Abstract: In a method of removing metals such as mercury from flue gas produced by combustion devices, ammonia and optionally carbon monoxide are injected into the flue gas in a manner so that there are sufficient amounts of these materials in the flue gas when the flue gas is at a temperature of from 900° F. to 1350° F. to oxidize the metals within the flue gas. The oxidized metals are then attracted to particulates present in the flue gas. These particulates bound with oxidized metals are removed from the flue gas by a particulate removal device such as an electrostatic precipitator or baghouse.