London-listed Pensana has announced that a carbonatite 4.7% total rare earth oxide (TREO) bastnaesite sample from Coola and a 4.8% TREO-enriched laterite sample from Sulima West, both in Angola, have been sent for bulk metallurgical test work in South Africa. 

Samples of fluorite and apatite have also been sent.

These bulk samples will be tested for low-cost beneficiation to a high-grade concentrate at site for trucking to Pensana’s Longonjo project for processing.

This follows the interpretation of the geophysical surveys conducted late last year over the Coola carbonatite and the Sulima West laterite, which are located 75 km north of Longonjo.

One of the highlights is that Coola has been confirmed as a 900-m-diameter carbonatite ring dyke with a similar scale and prospectivity to Longonjo.

Additionally, Sulima West has reported strong anomalies of high-grade TREO mineralisation for drill testing.

“The Coola carbonatite magnetic survey has identified a number of compelling targets for follow-up and has clearly identified a large . . . circular magnetic feature, with a unique magnetic signature occupying the central caldera. We believe this to be a highly prospective, deeply weathered, volcanic pipe, or diatreme, which appears to have a similar scale to Longonjo. 

“We know that the central areas of carbonatites often host supergene-enriched rare earth element (REE) deposits, as is the case at Longonjo, and so we are looking forward to drill testing this highly prospective target,” Pensana exploration manager Grant Hayward said on March 11.

A metallurgical test work programme at Blu Sky Mining laboratory in South Africa is under way to test the identified mineralisation for low-cost physical separation techniques that can be applied at site to produce a high-grade rare earth concentrate.

Successful results from these separation techniques will allow the drill programmes to target zones of mineralisation which have the potential to produce a high-grade concentrate at site, Pensana said. These concentrates may then be trucked to the Longonjo facility for processing.

These samples will be tested for multi-gravity, wet tables, wet high intensity magnetic separation, magnetic separation, and X-ray fluorescence/optical sorting with a view to concentrate generation ahead of processing at Longonjo, or as standalone mining opportunities in the case of the fluorite and apatite targets.