Sigma Lithium has announced a 40% increase in proven and probable mineral reserves at its Grota do Cirilo lithium project in Vale do Jequitinhonha, in the Brazilian state of Minas Gerais.

This expansion equates to an additional 22.2mt, raising the consolidated reserve balance to 77mt at 1.40% lithium oxide (Li2O), up from 54.8mt at 1.44% Li2O.

The reserve increase is concentrated within the combined phases three and four mines, which will extend the lifespan of Sigma Lithium's integrated mining and beneficiation operations to an estimated 25 years.

This includes two processing lines with a combined capacity of 520,000t per annum, of which the second line, currently under construction, will contribute 250,000t.

The company noted that the enhanced mineral reserve balance paves the way for sustained, low-cost lithium production growth at the Grota do Cirilo operations.

It supports the potential addition of a third and fourth processing facility or an extended operational life for the company's planned lithium throughput.

Sigma Lithium anticipates maintaining its phase one low-operating-cost model as it progresses into subsequent phases, given the consistent mineralogy of the reserves and their accessibility through open-pit mining operations.

The company has clarified that the reported increase in mineral reserves does not represent the full potential of the mineral resources conversion, as previously announced on 31 January 2024.

Sigma Lithium remains committed to its mineral and geological development work, aiming to further convert its resources into reserves over time.

Sigma Lithium co-chairperson and CEO Ana Cabral said: “This significant increase in mineral reserves demonstrates our commitment to continuously invest in Brazil to unlock the full economic potential of our mineral concessions.

“This includes our commitment to build in the country, in the same region where the lithium is mined, a second state-of the-art, large-scale lithium processing green industrial plant.

“We believe Brazil is poised to become one of the global leaders in lithium production as a result of its optimum conditions for integrated lithium industrial processing and mining: legal certainty in a consolidated mining code, rule of law, straightforward permitting processes, tropical climate, green and affordable renewable energy and power lines infrastructure.”