Raw materials scarcity and the geographical dependency for critical materials is a growing concern within the EU and worldwide. As demands for materials and minerals keep on increasing, making existing processes more efficient and creating new pathways to produce ferrous and nonferrous metals in a sustainable way becomes an important focus point. Pyrometallurgy and high temperature processes play an extermely important role in this. But testing the processes under the relevant conditions is time-consuming and expensive. Modelling can play a pivotal role in this, but a combination with experiments is still required as either input or experimental validation. The experimental and modelling work tackle industrially relevant processes from a fundamental viewpoint and combine multiple length scale investigations.