| Vanadium is a very important metal, which are widely used in iron and steel, chemical industry and the energy fields. In nature the V-Ti-magetite is the important parasitic deposits of vanadium, in the west of Pangangzhihua there are abundant V-Ti-magetite. In present, extracting the vanadium from the V-Ti-magetite in Pangzhihua Ltd is pyrogenic process, which is extracting vanadium from V-Ti-magetite into hot metal in BF and oxidizing vanadium to vanadium oxide into slag in converter.The characteristic of V-Ti-magetite is hard agglomeration, hard smelting and hard ore dressing, there are a mass of aluminum and titanium in burden and that will deteriorate the furnace condition. In recent years, with the optimization of burden structure, the ratio of V-Ti-magetite in burden have been cut down and the ratio of common ore have been raised at the same time, so the content of Titanium dioxide lessened and the technical economical index have been improved markedly in the process of smelting V-Ti-magetite in BF. With the decreasing of ratio of V-Ti-magetite, the content of vanadium in burden decreased, but the recovery of vanadium improved. How increase the content of vanadium in burden simultaneously improve the thermodynamics conditions of reduction of vanadium oxides and the recovery ratio of vanadium is a burning question and it need further research.In this work, the tests, which simulated an actual blast furnace under certain conditions, have been carried out to look for the effect of temperature, the ratio of V-Ti-magetite in burden, granularity and the charging method on the reduction of vanadium oxides; the activity of vanadium in hot metal and influencing factor have been analyzed by the thermodynamic calculations; the effect of temperature, the content of vanadium in hot metal and component of slag on the distribution ratio of vanadium between slag and hot metal in hearth have been calculated and made experimental research.The research results indicate that:①The mode of occurrence of V in burden is vanadium-iron spinel, thermodynamic calculations have shown that the high temperature and the sufficient reduction of iron oxides can improve the thermodynamic condition of the reduction of vanadium oxide.②In lumpy zone, when the temperature is higher than 850℃, the particle size of ore lies between 5mm and 10mm and the ratio of V-Ti-magnetite lies between 70% and 75%, the ore has a good reduction, under these conditions vanadium oxide can be reduced, too. When the reduced degree of iron oxides is between 85% and 90%, the reduction of vanadium would happen, and when the reduction degree exceeded 90%, the content of vanadium in iron would increase gradually.③In soft dripping with molten, the content of vanadium in iron increased with the increasing of reduction degree and the ratio of coke in ore, decrease with the increasing of the ratio of V-Ti-magetite. When the ratio of coke in ore reached 50%, the content of vanadium in iron can reached 0.36%, but when the ratio of coke exceeded 75%, the content of vanadium began to decrease. When the ratio of V-Ti-magetite is 60%, the content of vanadium is 0.29%, but when the ratio of V-Ti-magetite is 77%, the content of vanadium is only 0.16%;④The thermodynamic calculations have shown that the content of Si, V in hot metal can increase the activity of V, but the content of P, S, C in hot metal can decrease the activity of V; and the activity of V decreased with the increasing of temperature;⑤Under the standard condition the reduction of vanadium oxides will priority react to the reduction of silicon oxides and titanium oxides; the thermodynamic calculations and the results of experiment have showen that the high temperature, high basicity, high silicon content in hot metla can be benefited to the reduction of vanadium, increase the content of vanadium sesquioxide and titanium dioxide can shorten the distribution of vanadium, but with the increasing of content of vanadium sesquioxide, the content of vanadium in iron increased and with the increasing of content of titanium dioxide, the content of vanadium in iron decreased. |
