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 by-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 60% since 1960.
Today, it is estimated that the global steel industry used about 2.1 billion tonnes of iron ore, 1.1 billion tonnes of metallurgical coal and 560 million tonnes of recycled steel to produce about 1.7 billion tonnes of crude steel.
Recycled steel (sometimes 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. It is estimated that around 630 million tonnes of scrap were recycled in 2017. Of this, approximately 560 million tonnes were used by the global steel industry and about 70 million tonnes were used in foundries.
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.
Iron ore and metallurgical coal are primarily shipped in cape-size vessels, huge bulk carriers that can hold a cargo of 140,000 tonnes or more. According to United Nation’s COMTRADE Statistics Database, global exports of iron ore in 2015 amounted to around 1.4 billion tonnes, representing the second largest commodity trade volume globally, behind global crude oil exports.
The global steel industry is currently faced with the following key challenges in raw materials procurement and processing operations: