Deformation Characteristics and Influential Parameters of Iron Coke Hot Briquette During Carbonization Process

Iron coke hot briquette (ICHB) is considered as a typical low-carbon ironmaking charge. Much research has been done on its properties including strength, reactivity and post-reaction strength. However, the properties of ICHB in the carbonization process are also very important, which can affect the choice of reactor and the quality of the product. This paper complements the theory of ICHB during the carbonization process. ICHB was prepared with 20 pct iron ore A (referred to as ICHB-A) and iron ore B (referred to as ICHB-B) to study the effect of the reduction process of iron oxide on the deformation ratio and compressive strength of ICHB during carbonization. The main component of iron ore A is Fe₃O₄ and that of iron ore B is Fe₂O₃. The results show that Fe₂O₃ in ICHB-B is reduced at about 500 °C, and more gas is generated to inhibit the contraction of ICHB. However, the compressive strength of ICHB-B during carbonization is higher than that of ICHB-A, which is believed to be related to the closer bonding between hematite and coal. This study also compared the effect of the ratio of iron ore A on ICHB deformation ratio and compressive strength. The results show that the expansion ratio and shrinkage ratio of ICHB decrease with the increase of iron ore A ratio. By analyzing the deformation characteristics of briquette with the same proportion of Al₂O₃ during carbonization, it is considered that the influence of different proportion of iron ore A on ICHB deformation ration is mainly caused by the inhibition of inert material on the deformation behavior of coal. The iron ore can enhance the compressive strength of coke, but the reinforcing effect decreases with the increase of iron ore ratio. In addition, the influences of carbonization heating rate, forming pressure and particle size of iron ore on ICHB deformation behavior are also included in this study.