Shima Barakan - Ph.D. Student of mineral processing۱, Assistant Professor in Mineral Processing
Valeh Aghazadeh - Mining Engineering Faculty of Sahand University of Technology, Tabriz, Iran

To improve adsorption ability in bentonite, two factors of basal spacing and crystallite size in the structureof this mineral were considered. Reducing the crystallite size and achieving the nano crystallite size in structure ofthis mineral cause increasing in specific surface and also increasing in the absorption places. In order to increase inbasal spacing, specially distance between the layers increase the absorption places. Results showed by reducing thecrystallite size, basal spacing was reduced; therefore to improve this condition Na-activation was used for bentoniteuntil establishing more swelling ability in structure of this mineral, one can increase the basal spacing. Thenpreparation procedure was done on six samples for compare with crystallite size, basal spacing and Na-activationeffect. In this research the sample of Na-bentonite with dimension of 2nm, the basal spacing of 12.5 nm and swellingindex of 17.6 ml/2gr used as an absorbent agent for adsorption of zinc as heavy metal. In this sample the countereffect of swelling index on basal spacing caused ~30% increasing in adsorption recovery in compare to non-activatedbentonite. Finally, this sample with adsorption recovery about 95% was selected as the best absorbent.

Crystallite size, swelling index, basal spacing, zinc, Na-activation