Page 35 - Hub-4 Magazine Issue 70

Recycling-MRF’s/Shredders/Balers
Sorting technology turns aluminium green
Karl Hoffmann, Global Sales Director from the Metal Recycling Division at STEINERT about recycling aluminium, technological breakthroughs, the distinctive features of the market and his expectations for the future.
Mr. Hoffmann, how can so much energy be saved by recycling aluminium?
Karl Hoffmann: Basically, you have to compare primary and secondary aluminium. In the case of primary aluminium, firstly bauxite has to be mined and then a complex process is undertaken to produce aluminium oxide from this. The molten salt electrolysis process then produces aluminium with a purity of up to 99.7 %. This is a very energy-intensive process, which causes a lot of environmental pollution. Recycling is brought into the equation when producing secondary aluminium.
By using scrap aluminium in smelting works, much less energy is used. What’s more, the aluminium can be used again and again – in theory, it can be recycled infinitely. And the figures involved are significant: around 75% of the aluminium ever produced is still in circulation. This is firstly because products
made from aluminium have a long life and secondly because metal can be recycled with great ease.
So how much less energy is needed to recycle aluminium compared with producing it from scratch?
Hoffmann: You can assume a saving of up to 95 %. Of course, this is great news for climate protection. Recycling aluminium has the potential to produce 92 % fewer CO2 emissions than new aluminium. In 2019, 20 million tonnes of aluminium was recycled globally, which is an equivalent saving of 300 million tonnes of greenhouse gases.
Processing one tonne of aluminium scrap also saves 8 tonnes of bauxite from having to be mined. All things considered, it’s a saving of 14,000 kWh.
www.hub-4.com Sept-Oct 21 - Issue 70
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