8th International Congress on Science and Technology of Ironmaking - ICSTI 2018

Cooling of hot sinter involves the release of significant quantities of energy and is a source of fugitive dust emissions. The increasing pressure that steel producers are facing in regard to energy consumption, reduction of CO2 and air emissions, require new processes and technologies to maximise energy recovery of the sinter cooling and to lower its environmental impact. Paul Wurth has been working intensively on the improvement and redesign of sinter coolers and recently finished developing a new type of shaft cooler based on the counter-flow principle, resulting in advanced thermal efficiency and energy recovery rate. In parallel, the higher amount of energy recovered from the sinter cooling allows boosting the efficiency of the processes that reuse this energy. Examples are the partial recirculation of hot air to ignition hood and/or the sinter strand and the generation of steam that may be combined to the production of electricity. An interesting alternative is to use the steam for driving a turbine which is coupled directly to the main fan, a setup which increases the yield of thermal energy conversion even further. In this regard, Paul Wurth recently joined hands with a renowned turbine manufacturer to be able to propose complete heat recovery solutions specifically adapted to each customer's requirements. As the new cooler is based on the suction of cooling air through the bed of hot sinter, dust emissions are strongly reduced compared to existing sinter coolers, making this technology fit for upcoming reinforced legislations on dust emissions. With a very small footprint, the new cooler can be retrofitted in most existing plants even with reduced available space or it can be implemented in greenfield projects in order to reduce the overall plant footprint.