An overall reduction of 97% has been attained in the emission concentration of PCDD/F in the flue gases. In rough terms that reduction can be broken down into three substantial stages. Firstly, adding burnt lime into the sinter mix resulted in an approximately 50% decline in PCDD/F emission concentrations. Secondly, selecting a series of process-integrated measures achieved an additional 35% reduction. Lastly, an extra 12% reduction was realised by building the active carbon injection installation.
The dust with the adhering dioxins is separated in the multi-centrifuge and in the filters and then reused as recycled dust in the raw materials mix. During the combustion process, they decompose and burn.