SLR Consulting has completed a geotechnical assessment of the quality of rock at Wolf Minerals’ Hemerdon tungsten and tin project in Devon to asesss slope stability and improve efficiencies at the mine.
The six-hole diamond drilling programme completed a total of 1,140m around the perimeter of the Hemerdon open pit and was designed to provide additional geotechnical information to optimise the slope angles for the open pit, while maintaining slope stability and safety.
The drilling results indicate that an additional four to 6M.t of ore may be available to be mined from the project and that there is the potential to increase ore reserves by 15-23% as a result of steepening the open pit walls and broadening the open pit perimeter within the existing planning permission.
The majority of previous drilling undertaken at the site concentrated on the ore body, rather than the surrounding waste rock. As a result, the pit slope angles were conservatively designed at between 35° and 44°, with flatter slopes near the surface reflecting weathered rock conditions.
Following the completion of the drilling and geotechnical analysis, pit optimisation and design will now be undertaken using the revised slope parameters, which will lead to the ore reserves being revised. This work is expected to be completed in January 2015.