Recovery of chemicals from waste iron sulfate. A laboratory test of the production of iron chloride and/or electrolytic iron

Waste iron sulfate is produced in titanium dioxide manufacture and in steel pickling with sulfuric acid. Many processes have been proposed to use this waste as a source of chemicals or raw materials. The process developed here is based on the reaction with pure or waste calcium chloride (Solvay brine) to obtain iron(II) chloride and gypsum as a by-product. The iron chloride solution can either be directly oxidized to iron(III) chloride by reaction with chlorine or electrolyzed to produce electrolytic iron and gaseous chlorine. The more interesting procedure is to electrolyze one-third of the iron(II) in solution and to oxidize the remainder with the chlorine obtained from the electrolysis.