In the RESycling project, Fraunhofer IBP’s task is to develop practical solutions for processing and recycling hot metal desulfurization slags (abbreviated to RES in German, hence the name “RESycling”) together with collaborative partners. The joint project is funded by the German Federal Ministry of Education and Research (BMBF) as part of the measure to “Avoid climate-relevant process emissions in industry (KlimPro-Industrie)” and coordinated by Fraunhofer IBP. By processing hot metal desulfurization slags, valuable raw materials can be obtained. Three industrial sectors are testing the usability of these materials - namely the steel, cement and fertilizer industries. IBP has been tasked with processing the slags, optimizing the process steps, determining climate-relevant process emissions, and performing an analysis of technological and economic aspects.