CO_2炼钢对氧气高炉循环煤气的改质及加热

Modification and Heating of Circulation Coal-Gas for Oxygen Blast Furnace via CO_2 Steel-Making

为解决氧气高炉循环煤气CO_2脱除和加热过程中的析碳问题,提出了一种利用CO_2炼钢对煤气进行改质和加热的方法,并通过热力学计算探讨了铁水和煤气成分对炼钢过程的影响,得到了合理的循环煤气处理方案。结果表明,CO_2炼钢反应总体上是大量吸热的,需要外部热源提供热量;以氧气高炉炉顶煤气为氧化剂时,炼钢温度范围内铁水中碳的脱除限度在0.02%以下,脱除率高于99%;煤气处理能力和改质煤气成分受铁水成分影响,并且铁水中碳含量的影响更大;通过CO_2炼钢与变压吸附2种工艺的结合,可满足氧气高炉对循环煤气量和温度的需求。

A new technology by using of CO2 steel-making was proposed to prepare and heat the circulation coal-gas for oxygen blast furnace, which eradicated the issues of CO2 desorption and carbon precipitation in heating process. The ef- fects of coal-gas as well as molten iron composition on steel-making process were discussed through computation in ther- modynamics, and rational solution on processing coal-gas was proposed. The steel-making reactions in CO2 are strongly endothermic on the whole, thus, heat source needs to be provided in steel-making process. The removal limit of carbon in molten iron is below 0.02%, and removal ratio of which exceeds 99% in the temperature range of steel-making, when top coal-gas of oxygen blast furnace is used as oxidant. The capacity and composition of coal-gas modification are influenced by chemical composition of molten iron, and the content of carbon is dominant. The requirements on volume and tempera- ture of circulation coal-gas are met through combining processes of steel-making by CO2 and pressure-swing adsorption.