Modern society challenges include increasing overall metalMetal demandDemand and associated shortage of good quality concentratesConcentrate, increasing variety of metalsMetal needed for high-technological devices, changes associated with energy transitionEnergy transition, rapid growth of recyclingRecycling, present sustainabilitySustainability, circular economyCircular economy, and environmental constraints. These factors increase the complexity of the pyrometallurgical process chemistry that in turn require robust predictive capabilities. Significant recent progress in analytical and experimental techniques, thermodynamicThermodynamics theory, and computational capabilities in high-temperature research are critical to tackle this task. An integrated experimental and thermodynamicThermodynamics modellingModelling research program on complex multicomponent multi-phase gas–slagSlag–matteMatte–speissSpeiss–metalMetal–solids systems with the Cu2O–PbO–ZnO–FeO–Fe2O3–CaO–Al2O3–MgO–SiO2–S major and As–Sn–Sb–Bi–Ag–Au–Ni–Co–Cr–Na minor elementsMinor element is under way in response. The program has been supported for nearly two decades by several consortia currently consisting of 15 major international companies with over 30 operationsOperation in 15 countries around the world that brings together many different groups of professionals. The experiments involve high-temperature equilibration in controlled gas atmospheres, rapid quenching, and direct measurement of equilibrium phase compositions using a combination of the microanalysis techniques including electron probe X-ray microanalysis and laser ablation ICP-MS. The thermodynamicThermodynamics modellingModelling is undertaken using the FactSage™ software package with advanced thermodynamicThermodynamics solution modelsModel. Implementation of the research outcomes involves ongoing collaboration of researchers and industry technologists and systematic advanced professional training. An overview of recent progress in research, implementation, and applications in industrial practice will be presented in the paper. The aim of the paper is to share the authors’ experiences in developing and running this research program to facilitate possible future further developments and collaborations in the field of complex pyrometallurgyPyrometallurgy thermochemistryThermochemistry research.