The award of two major new contracts integrating geotechnical and geophysical investigations sees Fugro continue its site characterisation services at Sirius Minerals’ North Yorkshire polyhalite project.
A new geotechnical package comprises seven deep boreholes in shaft and tunnel locations at the new UK mine, located 3.5 kilometres south of Whitby in North Yorkshire. Fugro is undertaking strength tests of the rock formation, drilling to depths in excess of 420 metres.
The project is developing the world’s largest known high grade polyhalite deposit, a highly effective organic agricultural fertiliser. Construction includes a new mine to extract the ore, a 37-kilometre tunnel hosting an underground mineral transportation system (MTS), a granulation facility in Teesside, and an export quay on the River Tees.
Under the second contract, Fugro is carrying out an 11-month programme of seismic investigations and wireline logging which will be fully integrated with the geotechnical work to maximise both data yield and quality. The combined programme will allow a detailed assessment of geological conditions to 500 metres depth ahead of tunnel boring machine operations along the MTS alignment.
Polyhalite is an evaporite mineral, a hydrated sulfate of potassium, calcium and magnesium with formula: K2Ca2Mg(SO4) 4· 2H2O.
Polyhalite crystallizes in the triclinic system, although crystals are very rare. The normal habit is massive to fibrous.