Sandfire Resources Ltd (ASX:SFR) saw its stock price soar 5.07% during intraday trading on Friday, following the release of an updated pre-feasibility study for its Black Butte Copper Project in Montana.

The study revealed substantially positive developments including a 255% increase in the Lowry mineral resource to 31.5 million tonnes grading 1.3% copper, containing 400,000 tonnes of copper. Total ore reserves increased by 49% to 14.3 million tonnes grading 2.6% copper, containing 370,000 tonnes of copper, which extends the planned mine life by about 50% to 12 years.

The project is expected to produce 35,000 tonnes per annum of contained copper in its first four years, averaging 31,000 tonnes per annum over the initial mine life, with the Johnny Lee deposit fully permitted and Lowry advancing through approvals. These positive developments in resource expansion and project economics appear to have driven investor optimism and the stock's upward movement.