Experimental Study On Reasonable Burden Structure Of Blast Furnace For Smelting Imported High Chromia Vanadia-Titania Magnetite

With the development of our iron and steel industry, and being short of domestic iron ore resources, the demand of imported ores has been gradually increasing. To meet the requirement of iron ore resources, a huge of iron ores are imported from Russia every year, including high chromia vanadia-titania magnetite with many mineral’ associations among its main elements besides Fe, V, Ti and Cr. The ore phase of high chromia vanadia-titania magnetite is complex, and the smelting is also difficult. No mature uses at home have yet been applied. During the production of blast-furnace ironmaking, the reasonable burden structure is contributed to improve iron ore’s comprehensive metallurgical properties, which has a direct effect on the tech-economic indexes of blast furnace. Therefore, exploiting a reasonable burden structure of high chrome vanadia-titania magnetite in blast furnace has been an urgent problem for the steel company.Aiming at blast-furnace ironmaking’s actual production of the steel company, taking high chromia vanadia-titania magnetite as raw material, a new program of imported high chromia vanadia-titania magnetite’s reasonable burden structure in blast-furnace ironmaking has been proposed in this study. The influences of MgO on sinter’s metallurgical properties and oxide pellet’s metallurgical properties, and the effects of basicity on sinter’s metallurgical properties have been systematically studyed. On that basis, the influence rules of sinter’s basicity collocations oxide pellets on reduction-swelling property have also been investigated. Some conclusions are obtained as follows:(1) When the content of MgO increases from1.95%to2.63%in sinter, the vertical sintering speed is decreased, the utilization coefficient changes a little, the yield, tumbler index, and composite indicator are all improved more or less. RDI+3.15is increases from80.57%to82.71%, meanwhile the high content of MgO in sinter with good quality can be gained.(2) When the content of MgO increases from1.95%to2.63%in pellet, the shatter strength of green pellet is changed little, and the compression strength of green pellet is improved slightly, the compression strength of finished pellet is decreases significantly. RSI is decreases from15.2%to8.6%.(3) Comprehensive consideration of the inflects of MgO on sinter and pellet’s metallurgical properties, high content of MgO in sinter collocations low content of MgO in pellet should be the reasonable burden structure of imported high chrome vanadium-titanium magnetite in BF.(4) When the basicity of sinter increases from2.1to2.7, the vertical sintering speed is becoming fast. The utilization coefficient, yield, tumbler index, and composite indicator are improved. RDI+3.15is increase from78.15%to83.69%, meanwhile the high basicity sinter with good quality can be gained.(5) The study of compositive burden’s high temperature cohesive properties are shown that the compositive burden’s high temperature cohesive properties can be improved by increasing the basicity of sinter and the ratio into BF of pellet. Under the condition of this study, as the basicity of sinter and the ratio of pellet in burden has increased, the soften-melting zone is narrowed, the slag-iron dropping rate is increased, the permeability of burden is improved, the reduction-swelling property of compositive burden is remarkablely promoted, and the smelting results of blast furnace ironmaking can be enhanced.