Co-carbonization of coking coal and rapid distillation residue of low rank coal

ZHANG Yuzhu; ZHANG Huichao; WU Dinghu; ZHU Yaming; CHENG Junxia; WANG Ying; ZHAO Xuefei

doi:10.3969/j.issn.1007-7677.2025.03.001

Abstract：Based on that the coke is an important carbon source in the blast furnace ironmaking and plays an irre-placeable role in supporting,infiltrating and indirectly reducing iron ore in the melting and dropping zones of the fur-nace,the preparation of coke by co-carbonization of coking coal through addition of aromatic heavy substances is one of the important ways to achieve coke quality and cost reduction.In order to realize the high value-added utilization of low-rank coal rapid distillation residue(CRDR)and broaden the source of raw materials for coking,the study was conducted to prepare a series of coke by using CRDR as a thermoplastic additive and co-carbonization with three types of coking coals with different metamorphic degrees,respectively.Tumbler strength,micro-strength,polarized light microscopy,scanning electron microscopy(SEM),XRD and Raman spectroscopy were used to explore the interac-tions between CRDR and three coking coals with different metamorphic degree during the co-carbonization process,respectively,and to investigate the effects of CRDR on the structural properties and microcrystalline structure of the co-carbonization coke.The results show that the influence of adding CRDR on the performance of co-carbonization coke becomes more and more obvious with the increase of the metamorphic degree of coal;the tumbler strength and micro-strength of co-carbonization coke have no obvious change after the addition of CRDR to 1/3 coking coal,and the optical anisotropy index(OTI)of the co-carbonization coke reaches 82.61 and the carbon microcrystalline struc-ture becomes more regular when the amount of CRDR is increased to 7％;the addition of CRDR to coking coal and lean coal greatly improves the tumbler strength and micro-strength of co-carbonization coke;however,when the CRDR addition exceeds 3％,the OTI index and graphite structure content of the co-carbonization coke decrease,which is not conducive to the growth of the crystal structure.