Mill scale is the flaky surface of hot rolled steel, consisting of mixed iron oxides iron(II) oxide (FeO), iron(III) oxide (Fe203), and iron(II,III) oxide (Fe304, magnetite). Mill scale forms on the outer surfaces of plates, sheets or profiles when they are being produced by rolling red hot iron or steel billets in rolling mills. Mill scale is bluish-black in colour, is usually less than 0.1 mm thick, adheres to the steel surface and protects it from atmospheric corrosion - provided no break occurs in this coating.
Mill scale generated in rolling mills is generally collected and recycled at a sinter plant. Ras al Madeena has been in the business of Mill Scale supply since 2003 and supplied to Domestic Indian customers as well as exported several consignments internationally.