Cape Silica is a joint venture company between Sibelco and Diatreme Resources. Sibelco previously had an 11 per cent stake in the company and lifted it to 26.8 per cent ahead of schedule.

That stake has cost it $35 million in total and provides a “look through” value of $160 million.

Sibelco also now holds a significant shareholder stake in Diatreme after it signed up for a $14 million placement in June, 2022.

Diatreme chief executive Neil McIntyre said Sibelco had shown an extraordinary degree of confidence in the joint venture and its second tranche would provide a significant financial boost that would help the project’s development.

He said it was also a sign of confidence in Diatreme’s management.

“We can move forward with greater conviction, backed by an extraordinarily long funding runway, through the important next steps of permitting and regulatory approvals to eventual mining of this key critical mineral,” McIntyre said.

A recent scoping study for the company’s Northern Silica Project showed a potential production rate of 5 million tonnes a year for 25 years.

It also highlighted the potential for silica critical minerals hub around Cape Flattery.

The project is in the Hope Vale Aboriginal Shire in north Queensland. The production was aimed at the photovoltaic glass market.

Diatreme’s chair is former Federal Treasurer Wayne Swan.