A fascinating article from a Resource Investor site across 5 pages. The really interesting stuff comes after page 3, where the commentators turn to the opportunity represented by millions of cars, each with a catalytic convertor that contains platinum group metals (PGM). Recycling of cars is the next ore body.
One company referred to in particular is Pro-Or which can extract PGM for 1% of the cost of a traditional smelter. The numbers stack up for recycling. On a really good seam of ore, you might get 5–8 g/t. If you remove the catalytic converter from a car and crush it, the ore body is in the range of 2,000 g/t. Given PGM trades for up to $2000 per ounce, a tonne of crushed converters contains something like $140,000 of PGM.