[Characteristics of Particulate Matter Emissions from the Coking Process]

To investigate the particulate matter emission characteristics of various emitting sources of the coking process of iron and steel plants, an automatic dust (smoke) tester and an eight-staged Anderson sampler were employed to conduct onsite sampling of particulate matter emissions from the coking process, including coal loading and coke pushing, coke dry quenching exhaust and coke screening and transferring in a steel plant, based on the measurement of particulate matter in the exhaust of fixed sources and sampling of gaseous pollutants. The morphology, particle size distribution, and chemical composition of the particulate matter from different sources were investigated. The results show that the single particles can be divided into five categories:iron-rich, silicon-rich, calcium-rich, carbon, and smoke polymer. They mainly appear in four forms:polygon block, irregular lamellae, lumps, and floc. The particle size of the coal loading and coke pushing unit mainly is 3.3-4.7 μm, while it is 3.3-4.7 μm and 5.8-9.0 μm for the dry quenching exhaust and 4.7-5.8 μm for the coke screening and transferring unit. The main chemical components of particulate matter in the coking process are C, SiO₂, Al₂O₃, S, CaO, and TFe, with contents of 76.30%-81.30%, 5.36%-5.91%, 3.96%-4.26%, 1.15%-1.34%, 0.52%-1.59%, and 0.81%-1.34%, respectively.