Overview

Mine Type	Open Pit
Stage	Permitting
Commodities	Lithium
Mining Method	Truck & Shovel / Loader
Production Start	...
Mine Life	...
Snapshot	In April 2024, Sigma Lithium announced the final investment decision (FID) on Phase 2 of their Grota do Cirilo Project. Sigma expects the second phase to double production from 270,000 tonnes per annum (tpa) to 520,000tpa. Sigma has already been awarded an environmental license to build and operate the Phase 2 plant.
Related Asset	Grota do Cirilo Phase 1 - Xuxa

Deposit type

• Pegmatite

Summary:

The Barreiro pegmatite body is emplaced into biotite–quartz schist. Pale greenish–grey coloured, multicentimetre-sized microcrystalline quartz–feldspar intercalations have been noted in the schist, with disseminated green, sub- to one-millimetre-sized amphibole and pink garnet crystals. Pegmatite xenoliths can be found within 3 m of the dike edge within the schist and can range from a centimetre to as much as a metre in size.

The pegmatite strikes northeast–southwest and dips to the southeast at 30–35º. Based on drill data, the dike is about 600 m long, 800 m wide, and has an average thickness of 30–35 m. It remains open to the northeast and at depth. The deepest drill hole reached 374 m. The pegmatite is apparently intruded discordant to the host crenulated biotite schist in surface exposures, but at depth, can be concordant, and emplacement may be related to local fracturing.

The dike is slightly zoned into distinct spodumene-rich and albite-rich areas and is divided into an edge (or border), and a central zone. Overall, spodumene is about 20–24% of the dike mass, albite–microcline is approximately 32–40%, and around 10–18% is mica (muscovite).

The border zone is about 45 cm in thickness, and consists of fine-grained albite, quartz and muscovite. Heavy minerals such as cassiterite and tantalite may occur associated with albite units. The central zone is spodumene-rich and consists of albite and spodumene crystals that are typically 10–25 cm in length but can more rarely can attain as much as a metre in length. Spodumene crystals are also present as short, prismatic, elongated laths. The spodumene laths are colourless or pale green, sometimes displaying a poikilitic texture of fine- to medium-grained quartz and/or pale green sericite. Petalite occurs sporadically, as both colourless, translucent to transparent, coarse to very coarse-grained crystalline aggregates. It can also be present as cryptocrystalline, translucent masses.

Mining Methods

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Comminution

Crushers and Mills

Processing

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Production

Operational metrics

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Personnel

Job Title	Name	Profile	Ref. Date
.......................	.......................		Jan 18, 2024
.......................	.......................		May 30, 2022
.......................	.......................		Jan 18, 2024

Total Workforce	Year
......	2022