RABAT - London-listed mining company Emmerson Plc expects to start building its $400 million Moroccan potash plant in late 2021 and start production by the end of 2023, Chief Executive Graham Clarke said.

The project, at Khemisset in northern Morocco, is expected to be Africa's largest potash project, and a feasibility study this summer showed it had potential to produce 735,000 tonnes of muriate of potash and 1 million tonnes of de-icing salt a year.

"With the low capital cost and high margins the company will generate the payback period is three-five years depending on the potash price," Clarke said in an email to Reuters.

The Khemisset project benefits from low production costs and easy access to main markets for potash, an ingredient in fertiliser production, he added.

A study Emmerson released in August said that once fully operational, the project would create 760 direct jobs, increase Moroccan mineral exports by 8% and generate up to $63 million a year for the Moroccan government in taxes.

(Reporting by Ahmed Eljechtimi; Editing by Steve Orlofsky) ((ahmed.eljechtimi@thomsonreuters.com;))