炼铁系统低碳技术发展前景与途径

 现代高炉炼铁是以人造矿石和焦炭为物质基础的。现代高炉实现绿色低碳炼铁,需要从炼铁工序的层次优化工艺流程和关键技术,实现烧结、球团、高炉等多工序的协同优化。面向未来,在提高资源和能源利用效率的同时,基于现有技术推进采用低碳节能技术和先进工艺。对于烧结、高炉等传统工艺技术,要进一步研究并应用先进技术,提高生产效能、降低能源消耗和碳排放。持续研究推广绿色低碳烧结技术,如低碳厚料层烧结技术、烧结料面富氢气体喷吹技术、烧结返矿高效回收利用技术、低温烧结技术和热风循环烧结技术等,有效降低烧结过程的能源消耗和CO₂排放。充分利用中国精矿粉资源生产球团矿,提高球团矿产能和产量,进而提高球团矿入炉比率和炉料综合品位,有效降低碳素燃料消耗。提高高炉富氧率和喷煤量,持续提高风温、降低燃料消耗,提高高炉顶压和煤气利用率。有条件的高炉喷吹富氢气体以减少焦炭消耗,开发应用高炉炉顶煤气循环及CO₂脱除再利用(CCUS)等技术。研究解析了高炉炼铁工艺碳-氢耦合还原的热力学机理,讨论了在高炉内不同温度区域固体碳、CO和H₂的还原能力,提出了直接还原与间接还原的耦合匹配是实现最低燃料比的技术核心,探讨了高炉炼铁喷吹全氢/富氢气体的技术可行性和经济性。这些综合技术措施对于进一步降低高炉工艺流程的碳素消耗、减少CO₂排放具有显著效应。与此同时,设计先进合理的流程系统和耗散结构,优化工序界面技术,构建信息物理系统(CPS)实现炼铁工序协同高效、动态有序运行,这也是高炉炼铁工艺实现绿色低碳的关键共性技术之一,具有广泛的适用性和显著的应用效果。

Development prospects and methods on low- carbon technology in ironmaking system

The man-made agglomerate iorn ore and coke are the modern blast furnace ironmaking material basis. Modern blast furnace realizing green and low-carbon ironmaking needs to optimize the technical process and key technologies from the level of ironmaking procedure, and realize the collaborative optimization of multiple processes such as sintering, pelletizing and blast furnace. Facing the future, to improve the resource and energy utilization efficiency, adopt low-carbon energy saving technology and advanced technical process base on the fundation of existing technology. For the traditional technologies such as sintering and blast furnace, advanced technologies should be further researched and applied to improve production efficiency and reduce energy consumption and carbon emissions. The green and low-carbon sintering technologies should be continue to study and promote, such as low-carbon and thick material layer sintering technology, hydrogen-rich gas spraying technology of sintering material surface, reback sinter ore efficient recovery technology, low temperature sintering technology and hot air circulating sintering technology, to effectively reduce energy consumption and CO₂emissions in the sintering process. Make the most of China's concentrate iron ore fine resources to produce pellet, improve the production capacity and output of pellet, and then improve the pellet charging ratio and the comprehensive grade of burden, and effectively reduce the carbon fuel consumption. Increase the blast furnace oxygen enrichment ratio and pulverized coal injection rate, continue to increase the hot blast temperature and reduce the fuel consumption, and improve the blast furnace top pressure and gas utilization ratio. The hydrogen enrichment gas injection to reduce coke consumption, develop and apply the blast furnace top gas recycle injection and CO₂ removal and reuse technology (CCUS) in some conditional blast furnaces. The thermodynamic mechanism of carbon-hydrogen coupled reduction in blast furnace ironmaking process is researched and analyzed, the reduction capacity of solid carbon, CO and H₂ under different temperature zone in blast furnace is discussed, and the coupling and matching of direct reduction and indirect reduction is the technological core of the lowest fuel ratio are prosoed. The technical feasibility and economy of full hydrogen or enriched hydrogen injection into blast furnace are discussed. These comprehensive technical measures have a significant effect on further reducing the carbon consumption and reducing the CO₂ emission of the blast furnace process. As while as, design advanced and reasonable process system and dissipative structure, optimize the procedure interface technology, and construct a cyber physical system (CPS) to realize the coordinated, efficient, dynamic and orderly operation of ironmaking process. It is also one of the key and common technologies of blast furnace ironmaking process to achieve green and low carbon, and has wide applicability and significant application effect.