By-products
More than steel
Steelmaking produces valuable by-products. Most are reused in the process or sold for uses such as road construction and agriculture. With a material efficiency rate of over 97%, the steel industry already uses almost everything it produces. At ArcelorMittal, we are chasing a goal of 100% efficiency and zero waste.
At ArcelorMittal, we see by products as valuable resources. Given the right application, they have a second life, helping us reduce landfill waste and conserve raw materials. Here are some of the main by products from our steelmaking operations.
Blast furnace slag
A dense, glassy mineral material formed when iron ore impurities are separated during smelting.
Steel making slag
A harder, denser material made as molten iron converts to steel in the basic oxygen furnace.
Process gases
Energy-rich gases captured during steel production and reused instead of being flared.
Dusts and sludges
Residues collected from filtration systems that contain recoverable iron, zinc and other metals.
Coke derivatives
Materials such as tar and benzole recovered from coke production for further industrial use.
We want to eliminate all unnecessary landfilling of residues. This ambition energises us to keep innovating – finding, developing and scaling applications for every by-product stream. Here are just some of the ways we do this.
Lower-carbon cement
Blast furnace slag is processed into a more sustainable replacement for construction cement.
Roads and railways
Steelmaking slag is widely used in asphalt, railways and roads, where it replaces newly mined gravel.
Offshore wind turbines
Slag provides ballast for offshore wind turbines, avoiding extraction of natural materials.
Energy recovery and generation
Captured blast furnace and coke oven gases are reused for heat and electricity – even on site.
Ecological innovation
Artificial reefs built from slag support marine biodiversity and local fisheries.
Our goal is a steel industry without residual waste: one where every output has a defined, valuable, and sustainable destination. ArcelorMittal is transforming by products into strategic resources that generate revenue, reduce emissions and enable cross-industry decarbonisation.
Reducing waste
High reuse rates minimise landfill and environmental impact.
Lowering emissions
Slag-based cement and internal gas recovery cut carbon across multiple sectors.
Saving resources
Recycling metallic residues reduces the need for iron ore and coal.
Transforming infrastructure
Slag supports wind, rail, road and grid projects essential to electrification.