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

✍ Scribed by Tóth, Viktor; Sipiczki, Mónika; Pallagi, Attila; Kukovecz, Ákos; Kónya, Zoltán; Sipos, Pál; Pálinkó, István

• Book ID: 121487953
• Publisher: Versita
• Year: 2014
• Tongue: English
• Weight: 692 KB
• Volume: 68
• Category: Article
• ISSN: 0366-6352
• DOI: 10.2478/s11696-013-0500-z

✦ Synopsis

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.