Carbon Solubility in Liquid Iron Containing V, Mo and Ni

Liquid iron alloys containing V, Mo, and Ni can be produced by the carbothermic reduction of spent catalysts used in petrochemical industry. Thermodynamics of carbon in these alloy melts is important for refining these alloys. In the present study, the carbon solubility in Fe-V, Fe-Mo, Fe-Ni, Fe-V-Mo, Fe-V-Ni, Fe-Mo-Ni and Fe-V-Mo-Ni alloy melts of various compositions was measured at 1873K. The additions of vanadium and molybdenum significantly increased the carbon solubility in liquid iron alloys while nickel decreased the carbon solubility. The temperature dependency of carbon solubility in Fe-V melt was also measured in the temperature range from 1823 to 1923K. The present and previous experimental results were thermodynamically analyzed using Lupis' relation at constant activity to determine the first- and the second-order interaction parameters of vanadium, molybdenum and nickel on carbon at carbon saturated condition in liquid iron alloys. Using thermodynamic parameters determined in the present study, the carbon solubility in Fe-V-Mo-Ni alloy melts of various composition were accurately predicted and verified experimentally at 1873 K.