Structural and textural evolution under thermal treatment of natural and acid-activated Al-rich and Mg-rich palygorskites
1990; Elsevier BV; Volume: 5; Issue: 1 Linguagem: Inglês
10.1016/0169-1317(90)90004-9
ISSN1872-9053
AutoresF. González, C. Pesquera, C. Blanco, I. Benito, S. Mendioroz, J.A. Pajares,
Tópico(s)Bauxite Residue and Utilization
ResumoThe structural and textural evolution under thermal treatment of two Spanish palygorskites, one magnesium-rich and the other aluminium-rich, and also of the same palygorskites previously activated with HCl, has been studied. Using IR and X-ray techniques, the structural modification that the samples undergo on heating, is shown. By means of N2 adsorption-desorption isotherms and Hg porosimetry the changes in the texture were followed until 1000°C. The texture of both natural palygorskites is maintained until 600°C, despite the structural changes which they undergo. On heating at 1000°C a great decrease of surface area is observed. In samples previously activated with HCl, a greater evolution of the texture is evident. On heating above 300°C there is a sharp decrease of the surface area, owing to the disappearance of the microporosity created by acid-leaching. This decrease of the surface area is greater in the magnesium-rich sample.
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