Granules of com. fresh and spent activated cokes used for aftercleaning flue gases from incineration of communal wastes were mech. abraded to remove the surface layer. Both the resulting coke powder and the granule cores were then analyzed for porosity, mass loss during heating up to 600 degrees C, acidity, as well as contents of ash, sulfates, chlorides, and 12 heavy metals. The surface layers of the granules were acidic and contained many volatile substances. The spent granules contained also much more Hg, Sb, Pb, Cd and Ni than the fresh ones.