Research On Steelmaking Technology Of 300 Ton Converter By Blowing Carbon Dioxide

Carbon dioxide emission reduction and carbon trading have become hot issues because of the greenhouse effect and global warming.There are many problems such as large dust,difficulty in dephosphorization and difficult to control the temperature in the process of converter smelting.When CO2 is introduced into the converter,it will provide a new solution way for CO2 taking part in the decarburization reaction of the liquid steel as a weak oxidant.Because the CO2 is involved in the decarbonization reaction,it can reduce the temperature of the molten pool,promote the dephosphorization reaction,and adjust the temperature of molten steel.Firstly,the steelmaking mechanism of the converter blowing CO2 is analyzed in this paper.Then the feasibility of the bottom blowing of the CO2 is studied from the angle of the converter bottom blowing element,and the experiment is done by the medium frequency induction furnace.At last,in the 300 tons dephosphorization converter and the conventional converter,industrial experiment are carried on using the top blown O2-CO2 bottom blowing CO2 smelting process,to study the steelmaking technology of the converter blowing CO2.The experimental study of medium frequency induction furnace shows that the decarburization of molten steel at the bottom of CO2 has no effect on increasing oxygen content in molten iron.CO2 absorbs heat from[C]in molten iron,which has certain cooling effect on bottom blowing brick.After about 20 times of experiment,the bottom blowing hole is not blocked,and the bottom blowing hole is slightly eroded.The injection of CO2 gas is beneficial to increase the service life of bottom blowing brick of converter,which can increase the bottom blowing rate of converter,increase the intensity of bottom blowing gas supply,increase the agitation of molten pool,and then bring a series of smelting indexes improvement.The industrial test results of blowing CO2 in the converter of dephosphorization show that the CO2 process is feasible,and the bottom blowing CO2 of the converter will not cause the bottom blowing elements to erode and block.The top and bottom combined blowing CO2 process can improve the dephosphorization rate of semi steel and reduce the decarburization rate,and achieve the task of dephosphorization and carbon conservation.As the amount of CO2 injection into the steel per ton increases,the final phosphorus content decreases,the dephosphorization rate increases,and the carbon content of the end point increases.The conventional converter blowing CO2 industrial test results show that 300 tons of large converter steelmaking using conventional blowing O2-CO2 bottom blowing CO2 smelting process is completely feasible.It can guarantee the end point temperature and composition requirements.As CO2 injected into the reaction CO converter absorbs heat,the converter gas recovery amount,the converter end point temperature can be controlled.The results of this paper provide theoretical and practical basis for smelting CO2 gas in large converter,and promote the progress and development of steelmaking technology.