In zinc leaching, iron is removed from zinc sulphate solution by iron precipitation. The mainstay of iron precipitation includes jarosite, goethite and hematite, of which goethite is of the most economic and environmental-friendly superiority.

Goethite residue from zinc hydrometallurgy can be treated by flash magnetization roasting.It can enrich the goethite residue into standard iron ore for sale. It is the best accessible green solution to recycle iron at high efficiency but low cost.