A method has been provided for the operation of a blast furnace wherein air is introduced in the blast furnace through a tuyere zone and an air flow maintained at high velocity. This method comprises of introducing the supplemental fuel into said tuyere zone and admixing the same with the air flowing through the tuyere zone; maintaining at least one lower velocity turbulent zone in said tuyere zone, said lower velocity being in respect to the velocity of the flowing air and supplemental fuel admixture, said lower velocity turbulent zone initiating and sustaining the combustion of said fuel; and controlling the amount of supplemental fuel consumed in the tuyere by varying the distance of the turbulent zone in respect to the zone at which the air flow exists from said tuyere. Apparatus illustrating various flow retarding devices and thus flame source and fuel combustion control means also have been disclosed.