Rare-earth elements (REE) mining company Rainbow Rare Earths will start its Phase 2 drilling campaign at its Gakara project, in Burundi, this month, which will consist of about 750 m of further core drilling at the Kiyenzi prospect, says Rainbow CEO Martin Eales.
Gakara is one of the highest-grade rare-earth elements mining projects globally, with an estimated in situ vein grade of 47% to 67% total rare-earth oxide (TREO), and Rainbow is targeting production ramp-up to a rate of 5 000 t/y of concentrate by the end of this year.
The Phase 2 drilling campaign will be complemented by further trenching and terracing at Kiyenzi, particularly of the shallow intersections, together with mineralogical and metallurgical testing of the breccia material.
Rainbow’s Phase 1 drilling campaign took place over the first half of this year and targeted the current production site at Gasagwe, also at its Gakara project; the Kiyenzi prospect, where a high-priority gravity anomaly had been found; and a number of anomalies revealed by the airborne magnetic survey conducted in the fourth quarter of 2017.
Five drillholes at Kiyenzi encountered REE mineralisation over multiple intersections. More than 90 core samples have now been laboratory-tested to confirm the precise nature of these intersections and the results are “extremely encouraging”, according to Rainbow.
The results have confirmed the initial field analysis and highlights include 6.5 m at 7.1% TREO and 1 m at 27.8% TREO. When compared with the average 30 mm to 150 mm mined from the narrow veins at Gasagwe, this suggests the possibility of a “significantly exciting” deposit, Eales mentions.
Unlike the cleaner veins being mined at Gasagwe, the intersections revealed in the Kiyenzi drill core are breccias that vary in thickness and are much more heterogeneous (according to the company).The intersections contain lower global grades on a TREO basis per tonne of in situ rock than a cleaner narrow vein.
“This suggests much wider mineralised zones that should be much more suited to mechanised mining at higher volumes.”
Should the mineralisation discovered to date prove sufficiently consistent, Rainbow intends to model and report a code-compliant resource by the end of this year, which will also include further resource tonnes at Gasagwe and the next planned mining area.
“We wish to further ramp up our production of REE concentrate in the near term to achieve our 6 000 t/y run rate target by the end of 2019.”
Eales highlights that Rainbow is confident that it will operate at Gakara for many years, having begun production of rare-earth concentrates in the last quarter of last year, adding that the company is not aware of any other rare earths project in the world with grades as good as those at Gakara.
As Rainbow is also eager to grow and to maximise value for its shareholders, Eales notes that the company regularly reviews other investment opportunities in Burundi and across Africa.
“Ultimately, it has always been part of our strategy to consider moving downstream – that is, to investigate the economic benefits of further processing our own concentrate into a higher-value product, and this is something we are looking at with renewed focus,” he concludes.