Patent ID: 6368104
Filing Date: 2002-04-09
Classification: C21B,Y02P

Abstract:
A rotary hearth furnace having a heating zone and a reducing zone comprising:a cylindrical chamber into which pellets comprising metal oxide and carbon are introduced; a belt for transporting said pellets radially around the axis of said chamber in a first direction; a plurality of oxy-fuel burners capable of introducing a mixture of fuel and oxidant into said furnace wherein said mixture travels radially in the direction opposite to said first direction; and one or more oxygen injectors for injecting oxygen or a mixture of oxygen and air into said heating zone and said reducing zone, wherein said plurality of oxy-fuel burners and said one or more oxygen injectors are placed such that a substantial majority of the fuel will be introduced into said reducing zone in a ratio of oxygen to fuel between approximately 1:1 and 1.8:1 thereby providing a fuel-rich atmosphere therein, the remaining fuel being introduced in said heating zone in a ratio between approximately 2:1 and 5:1 thereby providing a fuel lean atmosphere therein.