Rio Tinto raises Yukon copper project stake, cuts diamond plan interest

Rio Tinto is spending $6 million to increase its stake in Canada’s Western Copper and Gold (TSX: WRN) to 9.7% from 8%, the companies said on Wednesday. The Canadian company is advancing the copper-gold Casino project in the Yukon. 

The global miner also said it’s selling its 75%-interest in the Fort à la Corne diamond project in central Saskatchewan to joint venture partner Star Diamond (TSX: DIAM) in exchange for 19.9% of the junior.

Rio Tinto is pivoting to invest more in battery metals following years of tension with Star over how to develop the diamond project. Both companies faced off in court and, at one point, Star considered cutting Rio out of the project. The Western Copper and Gold backing is a sign of support for a project some have criticized for low grades in a remote part of the Yukon. 

“The majority of Rio Tinto’s global exploration program is now firmly focused on metals and minerals to support the energy transition,” head of exploration Dave Andrews said in a release on Wednesday. “We continue to see potential in the (Fort à la Corne) project.” 

Molybdenum

Vancouver-based Western Copper and Gold said it would use the investment to fund specific areas of study with the aim of progressing through permitting to develop the proposed mine. Watch a site visit video where CEO Paul West-Sells explains the project’s economics and the value of its molybdenum. 

“We are pleased that Rio Tinto has elected to continue to invest and work with Western to advance the Casino project, with a focus on furthering infrastructure development and streamlining the regulatory process,” West-Sells said in a statement. 

In Saskatchewan, Rio Tinto put the diamond project on hold in 2021 until it could determine whether it wanted to continue or exit the venture. The camp was demobilized and the project put on care and maintenance in the first quarter of 2023. 

“We are grateful to Rio Tinto for the significant monetary investment and expertise it has contributed to the project over the past more than five years,” Star president and CEO Ewan Mason said in a release. It has advanced “one of the most promising diamond projects in the world,” he said.