Initial construction was already underway in anticipation of formal approval, after the company teed up a US$120 million financing in January and a fixed price $76.5 million EPC contract for the process plant.
Las Chispas' all-in sustaining costs were in the lowest quartile globally, SilverCrest said, with average project-level AISC estimated at $7.07/oz Ag-eq and $6.68/oz during seven years of full production.
Las Chispas was expected to produce 12.4 million ounces silver-equivalent annually between 2023-2029.
The feasibility study considered a 1,250 tonne per day operation, with initial capex of $137.7 million which excluded $25.8 million of sunk capital spent prior to January 1.
It put the after-tax NPV5 at $486.3 million, IRR at 52% and payback at one year.
Net free cash flow was expected to begin in 2023.
The study used base case metal prices of $1,500/oz gold and $19/oz silver, well below current spot prices of about $1,840/oz and $26.50 respectively.
SilverCrest said the most significant differences to the May 2019 preliminary economic assessment were increased mineral resources, increased mineable grades, decreased mineable tonnes, increased recoveries, more payable ounces, higher mining dilution and higher mining and capital costs.
The company also announced a high-grade, initial reserve of 3.35 million tonnes grading 4.81g/t gold and 461g/t silver, or 879g/t Ag-eq for 94.7Moz Ag-eq.
The resource was updated to a measured and indicated 108.1Moz Ag-eq and an inferred 29.7Moz.
CEO Eric Fier said SilverCrest was thrilled to have completed a robust feasibility study within five years of drilling the first hole at Las Chispas.
"We are excited about the extensive opportunities that remain to grow and optimise Las Chispas," he said.
"While there is a lot of hard work ahead of us, we look forward to making the shift to production and cash flow which we expect will finance our continued growth."
SilverCrest said it had $125 million in cash at January 31 and $90 million available under its credit facility.
SilverCrest shares (TSX: SIL) closed down 12.6% to C$12.58 yesterday as the heat came out of the silver market as the GameStop-inspired retail investor frenzy cooled.
It had reached a one-year high of $16.37 in January and is capitalised about $1.6 billion (US$1.2 billion).