Theoretical formation model of dioxin in iron ore sintering process

摘要

Dioxin is the unintentional synthesized extreme toxic Persistent Organic Pollutants (POPs) in the sintering process. The process of dioxin's formation and decomposition in the sintering bed layer, as well as the reaction mechanism and related theoretical model of different temperature sector were expounded in this paper. The correlated research indicated that: in the low temperature sector (200-500°C), chlorobenzene and chlorphenol are the representation precursors of dioxin's precursors catalytic reaction, the dioxin formed in this temperature sector cased by the "de novo" under catalyst (like Cu2+) on the surface of smoke particles, its catalytic mechanism of the same phases and heterogeneous all satisfied the four-step reaction model;high-temperature gas phase reaction mechanism of dioxin satisfied the first-order kinetic model, the formation of gas related with suitable precursors, it is the result of chlorinated precursors' pyrolytic rearrangement like chlorobenzene and chlorophenol in the temperature sector 500-800°C in the gas.