Reduction And Melting Separation Of Carbon Composite Pellets Of Bayan Obo Ore

Bayan obo ore is a low iron ore with a variety of valuable resources， with the trait of complex symbiosis, fine grain size and low grade, so the comprehensive utilization of Bayan obo ore have to face many difficulties. In recently fifty years, Bayan obo ore was only used the iron and the rare earth resources, but niobium, Scandium and other resources not be available, the tailings not only bring environmental threat to the surrounding, but also make substantial resources slack. In order to study the behavior of niobium, phosphorus and iron, the experiment, which reduce carbon complsite pellets by tube furnace is carried out. This paper try to find a new way to utilize Bayan obo complex iron ore and preliminary study reduction of Bayan obo ore by rotary hearth furnace.The research was carried out in the laboratory. The experiment studied enrichment niobium Bayan obo complex ore, which be reduced at lower temperature and higher temperature respectively. First of all, Bayan obo ore is detected to make sure the chemical composition and comprehend the main mineral phases. The experiment control the condition of heating time and temperature respectively to study the process of iron oxide reduction at lower temperature, and then controlling the condition of C/O and heatng time investigate the behavior of iron and phosphorus migration from slag to iron phase. In the process of reduction in lower temperature the metalization rate was increased obviously with the reduction temperature rising. In the early stage of reduction the wustite, which generated by ferric iron being reduced, cumulated in pelltes; The small slag beads oozed from the carbon composite pellets at1200℃for7minutes. The chemical composition of small beads is in olive stone phase formation region of the CaO-SiO2-FeO slag systerm, and its smelting temperature is below1200℃. In higher temperature reduction and melting separation experiment, C/O and the heating time were the key factors of controlling niobium and phosphorus migration, both of them effected the (%Nb2O5)/(%P2O5) and recovery rate of niobium. At the beginning of melting separation the phosphorus moved from slag to iron phase, so (%Nb2O5)/(%P2O5) rose quickley. However, amount of niobium migrated to iron phase after phosphorus being reduced, as a result in (%Nb2O5)/(%P2O5) decreased. The last, there are calcium fluoride phase and mixtrue slag phase existing in slag.