Preparation and characterization of acids and alkali treated kaolin clay

Abstract

Kaolin was refluxed with HNO3, HCl, H3PO4, CH3COOH, and NaOH of 3 M concentration at 110 °C for 4 hours followed by calcination at 550 °C for 2 hours. The physico-chemical characteristics of resulted leached clay were studied by X-Ray Fluorescence spectroscopy (XRF), X-Ray Diffraction (XRD), Fourier Trans-formed Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Differential Thermal Analysis (DTA), Scanning Electron Microscope (SEM), Temperature Programmed Desorption (TPD) ammonia meth-od, and N2 adsorption techniques. XRF and FTIR study indicate that acid treatment under reflux conditions lead to the removal of the octahedral Al3+ cations along with other impurities. XRD of acid treated clay shows that, the peak intensity was found to decrease. Extent of leaching of Al3+ ions is different for dif-ferent acid/base treatment. The chemical treatment increased the Si/Al ratio, surface area and pore volume of the clay. Thus, the treated kaolin clay can be used as promising adsorbent and catalyst supports. © 2013 BCREC UNDIP.