Various metallurgical processes are still operated by utilizing fossil-based carbon sources for reduction and energy supply generating a carbon footprint which will influence future competitiveness in terms of economy and market. More and more customers look for a kind of green label on the metal product, forcing smelters to bring their CO₂-output down to a certain level.

Hydrogen has been and still is the most popular option to replace fossil carbon in metallurgical processes even though the enthusiasm of previous years has changed into a more realistic view when facing available amounts and prices in near future. Electricity, in some cases could serve as energy source as well as for reduction at least offering the chance to have green electrical power sources and with this a carbon-footprint reduced production. Alternatives like biomass, biogas and charcoal have to be considered as well.

Hydrometallurgy in general is often seen as an option to reduce the carbon footprint due lower energy consumption but suffers often from high efforts for effluent treatment and low product qualities.

The presentation gives an overview about different metallurgical processes and the options to use CO₂-neutral reducing agents. A detailed comparison is done for steel mill dust recycling processes showing opportunities but also challenges for alternative reducing agents.