Its preliminary economic assessment was based on Cordero's plus-1 billion ounce global silver-equivalent resource, updated in October, of which 910Moz is measured and indicated. 

The PEA put initial capex at US$368 million, for a 16-year mine producing an average annual 26 million ounces silver-equivalent, at an all-in sustaining cost of $12.35/oz Ag-eq.

It was expected to ramp up to 33Moz annually in years 5-12, positioning Cordero as one of the largest silver mines globally, the company said.

It would only lag Coeur Mining, Hecla Mining and First Majestic Silver's silver-equivalent output, according to a presentation this month.

The PEA pointed to a base case after-tax NPV5 of US$1.2 billion and IRR of 38%.

Payback was two years, using base case prices of $22 an ounce silver, $1,600/oz gold, $1 per pound lead and $1.20/lb zinc.

The well-funded company said there was "exceptional silver price leverage", citing the upside case which used a $27.50/oz silver price that helped lift the IRR to 55%.

"With annual silver-equivalent production averaging more than 26Moz over a +15-year mine life, we believe this PEA clearly positions Cordero as a Tier 1 silver asset," president and CEO Taj Singh said.

"Importantly, the outstanding metrics demonstrated in the PEA are supported by a mine plan with more than 99% of tonnes in the measured and indicated category, and a simple and conventional process design based on our detailed metallurgical testwork programme completed earlier this year.

"This provides us with a huge head start as we look ahead to the delivery of a prefeasibility study on Cordero in 2022."

The company, which changed name from Discovery Metals in April, reported having a cash position of C$73.1 million last week.

It had received about $31 million from warrants exercised at $1 in February, which took its cash balance at the time to $98 million.

Its shares (TSXV: DSV) are trading near the middle of a one-year range, closing up 4.4% yesterday to $1.89 to value it at $625 million (US$491 million).