Aluminum, some will say, is eternally recyclable or indefinitely recyclable and doesn't lose its key characteristics. It's a very sustainable material.
One of the key benefits of recycling aluminum is that you need only 5% of the energy that is required to do primary metal when you recycle aluminum. Thereby, not only do you reduce by 95% the use of energy, but you also reduce emissions in the order of 95%, which is a great achievement in terms of greenhouse gas emissions.
There are complexities. As I mentioned earlier, some of the aluminum that comes back into the system needs to be segregated in terms of alloys—original alloys or series—and cannot necessarily be repurposed for the same use or for another use. There is an extra level of complexity to ensure you can optimally recycle all the metal that comes back into the stream, but increasing the use of recycled aluminum in the future to produce new material is certainly part of the world's aluminum pathway to decarbonization.
One of the key examples is what we now call “hybrid” smelters, which we will see more and more of. They are smelters producing primary metals, but they use their dilution factor to increase the use of recycled aluminum, and by doing so, they reduce their carbon footprint at the end.