In-situ observation, detailed characterisation and advanced modelling of high temperature reactions during steel processing is essential to understand the underlying mechanisms. We use a range of modern techniques to characterise and quantify high temperature reactions, including high temperature confocal laser scanning microscopy, controlled atmosphere furnaces (operating under various flammable gases), O18 for oxidation tracking, droplet levitation furnace, high temperature viscometer, mass spectrometer and micro XCT. We use the latest modelling tools (e.g. thermodynamic, phase field modelling) to simulate high temperature reactions and steel manufacturing processes.