doiSerbia

Thermal treatment of kaolin clay to obtain metakaolin

Ilić Biljana R. (Institute for Testing of Materials, Belgrade)
Mitrović Aleksandra A. (Institute for Testing of Materials, Belgrade)
Miličić Ljiljana R. (Institute for Testing of Materials, Belgrade)

The metakaolin was produced by thermal treatment (calcination) of the starting high-quality kaolin clay from Serbia. The optimal calcination parameters, for which nearly complete dehydroxylation of the material was achieved, are: temperature 650°C and heating time of 90 min. The conversion of the kaolinite to metakaolin was confirmed by XRD and IR analyses of the starting and thermally treated kaolin samples. The pozzolanic activity was determined by Chapelle test. The obtained value 0.65 g Ca(OH)2/g of metakaolin indicates that produced metakaolin may be used as supplementary cementitious material.