New report shows lead swinging into 91,000 tonne deficit and zinc undersupply increasing by a third to 178,000 tonnes during first five months of 2017.
Codelco, which sends all its profits to state coffers, posted a larger profit in the first quarter of 2017 than in all of 2016 as a result of a strict policy of containing costs and a modest recovery in global prices for the red metal.
The spin-off business would go after royalty agreements in copper, zinc, nickel and cobalt, worth more than $300 million, while looking to attract a strategic partner to fund further deals.
The Resolution copper project in Arizona would be a prototype for a looming era of more invasive US mines as companies run out of easy-to-reach deposits.
