Courtesy of Vale Canada
Cementation used a Strata 950 raise drill from its fleet to ream both raises at the Thompson T3 mine.
Record-breaking depths The construction of twin raises at the Thompson T3 mine was a key part of a ventilation upgrade that helped to extend the mine’s life by at least a decade By Mehanaz Yakub
T
he dual-shaft return air raise at Vale Canada’s Thompson T3 nickel mine in Manitoba, developed by underground mine contracting and engineering firm Cementation Canada Inc., reached a milestone in September 2023. After nearly 600 days of operation, the project set a new record for the longest continuous raise bore in the Americas at 1,076 metres (3,529 feet). A major nickel deposit was discovered in northern Manitoba in 1956 by the International Nickel Company (INCO), and the Thompson mine opened there in 1961. At its peak in the 1960s, it was the world’s largest integrated nickel mine, smelter and refinery and second-largest nickel-producing operation globally. Today, Vale—which acquired INCO in 2006—continues operations at Thompson through two connected underground mines, T1 and T3. According to the latest figures from Vale Canada, the mine produced 11,400 tonnes of finished nickel in the 12 months ending in Q1 2025. 42 | CIM Magazine | Vol. 20, No. 3
Recognizing the need for long-term sustainability, discussions within Vale in 2018 led to the launch of the Thompson Mine Extension Project (TMEP). This initiative focused on critical infrastructure improvements to support the development of deeper ore bodies, which would extend the mine life. One of the key components of the expansion project was the construction of a new ventilation system for the T3 mine, which would more than double the airflow to its most active zones. “The whole goal was to expand the life of the mine by an additional 10 years and probably beyond,” said Mark Johnson, senior project manager—TMEP at Vale. To achieve this increased ventilation capacity, Vale needed to develop a dual-shaft return air raise. “We were putting in return air raise fans to exhaust air out of the mine, so it works as one big circuit,” said Johnson. “Fresh air gets pulled into the mine, and then we exhaust out the used air. The whole idea for the raises is to improve the ventilation for the mine to support the ability to mine at deeper depths.”