Riskless application of activated lignite for the cleaning of waste gases from metallurgical processes

摘要

Thermal processes are currently the most important source of dioxin entry into the atmosphere [1, 2]. While the highest dioxin emissions were released by waste incineration some years ago and the statutory limits are now observed in these plants, the focus has meanwhile shifted to metallurgy/secondary metallurgy production plants, e.g. iron ore sintering plants, plants recycling steel, copper, aluminium scrap etc. Therefore, efforts must also be made by these plants to ensure compliance with the limit values (as defined in the 17~(th) Federal Immission Control Ordinance -17. BlmSchV). An appropriate process is the adsorption of pollutant gases by carbon adsorbents in the entrained phase followed by joint separation of adsorbents and process dust in filter systems [1,2]. For cost reasons, only low-cost carbon adsorbents are eligible for cleaning large waste gas flows downstream of metallurgical plants. Due to the high efficiency of reactivity-enhanced pulverized activated lignite (HOK Super) in pollutant elimination, this sorbent is particularly suitable for waste gas cleanup downstream of metallurgy and secondary metallurgy plants. In a mixture with catalytically active process dust, however, the dust separated in the filter systems can have an increased ignition propensity.