London-listed Pensana has started preparation for a 7 000 m infill drill programme at its Longonjo rare earths project, in Angola.

The programme is designed to provide both detailed geological and grade control information ahead of the start of mining and stockpiling or blending activities in early 2027 alongside the resource expansion drilling programme announced last year.

Two reverse circulation drilling rigs are planned to be mobilised ahead of drilling activities throughout the anticipated dry season from May to October.

The programme anticipates completion of a 10 m x 10 m drill grid across the weathered run-of-mine from the initial pit production zones.

The Longonjo deposit comprises a near-surface blanket of high-grade, neodymium/praseodymium-rich total rare earth oxides (TREO), with an average depth of about 30 m.

Previous drilling has confirmed that mineralisation extends to depths in excess of 100 m beneath the current resource, indicating significant potential to increase the resource base through further drilling, Pensana explains.

During the campaign, samples will also be collected at depth to develop a detailed understanding of the full vertical extent of the mineralisation and support assessment of the potential for an increase in inferred resources from the existing 313-million tonnes at 1.43% TREO towards one-billion tonnes at a similar grade.

This would make it one of the world’s largest rare earth deposits currently in development, Pensana highlights.

A laboratory is being procured for delivery to site alongside drill rig mobilisation.

This containerised unit will include sample preparation facilities and an automated X-ray fluorescence analyser enabling timeous and cost saving multi-element analysis on site, Pensana points out.

Grade control drilling will be ongoing for most of the Longonjo life-of-mine, staying a year ahead of mine planning.

These results will further support the current mine and stockpile blending plan developed with Practara, ahead of commissioning, and enhances the existing dataset.