Optimization Study And Viscosity Measurement Model Of Blast Furnace Slag System For Smelting Vanadium-titanium Magnetite

Vanadium-titanium magnetite(abbr.V-Ti magnetite)is a kind of multielements-coexistent mineral and has a very high comprehensive utilization value.Currently,the process that is blast furnace-vanadium extraction process in BOF-semisteel steelmaking is adopted to make full use of V-Ti magnetite magnetite.Compared with ordinary blast furnace smelting iron,the blast furnace slag of Vanadium-titanium magnetite were poor fluidity,poor stability,and furnace temperature control range is narrow in smelting vanadium-titanium magnetite process,it is difficult for blast furnace production to reach the level of strengthening smelting.Therefore,in this study,all experiments samples were synthesized by adding analytical reagent oxides into the base BF slag provided by a domestic enterprise.In this study,the effects of slag components on the viscous behaviors of BF slag were studied first.Then based on the experimental data,for further improving the viscous behaviors of BF slag,the orthogonal optimization test was carried out and analyzed by multi-index synthetic weighted scoring method to obtained the optimal slag compositions of titanium-bearing BF slag.Besides,a experiment scheme was designed to decreased the MgO/Al2O3 ratio of the optimal slag.Finally,based on the acquired experiment data,the viscosity prediction model was established using Weymann-Frenkel equation and the formula of calculating the fixed optical basicity.The conclusions were as follows:(1)With increase of binary basicity,TBr of slag was increased,?TBr were decreased,?1500? were decreased first and then increased,and E? became better.As increasing MgO content,TBr of slag,?TBr and ?h decreased first and then increased,thermostability was worse first and then got better.With increase of Al2O3 content,TBr and ?1500? of slag were rised,but ?TBr was first increased and then decreased,thermostability became worse.When the TiO2 content was increased,TBr of slag,?TBr and ?1500? were first decreased and then increased,thermostability was better first and then got worse.Based on those evidence,the suitable components of BF slag system were as follows:binary basicity was 1.20,the content of MgO,Al2O3,TiO2 was 12.00%,11.00%,10.00%.(2)In the present study,an orthogonal optimization test was carried out and analyzed using the multi-index synthetic weighted scoring method.The optimal slag compositions were CaO/SiO2 1.25,MgO 12.00wt%,Al2O311.00wt%,TiO2 10.00wt%,and the affecting sequence of components on the viscous behaviors of slag was CaO/SiO2,Al2O3,MgO,TiO2.Compared with the basic BF slag,the flowability,thermostability and chemical stability of the optimal slag system were improved.(3)Based on the optimal slag system,the MgO/AlO3 ratio was decreased to 0.6.The final optimal slag system accepted by the factory was binary basicity 1.30,MgO content 7.2%,Al2O3 content 12%,TiO2 content 10%.(4)Combined with the Weymann-Frenkel equation and the modified optical basicity(?corr),a viscosity prediction model suitable for the BF slag system of V-Ti magnetite was established,and validated by measured viscosity data.The results of calculation showed the average deviation of the model was 12.73%.The predicted viscosity values achieved a good agreement with the experiment data.The viscosity model was applied under the condition of 1673K?1773K.The range of slag components were binary basicity 1.00?1.30,MgO content 6.00%?14.00%,Al2O3 content 10.00%?18.00%,Ti02 content 5.00%?12.00%.