Selective Gas Adsorption by Amorphous Clay-Mineral Derivatives

Cristina Volzone1, John G. Thompson2, Alexandra Melnitchenko2, José Ortiga1 and Stephen R. Palethorpe2
1 Centro de Tecnología de Recursos Minerales y Cerámica (CETMIC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Cno. Centenario y 506, CC 49 (1897) MB Gonnet, Buenos Aires, Argentina
2 Research School of Chemistry, Australian National University, Canberra ACT 0200, Australia

Abstract: Amorphous derivates prepared by aqueous reaction of various aluminosilicate clay minerals with concentrated KF solution at 80–110°C were studied for their gas adsorption properties. The four clay minerals studied are halloysite, a well-crystallized kaolinite, a poorly crystallized kaolinite, and a montmorillonite. The gases tested are N2, O2, CH4, CO, CO2, and C2H2. The kaolin-group mineral derivatives are characterized by substantial reduction in particle size, high specific surface, and significant selectivity towards CO2 and C2H2 relative to the other gases. The montmorillonite derivative shows no increase in adsorption over the starting material, however, for all the materials high adsorption of CO2 and C2H2 was observed. Levels of gas adsorption and gas adsorption ratios are comparable to pillared clays.

Key Words: Amorphous Derivative • Gas Adsorption • Gas Separation • Halloysite • Kaolinite • Montmorillonite • Potassium Fluoride • CMS Source Clay SAz-1 • Specific Surface

Clays and Clay Minerals; October 1999 v. 47; no. 5; p. 647-657; DOI: 10.1346/CCMN.1999.0470511
© 1999, The Clay Minerals Society
Clay Minerals Society (www.clays.org)