Document Type: Research Paper
Vanadium is distributed widely and scarcely (150 ppm) on the earth. Its major applications are in steelmaking, dye-production and catalyst-fabrication industries. With the ever-increasing demand for this metal, secondary resource-exploitation of such waste materials as spent catalysts is recommended. Many reactions are involved in vanadium-extraction from these resources. Since roasting in comparison with other reactions is too slow, its investigation is crucial for vanadium revitalization. This paper focuses on sodium-carbonate roasting of vanadium oxide and brings about both process kinetics and the governing rate equations. Experiments are carried out at isothermal conditions with different molar ratios of vanadium oxide to sodium carbonate species (1:1, 3:1 and 6:1). Prevailing mechanism and the activation energies of the roasting steps are determined by application of shrinking core model to the pertaining two-phase reaction.