1982 Volume 68 Issue 8 Pages 956-964
Reduction of molten iron oxide and FeO bearing slags with hydrogen-argon plasma was studied using a water-cooled Cu crucible. The weight of melts was 25 to 75 g, the flow rate of mixture gas was 20 l/min and DC electric power was 8.3 kW. Results obtained were as follows.
(1) The reduction of molten iron oxides proceeds linearly with time and the reaction rate is proportional to the partial pressure of atomic hydrogen, PH. Therefore, it is considered that the rate determining step is the chemical reaction with hydrogen atoms formed by the thermal dissociation of hydrogen molecules in the plasma gas.
(2) The rate of reduction of FeO bearing slags is lower than that of molten iron oxide and is proportional to the FeO concentration in slag. It is presumed that the reduction rate is controlled by both the chemical reaction with dissociated hydrogen at the interface and the mass transport across the boundary film of the molten slag.
(3) The reduction of molten iron oxide and FeO bearing slag with hydrogen-argon plasma takes place only on the surface of the cavity formed by the momentum of plasma gas jet.