Cleveland Potash Limited (CPL), a subsidiary of Israel-based ICL Fertilizers, has received a grant of £­4.9 billion to expand into polyhalite production at its Boulby mine in northeast England.

The investment is part of a £38 million investment program by ICL to increase production capacity and mining of the mineral used in fertilizer to more than 600,000 t/y from 130,000 t/y currently.

Over the coming year, ICL said it would evaluate potential for further expansion.

CPL is the only company currently mining polyhalite, which it has marketed since 2010 as a new fertilizer ingredient under the trade name Polysulphate.

ICL said its geological studies indicate that there are deposits amounting to more than 1 billion t under the Boulby mine, the UK's only potash producer, in business in northeast England since 1969.

Polyhalite is a complex salt comprising the essential nutrients for crop protection sulfur, potassium, magnesium and calcium. ICL said its Polysulphate brand has the additional benefit of being low in chlorides, so that it is suitable for fertilizing crops and agricultural land that are sensitive to chlorine.

Over the last two fertilizer seasons, the company has introduced the product into agricultural markets in amounts of tens of thousands of metric tons and has been "very encouraged" by farmers' reactions, said CPL managing director Phil Baines.