Electrochemical process for the recovery of metallic iron and chlorine values from iron-rich metal chloride wastes

An electrochemical process for the recovery of metallic iron and chlorine gas from an iron-rich metal chloride solution, which process comprises:

• a) providing an iron-rich metal chloride solution;
• b) electrolysing said iron-rich metal chloride solution in a two-compartment electrolyser comprising a cathodic compartment equipped with a cathode having a hydrogen overpotential higher than that of iron, and an anodic compartment equipped with an anode and containing an anolyte, said cathodic and anodic compartments being separated by an anion-exchange membrane, said electrolysing step comprising circulating said iron-rich metal chloride solution, adjusted to a pH below about 2, as a catholyte in said cathodic compartment of said electrolyser, thereby causing iron to be electrodeposited at the cathode and chlorine gas to evolve at the anode, and leaving an iron-depleted solution;
• c) separately recovering said electrodeposited iron and said chlorine gas;
• and
• d) recirculating at least part of said iron-depleted solution into said iron-rich metal chloride solution in a).