Case Study

Cameco’s McArthur River deposit is blessed with some of the most valuable ore in the world, but that doesn’t mean the mine is resting on its laurels.

Recent improvements to ground freezing technology to isolate mining areas have resulted in significant capital savings and scheduling consistency in maintaining long-term production for Cameco.

“We had a production target a number of years ago and needed to put in a freeze wall in less time than we had ever done before,” said Cameron Chapman, operations manager. “So our engineering crews started looking at ways to improve how we freeze around the orebody.”

Ground freezing is essential at McArthur River because the sandstone that overlays the deposit and basement rocks is water-bearing, with large volumes of water under significant pressure. The freezing forms an impermeable wall around the area being mined, preventing water from entering the mine and helping stabilize weak rock formations.

McArthur River’s team succeeded in improving both the time it took to drill freezeholes as well as the accuracy of deviation in drilling. They accomplished this through a number of customizations and innovations to drill technology used at site, as well as improving their drilling techniques.

It used to take the site approximately 20 days to drill a single freezehole. Today the job is done in about eight days. The improved drilling accuracy and length of holes drilled has also allowed for increased spacing, which means drilling fewer holes and less freezing capacity required.

“It has essentially changed how freeze walls are built in some ways, in terms of efficiency towards the capital costs of building the freeze walls, and more importantly, some of the capital infrastructure,” said Cameron.

The crunched numbers are significant. When two ore zones at site were compared using old freezing methods versus new ones, four million dollars was saved for Cameco.

And based on current life-of-mine plans, McArthur River estimates over 31 million dollars will be saved for Cameco in ground freezing activities for future ore zones.

“Freeze drilling is as much our bread and butter as raiseboring, our mining method,” said Cameron. “This is really a great story about innovation, starting from a technical design challenge right down through the execution by people on the front lines.”

“We’ve seen the impact of these new methods in areas we mined in 2015, so now we’ll be able to get the most economic value for Cameco by minimizing significant capital costs in future mining areas.”