Increasingly, scientific and technological developments are moving to a more environmentally friendly direction [1]. Therefore, the necessary adaptation of state-of-the-art processes with modified systems to an overall cleaner and more energy efficient state is imminent and requires a lot of research work, a more detailed look at processes and new test equipment. This is particularly true for the metallurgical industry, where carbon is needed not only as an energy source but also for reduction, and where the transition to greener processes has to work in tandem with the difficulties of recycling new complex multi-metal wastes such as magnets, batteries, e-waste and complex slag systems.
The Institute of Nonferrous Metallurgy and Purest Materials (INEMET) aims to look more closely at utilizing hydrogen as a key challenge for the near future with regard to metallurgical process decarbonization [2]. This is planned as a substitute for fossil fuels, e.g., natural gas for smelting copper cathodes prior to casting; nonetheless the influence of hydrogen on the copper melt, furnace refractory, fluid-dynamics, heat transfer and process control have to be assessed. In addition, the utilization of hydrogen for the molten phase reduction, e.g., in the reduction metal oxides, e,g. SnO2 in the context of a smelting process or of iron ore in the context of fluidized bed gas-solid processes is planned. [3].
The use of atmospheric thermal plasma jets as an alternative to conventional gas burners is also being investigated. The ability to use different gas compositions enables new ways of heating and treating slags, scrap and ores and is identified as a key technology in modern metallurgy [4]. Thermal plasma can be used to form species such as atomic hydrogen or even H+, which can reduce any metal oxide, allowing processes that cannot be decarbonized with molecular H2 to be carried out completely without CO2 emissions [5]. The fuming behavior of melt components can differ in these systems hence opening further pathways for metal refining.
Various new sensors are being installed and used to improve the measurement capabilities and to combine all the sensor data to gain better process knowledge. For example, new phase-differentiating melt height measurements are being tested with radar sensors. The aim is to identify the height of the slag and metal phases in a smelting unit operation. In addition, acoustic measurements may aid to analyze process fluid-dynamics. To link the different parameters of the experiments, a digital twin (on-line process model receiving experimental data) of the Institute's TSL is being built. Developments realized within the EU-HORIZON Mine.io project will be analyzed in detail.
In order to enable new process designs for industrial use, the key expertise lies in scaling up from laboratory scale to pilot scale experimental campaigns. To this end, new experimental fields are being designed within a newly planned furnace hall.
All in all, the directions for future-oriented pyrometallurgical research have been set and will be realized and carried out hand in hand throughout the university, by undergraduate/ graduate students, technical/ academic staff and industry alike.