What is mill scale?

Mill scale is a flaky surface layer of iron oxide that forms on steel surfaces during hot rolling processes. It is a byproduct of steel manufacturing and is typically black in color. Mill scale is composed of iron oxides, primarily magnetite and hematite, along with smaller amounts of other metal oxides and impurities.

Mill scale is considered a waste material in the steel industry, but it can also be recycled and reused in various applications. One common use of mill scale is as a raw material in the production of iron-based materials, such as steel and pig iron. It can also be used as a source of iron in cement production, as a pigment in paints and coatings, and as a raw material in the production of ferrous sulfate.

However, due to its high iron content, mill scale can also be a potential source of environmental pollution if not properly managed. It can contain heavy metals and other contaminants that may leach into surrounding soil and water if not properly disposed of.

Overall, mill scale is a valuable material that can be repurposed and utilized in various industries, but its management and disposal must be carried out in a responsible and environmentally conscious manner.