CENTRO DE INVESTIGACION Y DESARROLLO EN CIENCIAS APLICADAS "DR. JORGE J. RONCO"
Unidad Ejecutora - UE
congresos y reuniones científicas
PHYSICOCHEMICAL ASPECTS OF NATURAL AND MODIFIED KAOLINITE FOR
LAPUENTE, L.; MUNÓZ,M; GONZALEZ, M; SOTO, E.; CABELLO, C; BOTTO,I.
Congreso; XX International Material Research Congress; 2011
Sociedad Mexicana de Materiales
Kaolinite is a 1:1 laminar type phyllosilicate whose ideal chemical composition is Al4Si4O10(OH)8. This mineral has a lot of industrial applications by its physicochemical properties as well as by its abundance and low cost. The material obtained from thermal transformation of natural species by acid extractive treatment and surface modification led to the study of its structural, surface and chemical properties. This facilitates the possibility of its application as support in catalytic systems or as adsorbents in environmental processes. The work was carried out using mineral from Argentinean deposits. The raw mineral was characterized by X Ray powder diffraction and chemical analyses. Then it was thermally and chemically modified by different methods: conversion into metakaolin at 550 °C, 1:1 sulfuric acid treatment, washing and drying. A noticeable increase of surface areas and porosimetry and also a chemical composition change occurred by acid treatment .The new geomaterial was functionalized with different amino-siliceous agents in order to reach an appropriate surface for the adsorption of iso and heteropolyoxoanions such as [Mo7O24]6- and [AlMo6O24H6]3-. So, 10 mg Mo/ml aqueous solutions of these ammonium salts were used for the equilibrium impregnation of kaolinite derivative materials. The typical characterization was carried out by XRD, SEM-EDS; FT-IR Spectroscopy and SBET. Also the hydroadsorption capacity was analyzed by the Speckle Laser Dynamic (SLD) technique. Chemical analysis showed a Mo adsorbed concentration similar to commercial catalysts. Results are of interest in the catalysis field while the surface properties show the potentiality of these materials as adsorbents, for example in the removal of ionic contaminants in aqueous media.