CO_2在转炉中的应用技术研究

Technology study on applying CO_2 in BOF

通过转炉顶吹混合气体CO2＋O2的热力学分析，结合实验室热模拟结果，探讨了在顶吹转炉中喷吹CO2＋O2进行脱碳抑氧及脱碳保铬的可行性。研究结果表明，喷吹纯CO2可以脱碳，但温降较大；当CO2供气强度为3．0m^3／（t·min）时会导致15．1℃／min的温降速率；为实现温度平衡，采取喷吹混合气体CO2＋O2模式，利用O2-Fe反应放热弥补CO2-C反应吸热，当O2和CO2脱碳整体热效应为零时，其中混合气体CO2＋O2中CO2的最大理论体积分数为79．1%；当φ（CO2）：φ（O2）=1：1时，顶吹转炉终点碳氧积可控制在0．0025～O．0032，达到复吹转炉效果；当φ（CO2）：φ（O2）=2：1时，顶吹CO2＋O2出现“脱碳保铬”效果。

Through the thermodynamic analysis of top blowing CO2 ＋ O2 mixture gas in BOF, combined with laboratory thermal simulation result, the feasibility applying CO2 ＋ O2 in top blowing converter for decarburizing-restraining oxygen and decarbonization- preservation of chromium were discussed. It was concluded that carbon could be reduced by blowing pure CO2, but the loss of temperature was relative large. When the intensity of supplying CO2 was 3.0 m^3 /（t-min）, the velocity of temperature dropping could reach 15.1℃/min; to achieve temperature balance, the mode of top blowing mixture gas CO2 ＋ O2 was taken. The heat from exothermal reaction O2-Fe could make up for the loss from endothermic reaction CO2-C, and the whole heating effest was zero when decarburized by O2 and CO2, the maximum theoretical volume fraction of CO2 in mixture gas CO2 ＋ O2 could be increased to 79. 1%. When the mixture gas was φ（CO2） ： φ（O2） = 1 ： 1, the [%C]·[%O] could be controlled between 0. 0025 -0. 0032 in top blowing con- verter, almost equalled to the effect in combined converter. When the mixture gas was φ（CO2） ： φ（O2） = 2 ： 1, the effect of decarbonization and preservation of chromium by top blowing CO2 ＋ O2 occurred.