亚临界H2O-CO体系改性贫瘦煤的配煤炼焦特性研究OA

Global steel production remains at high levels,and the demand for coke is steadily increasing,while the supply of high-quality coking coal faces a significant shortage.Consequently,there is an urgent need to explore alternative coal types to expand the potential applications of coking coal resources.To address this,meager-lean coal(ML)was hydro-modified using a subcritical H2O-CO system.The coal blending performance of the resulting modified meager-lean coal(MML)as a substitute for fat coal was then evaluated.Additionally,the effect of the modified coal proportion on coke quality was analyzed using specific surface area pore analysis,X-ray diffraction,and Raman spec-troscopy.The results indicate that hydrogenation modification removes oxygenated functional groups from the coal,increases the content of aromatic C=C and aliphatic—CH2—structures,and raises the caking index(GRI)of MML from 12.00 to 80.12.When MML replaces fat coal in coking,the cold and hot strengths of the coke initially increase and then decrease as the proportion of MML in the blend increases.When a small amount of MML(w＜9%)replaces fat coal in coking,the carbon layer spacing of the coke decreases,while the height of the microcrystalline stack increases.This leads to greater structural ordering and graphitization,resulting in a denser structure that reduces coke reactiv-ity,and increases post-reaction strength.Since MML has lower caking property than fat coal,when its content reaches or exceeds 9%,the caking property of the blended coal decreases.This weakens the fusion between coal particles,leading to an increase in the specific surface area and pore volume of the coke,a higher surface activity,and elevated coke reactivity,ultimately reducing coke quality.The use of MML(w＜9%)to replace an equal amount of fat coal in coal blending improves coke quality,demonstrating the feasibility of using modified meager-lean coal as a substitute for fat coal in coking.This study offers a novel solution to address the coking coal shortage in China.