Recycling rates report by the UN

[Human No More]

Originally Posted by auroraglacialis

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.

In a few million years - potentially yes; longer for high recovery rate materials.

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.

That would be true if rare earths were evenly distributed, but they aren't past the traces - if it's 0.0001ppm average, any random location could be orders of magnitude less. They still occur in specific locations the name 'rare' has nothing to do with abundance, but everything to do with the form they come in - grouped with other metals and each other.

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.

See above - that would be true if and only if the only way to get it was to mine the 'vegetable patch' metaphor in the article. However, that isn't the case.