The company announced the completion of the work in November, which included the installation of a new crushing circuit - specifically a new primary jaw crusher and conveyor belt for the feeding of the facility's secondary cone crushers.
Winston expects to be mining and milling high grade gold and silver from the Custer and Parallel veins at a rate of 150 tonnes per day nameplate capacity by May 2021.
In addition, underground development work at its wholly-owned Winston gold mine, near Helena, Montana, has allowed mining operations to increase to a rate of 120 t/d, or 3,000 tonnes per month.
The last significant upgrade to be installed at the mill is a filter press, which will eliminate the labor-intensive process of recovering flotation concentrates from the leaf filter and improve safety.
Once the filter press is operational, Winston plans to run the mill around the clock for six days a week to process the high-grade stockpile from the Winston mine.