RobPE:
Recognize this reply is from a recovering geologist become engineer...
I think the timeframe will hinge primarily on demographics, which definitely are out of the realm of this forum. But I bet the demographers are simply scaling up the take-off points for the industrial and green revolutions, as well as glomphing them together since Indian and Chinese development may benefit from the synergies of both those waves. That is, the amplitude oughtta be something.
There may be some relative moderation of commodity usage and pricing due to the efficiencies established since the earlier North American and European industrial expansions. Nonetheless, the simple demographics are going to drive commodities dramatically for quite a while.
This 52-yr old expects to be busy as long as desired, certainly beyond 10 years since my kids are still in junior high and high school. And whether mining-related or not, they probably will have careers serving economic sectors affected by the Indian and Chinese expansion.
Do you reckon Adam Smith spoke Mandarin or Cantonese?
Given the discovery-to-production lead times, a ten year horizon for high commodity prices is virtually a given. These lead times may not change markedly with 'relaxed' environmental constraints in the expanding economies. The relative remoteness and lack of industrial infrastructure may keep the lead times fairly long. Also, the 'relaxed' environmental constraints are tightening on a project-by-project basis, if not quicker. The developing economies, even the forced ones, are finding that the market will bear clean air and water, just like the developed economies have found.
Oh, and if inflation is taking off, all bets are off on where copper's new bottom will be... .
Perhaps the greatest differences between previous expansive markets and the current situation are the intervening technological revolutions, as in materials and information handling. Nonetheless, the heavy lifting in power and fabrication still will require copper and iron. And the glamorous materials still will require petroleum for either raw material or process energy.
Any way you cut it, commodities should remain strong for at least ten years, probably more. Any dips simply will be market opportunities within a rising trend. That's where I've put my IRA.
Best of fortune.