铁焦制备与高炉应用的研究进展

 钢铁工业长期面临着资源短缺和环境污染的的发展现状,实现节能减排和绿色冶金是钢铁工业实现可持续发展的重点。而高炉炼铁是钢铁工业节能减排的关键,急需研发低碳高炉炼铁新技术。复合铁焦是实现低碳高炉炼铁的一种新型碳铁复合炉料。高炉使用铁焦后可降低热储备区温度,提高冶炼效率,降低焦比,从而实现CO₂减排。综述了国内外铁焦制备与应用的研究进展,主要包括铁焦的制备工艺和高炉应用。归纳了各种铁焦制备工艺的特点。同时提出并研究了矿煤压块-竖炉炭化-高炉应用的冷压型铁焦制备与应用新技术。重点进行了冷压型铁焦的制备及冶金性能优化、高炉应用冷压型铁焦等试验研究。冷压型铁焦制备适宜的工艺条件为,质量分数为30%铁矿粉、45%烟煤1、10%烟煤2、10%烟煤3、5%无烟煤、5%沥青类黏结剂B混合加热至60 ℃,并进行冷压成型;成型压块再经竖炉1 000 ℃炭化4 h;获得抗压强度3 977 N、I型转鼓强度77.7%、反应性69.7%、反应后强(固定气化溶损量20%)42%的优质铁焦。高炉综合炉料中添加质量分数20%~30%冷压型铁焦,综合炉料熔滴性能明显改善。以上研究为铁焦实现工业化生产与低碳高炉炼铁应用提供了参考。

Research progress on preparation and application of iron coke in blast furnace

The iron and steel industry has been facing the current situation of resource shortage and environmental pollution for a long time, and energy saving, emission reduction and green metallurgy are the key points for the sustainable development of iron and steel industry. Blast furnace (BF) ironmaking is the key to energy conservation and emission reduction in iron and steel industry. So it is urgent to develop new low carbon blast furnace ironmaking technologies. Iron coke is a new type of carbon-iron compound burden for low carbon BF ironmaking. The utilization of iron coke in BF can decrease the temperature of heat reserve area, improve smelting efficiency, reduce coke ratio and reduce CO₂ emission. The research progress on the preparation and application of iron coke at home and abroad were reviewed, mainly including the preparation process and BF application. The characteristics of various iron coke preparation processes were summarized. At the same time, the new technology of cold press molding-shaft furnace carbonization-BF application for iron coke preparation and application was proposed and studied. The preparation, metallurgical properties optimization and application in BF of iron coke by cold press molding were studied systematically. The suitable process conditions for the preparation of iron coke by cold press molding are as follows: 30% iron ore powder, 45% bituminous coal 1, 10% bituminous coal 2, 10% bituminous coal 3, 5% anthracite and 5% asphalt binder B are mixed and heated to 60 ℃, and then cold pressed into briquettes. The briquettes are carbonized at 1 000 ℃ for 4 h by shaft furnace. High quality iron cokes with compressive strength of 3 977 N, I type drum strength of 77.7%, reactivity of 69.7%, post-reaction strength (fixed gasification solution loss 20%) of 42% were obtained finally. By adding 20%-30% iron coke into the blast furnace burden, the melting and dropping performance of the burden are improved obviously. The above research results can provide a reference for the industrial production of iron coke and the application of iron coke in low carbon BF ironmaking.