Keeping it steel
The value of metal recycling
Steel recycling has a fascinating past. From railroads to automobiles, the history of recycling is almost as old as these industries themselves. At the turn of the twentieth century, it was common to see people scouring the streets or demolition sites in American and European cities looking for discarded machinery or old pots and pans. Trying to make a buck, the steel they found would normally be sold back to the large corporations that had generated it in the first place.
The demand for used steel at this time was primarily driven by the financial benefit that melting old metal has over extracting new mineral ore. Whilst such economic considerations are still important today, the expansion of steel recycling can also be seen as part of a greater trend: the shift from a linear to a circular economy. As global pressure on resources increases, steel is leading the way when it comes to ensuring materials remain in use for as long as possible and reducing waste.
The deal with steel
One of the greatest assets of steel: it is 100% recyclable. It can be used over and over again and doesn’t lose inherent qualities. Furthermore, its magnetic qualities mean it is easy to separate from waste streams, enabling high recovery rates. Everything can be recycled, from scrap generated during production and manufacturing (pre-consumer) to goods that have reached the end of their use, such as household appliances, steel structures and ships (post-consumer). The only barrier to recycling the latter is that they can often be in use for decades. Think bridges.
Alongside improving the economic viability of the industry, recycling also has a positive impact on the environment. Reducing the need for iron ore extraction significantly reduces CO2 emissions, water consumption and air pollution. Using ferrous scrap rather than virgin materials (iron ore) for steel production also requires 56 percent less energy.
It is perhaps no surprise then that steel is now the most recycled material on the planet, more than all other materials combined. Ferrous scrap has also become a globally traded commodity, regarded as a raw material for manufacturing new products worldwide. To put some numbers to it:
- Around 650 million tons of steel are recycled annually
- The U.S. recycled the equivalent of nearly 12 million cars in 2013
- In 2014 the U.S. ferrous scrap industry was valued at more than billion
- By sector, global steel recovery rates are estimated at 85% for construction, 85% for automotive, 90% for machinery and 50% for electrical and domestic appliances.
The China factor
For many years a number of discrepancies have existed behind the global figures, with different countries and regions recycling different amounts of steel (relative to what they produce). However, now it seems these variations could be set to reduce – as more and more manufacturers around the world begin to integrate recycling into production cycles. One such example is China. In recent years, the country has been racing ahead with steel production – but lagging behind in recycling. This has made them a significant consumer of iron ore imports. According to a recent Bloomberg report, in 2015 China sourced 78.5 percent of its total iron ore from overseas (933 million tons). Now however, they have accumulated so much steel so rapidly that the total amount of metal available for recycling stands far beyond the level that would be typical for an economy its size. As a result, the country is now reportedly looking to better harvest and recycle vast amounts of its own steel (buried in landfills or encased in concrete in demolished buildings). What this means for the global market and the environment remains to be seen.
Going full circle
Globally, steel is produced via two main routes: the blast furnace-basic oxygen furnace (BF-BOF) and the electric arc furnace (EAF). Although scrap metal can also be used in blast furnaces alongside iron ore and coal, it is mainly used in EAFs, which can be charged with up to 100% of recycled steel. Pre-consumer scrap can normally be used directly, whereas post-consumer scrap often needs to be prepared in order to provide pure steel.
EAFs melt and convert scrap metal into high quality steel using high-power electric arcs. Additives, such as alloys, are used to adjust to the desired chemical composition. Tenova is a global benchmark supplier of electric arc furnaces, pioneering secondary steel production and recycling. As washing machines become cars, ships become paper clips, and bikes become fridges, it is clear that steel has distinctive properties to enable resource efficiency – and that the industry is taking steps to ensure a circular economy is achieved.