Study Metallurgical Thermodynamics And Kinetics Of Extracting Nb From BaoSteel Tailings

Niobium and niobium compounds have been widely used in the steel,aerospace,electronics industry and other fields because of their high strength,high hardness,high melting point and very stable characteristics.Hydrometallurgy required repeated progresses;flow of blast furnace-BOF-EAF process is so long.At present,all utilizations of tailings to distill niobium are the inadequacies in niobium steel technology,so it is needed to develop a new process to extract the Nb component from Baotou tailings and effectively make use of other valuable metal.The subject takes Baotou tailings as raw materials,chlorine as the chlorination agent,activated carbon as reducing agent,which uses carbothermal chlorination separates niobium and other metals,thermodynamics analyses the possibility of chlorination of the tailings,and chlorination ability of oxides is: N b5 O5 > Na₂O> CaO > MnO> FeO ( FeCl₂)> MgO> Fe₂O₃ ( FeCl₂)> TiO₂> SiO₂ > Al₂O₃ ,according with different physicochemical nature of reaction products, initially achieving the separation of the Nb and Fe,Si and other elements from the tailings through the sub-condensation.Experimental study of the tailings and tailings sinterred, temperature, carbon amount to the effects of niobium chlorided.The best conditions for Nb collected: chloride at 700℃in 2h, volatiles Nb collected in condenser wall,Nb collection rate is 30%,rare-earth collection rate is 48%,iron collection rate is 85%. As raw materials added carbon sintered are chlorided,chloride at 800℃under 2h,sinterred ore chloridized is higher than that of Nb tailings;the same chlorination conditions,600℃,700℃,the rate of chlorination of Nb unsinterred is better than sinterred.Therefore, the best parameters of niobium chloridized are follows: the flow of Cl2 gas is 100ml/min,the tailings are not treated, chlorination in 2h at 700℃, the chlorination rate of Nb is 99.47% and the Nb yield is 30%.CO deoxidizes tailings in 3h at 1350℃,Nb goes into the slag and then it come into the Nb-rich slag,Nb content will be raised from 0.160% to 0.266%.