Water shortfall shutters Centerra’s Mount Milligan mill

VANCOUVER (miningweekly.com) – Drier-than-normal spring and summer weather conditions, combined with unexpectedly frigid temperatures during the current quarter, have contributed to a water shortage at Centerra Gold’s Mount Milligan mill, in British Columbia, forcing the company to temporarily shutter the plant.

The Toronto-headquartered miner expects a partial restart of milling operations by the end of January, with full capacity to resume following the spring snow and ice melt.

Centerra advised on Wednesday that it had sought to mitigate the water shortage during the period by drilling new water wells to draw water from nearby aquifers located on the property. It said that while such wells were partially successful, the additional water obtained was not enough to offset the loss of water volumes in the tailings storage facility due to ice formation.

The company has launched an amendment to Mount Milligan’s environmental assessment to allow pumping of water from nearby Phillips Lake and is applying for the additional related permits.

Centerra plans to restart only one of the ball mills at the end of January, operating at 38 000 t/d to reduce water consumption. The company expects that more fresh water will become available after the spring melt, typically in April, at which time it expects to re-start the second ball mill, and returning mill processing operations to full capacity. 

The company will make use of the down time to carry out outstanding preventative maintenance activities and will look to 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 about 225 000 oz of payable gold and about 54-million pounds of payable copper.

Meanwhile, output at the company’s Kumtor mine, in the Kyrgyz Republic, has continued to be strong and the mine is expected to finish the year with production of about 560 000 oz of gold.

Centerra advised that Kumtor has also received its maximum allowable emissions permit and its maximum allowable discharge permit from the Kyrgyz Republic State Agency for Environmental Protection and Forestry for the full calendar year of 2018. With these permits in place, Kumtor now has all the necessary permits and approvals to operate throughout 2018.

The company expects to issue its 2018 full-year production guidance in mid-January and will be providing additional information regarding Mount Milligan as it becomes available, including updates on and additional steps to mitigate Mount Milligan’s water shortfall.

Centerra expects to produce between 785 000 and 845 000 oz of gold in 2017.

Centerra's TSX-listed equity fell more than 12% on Wednesday, to C$6.36 a share.