碱金属对焦炭热性能的影响

通过模拟高炉内焦炭同时受钾和钠蒸汽影响的实际情况,得到在钾和钠不同比例条件下焦炭结构和热性能(CRI、CSR)的变化。结果表明,碱金属的比例达到3%时,就会破坏焦炭结构,而且随着钾蒸汽比例的提高,焦炭粉末也会增多,这表明钾蒸汽对焦炭结构造成了巨大破坏。当钾和钠的质量比为3︰7时,焦炭的反应性(CRI)达到最高,反应后强度(CSR)达到最低。通过扫描电镜和能量光谱仪观察发现,焦炭基体和矿物质中均存在钾和钠;通过X射线衍射检测发现,焦炭和碱金属蒸汽发生反应生成了霞石,霞石中钾和钠的含量取决于碱金属蒸汽中两者的比例。

Effect of alkali metals on thermal properties of coke

Through simulating the actual situation where coke was simultaneously affected by K and Na vapours in blast furnace, the evolution of coke structure and thermal properties（CRI，CSR）after alkalization with different proportions of K and Na vapours were revealed. Results showed that the coke structure was broken when the proportion of alkali vapours reached 3%，and the coke fine formation rate increased with the increase of K vapour，which indicated that K vapour caused a great damage to coke structure. The CRI of coke reached the highest and the CSR reached the lowest when mass ratio of K/Na was 3/7. It was observed with SEM and energy dispersive spectrometer that K and Na existed in both mineral matters and carbon matrix; nepheline, generated when coke reacted with alkaline (K，Na) vapours, was determined by XRD. The content of K and Na in nepheline is dependent on the ratio of alkaline (K，Na).