Thermodynamic Calculation and Experimental Study on Pre-reduction of Vanadium-titanium Iron Concentrate in Shaft Furnace

The equilibrium compositions,metallization rate and reduction degree of carbon-added pellets of Panzhihua vanadium-titanium iron concentrate pre-reduced in shaft furnace were calculated by HSC software.The metallization rate and reduction degree of the carbon-added pellets at different pre-reduction processes were studied experimentally.The experimental results show that with the increase of reaction temperature the metallization rate and reduction degree of the pellets increase,and the maximum metallization rate of 99.2% can be obtained at 800 ℃.The maximum reduction degree reaches 87.2% when the temperature rises to 1 000 ℃.The variation of metallization rate and reduction degree coincides well with the theory predictions.The maximum metallization rate and reduction degree are respectively 85.23% and 80.15% at 1 200 ℃.With the reduction atmosphere of 10% N₂+30% H₂+60% CO introduced from the bottom,the maximum metallization rate and reduction degree of 88.43% and 90.42% can be respectively gained at 1 200 ℃.Therefore,the reduction process can be reinforced obviously in circumstance of introducing reduction gas into the system.