Imperial Metals is moving ahead with plans to expand the Huckleberry mine, even as it waits for a revised Mines Act permit to build a larger tailings pond.
On Nov. 22, the company released a technical report that describes how engineers plan to extend Huckleberry’s mine life “by mining an expanded Main Zone pit and developing a new tailings storage facility.”
If B.C.’s natural resources ministry gives Huckleberry the okay to expand its tailing pond, the mine expected to run seven years beyond its original 2014 closure date to 2021.
“No permitting hurdles are expected,” said the Nov. 22 report, which was prepared for Imperial Metals by two lead engineers and a geologist with the project.
The company plans to start digging into new material by early 2012.
It has already ordered new equipment and logged trees where it plans to extend a tailings pond.
Mining officials have consulted area First Nations, an archaeological surveys in 2010 and 2011 found no sign of any cultural artefacts on the site.
Aquatic biologists also found the expanded mine is unlikely to affect fish habitats. In general, surveys show the area has poor habitats for aquatic life—most of its streams dry up or slow to a trickle in summer and winter.
The main challenge is engineering.
Drillers found extra mineral deposits buried under an already backfilled area of the open-pit mine.
After weighing the options, the report authors recommend digging out the new material with excavators and hauling trucks.
That will mean building temporary platforms for the equipment to drive on, since the work will be done on wet and unstable backfill.
Huckleberry would produce an estimated $221 million in after-tax profits if it is extended another seven years. The final figure hinges on metals prices and foreign exchange rates.
From 2014 to 2021, Huckleberry is expected to produce 424 million lbs of copper. So far, the mine has produced 879 million lbs of copper as well as gold, silver and molybdneum.