Elaboration and characterisation of new mesoporous materials from diatomite and charcoal

New inorganic composite materials (ICM) were prepared combining a diatomite (Kieselguhr) from Algerian origin and charcoal from pine. After pyrolysis at 850 degrees C and chemical treatment with HCl, several techniques were used for the characterization of the obtained ICM. X-ray diffraction patterns and FT-Infrared spectroscopy showed that calcium carbonates, initially present as impurities in the natural Kieselguhr, have totally disappeared after treatment. A phase transition for diatomite was observed from quartz, dolomite and amorphous phase to cristobalite after mixture with charcoal. According to the nitrogen adsorption-desorption analysis, the surface properties of diatomite were found to be profoundly affected by the presence of charcoal. Indeed, the surface increased from 5 to 405 m(2)/9. The obtained products also exhibit a hydrophobic characteristic, contrary to the hydrophilic nature of the initially used diatomite material. These new ICM seem to be promising materials for use as industrial adsorbents in different applications like for the wastewater and air treatment, and for solvent recuperation. (C) 2007 Published by Elsevier Inc.