近年来，钢铁产量急剧上升，CO2排放呈直线上升趋势。而将CO2作为资源用于炼钢过程，在实现CO2减排的同时可提高钢铁产品质量。其中石灰石（CaCO3）作为携带CO2气源的熔剂直接加入转炉工序，在完成造渣同时可资源化利用其分解的CO2。但石灰石通过顶部料仓集中加入时，其密度低于铁水且分解吸热量大，这些特性致使部分石灰石在转炉内未完全分解，CO2利用率不高。课题组在前期研究的基础上，提出转炉底部高压喷吹石灰石粉冶炼工艺。拟通过理论计算、热态实验和数值模拟，借助高温在线显微镜、在线气体质谱分析技术等实验手段，探究石灰石颗粒由转炉底部喷吹进入高温熔池后的运动行为和分布规律；研究石灰石颗粒与铁水的界面反应机理，明确石灰石粉在高温熔池中的分解熔化机制；明晰石灰石分解产生的CO2参与炼钢反应的介质形式以及CO2的选择性氧化规律。课题的完成为CO2在炼钢过程中的进一步资源化利用提供新思路及基础理论指导。

With the sharp rise in steel production in recent years, CO2 emissions have also shown a linear upward trend.The use of CO2 as a resource in the steelmaking process can achieve energy saving and cost reduction and improve the quality of steel products while achieving CO2 emission reduction.Limestone (CaCO3) is directly added to the converter process as a slag-forming agent that carries a CO2 gas source. It can recycle its CO2 while completing the slagging task.However, when limestone is concentratedly added through the top silo, its density is lower than that of molten iron and the decomposition heat absorption is large. These characteristics cause some limestone to not be completely decomposed in the converter, and the CO2 utilization rate is not high.On the basis of the previous research, the research team proposed the high-pressure injection limestone powder smelting process at the bottom of the converter.Through theoretical calculations, thermal experiments and numerical simulations, by means of high-temperature on-line microscopy and on-line gas mass spectrometry，dynamic behavior and distribution law of limestone particles from the bottom of the converter into the high-temperature molten pool is explored .The interfacial reaction mechanism between limestone particles and molten iron, and the decomposition and melting mechanism of the size limestone in the high temperature molten pool will be clarified;The medium form of CO2 involved in steelmaking reaction generated by limestone decomposition and the selective oxidation law of CO2 will be clarified.The completion of the project provides new ideas and basic theoretical support for the further resource utilization of CO2 in the steelmaking process.