Study On The Process Optimization Of Hot Metal Pretreatment And Semi Steel Dephosphorus In Chengde Steel Company

The production process of steel mills with vanadium titanium magnetite need to extract vanadium which is quite different from the others steel making processes.Pretreatment process of hot metal containing vanadium,has not been well studied so far.The main research work of this paper includes:desulfurization process optimization of hot metal in the ladle with reductant composite,study on the V-recovering kinetics in converter,controll model development for the V-recovery in converter,dephosphorization process development in the ladle etc.The following results were obtained:1)The impact of desulfurizer injection rate and its consumption,the reasonable lance position was determined.The effects of the desulfurizer injection rate and the agent component on desulfurization efficiency,reasonable material ratio and injection rate were obtained.When Si,Ti content in hot metal was less or temperature was not suitable,injection rate should be adjusted to improve the desulfurization efficiency.2)The better results were obtained for extracting vanadium(?)in converter with swirl lance by water model and industrial experiment.Swirl lance significantly improved the dynamic conditions of BOF and oxygen utilization efficiency.C content in semi steel increased by 0.17%,V oxidation rate increased by 3.6%.The vanadium extractive in converter endpoint control model based on the amount of oxygen and gas analysis was validated by industrial experiment.The C content prediction of semi-steel reached 87%,V content prediction reached 93%,which can meet the requirements of the endpoint control.3)The Induction furnace experiment,the numerical simulation,water model experiment and Industrial experiment were carried out for dephosphorization process in Ladle.Lance was designed to the semi steel ladle improved the liquidity and oxidation of semi steel.The impact of composite inflatable on flow field,Top-blown lance and bottom blowing arrangement and parameters were determined.Dephosphorus process in the ladle during semi-steel pouring from BOF was developed.The average of dephosphorus efficiency is 51.8%.4)A new type pretreatment process of hot metal containing vanadium was developed which achieved good results and are good for guiding the real steel making process.