Maximising scrap use helps reduce CO2 emissions
Today, it is estimated that the global steel industry used about 2 billion tonnes of iron ore, 1 billion tonnes of metallurgical coal and 575 million tonnes of steel scrap to produce about 1.7 billion tonnes of crude steel.
Recycled steel (also called scrap steel) is one of the industry’s most important raw materials. It comes from demolished structures and end of life vehicles and machinery as well as from the yield losses in the steelmaking process.
Every steel plant is also a recycling plant, and all steel production uses scrap, up to 100% in the electric arc furnace (EAF) and up to 30% in the blast furnace (BF) route.
All scrap that is collected is recycled, and the overall recycling rate today is estimated to be about 85%. This high level of recycling means that there is limited room for improvement.
Scrap plays a key role in reducing industry emissions and resource consumption. Every tonne of scrap used for steel production avoids the emission of 1.5 tonnes of carbon dioxide, and the consumption of 1.4 tonnes of iron ore, 740 kg of coal and 120 kg of limestone.
The future expansion of scrap-based steel production will depend on the availability of high-grade scrap.
While iron ore supply can flex with demand, global scrap availability is a function of steel demand and the arising of scrap at the end-of-life of steel-containing products.
Global steelmaking capacity experienced a phase of explosive growth from the early 2000s largely fuelled by investment in new capacity in China.
With steel products having an average lifespan of 40 years, this steel will begin to enter the scrap market in the next decade, enabling a significant reduction of steel industry emissions.
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.
According to United Nation’s COMTRADE Statistics Database, global exports of iron ore in 2017 amounted to around 1.5 billion tonnes, representing the second-largest commodity trade volume globally, behind global crude oil exports.
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.