As part of Cleveland Potash’s continued upgrade of their Boulby mine in North Yorkshire, UK, Qualter Hall who are based in Barnsley, UK have been awarded a further major contract for the mine, this time for the design, supply, installation and commissioning of a new polyhalite process facility. Work has already begun and is scheduled for completion in 2016.

This contract follows Qualter Hall’s successful replacement of the Boulby mine’s headgear in 2013 and the round house transfer tower in 2014, along with the ongoing consultancy works by Qualter Hall for this latest requirement. The scope of works for this new polyhalite process facility is to build a new crushing and screening facility within the curtilage of the mine. It includes a 1,000 t/h x 300 mm diameter pipe conveyor leading from the round house transfer tower, now known as the cube, into the ROM stockpile shed which comprises a tripper conveyor, loading trunk, 12,000 t stockpile bay, drawdown chutes and uncoaler feeders.

Then there is a process cell which includes nine process conveyors and five bucket elevators, two 100 t storage bunkers, two vibrating feeders, four megatex screens, process pipework, impact crusher, dust extraction and oil coating system. This is followed by the finished product shed with three product storage bays, three stockpile conveyors and loading chutes, drawdown chutes, uncoaler feeders and finally discharging to the rail outloading system comprising three new conveyors and gantry with upgraded rail loader.

In addition, Qualter Hall are also responsible for all civil works and electrical control works, with the whole process being fully automated and computer controlled. Cleveland Potash Ltd currently supplies around 55-65% of the UK’s potash consumption from its Boulby mine, which has been operating since 1973 and which is currently the UK’s only potash mine. Employing over 1,000 people, workings extend down to over 1,300 m below ground level and as far as 12 km out underneath the North Sea.

The mine can hoist up to 3 Mt of potash ore and more than 0.5 Mt of salt each year, producing up to 1 Mt of potash. Potash is used for fertiliser production as well as for glass making and applications in the chemical and pharmaceutical industries. The mine also produces salt as part of the potash mining process, which is used for a variety of needs, from road de-icing in winter to sugar beet cultivation and as an ingredient in animal feeds.

The polyhalite to be processed by this new facility has been located in vast quantities (indications of more than a billion tonnes) beneath the potash reserves currently being mined. Polyhalite is a unique mineral salt which is used as fertiliser. To take full advantage of this opportunity this new polyhalite process facility is being established next to the Boulby mine for processing the polyhalite into speciality fertilisers and industrial products.

George Orton, Qualter Hall’s Managing Director stated: “We are of course delighted to be continuing to build on our excellent working relationship with Cleveland Potash. This is our third major contract at Boulby mine in the last four years, two having already been successfully completed. Given our own breadth of engineering expertise, particularly within the mining sector, combined with the excellent rapport we have with the Cleveland Potash team, we are confident of meeting the demands of this challenging project.”