A METHOD FOR OXIDIZING MERCURY IN EXHAUST GAS

A method for oxidizing mercury in combustion exhaust gas, which is excellent in oxidation activity and economic efficiency when changing metal mercury contained in combustion exhaust gas exhausted from a large boiler into mercury chloride, is provided. A method for oxidizing mercury in combustion exhaust gas comprises mercury in the combustion exhaust gas into mercury chloride in the presence of a chromium oxide catalyst supported with a magnesium oxide-aluminum oxide prepared by coprecipitating a magnesium salt, an aluminum salt and a chromium salt at a ratio of 1:1:1 and drying the coprecipitated material at 110 deg.C. The chromium oxide supported with the magnesium oxide-aluminum oxide is prepared by adding a magnesium salt, an aluminum salt, a chromium salt and a precipitant into water to form a precipitate and calcining the precipitate to a temperature from 300 to 700 deg.C under an air atmosphere.