Catalytic Effect of Alkali Metals on the Gasification Dissolution Reaction and Deep Reaction Behavior of Metallurgical Cokes.

Abstract

In this paper, the deep reaction behaviors of tamping and top-charging cokes with different K2CO3 and Na2CO3 contents were investigated and the evolution of the functional group structure and the carbon structure of coke with the extension of the deep reaction was clarified. The results showed that the deep reaction gasification of coke steadily increased with the K2CO3 and Na2CO3 content. However, the catalytic effect of different contents of K2CO3 seemed to be stronger than that of different contents of Na2CO3. Meanwhile, the catalytic effect of alkali metals on the gasification reaction of tamping coke was more significant. The gasification dissolution of coke gradually decreased from the outside to the inside of the particle with the extension of the deep reaction, while the catalytic effect of K2CO3 and Na2CO3 seemed to be more dramatic on surface of the coke particle. In contrast, the gasification dissolution reaction on the surface of tamping coke was more severe; consequently, the surface pore area of tamping coke was much higher than that of top-charging coke. According to the variations in the functional group structure of cokes, aromatic hydrocarbon gradually became the dominant functional group in the coke structure with the extension of the deep reaction. The above variation led to a gradual decrease in the reactivity of coke, though the decomposition reactions of oxygen-containing functional groups in coke were promoted to some extent by the addition of K2CO3. With the extension of the deep reaction of coke, amorphous carbon was gradually transformed into sequential carbon.