【作者】 梁林旺；

【导师】 张朝晖；

【作者基本信息】 西安建筑科技大学 ， 钢铁冶金， 2008， 硕士

【摘要】 在高炉生产中,提高煤比是降低焦比、控制炼铁生产成本的重要手段,而在大幅提高煤比的同时可能带来高炉风口前未燃尽煤粉数量增多,高炉料层透气性降低等问题。通过采取强化燃烧的措施,可促使煤粉在高炉风口区快速燃烧。在煤粉中加入适量的助燃剂并配合高炉操作等措施,可降低煤粉入炉的着火温度,提高燃烧效率,降低高炉的入炉焦比,从而达到降低炼铁生产成本的目的。翼钢在提高喷煤比的实践中,随着喷煤量的日益提高,出现煤粉燃烧率下降、瓦斯灰含碳升高等问题。本课题结合翼钢炼铁生产实际情况,以在高炉喷吹用煤中添加助燃剂作为主要技术手段,采用理论分析、实验研究及实际生产相结合的方法,研制开发了适宜于翼钢高炉喷煤实际情况的高炉喷煤助燃剂,并为其在翼钢高炉以后合理的工业化生产应用提供依据。通过本次高炉喷煤添加助燃剂在试验室开发测试、工业生产应用两个阶段的实践研究,得出以下结论(1)实验室阶段试验结果表明助燃剂能有效改善粉煤的燃烧特性,以2~#配方效果最为显著。添加0.4%的2~#配方助燃剂后,煤粉着火点降低了24℃,燃尽温度降低了51.5℃,相对燃尽时间减少了15.4%。同时采用计算DSC曲线放热面积法对比分析表明加入量在0.4%时,粉煤试样的放热面积最大,超过0.4%以后燃烧效率有下降趋势。(2)增加煤粉中-200目的比例,提高富氧率,均有利于改善粉煤的燃烧特性,并更有利于发挥助燃剂对粉煤的助燃作用。通过对比分析,实验结果表明在粒度组成-200目70%,富氧率3%,添加0.4%助燃剂条件下,煤粉的燃烧性能最佳。(3)通过翼钢高炉喷煤添加助燃剂的工业生产实践研究发现,助燃剂的添加提高了翼钢高炉的喷煤量和喷煤效果,降低了煤粉的着火点、提高了燃烧速度及燃烧效率,基本达到了试验的预期目的,但还需要更进一步的生产实践来研究掌握高炉操作、原燃料品位等对高炉喷煤效果的影响,优化设计适宜于高炉生产的助燃剂添加设备和工艺成为下一步的目标。更多还原

【Abstract】 It is an important measure to increase the pulverized coal injection (PCI) for reducing the coke ratio and production cost of iron-making in the blast furnace (BF) production. However, as the greatly increasing of the coal injection ratio, the measure appears many problems such as the unburned coal powder increasing before the tuyere, permeability deterioration in a certain condition of burden, etc. By taking measures to enhance combustion of pulverized coal (PC), the coal powder can burn faster in the tuyere. By adding the appropriate amount of combustion-supporting agent on pulverized coal injection for BF, and combining with measures such as blast furnace operation, the ignition temperature of coal powder to furnace can be decreased, the combustion efficiency be improved, the coke ratio of BF and production cost of iron-making be decreased accordingly.In practice of increasing the PCI of YiCheng steel company, along with the increase of the coal injection ratio, many problems were found, such as decline in burning rate of pulverized coal, increase in the carbon content of blast furnace Gas Ash. According to actual condition of iron manufacture in YiCheng steel company, by using the methods of theoretical analysis and experimental research, the practical production to seek for the suitable combustion-supporting agent on PCI for BF in YiCheng steel company was studied; meanwhile, some suggestions were given to the reasonable industrial production for BF in YiCheng steel company.Through the two stages of the development in laboratory and the industrial production of combustion-supporting agent on PCI for BF, conclusions are as follows:(1)The laboratory result showed that the combustion properties of PC can be improved obviously by adding combustion-supporting agent, and the addition of the second formula has the best effect. By the addition of the second formula in 0.4%, the ignition temperature of PC decreased 24℃, the burning completely temperature decreased 51.5℃, and the relative completed burning time reduces 15.4%. Meanwhile, the calculation of exothermal area on DSC curve method was used to compare and analyse the influence when the combustion catalyst was injected into the PC, the results showed that the addition in 0.4% has the best effect, and the combustion properties has a downward trend over 0.4%.(2) By increasing the proportion of PC at -200 mesh and improving oxygen-enriched rate, the combustion properties of PC can be improved more favorable, and the combustion-supporting effect can be given more fully play. The laboratory result showed that a better combustion efficiency has been achieved in the condition of 70% pulverized coal -200, 3% oxygen-enriched rate and 0.4% combustion-supporting agents blending rate.(3) It was found that in the industrial production of combustion-supporting agent on PCI for BF in YiCheng steel company , the coal injection rate and the coal injection effect has a great improving by adding with the combustion-supporting agents. Meanwhile, the ignition temperature of PC was decreased; the combustion rate and the combustion efficiency were improved. Though the expected goal of the experiment has be achieved basically, it is also needed more industrial production practice for master the coal injection influence of blast furnace operation and the grade of raw mineral. And the next goal is designing a suitable equipment and process of combustion-supporting agent on PCI for BF.更多还原