Rotary hearth reducing furnace and method of operating the same

摘要

A combustion method of a rotary hearth reducing furnace for suppressing the generation of nitrogen oxides in the rotary hearth reducing furnace to significantly reduce the emission amount is provided. In the rotary hearth reducing furnace of counterflow heating type, a metal oxide and a reducing agent charged thereinto are heated and reduced with burners arranged in a heat combustion area and a reduction combustion area. The reduction combustion area in which the theoretical air-fuel ratio produced by the total combustion device is less than 0. 98 occupies at least 15% of the entire combustion space, and the oxygen concentration in a combustion exhaust gas at a exhaust gas outlet portion of the furnace is 5% or less.