The PEA put initial capex at C$3.25 billion, about 10 times the company's current market cap.
The after-tax NPV8 was estimated at $2.33 billion and IRR came in below 20%, at 19.5%.
The study envisaged a 25-year openpit operation, producing an average annual 178 million pounds of copper, 231,000 ounces of gold, 1.36 million ounces of silver and 16.6Mlb of molybdenum.
A second phase of development could take minelife to 47 years and barely increased the initial capex, from $3.251 million to $3.256 million.
Base case payback was put at three years using metal prices of US$3.35/lb for copper, $1,600/oz for gold, $24/oz silver and $12/lb for molybdenum.
"This study reaffirms Casino as one of the very few long-life copper-gold projects with robust economics in a top mining district, the Yukon," CEO Paul West-Sells said.
"We look forward to continuing working with our recent strategic investor, Rio Tinto, First Nations and other stakeholders to advance this project through additional engineering to feasibility."
The company said it has spent more than C$75 million since 2006 to further the project.
Rio invested C$25.6 million in Western Copper and Gold in May to advance Casino, at $2.17 per share giving it an 8% stake.
Investors appeared underwhelmed by the PEA yesterday, sending the junior's shares (TSX: WRN) down 3.1% to $2.49 to value it at $368 million (US$298 million).
