1985 Volume 71 Issue 2 Pages 204-211
The reduction rate of liquid wustite contained in an iron crucible under Ar-CO, CO-CO2 or Ar-CO-CO2 gas mixtures has been measured by using thermobalance at 1 400 and 1 450°C. The experimental region of partial pressure of CO was PCO=0.02 -0.18 atm (Ar-CO) and PCO=0.07-0.84 atm (Ar-CO-CO2 and CO-CO2).
The apparent reduction rate became constant in the region of gas flow rate above 2.5 l/min. Under this experimental condition, the rate of reduction was controlled by the chemical reaction at the interface, and was expressed by the following equation :
where Ke and α are the equilibrium constant of the reaction among gas, liquid wustite and solid iron, and PCO2/PCO in the gas phase, respectively. The apparent rate constant of the chemical reaction, kc, was expressed by the following equation :
kc=1.18 exp(-24 300/RT) (g-oxygen/cm2·s·atm).
The reduction rate of liquid wustite with CO was 6 times larger than that of solid wustite.