Grota do Cirilo
A Sustainable Future for Mining
The Grota do Cirilo project sets a new standard for environmentally sustainable mining operations, combining the best practices in its Greentech Plant process
Innovative mining technology
100% of water used to be recirculated
Grota do Cirilo boasts a high level of water efficiency, with 100% of the water used in the production process recirculated into the plant.
Roughly 10% of this is lost or evaporates. 90% of the water previously consumed is reused by the production plant.
100%
of water used to be recirculated
100% dry stacked tailings
Tailings from the production process are dry-stacked, which removes the need for a mud tailings dam and its associated environmental impacts.
Because the production process involves no hazardous chemicals, the tailings materials can be recycled for us within other industries.
100%
dry stacked tailings
100% green power
All water and power needs are provided by the Jequitinhonha River that runs adjacent to the site.
The hydropower plant 50km away from the mine delivers 100% green energy, significantly reducing the emissions generated by the production process.
100%
green power
Project Summary

Project Summary
Initial Investment
- Sigma Lithium’s founder acquires Sigma Lithium, alongside the Brazilian refractory products maker Magnesita
- Mineral exploration starts at Grota do Cirilo
Private Equity
- A controlling shareholder is established via a fund managed by A10 Investimentos
- The first stage of mineral exploration is completed
Follow-on Investment
- Convertible bond offering
- Auditing mineral mining exploration results
Demonstration Plant start-up
- Equity Offering I (Initial Public Offering and listing on the TSX-V)
- NI 43-101 resource report filed
- Pilot plant start-up
DFS and Offtake
- Second NI 43-101 resource report filed tripling M&I Resources to 46mt
- NI 43-101 Definitive Feasibility Study for Phase 1
- Environmental licenses for construction and installation of commercial production plant
- Sigma as a case study at COP-25
- Sigma joins Mining & Tailings Safety Summit in London
Equity Funded & Acceleration
- Equity Offering II
- Project Finance Term Sheet for Phase 1
- Decision to accelerate Phase 2
Construction Commences
- Equity Offering III
- Preliminary Economic Assessment for Phase 2
- 2024 net-zero target and ESG board committee implementation
- Sigma Lithium listed on Nasdaq
- LG Energy Solution binding offtake agreement
- Equity Offering IV (including BlackRock)
- Grota do Cirilo construction begins
Phase 1 Commissioning
- Phase 1 and 2 Technical Report
- Successfully commissioned the first module of the Phase 1 production plant (the “Greentech Plant”), on schedule and within budget
- Project expansion: mineral reserves increased by 63%, triples NPV to US$15.3 billion
- LG Energy Solution offtake
- Phase 1 construction begins
- Financing: Sigma secures US$100 million debt financing
Phase 2 Commissioning
Phase 1 Production- Concluded the crushing circuit (“dry module”) commissioning
- Concluded the commissioning of the system that pumps water from Rio de Jequitinhonha 6km away
- Commercial production to commence in April, generating cash flow in the second quarter
Phase 3 Commissioning
Phase 2 & 3- Expected production capacity of 104,200 LCE tonnes combined with Phase 1&2 annually.
Project details
Sigma Lithium has tremendous exploration potential including over 200 identified pegmatites on its ~20,000 hectare land package (200 km²), representing 29 mineral rights.
Sigma Lithium is currently focused on constructing the Grota do Cirilo Project in a phased approach, with Phase 1 production having commenced from the Xuxa deposit in 2023. Production is expected to be approximately tripled by 2024 via a Phase 2 & 3 expansion through the development of the nearby Barreiro and NDC deposits.
Sigma Lithium has conducted significant metallurgical testing at its Grota do Cirilo Project, conducting pilot plant production on site since 2018.
Reserves and Resources
Phase 1
Phase 1 is expected to produce 270,000 tonnes of high-purity 5.5% Green Lithium concentrate (36,700 LCE) per year over an 8 year mine life. The Phase 1 operation is expected to be one of the lowest cost hard rock lithium producers in the industry with a life of mine CIF All-in Sustaining Cost of US$459/t (CIF China). Importantly, Phase 1 capex includes key items to ensure a seamless transition to Phase 2 & 3, which is expected to double annual production by 2024.
Concluding the commissioning of 50% of the Greentech Plant, the first shipment was planned for April 2023.
Lithium Mineral Resources
Resources Category
|
Ore(Mt)
|
Grade (Li₂O %)
|
LCE (Kt)
|
---|---|---|---|
Measured
|
10.2
|
1.59%
|
401
|
Indicated
|
7.2
|
1.49%
|
266
|
Measured & Indicated
|
17.4
|
1.55%
|
667
|
Inferred
|
3.8
|
1.58%
|
149
|
Total
|
21.2
|
2.56%
|
815
|
Lithium Mineral Reserves
Resources Category
|
Ore(Mt)
|
Grade (Li₂O %)
|
LCE (Kt)
|
---|---|---|---|
Proven
|
8.3
|
1.55%
|
320
|
Indicated
|
3.5
|
1.54%
|
132
|
Total
|
11.8
|
1.55%
|
452
|
Phase 2 & 3
Phase 2 & 3 are expected to approximately triple Sigma Lithium’s production rate to 766,000 tonnes of high-purity 5.5% Green Lithium (104,200 LCE) per year. The Phase 2 & 3 operation will leverage infrastructure built for the Phase 1 operation and DMS testing results validate that Phase 2 & 3 material can be processed in a similar way as Phase 1. Construction for Phase 2 & 3 could start in 2023.
Lithium Mineral Resources
Resources Category
|
Ore(Mt)
|
Grade (Li₂O %)
|
LCE (Kt)
|
---|---|---|---|
Measured
|
18.7
|
1.41%
|
653
|
Indicated
|
6.3
|
1.30%
|
204
|
Measured & Indicated
|
25.1
|
1.38%
|
857
|
Inferred
|
3.8
|
1.39%
|
131
|
Total
|
28.9
|
1.38%
|
989
|
Lithium Mineral Reserves
Resources Category
|
Ore(Mt)
|
Grade (Li₂O %)
|
LCE (Kt)
|
---|---|---|---|
Proven
|
16.9
|
1.38%
|
577
|
Indicated
|
4.8
|
1.29%
|
153
|
Total
|
21.8
|
1.37%
|
730
|
Lithium Mineral Resources
Resources Category
|
Ore(Mt)
|
Grade (Li₂O %)
|
LCE (Kt)
|
---|---|---|---|
Measured
|
2.4
|
1.56%
|
93
|
Indicated
|
24.3
|
1.48%
|
889
|
Measured & Indicated
|
26.7
|
1.49%
|
984
|
Inferred
|
-
|
-
|
-
|
Total
|
26.8
|
1.49%
|
984
|
Lithium Mineral Reserves
Resources Category
|
Ore(Mt)
|
Grade (Li₂O %)
|
LCE (Kt)
|
---|---|---|---|
Proven
|
2.2
|
1.53%
|
82
|
Indicated
|
19.0
|
1.44%
|
677
|
Total
|
21.2
|
1.45%
|
759
|
Consolidated Reserves and Resources
1- Tonnages and grades have been rounded in accordance with reporting guidelines. Totals may not sum due to rounding.
2- Mineral Reserves are reported with an effective date of February 24, 2022 and Mineral Resources are reported with an effective date of January 2019, February 11, 2022 and May 30, 2022.
3- Consolidated Mineral Resources include the Murial and Lavra Deposits (in addition to Phase 1, Phase 2 and Phase 3).
4- Measured & Indicated Mineral Resources are reported inclusive of Proven & Probable Mineral Reserves.
Lithium Mineral Resources
Resources Category
|
Ore(Mt)
|
Grade (Li₂O %)
|
LCE (Kt)
|
---|---|---|---|
Measured
|
37.1
|
1.43%
|
1,314
|
Indicated
|
39.9
|
1.43%
|
1,410
|
Measured & Indicated
|
77.0
|
1.43%
|
2,600
|
Inferred
|
8.6
|
1.43%
|
304
|
Total
|
85.6
|
1.43%
|
2,904
|
Lithium Mineral Reserves
Resources Category
|
Ore(Mt)
|
Grade (Li₂O %)
|
LCE (Kt)
|
---|---|---|---|
Proven
|
27.4
|
1.44%
|
979
|
Indicated
|
27.3
|
1.43%
|
962
|
Total
|
54.8
|
1.44%
|
1,941
|