Electrolytic iron production from alkaline bauxite residue slurries at low temperatures

The primary iron metallurgy is characterized by significant direct CO2 emissions, due to the
carbothermic reduction of the iron ore. This paper deals with the electrification of primary
iron production by developing a new and innovative process for the carbon-free production
of metallic iron from Bauxite Residue (BR) which is a by-product of the alumina industry. It
is based on the electroreduction of iron oxides from BR suspensions in concentrated sodium
hydroxide solutions, at low temperature and normal pressure. The iron oxide source, used
in the present study is bauxite residue provided by Mytilineos S.A., Metallurgy Business
Unit-Aluminium of Greece. The research study is a preliminary screening of BR as a
potential raw material for iron production by performing experiments in a small-scale
electrolysis cell. The first results presented here, show that iron can be produced by the
reduction of iron oxides in the bauxite residue with high Faradaic efficiency (>70%).
Although significant optimization is needed, the novel process shows great promise.