Geopolymers from Algerian metakaolin. Influence of secondary minerals

The influence of secondary phases (illite, quartz) on the geopolymerization reaction of metakaolin has been investigated by comparing two metakaolins, one prepared from a pure kaolinite and the other from illite- and quartz-containing Algerian kaolin from the Tamazert region, respectively. Geopolymerization was achieved by mixing the metakaolins with an alkaline sodium silicate solution at room temperature and curing at 50 degrees C. The products were characterized by X-ray diffraction and Si-29 and Al-27 MAS-NMR. The results show that the secondary phases, at the concentration used in this work, do not prevent the geopolymerization reaction. (C) 2008 Elsevier B.V. All rights reserved.