高炉炉缸碳源渗碳性能及动力学

摘要：提高铁水碳饱和度，减弱侧壁炭砖侵蚀，实现炉缸长寿对高炉炼铁具有重要意义。利用静态法系统地研究了高炉系统中进入炉缸铁水的碳源的渗碳性能，并计算了表观反应速率常数K。研究结果表明，不同碳源的渗碳性能由强到弱为：NMA炭砖>碳棒>煤粉>焦炭>9RDN炭砖。碳源的渗碳性能随其石墨化程度的升高而降低。碳源中的灰分会极大影响其渗碳性能，但以团聚大颗粒形式存在的灰分并不能减弱其渗碳能力，同时Al2O3可明显降低碳源的渗碳速率。9RDN炭砖的渗碳性能低，预示着其可适应更加复杂的炉况条件。煤粉和焦炭渗碳性能偏差，煤粉以及炉料下行过程形成的焦粉进入炉缸会降低死料柱空隙度，造成炉缸不活跃，使得炉况波动频繁，并不利于死料柱渗碳和侧壁保护层的稳定。因此，要适当提升入炉焦炭粒度，增大风量，减弱未燃煤粉及焦粉对炉缸侧壁炭砖长寿的负面影响。

Carburizing performance and kinetics of carbon sources in blast furnace hearth

Abstract：It is of great significance to improve the carbon saturation of molten iron which weakens the erosion of sidewall carbon bricks, so as to realize the hearth longevity. Carburizing properties of various carbon sources in molten iron by static method was systematically investigated. The apparent reaction rate constant K of samples was calculated. The results show that the carburizing properties of different carbon sources from strong to weak are NMA carbon brick > carbon rod > pulverized coal > coke > 9RDN carbon brick. The carburizing performance of carbon sources decreases with the increase in its graphitization degree. Ash has a negative effect on the carburizing performance of carbon sources, but ash in the form of agglomerated large particles cannot weaken the carburizing performance of carbon sources. The Al2O3 phase can obviously degrade the carburizing performance of carbon sources. The 9RDN carbon bricks with low carburizing properties can be adapted to more complex furnace conditions. The carburizing properties of pulverized coal and coke are relatively weak. When the pulverized coal and coke powder formed in the tuyere raceway enter the hearth, the porosity of the deadman will be reduced, resulting in hearth inactivity and frequent fluctuation of furnace condition, and it is not conducive to the carburization of the deadman. Therefore, it is necessary to properly improve the coke particle size and increase the air volume for weakening the negative effects of unburned coal powder and coke powder on the longevity of the hearth sidewall carbon bricks.