Centerra Operations Suspended at Mount Milligan
As previously disclosed, the mine experienced a drier than normal spring and summer during 2017 with a limited amount of spring snow melt. This resulted in lower than expected reclaim water volumes in the tailings storage facility (TSF), 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 in the TSF due to ice formation.
The company sought to mitigate the water shortfall by drilling additional water wells during the fourth quarter. While the effort was somewhat successful, the additional water obtained was insufficient.
It is expected that by the end of January there will be adequate fresh water available to restart mill processing operations using just one of the ball mills (38,000 metric tons per day to minimize water requirements). The company expects that additional fresh water will become available after the spring melt, typically in April, at which time it expects to restart the second ball mill returning mill processing operations to full capacity.
Meanwhile, mill maintenance crews will continue to carry out preventative maintenance activities and may bring forward other maintenance work that had been planned for later in the year. The Mount Milligan mine continues to operate according to its mine plan and will continue to expose, mine and stockpile additional ores for future processing. Year-to-date the Mount Milligan mine has produced approximately 225,000 oz of payable gold and approximately 54 million lb of payable copper.