Abstract: Apparatus for producing molten pig iron by direct reduction of iron ore, comprises(i) a metallurgical vessel, in which with supply of coal and oxygen the iron ore undergoes a final reduction with production of a process gas and said process gas undergoes a partial post-combustion, and(ii) a melting cyclone in which the iron ore undergoes a pre-reduction and is melted. To improve the control of the thermal flows and to reduce maintenance, the vessel has(a) a top part, in which the partial post-combustion of said process gas takes place, in the form of a pressure-resistant hood having an interior wall comprising cooling water pipes, and(b) a bottom part for accommodating an iron bath having a slag layer in which said final reduction of said iron ore takes place, the bottom part having an internal refractory lining and means for water cooling the internal refractory lining.