Investigation on unrecognized catalytic contributing role of chlorobenzene oxidation by iron ore in sintering process

Abstract

The iron ore sinter process produced large amount of volatile organic compounds (VOCs) emission due to its high dependence on fossil fuel. Meanwhile, sintering process features of moderate temperature and oxygen concentration, which will induce the in situ VOCs oxidation at interface of iron ore particles when VOCs generated at the same time due to the natural intrinsic physic-chemical characteristics of iron-bearing material. In this study, we first investigated the unrecognized catalytic contributing role of VOCs oxidation by iron ore in sintering process, of which is dominant pollution unit in long-term steel making industry. Chlorobenzene (CB) was taken as representative sinter flue gas chlorinated VOCs molecule, and its catalytic oxidation performance was investigated by 5 distinct iron ores originated from different iron smelts in China. It was evident that iron ores exhibited different CB oxidation performance, following the order of YD>MK>BG>JS>YJC. Especially, YD and MK reached 89.0 % and 81.0 % CB conversion at 550 °C. According to material characterization result, YD and MK exhibited orthorhombic FeO(OH) phase as dominant structure with higher O_β/(O_α+O_β) ratio than other ores. The catalytic CB oxidation performance under diverse reaction conditions were also evaluated. By combining GC-MS and in situ DFIFTs analysis, CB conversion path and Marse-van Krevelen mechanism were proposed.