The largest investor is Global Sustainable Minerals, a Singapore-domiciled vehicle, which Emmerson said was backed by "a significant south-east Asian investor".

An initial investment of US$6.75 million equity investment will allow Emmerson to begin pre-construction activities at Khemisset, before moving into project finance discussions which the company hopes to close mid-2022.

The next tranche of the investment will comprise the purchase of up to US$40 million in convertible loan notes. The equity and convertible loan notes together will give the investors, including GSM, up to a 29.9% stake in Emmerson.

The convertible loan notes "allow Emmerson to further discussions with other providers of funding including project finance banks, sovereign wealth funds and royalty and streaming providers as the company seeks the optimal overall funding solution for the project".

"Our attention now moves quickly to the task at hand, which is to get the project into production as quickly as possible," Graham Clarke, CEO of Emmerson said.

A feasibility study on Khemisset released in June 2020 revealed a 735,000t per annum potash operation with a significant salt by-product, for an NPV of US$1.4 billion (post-tax, 8% discount) using a $412/t MOP price and costing $387 million to build.

In an operational update in June 2021, Emmerson said it expected production to begin by the end of the year. But according to the latest update, this target has been pushed back, with construction now expected to begin in 2022.

Potash prices are soaring due to a shortage of new projects, as crop prices rise.

Emmerson shares were up 18%, at 6.62p, at 8.54 London time.