The Gakara Rare Earth Project is located in the Bujumbura province of Western Burundi which consists of a Mining Licence and Exploration Licence. The Gakara Project is located approximately 20km south-southeast of Bujumbura and covers a combined area of approximately 135km².
Rainbow has a 90% interest in the Gakara Project with a non-dilutable 10% owned by the State.
The mining licence was granted in March 2015 and is valid for 25 years, and is renewable thereafter.
The project is easily accessible with good road links to Dar es Salaam, Tanzania and Mombasa, Kenya.
Historical mining at the site demonstrates the consistency of the grade and mineralisation of the concentrate whilst also providing significant detail and validation of the vein/stockwork rare earth mineralisation system.
- The Gakara project is notable for its exceedingly high in-situ grade of 54.3% on average TREO, low U-Th levels and familiar rare earth minerals, bastnaesite and monazite
- Rainbow’s team has defined a mineral inventory of 256,500t of ore at 54.3% on average TREO for 141,853t of contained TREO
- Rare earth mineralisation occurs in veins visible at surface with variable orientations and thickness (from a few cms to a few tens of cms)
- Veins are presumed to be related to late-stage hydrothermal events, associated with a carbonatitic source – bastnaesites subsequently infused by P-rich fluids creating monazites
- The rare earth hosting minerals, coarse-grained bastnaesite and monazite, occur in veins or stringers forming stockworks within the basement gneisses, pegmatites, schists and quartzites
- The Gakara monazites (and bastnaesites) are secondary phases of mineralisation accounting for the low U-Th levels
Please see Rainbow Exploration for further detail.
The Gakara Project was discovered in 1936 by Somuki, a private Belgian company, and was mined periodically between 1948 and 1978 by Somuki and Sobumines (a joint venture company between another private Belgian company and the Burundi government).
Photo of previous mining operations taken in 1971 and historic mining plan:
The mineralised veins at the Gakara Project are discrete and narrow, and the mineralised material separates easily from the less dense host rock which, in itself, is amenable to manual digging. The veins range in thickness from a few centimetres to a few tens of centimetres. The veins have been shown to typically extend laterally for tens of metres, the longest recorded being around 40 metres, and have been observed to extend down to depths greater than 25 metres. The veins outcrop at surface on steep slopes or river incisions but are frequently under cover.
At the time the Rainbow submitted its application for the Mining Licence, a feasibility study was also submitted under which Rainbow committed to an estimated work programme to allow it to begin operations. This work programme was included in the Mining Licence, but has since been revised and refined over the past two years in discussion with the Ministry though regular face to face meetings and quarterly and annual reports and the Mining Licence remains in good standing.
Exploration work undertaken by Rainbow to date at the Gakara Project includes mapping of geological traverses, geophysical and geochemical orientation surveys and the collection of 150 grab samples from REE veins which were submitted for analysis by an independent laboratory, ALS Chemex. The samples analysed by ALS Chemex yielded consistently high grades with an average of approximately 58% total REO and a range of between 47 and 67% total REO. Based on the average of samples of Gakara vein material, magnet REEs (principally neodymium, praseodymium and dysprosium) account for approximately 22% of the contained REOs within the Gakara ore, representing an average of approximately 80% of the contained value of REOs at current market prices.
More recent work by Rainbow includes detailed mapping of two localities, mineralogical and gravity separation test work, hydrometallurgical studies, design of a processing plant and a conceptual mining study based on a trial bench mining exercise at two localities within the Mining Licence, namely Gasagwe and Gashirwe West.
The Competent Person, MSA Group, has reported an Exploration Target, as defined in the JORC Code, at the Gakara Project despite considerable historic mining activities.