Sigma Lithium hikes resources, life of flagship mine in Brazil

Grota do Cirilo is said to be among the world’s largest and highest-grade hard rock lithium deposits. (Image courtesy of Sigma Lithium.)

Brazil-focused Sigma Lithium (TSX-V, NASDAQ: SGML)(BVMF: S2GM34) announced on Wednesday that it has bumped up proven and probable reserves at its flagship Grota do Cirilo hard rock lithium mine by 40% or 22.2 million tonnes.

The asset, located in the mining-rich state of Minas Gerais, now contains 77 million tonnes at 1.40% lithium oxide (Li2O), up from a previously estimated 54.8 million tonnes at 1.44%. 

The resource increase, Sima Lithium said, which will allow it to extend the complex productive life to an estimated 25 years at two phases of processing capacity at 520,000 tonnes/year.

Reinaldo Brandão, co-general manager and head of mining operations, said the mineral reserve update comes as a result of months of detailed specialized geo statistical technical modelling work to process and optimize mine plans.

Sigma’s mine began production in April 2023, generating over 105,000 tonnes of lithium concentrate in its first calendar year of operations. For first quarter 2024 alone, it produced 52,800 tonnes.

The Canada-based miner began a strategic review of its business last year, which has extended into 2024. In April, it announced it would add a second production line at its Greentech industrial plant in Brazil, aiming to nearly double its lithium output.

The new plant will increase Grota do Cirilo’s lithium production to 520,000 tonnes per year by 2025, from the current output of 270,000 tonnes.

Brazil, which heavily depends on biofuels and potash exports, ships most of the lithium it produces.