高炉炼铁碳足迹计算中铁渣分配方法

RESEARCH ON ALLOCATION METHOD BETWEEN IRON AND SLAG IN CARBON FOOTPRINT CALCULATION OF BLAST FURNACE

高炉是一个典型的复杂多功能系统,产出铁水、高炉渣等共生产品。按照生命周期评价的方法收集了高炉炼铁生产过程的清单数据,采用“投入-产出”法原理进行碳足迹计算,并分别利用系统扩展法、质量分配法、能量-脉石分配法和经济分配法,对输入输出高炉系统的碳负荷(碳抵扣)在铁水和高炉渣之间进行了分配计算,得出了铁水和高炉渣的碳足迹结果。结果表明,铁水碳足迹由高到低依次为:经济分配>能量-脉石分配>系统扩展>质量分配;高炉渣碳足迹大小顺序反之。其中,能量-脉石分配法从原料输入端即按照其对形成渣、铁的贡献能力进行分配,得出的结果更具科学性,由于该方法得出的铁水产品碳足迹较系统扩展法偏高,高炉渣碳足迹偏低,因此能量-脉石分配法更有利于促进高炉渣等副产品在钢铁下游水泥行业中的大量利用,但缺点是实施过程复杂。通过对不同分配方法碳足迹结果的比较,同时结合各方法的特点及用户接受程度,推荐优先采用系统扩展法或质量分配法来进行高炉炼铁工序铁渣间的碳足迹分配。

Blast furnace is a typical complex multifunctional system,producing hot metal,slag and other symbiotic products.According to the method of life cycle assessment,inventory data of the blast furnace ironmaking production process was collected.The input-output method is used to calculate the carbon footprint,and the carbon load(carbon deduction)of the input and output blast furnace system was allocated and calculated between the molten iron and blast furnace slag using system expansion method,quality allocation method,energy gangue allocation method,and economic allocation method,respectively.The results indicate that the carbon footprint of molten iron is obtained in the order of economic allocation,energy-gangue allocation,system expansion,quality allocation from high to low,while the carbon footprint of blast furnace slag is obtained in the opposite order.Among them,the energy-gangue allocation method allocates the raw material input according to its contribution ability to the formation of slag and iron,and the results obtained are more scientifically based,but the implementation process is complex.By comparing the carbon footprint results of different allocation methods,combined with the characteristics of each method and user acceptance,the system expansion method or the mass distribution method is recommended to allocate the carbon footprint among the iron slag in the ironmaking process of blast furnace.