Underneath the North York Moors lies a wonder-mineral that could prove invaluable to our economy
4 min read
If you’ve ever visited the North York Moors National Park, you may have marvelled at the vast swathes of heather spreading out like a purple carpet as far as the eye can see.
But did you know that 1.6 km below the Moors, there lies something just as beautiful when it comes to kick-starting economic growth?
I’m talking about polyhalite. It’s a dark grey, hard rock that’s made up of potassium, magnesium, calcium and sulphur, deposited 260 million years ago when the Whitby area was situated on the edge of a broad, shallow ocean called the Zechstein Sea. Hot and dry conditions meant the water in the sea evaporated quicker than it could be re-filled, leaving behind polyhalite.
The reason polyhalite is a beautiful thing is that this multi-nutrient mineral is a naturally organic powerhouse of a fertiliser.
Where conventional fertilisers tend to release nutrients quickly, polyhalite works more slowly. Trials have shown it improves the performance of crops, especially potatoes, vegetables and fruit as well as improving the quality of soil.
No wonder, then, that global giant Anglo American has sunk £2.7 billion to date into its flagship Woodsmith Mine, just outside Whitby.
The company’s ambition is to mine the biggest seam of polyhalite in Europe, to become a global leader in sustainable crop production and drive environmentally friendly fertiliser practices at scale.
A little way down the road, at Boulby Mine, ICL has been mining polyhalite since 2010 after switching from potash. This mine also produces the majority of the UK’s rock salt for road gritting and has a natty little underground science laboratory home to an incredible range of physics experiments. Who knew all of this was hiding under the Moors!
ICL Boulby is the world’s first and only producer of polyhalite. Boulby market it as polysulphate and Woodsmith call their pellet version POLY4. But it’s all the same magical mineral mix.
The difference is the scale. In 2023, Boulby produced 1 million tonnes of polyhalite a year. When Woodsmith is fully operational, the hope is for it to produce 13 million tonnes a year using its specialist continuous mining machines. This will then be transported to materials and port handling facilities in Teesside for export, via a 37km-long underground tunnel. It will be both the deepest mine in Europe and have the longest tunnel in Great Britain.
But as you drive over the Moors you won’t see a thing. The traditional pit head won’t be there. Instead, it is housed under the ground and the whole mine is screened by careful landscaping.
The project is not there yet. Last year, a hostile takeover of Anglo American by BHP was rejected, and the company announced a number of measures to de-leverage its balance sheet. These included slowing down the development of the Woodsmith project to a partial “maintenance mode” for 18 months, leading to the devastating loss of more than 800 jobs. Some 1100 people are still employed. The next steps include securing investment partners so that the mining operation can pick up speed again and reach first production in the early 2030s.
When fully operational, Woodsmith is expected to generate £1.5 billion per annum to the UK’s GDP and large-scale exports for the nation’s economy over a period of 40 years, supporting regional growth and jobs.
The government is supportive of this truly unique project, with Minister Sarah Jones recently visiting the mine.
As Mission Delivery Champion for Yorkshire and the Humber, I have also visited both Boulby – which sits just outside my constituency of Scarborough and Whitby – and Woodsmith.
I see it as part of my role to advance the understanding of polyhalite, whether as polysulphate or POLY4, and see it added to the critical mineral as well as being highlighted as strategic for economic growth.
This wonder stuff is a valuable asset for the UK and needs to be recognised as such. Coal mining may be a thing of the past. But the clean mining of polyhalite is a vital part of our economic future and a green stamp on Blueprint Britain.
