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A mining icon returns to find Thor Lake a working mine

Gren Thomas at the Nechalacho mine in August 2022
Gren Thomas at the Nechalacho mine in August 2022. Sarah Pruys/Cabin Radio

The man who first discovered rare earths by a lake east of Yellowknife returned last month to the working mine that has since developed.

Gren Thomas, an occupant of the Canadian Mining Hall of Fame since 2009, is best known for his role in the diamond discovery that established the NWT’s Diavik diamond mine in the 1990s.

However, in the 1970s, his first major breakthrough in the territory was the discovery of various minerals at Thor Lake, some 100 km east of the territorial capital.

Thomas flew back to Thor Lake in August, his first visit in a decade, to see what is now the Nechalacho mine, Canada’s first producer of rare earths and an operating mine since 2021.



“It’s great. It still has the same pleasant atmosphere it had when I first set foot here, it’s a very pleasant place to be,” said Thomas, now in his eighties.

“I once calculated 100 people from Yellowknife alone had worked out here. I could name them all. Since then, there has been double or triple that.”

Nechalacho employs around 30 seasonal workers at the site, shipping rare earths south for processing and ultimate sale to the likes of auto parts firms and manufacturers in Europe.

Owner Vital Metals – which this week announced the surprise dismissal of its managing director – has positioned Nechalacho as a solution for firms seeking critical minerals that don’t come from China, which is considered an unstable supplier by some western customers.



The NWT government has also built up Nechalacho as an example of the smaller-scale mining that, in the territory’s view, will be needed to help sustain the economy once diamond mining winds down in the years ahead.

Yet for decades, rare earths were all but ignored.

Kicking the moss

Thomas said he made his discovery at Thor Lake while trying, “without a great deal of success,” to find uranium at a time when the radioactive element attracted a lot of interest.

“We could find only one radioactive occurrence of any interest, and that was Thor Lake,” Thomas said.

“There’s certainly a lot of radioactivity but … not a lot of uranium. But Thor Lake piqued our interest because there were other minerals apparently around.

“Although we originally investigated for rare earths and uranium, we realized – after a year or so – that there was also a significant deposit of niobium and tantalum. We subsequently found that this deposit has many different metals in it.”

So began a decades-long quest to turn Thor Lake into a mine, with owners cycling through various minerals in an effort to get production off the ground.

Gren Thomas, left, and Chris Pedersen at a water settling pond on the Nechalacho site. Sarah Pruys/Cabin Radio
The NWT’s Nechalacho rare earths mine is seen in an October 2021 GNWT image.

Geologist Chris Pedersen arrived at the site with a colleague at Thomas’ invite, attempting to turn tantalum deposits in the area into a viable product.



“The first summer, we were out getting an introduction to the deposit and walking through the forest. We started kicking over some moss and finding little bits of quartz here and there,” Pedersen recalled.

“Then we started finding weird-looking minerals and crystals.”

Drilling in the area turned up a significant rare earths deposit now earmarked for the expansion of Nechalacho, which is currently considered a “demonstration-scale” project.

“I’ve been working on Thor Lake right from when we kicked that first piece of moss,” said Pedersen. “I’ve been here through three or four different iterations: tantalum, beryllium, rare earths, tantalum, and now rare earths again.”

Rare earths were of comparatively little interest at the time of the initial discovery, Pedersen said, as no real market for them existed. Now, despite criticism that mining by definition harms the environment, rare earths are promoted as a commodity that underpins developing green technologies.

Chris Pedersen, left, and Gren Thomas. Sarah Pruys/Cabin Radio

“All the colour in your TV screens and cellphones is the result of rare-earths phosphorus,” said Pedersen. “The demand started overreaching the supply, and that drove the prices up and made it economic here.”

The August trip reunited Thomas with Pedersen at a site that Thomas found quieter than in decades past, even with a mine now operating.

In the 1970s and 80s, he recalled, “dozens and dozens” of exploration camps would light up the airwaves with incessant chatter over SBX-11 bush radios. Partly because of advances in communication and in part because exploration has since died off, that experience no longer exists.



“We’re living in a spa resort compared to what it used to be,” said Pedersen.

“People start to panic if they can’t get on FaceTime at camp. We were lucky if we got out once or twice a week to get a message to somebody on an SBX-11.

“That was our entertainment. You’d sit and listen to what everybody was doing. It was the gossip channel for the North.”