variety of methods, such as X-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Elemental maps were constructed through a combination of SEM images and EDX measurements. The targeted CaAl-hydrocalumites were successfully synthesised. It was found that the method used for drying did not influence the basal spacing although it significantly altered the particle sizes.

Keywords: CaAl-LDH – synthesis – drying methods – structural characterization

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-013-0500-z

Chemical Papers 68 (5) 633–637 (2014)