BHP’s Jansen potash mine in Canada recently celebrated the successful completion of the excavation and lining of the two 1,000-m deep shafts at the mine, the largest of their kind in Saskatchewan. It’s a big step toward bringing online the project which is planned to be the largest potash-producing mine in the world.
Sinking a shaft in Saskatchewan is an impressive feat. BHP worked with partners to leverage the latest technology and innovative solutions for this ambitious project, which marks the first instance of mechanized shaft sinking in the world and entails artificial ground freezing to a depth of 800 m. Freezing the ground prevents water inflow and ensures ground stability during shaft excavation. Once excavated, a primary and final liner creates a waterproof seal to protect the shafts from underground aquifers.
“The team’s safety record and performance since January 2020 has exceeded our plan,” said Simon Thomas, President Potash. “Our approach to safety, work planning discipline and continuous improvement — along with our collaborative and integrated team approach — really shone in the final stages of this project.”
The shafts are one of the most technically risky parts of developing a greenfield project like Jansen, BHP explained, and their completion will significantly reduce the development risk. Larger diameter shafts like these (7.3 m diameter) require outfitting only one shaft for stage 1, significantly reducing upfront capital. For future stages, the same two shafts will enable options for multiple sequenced brownfield expansions of more than 16 million metrics tons per year, subject to business and regulatory approval.