With respect to aluminium this only applied for produce NEW aluminium from its ore (Bauxiet).

Recycled aluminium is MUCH less energy intensive. Interestingly enough recycled aluminium is practically undistinguishable from new aluminium even after having gone through many cycles.

That is why recycling aluminium (soda cans) is such a wide spread activity.

I keep saying it. Aluminium is a pretty wonderful material. Only it low 0.2% yield stress limit is somewhat of a party pooper.

Wouter