Emission reduction of dioxin in iron ore sintering by adding urea as inhibitor

Dioxins are a type of highly toxic persistent organic pollutant, and the sintering process has become one of the most important emission sources. In this paper, a detailed analysis of the waste gas from sintering pot experiments shows that when adding urea at 0·05, 0·1 and 0·5%, the dioxin emissions decrease by 63·1, 66·8 and 72·1% compared to zero urea. At 0·05%, the influence on the technical parameters of the sintering process is slight, and there is no emission of ammonia in the waste gas. However, at 0·1 and 0·5%, the sintering technical performance decreased and emissions of ammonia in flue gas at 0·07 and 0·11 mg m−3 occurred. It is concluded that an addition of 0·05% urea is the optimum amount to minimise dioxin without affecting sintering performance or the occurrence of secondary ammonia pollution.