In this study, intercalation of the bentonite clay mineral mined from Middle Anatolian was studied using iron pillar agents. Effects of the pillar solution preparation methods on the quality of the pillared intercalated layered clays (PILCs) and the variations in the pillared structure with drying types and calcination temperatures were investigated. Thermal behaviors of the starting mineral and the final product were investigated by thermogravimetric technique. Fe-PILC showed a more and lasting weight losses. Surface areas of the samples were measured using nitrogen sorption technique under continuous nitrogen-helium flow. Fe-PILC product having basal spacing as 13.79 Angstrom was obtained at 100 degreesC. The reasonably high surface area, which was measured as 95 m(2) g(-1) at 450 degreesC, confirmed that the preserving of thermal stability. (C) 2002 Elsevier Science B.V. All rights reserved.