Biocarbon utilisation in aluminium and in ferroalloy production

NTNU will in collaboration with the Université Laval employ a PhD (PhD 2A) that will investigate the potential use of biocarbon in the anodes in the aluminium process. Focus will be to understand the implications that biocarbon has on the process compared to conventional carbon and optimise the use of biocarbon in the anodes. For ferroalloy production, the difference in properties between biocarbon and other carbon materials and how this will affect processes for ferroalloy productions and methods to mitigate negative effects, will be investigated. This will be based on results from a long series of biocarbon projects and research infrastructure built up at NTNU/SINTEF but here focus will be on knowledge needed to industrialise research results as well as broadening the biocarbon resource base into new raw materials including both biocarbon and composite agglomerates that both enables reuse of waste and by-products.

Cracking of biogas has earlier been shown (SINTEF) to deposit carbon on raw materials for both Mn and Si production with hydrogen as by-product. This will be further investigated both to obtain fundamental understanding and for further development towards industrial use. NTNU will employ a PhD (PhD 2B) that will evaluate different types of biocarbon to be used in the ferroalloy and the Acheson processes. Carbon produced from cracking of biogas, agglomeration of carbon fines and different types of composite agglomerates will be tested. Also, the use of methane, from biogas, as a reductant will be evaluated. SINTEF will be responsible for development of characterisation methods for biocarbon as well as to understand the relationship between biocarbon and furnace operation.

Hydrogen pre-reduction of ores and plasma-based reduction of metals

INEOS and Eramet are investigating reducing their CO₂ emissions by pre-reducing the ore with hydrogen gas in FME HYDROGENi. In this task the smelting of the hydrogen pre-reduced ore will be studied both from a thermodynamic and kinetic perspective (PhD 2C). This activity is complementary to activities in the ongoing FME HYDROGENi. Plasma based metal production is a fully electrified method to reduce metaloxide. SINTEF has built a small-scale plasma reactor in which manganese metal can be produced by hydrogen plasma reduction. Other types of stable oxides such as SiO₂, TiO₂ and even Al₂O₃ are in theory also possible to reduce with hydrogen plasma, which will be further investigated in this task.

Metallothermic reduction

NTNU has proven that silica and Mn-ore can be reduced to silicon and manganese through exothermic metallothermic reduction, which is an alternative to the conventional endothermic carbothermic reduction. The advantage of using other reductants than carbon is that the no direct CO₂ emissions will be emitted from the process. The possibility of using metallothermic reactions also for other metals and waste from metal processes will be further evaluated by a postdoc enrolled at in this task.