Abstract

With the large-scale blast furnace and the wide application of oxygen enriched coal injection technology, the coke quality and its deterioration mechanism in the blast furnace are receiving significant attention in recent. By means of the characterization techniques such as chemical analysis, image analysis and X‑ray diffraction, the influence of oxygen enriched coal injection on coke quality and the deterioration mechanism of coke were revealed from the change trend of particle size, chemical composition, pore structure and microcrystalline structure of tuyere coke. The results showed that the feed coke would make particle size decrease significantly through the friction extrusion, at the same time through chemical erosion and high temperature reaction with different atmosphere medium in the blast furnace. The ash content of tuyere coke was significantly higher than that of feed coke, alkali metals and iron content in ash was enriched in tuyere, and calcium content was significantly increased. The proportion of slag and iron decreases first and then increases with the increasing the depths of tuyere, and reached 85% at the depths of 2.5–3 m in tuyere. The surface of tuyere coke pores was smoother; the small pores were expanded to micron scale and appeared round with large number of gasification reactions for coke in the blast furnace. The microcrystalline structure of graphitization increased obviously through high temperature reaction and the resistance of isotropic coke, silk carbon and fragments to high temperature alkali erosion is stronger than that of other anisotropic structures in coke.

中文翻译：

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高炉焦炭劣化行为对微晶结构特征的影响

摘要

随着高炉的大型化和富氧喷煤技术的广泛应用，近来高炉焦炭质量及其劣化机理受到了广泛关注。通过化学分析、图像分析、X射线衍射等表征技术，从粒度、化学成分、孔结构的变化趋势揭示了富氧喷煤对焦炭质量的影响以及焦炭的劣化机理。和风口焦的微晶结构。结果表明，进料焦炭通过摩擦挤压，同时通过化学侵蚀和与高炉内不同气氛介质的高温反应，使粒径显着减小。风口焦的灰分含量明显高于原料焦，灰分中的碱金属和铁含量在风口处富集，钙含量明显增加。渣和铁的比例随着风口深度的增加先减小后增加，在风口深度2.5~3 m处达到85%。风口焦炭孔表面更光滑；焦炭在高炉内发生大量气化反应，小孔扩大至微米级，呈圆形。通过高温反应，石墨化的微晶结构明显增加，各向同性焦炭、丝炭及其碎片对高温碱侵蚀的抵抗能力强于焦炭中其他各向异性结构。灰中碱金属和铁含量在风口处富集，钙含量显着增加。渣和铁的比例随着风口深度的增加先减小后增加，在风口深度2.5~3 m处达到85%。风口焦炭孔表面更光滑；焦炭在高炉内发生大量气化反应，小孔扩大至微米级，呈圆形。通过高温反应，石墨化的微晶结构明显增加，各向同性焦炭、丝炭及其碎片对高温碱侵蚀的抵抗能力强于焦炭中其他各向异性结构。灰中碱金属和铁含量在风口处富集，钙含量显着增加。渣和铁的比例随着风口深度的增加先减小后增加，在风口深度2.5~3 m处达到85%。风口焦炭孔表面更光滑；焦炭在高炉内发生大量气化反应，小孔扩大至微米级，呈圆形。通过高温反应，石墨化的微晶结构明显增加，各向同性焦炭、丝炭及其碎片对高温碱侵蚀的抵抗能力强于焦炭中其他各向异性结构。渣和铁的比例随着风口深度的增加先减小后增加，在风口深度2.5~3 m处达到85%。风口焦炭孔表面更光滑；焦炭在高炉内发生大量气化反应，小孔扩大至微米级，呈圆形。通过高温反应，石墨化的微晶结构明显增加，各向同性焦炭、丝炭及其碎片对高温碱侵蚀的抵抗能力强于焦炭中其他各向异性结构。渣和铁的比例随着风口深度的增加先减小后增加，在风口深度2.5~3 m处达到85%。风口焦炭孔表面更光滑；焦炭在高炉内发生大量气化反应，小孔扩大至微米级，呈圆形。通过高温反应，石墨化的微晶结构明显增加，各向同性焦炭、丝炭及其碎片对高温碱侵蚀的抵抗能力强于焦炭中其他各向异性结构。焦炭在高炉内发生大量气化反应，小孔扩大至微米级，呈圆形。通过高温反应，石墨化的微晶结构明显增加，各向同性焦炭、丝炭及其碎片对高温碱侵蚀的抵抗能力强于焦炭中其他各向异性结构。焦炭在高炉内发生大量气化反应，小孔扩大至微米级，呈圆形。通过高温反应，石墨化的微晶结构明显增加，各向同性焦炭、丝炭及其碎片对高温碱侵蚀的抵抗能力强于焦炭中其他各向异性结构。