Beneficiation and extraction of niobium resources in the Bayan Obo deposit: A review

The Bayan Obo deposit is the world's largest iron-rare earth-niobium polymetallic deposit, characterized by "low grade, fine grain size, complex composition, and disseminated distribution", and is intimately intergrown with rare earth and iron minerals, posing significant challenges to its efficient separation and extraction. This study reviews the current research progress, limitations, and improvement measures for Bayan Obo niobium resources in terms of physical beneficiation, hydrometallurgy, pyrometallurgy, and combined beneficiation-metallurgy processes, and compares the applicable scopes of various technological routes. The results indicate that physical beneficiation can achieve preliminary enrichment but is limited by low separation efficiency; metallurgical processes enable deep separation, yet suffer from high energy consumption and environmental concerns; and combined beneficiation-metallurgy and phase reconstruction represent key directions for synergistic recovery of polymetallic resources. Meanwhile, in response to the bottlenecks of economic utilization and green processing for low-grade resources, future development trends are proposed, including intelligent sorting, targeted reagent molecular design, and low-carbon metallurgy. The research findings may provide reference for the efficient utilization of refractory strategic metal resources in China.