(1. School of Material and Metallurgy, Inner Mongolia University of Science and Technology, Baotou 014010, Nei Mongol, China 2. Key laboratory of Integrated Exploitation of Bayan Obo Multi-Metal Resources, Baotou 014010, Nei Mongol, China)
Abstract:As a micro-alloyed element, Nb was recovered to made Nb-bearing microalloyed steel from Nb-bearing hot metal in a vacuum carbon tube furnace by decarburization and conversation of niobium with Fe2O3 oxidant at 1 500 ℃. The results show that when slag isn’t placed on the hot metal, silicon, niobium and carbon are oxidized simultaneously, which cannot make Nb-bearing steel. When basicity of SiO2-CaO-Al2O3 flux decreases, oxidation of silicon decreases, and decarburization is easy to complete in the molten iron and the oxidization of niobium is suppressed in the metal bath. By the way, carbon content of the molten iron is decreased to 0.032% and niobium content is decreased from 0.09% to 0.082%. When the basicity of SiO2-CaO-Al2O3 flux decreases, the lower silicon and niobium oxidize, the higher carbon oxidizes. On the other hand, when the vacuum of the furnace is lowed to 10 Pa, oxidization of silicon and niobium of Nb-bearing hot metal is suppressed and oxidization of carbon increases. By the test of the vacuum condition and acid SiO2-CaO-Al2O3 slag formed at 1 500 ℃, 50 kg scale experiments have been completed and it is important not only to provide laboratory findings of commercial test for recovery of niobium from Nb-bearing hot metal to make Nb-bearing microalloyed steel but also to provide a new method to recover Nb from Nb-bearing hot metal.
徐掌印,赵增武,姜银举,李保卫,. 含铌铁水直接冶炼含铌微合金钢的试验[J]. 钢铁, 2015, 50(4): 13-16.
XU Zhang-yin,,ZHAO Zeng-wu,,JIANG Yin-ju,,LI Bao-wei,. Experiment on Nb-bearing microalloyed steel made directly by Nb-bearing hot metal. Iron and Steel, 2015, 50(4): 13-16.