Deoxidation aluminium, or DeOx Al in short, is a key ingredient for steel mills, alloy producers and foundries. It is used as a deoxidizer or deoxidizing agent to remove oxygen from molten metal.
Taking the Basic Oxygen Furnace (BOF) production route for steel making, the molten steel typically contains between 400 to 800 ppm of oxygen when it’s ready to be tapped. To remove this oxygen and to prevent further oxidation of carbon, materials like ferromanganese, ferrosilicon or DeOx aluminium are added to the ladle as deoxidizers during tapping.
The choice of deoxidiser depends on specific requirements of the steelmaking process and the desired properties of the final steel product. Ferromanganese (FeMn) is usually added when moderate deoxidation is needed and ferrosilicon (FeSi) is used when a more powerful deoxidation effect is required – often following the use of FeMn.
DeOx aluminium is used when very strong deoxidation is needed, typically in the final stage of deoxidation, after initial additions of FeMn or FeSi. It is often used in low-carbon, high-strength steels or where a high degree of cleanliness is critical. Aluminium is a highly effective deoxidizer, as it reacts strongly with oxygen to form aluminium oxide (Al₂O₃), which helps remove oxygen very efficiently from the steel. Aluminium also helps control the grain size in the final product, acting as a grain refiner, which improves its strength and toughness. It is frequently used in the production of grain-refined steels, needed for automotive and aerospace applications, as well as in low-carbon and high-strength alloy steels. Aluminium-killed steels (i.e., those deoxidized with aluminium) are used when minimal oxygen content is required to avoid gas-related defects.
Producing DeOx aluminium can take different routes. The majority, however, is produced by melting aluminium scrap in a furnace, removing impurities and then casting it into the desired shape and size. And there are many. The shape affects how the deoxidizer is introduced, how it reacts with the metal and how it disperses in the molten liquid. Metal producers can choose between ingot, powder, pyramid, hemisphere, pellets, briquettes and more shapes to find the best addition to their production process.
The deoxidation aluminium market, valued at around $3 billion and growing at a 5.7% annual rate (Source), is also supported by Metis’ transaction-based price indices, offering regular spot prices to help buyers and sellers make informed decisions. By subscribing to the Metis services, users have access to robust prices for DeOx Al granules (96% Al, Si <1%) adjusted on a European FCA, pre-payment and average weighted prices bases.