Clay is a kind of cheap natural minerals in China. In order to study their performance for removal of elemental mercury in flue gas

the clays were modified by impregnating KBr and KI to prepare KBr-clay and KI-clay. A series of bench adsorption tests was carried out in a fixed bed to examine the removal efficiency of elemental mercury from simulated flue gas by KBr-clay and KI-clay. The effect of halogen loadings

adsorbent temperatures and the flue gas components (SO2 and H2O) on the performance was studied. The result showed that the modification did not much change the specific surface area and the pore structure of the clays

while there was little variation also in the surface functional groups. The sorption capacity of elemental mercury by KBr-clay and KI-clay was drastically improved

and it is of better activity for KI-clay than for KBr-clay under the same experimental conditions. The chemical adsorption played a dominant pole in the process of the elemental mercury removal. SO2 was found to have a promotional effect on elemental mercury adsorption

and the promotional effect of SO2 was more apparent for KBr-clay. H2O vapor exhibited a inhibitory effect on elemental mercury adsorption

but the effect decreased with the raising reaction temperature.