Brazil shuts down Sigma Lithium waste piles over safety concerns

Published: Jan 19, 2026 11:01
RIO DE JANEIRO, Jan 15 (Reuters) - Brazil's Labor Ministry has shut down three waste piles at Sigma Lithium's (SGML.V), opens new tab ‌flagship mine in the state of Minas Gerais, citing a "grave and imminent" risk to workers and the local community, according to documents seen by Reuters.

By

Summary

  • Order does not affect plans to restart production, firm says
  • Bank of America downgraded Sigma shares, causing 15% drop
  • Sigma still fighting former co-CEO in court over mining ​rights

RIO DE JANEIRO, Jan 15 (Reuters) - Brazil's Labor Ministry has shut down three waste piles at Sigma Lithium's (SGML.V), opens new tab ‌flagship mine in the state of Minas Gerais, citing a "grave and imminent" risk to workers and the local community, according to documents seen by Reuters.

The order adds to Sigma's ongoing struggle to restart the lithium mine, Brazil's largest, with annual capacity of 270,000 metric tons of lithium concentrate. It has been inactive since October, the documents show.

The restrictions do not affect Sigma's ability to operate or compromise ‌its schedule for resuming production, the firm said in a statement. The miner denied any safety ​hazards, adding that the piles only contain soil, with no contaminants.

The piles remain a concern despite the shutdown, the ministry said in a statement, adding that a collapsed waste pile could cover nearby houses or spill into the Piaui River.

SHARES PLUNGED ‍AFTER DOWNGRADE

In November, the firm said during an earnings call that the mine would resume production in two to three weeks.

Last week, with the mine still non-operational, Bank of America downgraded the firm's shares, citing a lack of clarity on when production would resume. Their assessment sent shares tumbling 15% ⁠in a single day.

On Tuesday, the Toronto-listed firm said it was advancing its plan to resume production.

Labor officials issued the ‍decision to close access to the piles on December 5, and on Tuesday, they dismissed the company's appeal to lift the order.

It is unclear ‌if ‌Sigma could produce lithium at the Grota do Cirilo mine, its only productive asset, without using the three prohibited piles, where the miner stacks waste after processing.

Sigma told inspectors that losing access to the piles would cause "significant operational and economic impacts, in addition to jeopardizing the continuity of mining activity," documents show.

INDUSTRY LEADER NOW STRUGGLING

Once the biggest player in Brazil's fledgling lithium industry, Sigma ⁠has struggled since 2023 with ⁠lower lithium prices and challenges ​expanding its mining operation.

The firm has also tangled with former co-CEO Calvyn Gardner, ex-husband of the current CEO Ana Cabral. Gardner is suing the company over mining rights and has voiced concerns about safety at Grota do Cirilo.

To resume using the prohibited waste piles, Sigma would have to ‍present documents proving it has fixed issues identified by the inspectors, according to a Labor Ministry document.

A labor inspector who visited the site of the mine reported on November 12 a "partial rupture" of one of the piles near a school in the small town of Poco Dantas, which he ​cited as evidence of structural issues.

"The company was given ample opportunity to ‍minimize its risks," said a labor inspector in a January 6 report dismissing Sigma's argument that the piles are safe.

Sigma said the piles are fully within the ​safety parameters established by authorities, which it is demonstrating to the ministry.

Source: https://www.reuters.com/world/americas/brazil-shuts-down-sigma-lithium-waste-piles-over-safety-concerns-2026-01-15/

Data Source Statement: Except for publicly available information, all other data are processed by SMM based on publicly available information, market communication, and relying on SMM's internal database model. They are for reference only and do not constitute decision-making recommendations.

For any inquiries or for more information, please contact: lemonzhao@smm.cn
For more information on how to access our research reports, please contact:service.en@smm.cn
Related News
SQM, Codelco Outline Expansion Plan to Lift Lithium Output to 470,000 mt/y
10 hours ago
SQM, Codelco Outline Expansion Plan to Lift Lithium Output to 470,000 mt/y
Read More
SQM, Codelco Outline Expansion Plan to Lift Lithium Output to 470,000 mt/y
SQM, Codelco Outline Expansion Plan to Lift Lithium Output to 470,000 mt/y
SQM and Codelco's lithium joint venture, Novandino, has outlined plans in an environmental impact assessment (EIA) filing to increase annual lithium production capacity from around 270,000 mt currently to as much as 470,000 mt. The expansion is aimed at meeting long-term demand from electric vehicles and grid-scale energy storage. According to the filing, production will first gradually rise to around 300,000 mt before transitioning over seven years to an integrated production system incorporating direct lithium extraction (DLE), with additional capacity expected to come online over several years.
10 hours ago
Congo cobalt exporters fear losing quotas due to administrative glitch, sources say
Jul 3, 2026 22:44
Congo cobalt exporters fear losing quotas due to administrative glitch, sources say
Read More
Congo cobalt exporters fear losing quotas due to administrative glitch, sources say
Congo cobalt exporters fear losing quotas due to administrative glitch, sources say
According to an industry letter seen by Reuters, exporters have been unable to submit export declarations through the customs platform since July 1 because ARECOMS, the Democratic Republic of Congo's strategic minerals regulator, has not formally notified customs to continue processing export quotas. As a result, major producers including CMOC Group, Glencore, Eurasian Resources Group (ERG) and Huayou Cobalt have been unable to complete export procedures. Meanwhile, ARECOMS requires companies to utilize their first-half export quotas by July 5, after which any unused volumes will be withdrawn and reallocated. Industry sources estimate that around 60%–75% of companies are unlikely to meet the deadline due to administrative delays. If the issue is not resolved promptly, up to 20,000 tonnes of cobalt exports, worth approximately US$1.1 billion at current prices, could be affected. CMOC alone could lose almost all of its second-quarter export quota. SMM will continue to monitor developments.
Jul 3, 2026 22:44
Tinci Materials Terminates 243,000-tpy Lithium Battery Materials Project
Jul 3, 2026 20:29
Tinci Materials Terminates 243,000-tpy Lithium Battery Materials Project
Read More
Tinci Materials Terminates 243,000-tpy Lithium Battery Materials Project
Tinci Materials Terminates 243,000-tpy Lithium Battery Materials Project
Tinci Materials announced that its subsidiary Nantong Tinci has terminated its planned 243,000-tpy lithium battery and fluorochemical materials project. The company said the decision was driven by an oversupply in the electrolyte industry, intensified market competition, and changes in the fluorochemical market, which weakened the project's expected returns. Tinci has begun evaluating new product plans for its Nantong facility.
Jul 3, 2026 20:29