高炉富氧喷吹还原性气体工艺分析

Technology analysis on reducibility gas injection into oxygen-enriched blast furnace

为降低高炉炼铁中固体碳耗、高效利用冶金高温副产煤气,提出高炉富氧喷吹还原性气体工艺流程,建立基于物料平衡与热平衡的高炉数学模型,并修正了理论燃烧温度计算公式。应用该模型分别对传统高炉、炉缸富氧喷吹还原性气体以及炉身喷吹循环煤气的炼铁流程进行技术参数分析。结果表明,炉缸富氧喷吹还原性气体以及炉身喷吹循环煤气的炼铁流程中,当氧气浓度达到50%、炉缸还原性气体喷吹量为267 m^(3)/t时,焦比为291 kg/t,煤比为150 kg/t,直接还原度为0.195,相比传统高炉,燃料比降低109 kg/t,综合能耗降低4.8%。还原性气体温度每升高100℃,可多喷吹5.8 m^(3)左右的还原性气体,降低焦比约5.5 kg/t;还原性气体喷吹量对理论燃烧温度影响较大,炉缸每喷吹1 m^(3)/t、1 000℃的还原性气体,理论燃烧温度可降低约1.9℃。

To reduce blast furnace ironmaking solid carbon consumption, and efficiently utilize high-temperature metallurgical by-product gas, the oxygen-enriched blast furnace blowing a reducing gas process was proposed, established the mathematical model based on material balance and heat balance of the blast furnace was established, and the theoretical combustion temperature calculation was revised. Using this model, the technical parameters of the ironmaking process of the traditional oxygen-enriched blast furnace, the hearth injection of oxygen-enriched reduction gas and furnace body injection of circulating gas were analyzed. The results showed that when the oxygen concentration reached 50% and the volume of reducing gas was 267 m^(3)/t, the coke ratio was 291 kg/t, the coal ratio was 150 kg/t, and the direct reduction degree was 0.195. Compared with the traditional blast furnace, the fuel ratio was reduced by 109 kg/t, and the overall energy consumption was reduced by 4.8%. For every 100 ℃ increase in reducing the gas temperature, more reducing gas about 5.8 m^(3) can be sprayed, and the coke ratio can be reduced by about 5.5 kg/t. The amount of reducing gas injection had a great influence on the theoretical combustion temperature. The theoretical combustion temperature can be reduced by about 1.9 ℃ for each 1 m^(3)/t reducing gas injected into the furnace hearth at 1 000 ℃.