低质焦炭下高炉炉尘及喷吹煤粉利用率

 为了研究低质焦炭条件下高炉喷吹煤粉的利用率，对安钢高炉两批低质焦炭及炉尘进行取样分析。测定了焦炭的常用质量评价指标及炉顶除尘灰的碳质量分数，并采用岩相测试技术分析了炉尘未消耗煤粉和焦炭的不同结构形态，定量地给出了炉尘中未消耗煤粉和焦炭颗粒的质量分数。结合安钢配煤现状，考察了3种高炉所用喷吹原煤不同粒径的燃烧率，并讨论了不同烟煤配比下挥发分质量分数对不同粒径煤粉燃烧率的影响，为低质焦炭条件下提高煤粉利用率提出合理化建议。结果表明，低质焦炭条件下，炉尘碳质量分数明显偏高并含有较多未消耗煤粉；炉尘中的未消耗煤粉分为热变煤颗粒和残炭颗粒，而未消耗焦炭则以镶嵌结构为主；控制焦炭质量波动、减少焦炭水分质量分数有利于降低炉尘碳质量分数；安钢喷煤首选无烟煤应为B煤，喷吹煤粉的挥发分适宜控制在17%左右。

Dust and utilization rate of pulverized coal injection into BF in low-quality coke situation

In order to investigate the effects of low-quality coke on utilization rate of pulverized coal into BF of Anyang Steel， two batches of charging coke and BF dust were analyzed. The quality of coke and carbon content of BF dust were measured. Since the petrographical microstructure of unconsumed pulverized coal and coke in dust were different， the amount of coal and coke could be quantitated via lithofacies analysis. Based on the present coal blending situation， the combustion rate of three pulverized coals was examined. Effects of volatile on combustion rate of pulverized coal with different particle size were researched， which could provide an effective guidance to improve the utilization rate of pulverized coal in low-quality coke situation. The results show that the carbon content and UPC (unconsumed pulverized coal) in BF dust are comparatively high. The UPC in the dust is made up of thermally altered coal and residual carbon particles while the unconsumed coke is mainly composed of mosaic structure. Keeping the coke quality steady and low moisture content could contribute to the decrease of carbon content of BF dust. It’s suggested that coal B should be the first selected anthracite and the volatile of pulverized coal should be controlled at around 17%.