It is also an important alloying element used in the manufacture of stainless steels, high-strength low alloy steels (HSLA), aluminium-manganese alloys and copper-manganese alloys. Manganese metal can be produced industrially and almost all of it is used in the steel industry to make ferromanganese alloys. Manganese ferroalloys can be obtained by reducing the appropriate proportions of iron oxide (Fe₂O₃) and manganese dioxide (MnO₂) with carbon (graphite) in a blast furnace. Pure manganese metal can be produced by electrolysis of manganese sulphate (MnSO₄).