The paper reviews the history of modern iron control processes in hydrometallurgy. Particular
attention is paid to the processes developed in the 1960s by the electrolytic zinc industry for the
removal of iron from zinc sulphate leach liquors - namely the Jarosite, Goethite and Hematite
processes. Problems faced by the industry in the safe disposal of the iron residues produced by these
processes are discussed. The lessons learnt over the past half century by the zinc industry are projected
on to the current efforts to develop hydrometallurgical processes for the treatment of copper sulphide
concentrates. It is argued that any attempt to create a “hydrometallurgical copper smelter” is doomed
to ultimate failure, unless and until methods are developed that can recover iron from solution in a form
that can be directly utilised by the steel or pigment industries.