Emissionsminderung bei Eisenerz-Sinteranlagen

The sinter plant is one of the major emission sources in an integrated steel mill. Most of the emitted dust is in the PM10 fraction and contains various heavy metals. The acid gases (SO₂, HCl, HF, NOx), ammonia and the organic compounds, which are also in the off gas from the sinter machine contribute to the formation of secondary aerosols in the atmosphere. The off gas from sinter machines for iron ore is usually de-dusted by ESPs. In the last one and a half decades, several new technologies for improved cleaning of the sinter machine off gas have been developed. In the last years, the installation of fabric filters downstream of the ESP in combination with dry adsorption technology (for reduction of emissions of acid gases and organic compounds) has been developed into the new state of the art for off gas cleaning of sinter machines. For a satisfying operation of such systems, it has been found that the selection of the appropriate fabric filter material is crucial. Results from the industrial pilot plant and the full scale plant at the iron ore sinter plant of voestalpine, Linz, A which both have been built by Siemens VAI are reported. The advantages of the process route comprised of a high-performance fabric filter and dry adsorption system compared to other systems regarding emission reduction and installation and operation cost is discussed.