The Fundamental Research Of New Metallurgical Processes In Steelmaking Refining Bed

Achieve the production goals of energy conservation,environmental protection,green and low consumption has become an important development direction of the iron and steel industry in the future.The refining bed equipment innovatively applies the fluidized reactor to the secondary refining process,and makes the traditional batch process continuous,which is an effective way to achieve the development goal.This paper discusses the feasibility study of continuous steelmaking process based on refining bed and the metallurgical operation characteristics of refining bed equipment,shows the feasibility and fluid movement status of this process,solves the problem of temperature and composition control of molten steel flow,and provides theoretical and design support for the realization of refining bed equipment and continuous steelmaking process innovation.Firstly,the process structure simulation model based on Flexsim software and the mechanical process model based on the balance principle are used to evaluate the EAF short process and the continuous steelmaking process based on the refining bed.The results show that,compared with EAF short process,the continuous steelmaking process based on refining bed has laminar flow production mode,good continuity,and high cooperation in the production process.On the other hand,the open transportation and turnover process has been canceled in the continuous steelmaking process,making its output increased by 42.86%,and its energy loss,power consumption,energy consumption,and carbon emissions have been reduced by 23.67%,17.82%,15.74%,and 13.99%,respectively.As a result,promote the iron and steel industry to achieve the production goal of energy conservation,environmental protection,green and low consumption.Secondly,the physical model and the VOF—DPM coupled numerical simulation model were used to simulate the flow field in the refining bed equipment,and the flow characteristics of molten steel under different equipment process conditions were compared and analyzed.The results showed that the molten steel can be fully mixed and stirred in the space of the refining section,then,enter the storage section slowly with uniform composition temperature,and leave the refining bed equipment through the tapping hole.On the other hand,different bottom blowing flow rate and bottom blowing hole arrangement will also affect the mixing effect of the flow field,and its optimization design is of great significance.Thirdly,based on the calculation results of mechanical process model,the thermal—fluid coupling research is carried out to explore the influence of heat supplement means on the flow field and temperature field distribution of refining bed equipment.The results show that the plasma heating method with the heating power of 10MW and the heating position at the center point between the first row and the second row of bottom blow holes has good heating effect,which can keep the average temperature in the refining bed equipment higher than 1823K(1550℃),and its outlet molten steel temperature up to 1809K(1536℃);At the same time,the application of induction heating equipment can effectively improve the flow pattern of molten steel in the channel,and its response time is only 63 seconds,shown its role in supplementing heat.In this study,combined with the Factsage thermodynamic calculation software and the sulfur partition ratio calculation model,the desulfurization slag system suitable for the refining bed system is explored through hot test.The results show that 65.1%CaO—13.0%SiO2—14.9%Al2O3—6.0%MgO—1.0%FeO slag system is in liquid state and has good fluidity at the production temperature of the refining bed,and has the best desulfurization effect(at 1550℃,the sulfur distribution ratio of the slag system is 51.10).On this basis,the coupling calculation model of KTH and CFD is established,and the numerical simulation of desulfurization behavior in the refining bed system is further completed.The results show that the good stirring effect and relatively uniform temperature distribution in the refining bed equipment can realize the desulfurization reaction in the whole refining process.When the refining bed smelting enters a stable state,the sulfur content of the end point molten steel is 0.0073%,and the desulfurization rate reaches 51.3%.The research results of this study will provide theoretical and data support for the design and development of refining bed equipment,support the realization of continuous steelmaking process innovation,and promote the steel industry to achieve the production goals of energy conservation,environmental protection,green and low consumption.