The Gakara Rare Earth Project is one of the world’s richest rare earth deposits. Located in Western Burundi, approximately 20km south-southeast of Bujumbura, covering a combined area of approximately 135km², the project benefits from good infrastructure, with road links to Dar es Salaam, Tanzania and Mombasa, Kenya.
Rainbow was granted a mining licence in March 2015, which is valid for 25 years and renewable thereafter. Rainbow has a 90% interest in the Gakara Project with a non-dilutable 10% owned by the Burundi State. The mining permit covers a large area, over 39km2.
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.
Geology & Exploration Upside
Gakara contains two styles of known mineralisation, locally termed vein hosted and breccia hosted. Both mineralisation styles contain the same basket of rare earth minerals and produce an identical quality saleable concentrate.
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 over 80 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.
Significant amounts of exploration work have been carried out across the project area since inception, which is being organised in a systematic exploration database by CSA Global. A summary of exploration programmes completed from 2011 to 2020 is as follows:
Using a combination of geophysical data and a comprehensive mapping database, accumulated over several years, TECT Geological Consulting have completed geological structural interpretation and surface exploration at Gakara, providing an updated JORC compliant Exploration Target for the project.
The presence of three large carbonatite bodies which represent the regional source of rare earth elements have been confirmed by this report, thereby underpinning the scale of the potential at Gakara.
Located on the Western area of the mining licence along a NNE- trending structure, the southernmost carbonatite has a diameter of approximately 2.6 km. These carbonatites are the most likely source of the rich rare earth mineralisation within the Gakara project area.
A simple, low-cost exploration programme has been defined, with a budget of US$3.2 million, with the intent of upgrading the vein hosted areas to JORC compliant resources. If the upgrade is successful, the resources are expected to be sufficient for development of a commercial scale mine, developed in a modular format, at Gakara, initially targeting 5,000 tonnes per annum of rare earth concentrate production at an expected grade of 54% TREO.
The Exploration Target defines clear strategy for modular development at Gakara, targeting 10,000 – 20,000 tonnes per annum of rare earth concentrate production.
See further details here.
Maja Mining Ltd (Maja) was commissioned in 2020 to compile a Technical Report on Gakara.
Mining and Processing
Trial mining and processing, carried out at the operation since 2017, has demonstrated the deposit’s amenability to simple open pit mining and low-cost gravity separation from ore sourced from high-grade stockwork vein systems across the licence area.
Various mining methods were trialled as the team seeks to evaluate the optimal mining method for a commercial-scale mine. The mineralised veins at Gakara have a high in-situ resource grade but are narrow and non-uniform in nature. Selective mechanical mining of ore delivers a grade of approximates 10% rare earth oxides, amongst the highest rare earth run of mine grades in the world, suitable for upgrade in our pilot processing plant.
Gakara produces a high-value rare earth concentrate of 52-58% TREO, with low levels of radioactivity. Neodymium and praseodymium (NdPr), the critical input materials in permanent magnets, represent approximately 80% of the overall basket value (whilst being only 19.5% of the mass).
No reagents are used to produce Rainbow’s concentrate, delivering both a low environmental impact and a low processing cost, compared to more complex rare earth processing requirements.
The concentrate is exported from Burundi, via road to Port of Mombasa in Kenya, where it is shipped to end customers, secured by Thyssenkrupp Material Trading under the existing distribution and offtake agreement for up to 10,000tpa of rare earth concentrate material.