Brazil's Ministry of Labor has urgently ordered the shutdown of three waste piles at Sigma Lithium's flagship mine in Minas Gerais over safety hazards, citing "grave and imminent" risks to workers and the local community. As Brazil's largest lithium mine with an annual capacity of 270,000 metric tons of lithium concentrate, the facility has been inactive since October. Although Sigma Lithium stated that the closure order does not affect its overall operations or plans to resume production, emphasizing that the waste consists solely of non-contaminated soil, authorities warned that the risk persists—a potential collapse of the waste piles could bury nearby houses or spill into the Piaui River. During an earnings call in November, the company had anticipated restarting production within two to three weeks, but operations have yet to resume. Last week, Bank of America downgraded its rating due to uncertainty over the production restart timeline, causing its stock to plunge 15% in a single day. Although the company announced on Tuesday that it is advancing its restart plan, its appeal against the December 5 order to close access to the waste piles was recently rejected.