Local dignitaries with Cameco and AREVA Resources Canada Inc. officials in Saskatoon, Saskatchewan, celebrated the opening of the Cigar Lake uranium mine and McCLean Lake processing facility Wednesday in a belated ceremony that included tours and speeches.
In addition, the mining group said that Cigar Lake had achieved the lower threshold for its 2015 production target range of 6 million to 8 million packaged pounds (100 percent basis) for the mine and the McClean Lake mill. By September 19, year to date, the mill had processed and packaged 6.1 million pounds of uranium concentrate, U308, from ore provided by the Cigar Lake mine.
Mining at Cigar Lake began in March 2014. By October, the mill at nearby McClean Lake had produced its first packaged uranium concentrate after the initial startup was halted due to flooding problems.
The mine is considered one of the world's richest deposits of uranium. In July 2014, mining was halted due to continued flooding, which the Comeco tried to halt by piping a brine solution into drilled holes in order to freeze the water coming into the mine. At the time, jet-boring was halted in order for the company to continue with attempts to freeze the water.
At this point, the jet boring mine system is operating as expected, the mining group said. The mine works with three jet boring systems commissioned for underground mining.
The orebody is located at depths ranging between 410 to 450 metres below the surface at the interface between dry basement rock and the water-bearing sandstone above. The ore zone and surrounding ground in the area to be mined must be frozen to prevent water from entering the mine and to help stabilize weak rock formations. The ore is removed using a jet boring method that mines out cavities in the frozen ore using a high-pressure water jet. The mixture of ore and water from the cavities is collected in a piping system and pumped to underground grinding and processing circuits. Thickened ore slurry is then pumped to the surface where it is loaded into tanker trucks and transported 70 kilometres to the McClean Lake mill for processing into uranium concentrate.
“As production ramps up to 18 million pounds (100% basis) by 2018, volumes may not be linear year-to-year, but will vary based on our operational experience. To ensure the most efficient operation of the mine and mill throughout the year, we expect to continually manage ore supply and, therefore, may halt and resume mining several times during a quarter without impacting planned annual production,” said Cameco
Now with three JBS machines commissioned for use underground, Cameco said it was reviewing the target and will provide an update in the company's third quarter report.
As production ramps up to 18 million pounds (100% basis) by 2018, volumes may not be linear year-to-year, the company warned, but will vary based on operational experience. To ensure the most efficient operation of the mine and mill throughout the year, Cameco expects to continually manage ore supply and, therefore, may halt and resume mining several times during a quarter without impacting planned annual production.
Meanwhile, the mill is expanding with construction activities slated for for completion in 2016. The mill ramp-up is progressing as planned with some feed grades exceeding 25 percent uranium and output well above historical mill production levels. The McClean Lake mill has achieved production of over 52 million pounds of uranium concentrate since its initial start in 1999. Once the expansion is complete, the mill will have capacity to produce 24 million pounds of uranium per year.