St Barbara (ASX:SBM) said evaluation work on an alternative design approach for the processing of ore from its Cochrane Hill gold project in Canada identified the potential to expand the proposed 15-Mile processing facility, according to a Wednesday Australian bourse filing.

The evaluation identified a processing capacity of 3 million tonnes per annum, compared with the 2.1 million tonnes per annum expected in the 15-Mile and Beaver Dam pre-feasibility study.

The preferred scenario involves trucking ore from the Cochrane Hill project to the 15-Mile process plant, along with the 15-Mile and Beaver Dam ore feed, using a quarry-style configuration.

It modeled over 15 scenarios to refine mine-to-mill optimization for the project.

To accommodate the larger combined feed of all three projects, an expansion of the proposed 15-Mile processing facility would increase the mill throughput.

The company said it will continue to evaluate the proposed design changes in the third and fourth quarters of fiscal 2025, aiming to design an integrated project that supports annual gold production of 100,000 ounces per annum or more.

St Barbara's shares fell almost 7% in early trading on Wednesday.