CO_(2)和H_(2)O对焦炭强度及微观结构的影响

Influence of CO_(2) and H_(2)O on Coke Strength and Microstructure

高炉喷吹富氢燃料是减少碳排放的有效措施之一,但喷吹富氢燃料产生的H_(2)O会造成焦炭的劣化。对比分析了不同温度下焦炭与CO_(2)和H_(2)O反应过程中,焦炭强度、两者的交互作用及微观结构的变化。分析结果表明:与H_(2)O反应溶损率SLR约为与CO_(2)反应SLR的2~5倍,温度升高,二者SLR差距缩小;焦炭反应后强度CSR随着温度的升高而降低,且SLR与CSR呈现负相关性;当H_(2)O/CO_(2)>1时,焦炭与CO_(2)-H_(2)O反应产生明显的交互作用;无论是焦炭与CO_(2)还是与H_(2)O发生溶损反应,微观形貌均表现为边缘部位溶损更严重;相比与CO_(2)反应,焦炭与H_(2)O反应在边缘更为剧烈,但内部气孔破坏较小。

Hydrogen-enriched fuel injection is one of the effective measures to reduce CO_(2) emission from the blast furnace,but H_(2)O generated from the injection of hydrogen-enriched fuel will cause the degradation of coke.The changes of coke strength and coke microstructure during the reaction process of coke with CO_(2)and H_(2)O at different temperatures and the in-teraction of the coke with CO_(2)and H_(2)O were compared and investigated.The analysis resultindicates that the solution loss rate(SLR)of coke reaction with H_(2)O is about 2-5 times that of reaction with CO_(2),and the SLR difference between them narrowswhen the temperature increases.The coke strength after reaction(CSR)decreases with the increase of temperature,and SLR is negatively correlated with CSR.When H_(2)O/CO_(2)>1,the reaction between coke and CO_(2)-H_(2)O leads to signifi-cant interaction.The microscopic morphology shows that the solution loss of coke at the edge is more severe no matter the solution loss occurs when reacting with CO_(2)or H_(2)O.However,compared with the reaction with CO_(2),coke reacts with H_(2) O more violently at the edge of the coke,but the damage of internal gas pores is less.