【摘要】 高炉采用高比例球团矿冶炼，可提升入炉品位进而降低高炉渣量及燃料消耗，同时还可大幅度降低炼铁工序CO₂排放及SO₂、NO_x、二噁英等污染物排放，是实现绿色低碳炼铁的重要途径之一。由于高炉块状带内球团矿向下运动过程气固还原温度及还原气浓度是动态变化的，探究基于高炉块状带工况的球团矿还原历程有利于正确理解及合理控制球团矿的还原行为，从而有助于高炉高效低碳顺行。模拟京唐高炉块状带工况，采用高温还原炉研究了球团矿还原历程变化，对比分析了实际工况与国标试验条件还原的差异，讨论了球团矿在高炉块状带停留时间对还原的影响规律。研究结果发现，模拟高炉块状带气氛，随着球团矿在高炉内的下降，其还原度增加，球团矿还原膨胀指数和还原粉化指数均呈逐渐增加趋势，但在温度为800～1 000℃时，球团外表生成的还原铁壳层增加了固结强度，使还原粉化指数出现突然降低。模拟京唐高炉块状带工况的实际还原度低于使用国标试验条件还原后的还原度。炉料在块状带的停留时间越长，其还原失重越多，还原度越大，但对球团矿还原膨胀指数的影响不大。研究结果为明晰球团矿在高炉内的还原历程提供了有效信息，为指导提升球团矿在块状带还原度、降低高球比炉料结构高炉固体燃料消耗提供了理论依据。更多还原

【Abstract】 The high charging proportion of pellet in blast furnace enhances the ferrous content grade of burden, leading to a reduction in both slag volume and fuel consumption. The emission of CO₂ and other pollutants, such as SO₂, NO_x, and dioxins during the ironmaking process can be reduced, thereby contributing to green and low-carbon ironmaking. Given that the temperature and concentration of the reducing gas vary dynamically as the pellet moves downward in the lump zone of the blast furnace, an exploration of the pellet’s reduction process, based on the conditions of the blast furnace’s lump zone, is instrumental in understanding and controlling the reduction behavior of the pellet. This, in turn, facilitates efficient and low-carbon operation of the blast furnace. The pellet reduction process in a high-temperature reduction furnace, simulating the working conditions of the lump zone in the Jingtang blast furnace was studied. A comparative analysis was conducted between the actual working conditions and the national standard experimental conditions. The influence of residence time of pellet on the reduction was also discussed. Under the simulated conditions of the blast furnace lump zone, the degree of reduction of the pellet escalates as it descends within the blast furnace. Both the pellet reduction expansion index and the reduction degradation index show a progressive increase. However, when the temperature reaches between 800 ℃ and 1 000 ℃, the formation of a reduced iron shell layer on the pellet surface enhances its consolidation strength, leading to a sudden drop in the reduction degradation index. Under the simulated conditions of the Jingtang blast furnace’s lump zone, the actual degree of reduction is lower than that under the national standard experimental conditions. The duration of the burden’s stay in the burden zone is directly related to the extent of reduction loss and the degree of reduction, but it has minimal impact on the pellet ore reduction expansion index. This study elucidates the reduction process of pellet ore within a blast furnace, offering valuable insights. Furthermore, it establishes a theoretical framework for enhancing the reduction degree of pellet ore in the lump zone, thereby contributing to a decrease in solid fuel consumption in blast furnaces with a high pellet ratio.更多还原