Brasília, October 1, 2026: Brazil’s mining regulator, the National Mining Agency (ANM), has ordered Sigma Lithium to suspend mining activities in part of its Grota do Cirilo lithium mine in Minas Gerais state, citing an unspecified “imminent risk.” The decision adds another regulatory challenge for the company’s flagship operation.
According to a document reviewed by Reuters, the ANM identified a problem on the eastern slope of the mine’s North Pit, including what it described as a “ruptured section.” The regulator ordered immediate corrective work and said the affected area would remain under interdiction until the required measures are completed.
Corrective Measures Ordered
The ANM has directed Sigma Lithium to begin corrective work immediately and implement additional measures aimed at reducing operational risks at the mine. The regulator also warned that it could take further action if the company fails to comply with the requirements.
The precise impact of the partial suspension on the mine’s overall production remains unclear.
Comes Amid Wider Regulatory Disputes
The latest order comes after a series of regulatory and legal developments involving Grota do Cirilo. Earlier in September, a Brazilian federal court suspended environmental licenses associated with the project and ordered mining activities to stop, in a case involving the Baú Quilombola community and questions surrounding environmental licensing and consultation requirements.
Separately, Brazilian authorities have previously imposed restrictions involving waste piles at the operation over safety concerns. In May, labor inspectors fined Sigma after finding that waste was being deposited on a pile that had previously been ordered shut.
Sigma Lithium’s Position
Sigma Lithium has previously disputed regulatory claims affecting its operations and has maintained that its mining and industrial activities could continue despite certain legal and administrative actions. The company had also challenged earlier government restrictions through legal proceedings.
Grota do Cirilo is Sigma Lithium’s key producing asset in Brazil, making regulatory developments at the mine significant for the company’s production plans and its position in the global lithium supply chain.
The latest ANM order now puts additional focus on the company’s ability to complete the required corrective work and satisfy Brazilian regulators before the affected mining area can return to normal operations.