Projektinitiativ #100: Electrolytic Extraction of metal in ionic melts

Today’s exploitation of metallic materials from metal oxides and sulphides is done by several reduction and oxidation processes following the extraction from the mines. In Sweden, most of the mining production follows this route. This production path presents a challenge to reach the global climate goals of moving towards a CO2 neutral production especially when using carbon as a reduction agent. One way of getting close to a CO2 neutral production of metals is to go towards electrolytic extraction of metals utilising electricity from green sources.

Johan Björkwall presents the initiative during the 2017 conference

There are several methods of electrolytic extraction of metals including electrolysis in both aqueous and ionic solution. Of particular interest is the re-emerging technology of electrolysis in ionic liquid solutions as this provides possibilities for higher productivity and minor problems with the formation of a passivation film on the electrodes compared with electrolysis in aqueous solutions.

Furthermore, there are complex or low-grade ore deposits, which are unsuitable for pyrometallurgical extraction with these methods due to significant technical challenges, the need for major capital investment or potential environmental damage. Also, large volumes of waste coming from steelmaking slags, fly ash, dust as well as sludge; unsuitable for conventional treatment methods.

There are several emerging technologies based on molten salt electrolysis that is interesting in the scope of metal production. One of the more intriguing of these technologies is the solid compound electrolysis for metal production from primary resources.

Electrolytic extraction of metal in ionic melts is a viable alternative to prevailing technologies for metal production using pyrometallurgical processes for treating complex ores and waste material. However, it is necessary to evaluate the scalability, productivity and industrial viability of these technologies in a framework of circular economy and eco-friendly processing.

Namn Johan Björkvall
Organisation Swerea Mefos AB