TORONTO (miningweekly.com) – Vancouver-based Taseko Mines has increased the mineral reserves at its Prosperity project, in British Columbia, by 70%, from 487-million tons to 830-million tons, the company announced this week.

"In keeping with our historically conservative approach to reserve calculations, we have modestly adjusted our gold and copper price assumptions to better reflect longer-term metal price expectations,” explained CEO Russell Hallbauer.

Altogether, three-million ounces of recoverable gold and 1,6-billion pounds of recoverable copper were added to the reserve base, bringing the total recoverable metal to 7,7-million ounces of gold and 3,6-billion pounds of copper.

Based on the current design for the operation, the additional reserves boost the projected life-of-mine from 20 years to 33 years, Taseko said.

The reserves were previously based on a $5,25 net smelter return (NSR) cutoff, using gold and copper prices of $500/oz and $1,50/lb, respectively, but have now been calculated at a $5,50 NSR cutoff, using gold and copper prices of $650/oz and $1.65/lb, respectively.

“This increase in metal price assumptions will allow us to mine deeper, higher-grade mineralisation,” Hallbauer said.

The project is currently working its way through the environmental-impact assessment processes at both federal and provincial levels and the company has said that it hopes to have all the necessary approvals in place to start development by around midyear next year.

Taseko already produces copper and molybdenum from the Gibraltar mine, in British Columbia.

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