Maximising scrap use helps reduce CO2 emissions

raw materials

Scrap is a term used to describe steel that has reached the end of its useful life, known as ‘post-consumer scrap’ or has been generated during the manufacture of steel products, known as ‘pre-consumer scrap’. While the term ‘scrap’ may lead one to believe this is a waste product, it is actually a valuable raw material used in every steelmaking process. Due to its inherent magnetism, steel is very easy to separate and recycle, making steel the most recycled material in the world.

Melting steel scrap at the end of its useful life allows us to create new steels, making adjustments to the chemistry and shape of the new product. Almost every steel plant uses scrap as part of its raw materials mix, and therefore almost every steel plant is also a recycling plant.

In blast furnace (BF) steelmaking, each charge of the basic oxygen furnace, in which carbon carbon-rich pig iron is refined into crude steel, typically contains up to 30% scrap.

Scrap acts as a cooling agent, absorbing excess heat from the exothermic decarbonisation process. In some cases, scrap is added directly to the BF as a source of iron units, reducing greenhouse gas emissions. In electric arc furnace (EAF) steelmaking, up to 100% scrap is used to make new steel products.

Around 650 Mt per year of scrap is consumed each year for steel production (compared with a total crude steel production volume of around 1.9 Gt per year), with comparable amounts of scrap used in the primary and secondary routes. This avoids the emission of approximately 975 Mt of CO2 annually and significantly reduces the use of other natural resources use, such as iron ore, coal and limestone.

In theory, all new steel could be made from recycled steel. However, currently, this is not feasible due to the scarcity of scrap. This is because of the long service life of steel products, given steel’s strength and durability.

The average life of steel products ranges from a few weeks for steel packaging to up to 100 years for buildings and infrastructure. The average lifespan of a steel product is 40 years. This means there is a significant delay between steel being produced and being available for recycling.   Continued growth in steel demand means that transitioning the industry to entirely scrap-based production is unlikely to be possible during this century.

Steel demand is growing at a faster rate than scrap is being released from the pool of ‘steel in use’. All scrap currently collected is recycled. As such there is only limited scope to increase scrap availability. Any future increase in availability will be drawn from the expected increase of post-consumer scrap availability.

worldsteel expects that global end-of-life scrap availability will reach about 600 Mt in 2030 and 900 Mt in 2050, a growth of more than 500 Mt in one of our main steelmaking raw materials in the next 30 years.

The steelmaking process is able to remove most impurities that may be present in scrap steel. Hence ‘downcycling’ of steel scrap into lower quality products is not an issue for the steel industry in the same way it can be for glass and aluminium.

However, some elements, especially copper, cannot be removed during the steelmaking process. Elevated copper levels in steel can lead to a loss of ductility and resulting surface defects. Copper content is currently carefully managed through a combination of sorting and dilution. Improved scrap sorting and better separation techniques to reduce contamination will be important to ensure all of steel grades can be produced via the EAF route.

Iron ore and metallurgical coal

Iron ore and metallurgical coal are used mainly in the blast furnace process of ironmaking. For this process, coking coal is turned into coke, an almost pure form of carbon, which is used as the main fuel and reductant in a blast furnace.

Typically, it takes 1.6 tonnes of iron ore and around 450kg of coke to produce a tonne of pig iron, the raw iron that comes out of a blast furnace. Some of the coke can be replaced by injecting pulverised coal into the blast furnace.

Iron is a common mineral on the earth’s surface. Most iron ore is extracted in opencast mines in Australia and Brazil, carried to dedicated ports by rail, and then shipped to steel plants in Asia and Europe.


RankingTop 10 iron ore producing countries2021
7South Africa73,091
10United States48,700


RankingTop 10 iron ore exporting countries2021
3South Africa67,932

Efficient use of natural resources is critical to sustainability

The steel industry uses advanced technologies and techniques to increase production yield rates, reduce its energy requirements, and facilitate the use of co-products.

On average, 20 GJ of energy is consumed per tonne of crude steel produced globally. The most efficient steel companies have reduced their energy consumption per tonne of steel by around 60% since 1960.


For further details on steel industry raw materials, check out our fact sheet available for download to the right of this text.