AngloAmerican currently develops a polyhalite mine in a sensitive local landscape, the North York National Park. To receive permission for mine development the company has to abide by strict environmental limits, which govern all activities during the construction phase. To reduce the visual impact of the mine shaft the head frames will be sunk below ground and surface buildings will be kept to a minimum.
The project area contains the largest, highest grade resource of polyhalite worldwide. Once the mine is at full operation, a capacity of up to 20 million tons per annum is awaited.
Two shafts with a shaft depth of approx. 1,600 meters each are required for mine development, which will be the deepest shafts sunk so far by the Shaft Boring Roadheader. R.
The design of the SBR has been modified according to the lessons learned and the project specific requirements. The roadheader based SBR enables the shaft sinking crew to cut variable shaft diameters of up to 12 meters in soft to medium hard rock. Due to the telescopic design of the boom the machine can excavate approx. 1.2 meters of shaft before the SBR itself has to be released from its stable vertical position and lowered by the shaft ropes. With a high shaft sinking rates, enhanced labor safety and the flexibility to react to challenging requirements resulting from strict environmental limits the SBR is prepared to contribute to the success of the North Yorkshire Polythalite Project.
In addition to the two SBRs, a Vertical Shaft Sinking Machine (VSM) was employed for the construction of a pilot shaft, which, with a diameter of 9 meters, excavated the world's deepest shaft of this type at 115 meters in 2018 and 2019.
In addition, a Single Shield TBM (Ø 5,940mm) from Herrenknecht is constructing a 35.6-kilometer tunnel. This will transport the mined polyhalite to the nearest port, thus relieving the roads of truck traffic.