Recycling rates report by the UN

[auroraglacialis]

Oh yes I agree - some materials cannot be recycled, but that is a problem. Because eventually they will in a way run out. What I mean by that is, that the amounts of ores that have a content of these materials that are "orders of magnitude higher" in concentration than the trash or the "vegetable patch" will eventually decline. First the high quality ores are mined, then the more abundant second grade and third grade ores are mined that have much lower contents already, requiring larger mining operations in open pit mines. This is not specifically about the two elemtns mentioned in the post but generally true for a variety of elements that behave in a similar way. Eventually the mining will reach a point where you need huge mines to produce low grade ore that has to be refined with a cost and energy intensive process. The price rises, availability drops. So maybe there will always be enough Gold or Silver because these are often recycled to 97% or more and it may take a while until that 3% loss depletes the remaining reserves. But for those non-recyclable materials the problem starts sooner.

That calculation in the quote makes no sense because of the very same argument brought up in that article. Namely that while the average prevalence may be 1 ppm or 0.001 ppm, this precisely means that it makes little sense to mine just any bit of crust. So it does not really help if there are millions of tons of these elements in the Earth or Earths crust, if they are dispersed like that or if they are inaccessible. Some elements for example prefer to stay in the lower crust. What is important here is not the overall dazzling amount of this element in all of earth, but the amount that is recoverable in a reasonable way by mining ores that have a much above average concentration. These are rare. To dump total amounts of some element makes little sense. You could claim that humans have not used a tiny fraction of all the gold in the world because there is still so much left in tiny bits in the earths crust - but look at the effort that has to be done to get to even the relatively concentrated ores today.

For the TE example, mining Te at the average prevalence of 1 ppb (0.001ppm) this means that one is in the order of several billion tons of soil/rock that has to be processed to get these 125 tonnes per year.

I hope the problem is clear - either the concentrated ores run out and supply drops at some point, or one keeps going until recovery from "ore" reaching the average concentrations in Earths crust is needed, which means vast amounts of processed materials.