Mercury adsorbed from combustion gas by activated carbon can be sequesteredin concrete containing air entraining admixtures. The activated carbon maybe made by providing a carbon char made from anthracite or low-volatile bituminouscoal that was devolatilized and carbonized in an oxygen-depleted environmentand activating this char in the presence of steam to provide an activated carbonwith an acid blue 80 index of less than about 30 milligrams per gram of carbon. Theactivated carbon may also be made by providing a carbon char that was devolatilizedand carbonized in an oxygen-depleted environment and activating this char inthe presence of oxygen to provide an activated carbon. The carbon may be injectedinto a combustion gas stream containing fly ash and mercury and may then be removedwith fly ash from the gas stream. The resulting composition may be used as a partialsubstitute for cement in air-entrained concretes.
