Rock Salt for De-icing Roads

Sodium chloride, as it is also known, is more than just seasoning for our food. It is an essential mineral with a variety of uses and we mine it here at our ICL Boulby. From domestic to industrial applications, it also helps to maintain road safety and is an essential regulator in human heart health. The salt that is mined at ICL Boulby was deposited over 225 million years ago, when ancient seas evaporated, leaving the substance behind.

ICL Boulby is responsible for supplying approximately half of the de-icing mineral which is used to keep Britain’s roads safe each year. If ICL Boulby did not supply the substance, the UK would almost certainly have to rely on imports from other countries.

Please also visit out dedicated knowledge hub on salt here!


It has a variety of uses; it’s essential for our health, it adds flavour to food, softens water and keeps roads from icing over which creates hazardous driving conditions. It is also a main component in some animal feeds. For thousands of years, it has been used to preserve food and at one point was considered invaluable, with Roman soldiers often being paid with it, hence the phrase ‘you’re worth your salt’.

But it’s not just food and preservation. Each year in winter, around two million tonnes of rock salt is spread onto the roads of Britain, keeping us moving and the economy flowing.

Sodium chloride that is high in purity is often used to soften water, using what is known as an ion-exchange process. There are environmental benefits, since less energy is consumed by our heaters, to regulating detergent consumption and the life of our fabric. It is used both in industry and domestic settings.



ICL Boulby is a producer and supplier of Polysulphate and Rock Salts (NaCl) for agricultural and industry use.

Balancing innovative production techniques required for extreme geological conditions with environmental sensitivity, we harvest mineral deposits from beneath the North Yorkshire Moors and from under the North Sea.

We have been mining rock salt for over 40 years. The sodium chloride, and other evaporate minerals encountered at ICL Boulby were deposited in late Permian times, some 230 million years ago. It can be found in a seam beneath the potash horizon, some 1100m underground.

We are a member of the Salt Assurance Scheme.


Our Approach

Here at ICL Boulby, we adopt a continuous mining approach. In this, a boring machine is used, similar to the machines used in cutting road and rail tunnels. These machines have a rotating head carrying tungsten-carbide tips. These tips bore into the substance, producing smaller lumps which can be taken directly to a crushing and screening plant. Prior to storage, the substance is treated with an anti-caking agent to stop the pieces coagulating. This ensures that it can be held in local storage depots, ready for use on the roads as soon as frost is forecast.

We have access to multi million tonnes of mineral deposits thus securing our position as a leading UK producer for many years to come.

Traditionally we mine between 350,000 and 1,000,000 tonnes p.a. Most of this output is used for winter road maintenance (road gritting, “de-icing” or “salting” ) as a de-icing agent, sold to Local Authorities and Highways Contractors throughout the UK.