Influence of mixed ratio of DRI and coke/coal on softening and melting behavior of vanadium-titanium burden
OY furnace is a smelting reduction ironmaking technology,with the characteristics of pure O2 blast,low burden height,and large temperature gradient,which is helpful to inhibit the formation of Ti(C,N)phase with high melting point and improve the gas and liquid permeability of the burden when smelting the vanadium-titanium magne-tite.However,the softening,melting and dropping behaviors of vanadium-titanium burden in OY furnace are differ-ent from those in a conventional blast furnace because it employs a charging mode with mixed DRI and coke/coal.Therefore,it is of great significance to carry out a study on the influence of the mixed ratio of DRI and coke/coal on the softening and melting behavior of vanadium-titanium burden in the OY furnace.The effects of the mixed ratio of DRI/coke-coal on the burden of softening and melting temperature parameters,dropping ratio,and pressure drop are studied,and the properties of the dropping and residual slag and iron are analyzed by electron probe X-ray microanaly-sis.The results show that the mixed loading of DRI and coke-coal promotes the reduction and carburization of the vanadium-titanium DRI during the softening and melting process,enhances the deformation resistance of DRI before melting,and moves the softening interval to higher temperature zone.At the same time,the dropping temperature of DRI decreases,and the melting zone contracts to a lower temperature zone,thereby thinning the cohesive zone of OY furnace.As the mixed ratio of DRI and coke-coal increases(from 0 to 100％),the dropping ratio of slag is nearly doubled,the vanadium yield of the hot metal is also improved.Although the increase of the mixed ratio accelerates the reduction of TiO2 and the formation of TiC in the slag,it has the effect of weakening the slag foaming phenom-enon due to the decreased residual slag used for foaming in the dropping zone,and the permeability of the burden layer is also improved.It can be seen that the mixed loading of iron ore and coke/coal in the molten gasifier is benefi-cial to the smelting of vanadium-titanium magnetite.The theoretical and technical basis for the smelting of vanadium-titanium ore in OY furnace is provided.
OY furnacevanadium-titanium DRImixed ratiosoftening and meltingslag foaming
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