5 October 2026, London, UK ( Net Zero Circle )| Sigma Lithium has temporarily suspended mining and industrial production at its Grota do Cirilo operation in Minas Gerais, Brazil, as the company awaits developments related to ongoing legal and regulatory proceedings.
The suspension affects mining and industrial production at the lithium operation, while Sigma has said that commercial and recycling activities are continuing.
The development comes amid a federal court process concerning environmental licences associated with the operation, alongside a separate order from Brazil’s National Mining Agency, known as ANM, relating to corrective measures at part of the mine.
Sigma Lithium confirmed that mining and industrial production at Grota do Cirilo was temporarily suspended on 30 September 2026.
The company said the decision came while it awaits a ruling from Brazil’s Federal Court of Appeals on an emergency motion related to a preliminary judicial decision concerning environmental licences.
The legal proceedings relate to the environmental licensing process for the project and its proximity to the Baú Quilombola community in Minas Gerais.
Sigma has challenged the preliminary ruling and is awaiting further consideration by the appeals court.
The company has stated that its mining rights and ownership of its mineral concessions remain unchanged during the proceedings.
In a separate development, Brazil’s National Mining Agency ordered corrective measures affecting part of the Grota do Cirilo operation.
The measure relates to the eastern slope of the mine’s north pit, where the regulator requested corrective work and temporary restrictions on activity in the affected area.
Sigma has been working on the measures requested by the regulator.
The ANM process is separate from the federal court proceedings concerning environmental licensing.
The temporary interruption has led Sigma Lithium to adjust its near-term production timetable.
The company has postponed its previous 12-month production guidance of 240,000 tonnes of lithium oxide concentrate by three months.
Sigma has, however, maintained its target of producing 330,000 tonnes in fiscal 2027.
During the temporary suspension of mining and industrial operations, the company said its commercial activities are continuing, including the sale of lithium fines recovered from its dry-stacked tailings.
Grota do Cirilo is Sigma Lithium’s producing operation in the Jequitinhonha Valley of Minas Gerais, an area that has attracted growing investment into lithium exploration, mining and processing.
The operation produces lithium concentrate for international markets and forms part of Brazil’s expanding presence in the global lithium supply chain.
Brazil has emerged as an increasingly important market for lithium development as demand for battery materials continues to support investment in new critical-minerals projects.
Grota do Cirilo has consequently become one of the country’s closely followed lithium developments.
Attention will now focus on the outcome of the federal appeals process and the completion of the measures required by Brazil’s mining regulator.
The timing for the full resumption of mining and industrial production will depend on developments across those processes.
Sigma Lithium has described the suspension as temporary and continues to maintain its longer-term production target for 2027.
Further decisions from the relevant authorities, together with updates from the company, are expected to provide greater clarity on the timetable for operations at Grota do Cirilo.
