Mining
Rukaragata is situated on a pegmatite ridge in Ngororero District, about 100 km west of Kigali. It was originally mined in the 1960s for tin. For most of that time, the tantalum that came out of the ground with the tin had little market and was often thrown away. We mine the same rock for both, and for everything else it carries.
It is a lithium–caesium–tantalum pegmatite, one of the more evolved in the Gatumba district of western Rwanda, in one of the world's leading tantalum regions. It formed about a billion years ago from the last, most fractionated melt of a granite, which is why it concentrates otherwise rare elements absent in most rocks.
Near the surface, the pegmatite has weathered into a soft, kaolin-rich rock that can be excavated directly, and the topography means very little overburden has to be stripped. Both keep costs low and environmental impact to a minimum.
We mine in an open pit, cutting the ore body from the top down in stable benches no more than 10 m high. The operation is fully mechanised: our own excavators and trucks, with a bulldozer to rip the harder zones, carry the ore a few hundred metres downhill to the plant. The mine runs 24 hours a day on four crews.
Our processing plant at the foot of the pit has an installed capacity of 360,000 tonnes of ore a year, expanding to 720,000 tonnes a year during 2027.
The plant is designed around gravity separation and uses no chemical reagents. It produces separate concentrates of tin, tantalum–niobium and lithium.
Process water is drawn from the river, settled in ponds and recycled to the plant. Power comes from the national grid, with generators as back-up.
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