The company has now fulfilled works to increase nameplate capacity by 45 per cent to 1.6 million tonnes a year, effective from the second quarter of 2021.

The $US6 million ($7.8 million) expansion involved the installation of a scrubber bypass conveyor, primary jaw crusher and associated upgrades.

Lucapa is now re-commissioning the upgraded plant and ramping it up to its new capacity, which is anticipated to be complete within the next week.

Lucapa managing director Stephen Wetherall said the completion of the Mothae expansion project was on time and within budget despite the challenges of COVID-19.

“Lucapa and the GoL (Government of the Kingdom of Lesotho) look forward to the increased recoveries and economy of scale benefits this expansion was designed to provide,” he said.

Lucapa holds a 70 per cent stake in the Mothae mine, with the GoL owning the remaining 30 per cent.

The partners have recovered five 100-plus-carat diamonds at Mothae to date, including a 215-carat and 101-carat D-colour Type IIa stones, while recording the highest average $US per carat price – nearly $US1200 – earlier this year.

This follows a production of more than 30,000 carats in Mothae’s first year of production, which commenced in January 2019.

The Mothae mine is located in Lesotho’s diamond-rich Maluti Mountains within five kilometres of the world’s highest $US per carat kimberlite diamond mine, Letšeng.

Lucapa plans to boost Mothae’s plant capacity even further to 1.8 million tonnes a year in due course by adding another secondary crusher.