Isothermal Reduction Kinetics of Chromium-Bearing Vanadium-Titanium Sinter Reduced with CO Gas at 1173 K

The reduction process of chromium-bearing vanadium-titanium sinter (CVTS) was studied under the simulated conditions of a blast furnace at 1173 K, and the kinetics and mineral phases were analyzed. The reduction kinetics of CVTS at different reduction times was studied using a shrinking unreacted core model. The microstructure, mineral phase and variations of the sinter during reduction were observed by x-ray diffraction, scanning electron microscopy and metallographic microscope. Results indicate that the porosity of the CVTS increased with the reduction time and that the reduction rate and degree of the CVTS both improved. Although internal diffusion resistance emerged during the reduction process and gradually increased, the interfacial reduction reaction controlled the entire process and was the rate-limiting factor. Increasing the ratio of microporosity in CVTS is found to be an effective way to improve both the reduction ability and the strength of the CVTS.