Mill processing operations at the Mount Milligan Mine – an open pit copper and gold mine located north of Fort St. James – have been temporarily suspended due to a lack of sufficient water resources.
Mill processing operations are expected to recommence at partial capacity by the end of January 2018, and at full capacity after the spring melt.
According to Centerra Gold, company that owns the mine, mill maintenance crews will continue to carry out outstanding preventative maintenance activities during this downtime and will look to bring forward other maintenance work that had been planned for later in the year.
According to John Pearson, Centerra Gold’s vice president of investor relations, there have not been any layoffs at this stage.
“Mining continues in the open pit and in the mill, we continue to carry out preventative maintenance activities and accelerate other maintenance work that had been planned for later in the year,” explained Pearson.
The mine has experienced a drier than normal spring and summer during 2017, with a limited amount of spring snow melt. According to the company, this resulted in lower than expected reclaim water volumes in the mine’s tailings storage facility, which is used for mill processing operations.
“The water shortage has been exacerbated by unanticipated extremely cold temperatures at Mount Milligan, which has resulted in a greater than expected loss of water volumes due to ice formation,” says a recent press release.
The company sought to mitigate the water shortfall in the fourth quarter of 2017 by drilling additional water wells to draw water from nearby aquifers located on the property.
“While such wells were partially successful, the additional water obtained was not sufficient to offset the loss of water volumes,” adds the release.
The company is also pursuing an amendment to Mount Milligan’s environmental assessment to allow pumping of water from Phillips Lake, which is located nearby the property, and is applying for the additional related permits.
“It is expected that by the end of January 2018 there will be adequate fresh water available to restart mill processing operations,” states Centerra Gold. “The company expects that additional fresh water will become available after the spring melt, typically in April, at which time it expects to re-start the second ball mill, returning mill processing operations to full capacity.”
However, the availability of water is subject to “natural forces that can be unpredictable,” adds the company.