The team at the Jansen Project in Saskatchewan, Canada have achieved a significant milestone: the service shaft completed the last cut to reach its final depth of 1,005 metres at 10pm Central Standard Time (CST) on 18 August. The team will now complete the excavation of the Dalla Valle shaft to its own final depth of 975m in the coming days.
“My sincere congratulations and gratitude to the teams that have worked toward this objective: safely reaching the first shaft bottom. Attaining this milestone has been such an incredible journey which has required a tremendous “team of teams” approach combined with ingenuity, not to mention a huge amount of resilience,” said VP Potash Projects Brock Gill.
The shaft sinking started in 2012 and was paused in 2014 to manage adverse ground conditions and concrete installations in the Service Shaft. It is a technical task and the Jansen shafts are the first in the potash industry to be excavated mechanically (using what is effectively a tunneling machine suspended on its end from the headframes above) rather than the traditional drill and blast method. “The past few years have certainly been a challenge, and we should all relish this moment with a sense of pride. We have demonstrated that safely sinking the shafts using SBRs [shaft-boring roadheaders] is possible, and have taken the first steps in proving this technology for the industry,” Brock added.
The team will spend the next few months removing the SBR machines which each weigh approximately 350 tonnes, raising them up the shafts and trimming any excess material off the shaft walls along the way. They will then prepare for the installation of the final waterproof liners.
New workstages for installation of the final liners are being built in modules in Estevan, Saskatchewan and these will be trucked to Jansen where they will be assembled and lowered into the shafts. The watertight composite concrete and steel final liners – made up of a total of about 30,000m3 of concrete and 7,500 tonnes of steel in one- to four-tonne plates, will then be installed from a depth of approximately 900m upwards to the surface.
These shafts are critical, multi-generational infrastructure necessary to create the world’s largest, most efficient and lowest cost Potash mine of the future at Jansen. The full project is still subject to Board approval.