An underground mine for extraction of Beauvoir granite

A well-known lithium deposit

Since the 1980s, surveys of the Beauvoir granite by the French Geological Survey (Bureau de Recherches Géologiques et Minières, BRGM) have identified rock that is particularly rich in lithium, with a lithium oxide (Li₂O) content of 0.9%.

A deposit of rare quality

In addition to its lithium concentration, the Beauvoir granite is easy to access (shallow, not extending much on the sides, and concentrated under the existing site). In addition, the underground mine would preserve the landscape and minimise the environmental impact of the project.

The first underground mine in France for 80 years

Mining of the deposit would begin at a depth of around 400 metres and would then rise, level by level, to 75 metres below the surface.
The granite would be extracted by opening galleries and excavating chambers measuring 25 metres high and across. Up to eight chambers would be mined simultaneously before being backfilled with non-recyclable materials. The granite would be crushed underground (to avoid noise and dust) before being brought to the surface.

What is the lithium content?

This is the lithium concentration of the extracted ore. It determines the potential profitability of a mine and its environmental impact. The higher the lithium content, the higher the concentration in the ore. The lithium content of the Beauvoir deposit is around 0.9% Li₂O, while many other deposits in Europe are around 0.6%, or even 0.2% elsewhere in the world!