Effects of coal moisture control and coal briquette technology on structure and reactivity of cokes

Abstract

In this work, the influences of coal moisture control (CMC) and coal briquette technology on structure and reactivity of cokes were investigated by adding a certain proportion of briquette into raw coal with different moisture. The coking experiments were carried out in a tested coke-oven of 70 kg, and the properties of as-obtained coke were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM) and so on. The coke reactivity index (CRI), coke strength after reaction (CSR) and the optical texture of different cokes were also measured. The results indicated that the two technologies both can improve the structure of coke and reduce the reactivity of coke. The improved coke properties can be attributed to forming a more compact microcrystalline structure of coke to enhance its pore wall structure, its optical texture index (OTI) and its graphitization degree. Noticeably, the introduction of CMC technology in coal briquette process can produce the superposition effect to the great improvement of the coke properties. In addition, the results also indicated that the introduction of CMC technology in coal briquette process can reduce the sulfur content of coke due to the overflowed sulfur in the form of gas during the coking, and can almost be equivalent to substitute 10% briquette in coal briquette process in the improvement of the CRI and CSR from coke, implying the reduced amount of briquette to save coal resources.