Patent ID: 8685882

Claim:
A method for removing nitrogen oxides, dioxin or a mixture thereof contained in flue gas, which is conducted at 150-400Â° C. at a gas hourly space velocity of 1,000-60,000 hr âˆ’1 in the presence of a catalyst comprising: (i) vanadium supported on titania, the vanadium being supported in an amount of 0.5-10 wt %, based on the element, of titania; and (ii) 5-30 wt % natural manganese ore having pyrolusite, wherein the catalyst is prepared by a method comprising the following steps: a) drying and calcining natural manganese ore followed by making powders of the dried and calcined natural manganese ore; b) separately, wet impregnating titania in a solution of vanadium precursor, followed by drying and calcining to give the vanadium supported on titania; and c) wet mixing said dried and calcined natural manganese ore with said vanadium supported on titania using ball milling, followed by drying and calcining, and wherein nitrogen oxides are removed by selective catalytic reduction, while dioxin is removed by oxidation, and wherein the natural manganese ore further comprises Si, Al, Fe, Ca and Mg in the form of oxide in addition to manganese oxide.