The storage of volatile, renewable energies as one of the unsolved questions of the modern energy economy is the focus of the Clean Circles cluster project. In this context, iron is being examined as an energy source for a climate-neutral circular economy. Part of the concept is the oxidation of iron particles for energy extraction. The resulting iron oxide particles are then reduced using energy from renewable resources to obtain pure iron again and thus close the cycle. The required process steps for reduction are initially separated into dissolution of the particles in electrolytic solvents and subsequent separation.