Mill scale

Mill scale is formed on the outer surface of plates, rolls, sheets or profiles when iron and steel are heated for rolling, forging, or other processing.

Being produced during the reheating, conditioning, and hot rolling operation, mill scale initially adheres to the steel surface and protects it from atmospheric corrosion, provided no break occurs in this coating. It can be removed from the steel surface by flame cleaning, pickling or abrasive blasting according to the steel mill technology.

From the chemical and physical analysis performed on the scrap, and according to the European Environmental rules, the raw material has been classified as a SPECIAL NON-DANGEROUS WASTE, listed in “GREEN LIST “.

Mill Scale can be classified as follows:
EINECS (EUROPEAN COMMISSION NO.): 266-007-8
WASTE CODE: 10 02 10
BASEL CODE: B 12 30
HS CODE: 2619.00

PHYSICAL PROPERTIES:

On visual inspection, it appears as a hard brittle sand, mainly composed of iron oxides, mostly ferric, and is bluish-black in colour. Its physical state is solid with a maximum size of 10 mm.

Tab.1 This data is believed to be accurate and was obtained from recognized technical sources, but cannot be warranted as to its accuracy or sufficiency.

CHEMICAL PROPERTIES
Mill Scale has been classified as a UVCB Substance since it is made of a large number of constituents and its composition can change according to the metallurgical plant production (reinforcement bar, special steel etc.).

The average chemical composition is detailed in Tab.2:

Tab.2. Average Chemical Composition. Please note that these data are believed to be accurate and representative of the average composition, but these details cannot be warranted as sufficient since the chemical composition can vary according to the production plant.

The Fe content detected in the raw material is present in different iron oxides, such as:

• Magnetite, Fe3O4, of characteristic blue-grey "steely" colour
• An extremely thin outer film of haematite, Fe2O3.
• The inner portion of the magnetite contains fine metal grains and sometimes, residual ferrous oxide as FeO, typically black coloured.

The hard blue-black scales may also contain a very low content of valuable alloy elements, such as wolfram, vanadium, and molybdenum. It is stable and insoluble in water and alkalis and soluble in most strong acids. As highlighted by the chemical analysis above, mill scale does not contain any dangerous, inflammable, radioactive or explosive substances. The material is free of dirt, nonferrous metals, or foreign material of any kind, and excessive rust and corrosion.

CONVERSION OF MILL SCALE WASTE INTO VALUABLE PRODUCTS
The material can be recovered in different processes and recycling plants, such as:

• Pig Iron Production (R4)
• Production of ferroalloys or other steel specialities (R4)
• Production of iron salts or pigments for the chemical industry (R5)
• Cement Industry for the production of counterweights or as an additive (R5)
• Other patented application for the production of rock wool, fertilizers, colour glass, batteries, water and soil treatment.

PACKING AND LOADING
The information above can, by no means, be an exhaustive listing of our mill scale characteristics. Please note that according to the end-user requirements, we can select and process a bespoke source that meets your criteria.
The material can be processed and delivered in 20’ containers or bulk vessels but in strict compliance with the Basel Convention/European Regulation regulating the transboundary shipment of waste materials