Enrichment of ferroniobium from Bayan Obo tailings using selective carbonization roasting and magnetic separation

This research presents a novel approach to beneficiate ferroniobium from Bayan Obo tailings (BOT) by combining selective carbonization roasting with magnetic separation. By exploiting different reduction pathways during roasting, niobium oxides are selectively converted into niobium carbide while titanium oxides preferentially associate with the silicate phase (diopside). The strong affinity between niobium carbide and in-situ metallic iron enables Nb enrichment through magnetic separation. Under optimal conditions (1050 °C), the process yields a concentrate with 92.91% Fe and 0.25% Nb, achieving peak separation efficiency with an Nb/Ti content ratio of 7:1 and recoveries of 90.31% for Fe and 72.09% for Nb. This approach produces valuable crude ferroniobium from waste resources.