6-K

UNITEDSTATESSECURITIES AND EXCHANGE COMMISSIONWashington, D.C. 20549

FORM6-K

REPORTOF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

Forthe month of February 2026

Commission File Number: 001-40786

SigmaLithium Corporation

(Translation of registrant's name into English)

181,Bay Street, Suite 4400Toronto, Ontario, M5J 2T3, Canada

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F [   ]      Form 40-F [X]

EXHIBITINDEX

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

SIGMA LITHIUMHIGHLIGHTS THE ISSUANCE OF AN OFFICIAL TECHNICAL STATEMENT DECLARING THE SAFETY OF ITS WASTE PILES BY BRAZIL’S NATIONAL MINING AGENCY

HIGHLIGHTS

Sao Paulo, February 4, 2026.Sigma Lithium Corporation (TSXV/NASDAQ: SGML, BVMF: S2GM34), (“Sigma Lithium” or “the Company”), a leading global lithium producer dedicated to powering the next generation of electric batteries with socially and environmentally sustainable lithium concentrate, highlights the issuance of a publicly disseminated official technical statement (“Statement”) by Brazil’s mining industry regulator, Agencia Nacional de Mineracao (“ANM” or “Mining Regulator”), explicitly attesting the safety of Sigma Lithium’s waste piles.

The Mining Regulatorunequivocally confirmed in the Statement the absence of evidence of serious technical risk and that it did not encounter any legal prerequisitesto adopt precautionary measures of closure.

The Statement, issued on February 2, mentioned that: “The inspections, which were carried out through drone overflight and visual assessment by walking, did notidentify geotechnical anomalies indicative of an imminent risk of global instability in the inspected structures.” The Statement continued "considering the absence of evidence of serious and imminent risk, it is concluded that, at present, the legal prerequisitesfor adopting precautionary measures of closure have not been met."

The Statement was issued following the abovementioned inspections of Sigma Lithium's mining operations by the Mining Regulator on January 20. The swift action by the Mining Regulator to conduct the inspections and issue a technical opinion regarding the Company’s waste piles underscores the official effort by the Government of Brazil to protect the legal security and certainty for companies with mining activities in the country, underscoring the strong governance of the industry in Brazil.

The Statement dispelled false information with respect to the Company’s waste piles disseminated illegally in a negative media campaign against Sigma Lithium, which included the falsification of a Brazilian government web domain as well as Brazilian government communications (through phishing, using false domains versus the official ".gov.br").

As stated in a press release issued by Sigma Lithium on January 23, the Company’s management does not consider that the ongoing administrative enquiry with respect to certain of the Company’s waste piles (“Enquiry”) by the Brazilian Ministry of Labor and Employment (“Ministry”) has a material effect on Sigma Lithium’s capacity to continue to execute its mining activities underway. Therefore, the Company's management considered the Enquiry as not constituting material information when it was initiated last year, and this remains the case. In December 2025, the Ministry conducted a regular safety and health inspection at Sigma Lithium, when it had the opportunity to verify the Company's impeccable safety records, with over 2 years without labor accidents with lost time. Following the visit, the Ministry opened the Enquiry.

The issuance of the Statement by the Mining Regulator, which unequivocally confirms the safety of Sigma Lithium’s waste piles, subsidizes the interactions of the Company with the Ministry with respect to the Enquiry. Sigma Lithium has maintained continuous dialogue and collaboration with the Ministry, providing all the necessary documents, technical reports, data collection sources and other requested information, demonstrating the full compliance of its operations with applicable rules and regulations.

Sigma Lithium believes that the timely involvement of the Mining Regulator supports the Company’s clarification to the Ministry that its “waste piles” are, in fact, hard schist rock mined from the pits and are a common feature of most base metals’ operations with host mineral rocks and contact zones. These hard rock piles have been routinely confused with “tailings piles” of lithium fines, which are less common in lithium operations globally, as few companies have deployed Sigma Lithium’s green technology for dry stacking (not utilizing dams).

The Company has been able to sell and generate substantial demand for these dry stacked lithium fines because their lithium crystal particles are kept intact after processing by Sigma Lithium’s Greentech Industrial Plant. These sales proceeds are an “environmental bonus” that is being reinvested in the operations of the Company, resulting from its clean Dense Media Separation technology that does not utilize chemical reagents to segregate the lithium crystal particles from its host rock to produce lithium oxide concentrate.

The overall disinformation in the marketplace about the Enquiry and Company’s “piles” has created significant volatility in Sigma Lithium’s share price and, in the Company’s opinion, it is very clearly the result of an ongoing well-orchestrated and well-funded defamatory campaign to confuse market participants, including investors, banks, newswires and even renowned expert opinion makers, such as research analysts at Bank of America, a thought-leader global financial institution (that has historically provided strategic advice to Sigma Lithium). The Company is in close contact with the appropriate authorities, including FINRA (US Securities and Exchange Commission), regarding these events.

ABOUT SIGMALITHIUM

Sigma Lithium Corporation (NASDAQ: SGML, TSXV: SGML, BVMF: S2GM34), (“Sigma Lithium” or “the Company”), is a leading global lithium producer dedicated to powering the next generation of electric batteries with socially and environmentally sustainable lithium oxide concentrate.

The Company operates one of the world’s largest lithium production sites—the fifth-largest industrial-mineral complex for lithium oxide concentrate—at its Grota do Cirilo operation in Brazil. Sigma Lithium is at the forefront of environmental and social sustainability in the electric battery materials supply chain, producing Quintuple Zero Green Lithium: zero coal power, zero tailings dams, zero utilization of potable water, zero use of hazardous chemicals and zero accidents.

Sigma Lithium currently has a nameplate capacity to produce 270,000 tonnes of lithium oxide concentrate on an annualized basis (approximately 38,000–40,000 tonnes of LCE) at its mine and state-of-the-art Greentech Industrial Plant. The Company is now constructing a second plant to double its production capacity.

For more information about Sigma Lithium, visit our website

FOR ADDITIONAL INFORMATION PLEASECONTACT

Anna Hartley, Vice President of Global Banking and Investor Relations

anna.hartley@sigmalithium.com.br

+44 7866 458 093

SigmaLithium

FORWARD-LOOKINGSTATEMENTS

Thisnews release includes certain “forward-looking information” under applicable Canadian and U.S. securities legislation, includingbut not limited to statements relating to timing and costs related to the general business and operational outlook of the Company, theenvironmental footprint of tailings and positive ecosystem impact relating thereto, donation and upcycling of tailings, timing and quantitiesrelating to tailings and Green Lithium, achievements and projections relating to the Zero Tailings strategy, achievement of ramp-up volumes,production estimates and the operational status of the Grota do Cirilo Project, and other forward-looking information. All statementsthat address future plans, activities, events, estimates, expectations or developments that the Company believes, expects or anticipateswill or may occur is forward-looking information, including statements regarding the potential development of mineral resources and mineralreserves which may or may not occur. Forward-looking information contained herein is based on certain assumptions regarding, among otherthings: general economic and political conditions; the stable and supportive legislative, regulatory and community environment in Brazil;demand for lithium, including that such demand is supported by growth in the electric vehicle market; the Company’s market positionand future financial and operating performance; the Company’s estimates of mineral resources and mineral reserves, including whethermineral resources will ever be developed into mineral reserves; and the Company’s ability to operate its mineral projects includingthat the Company will not experience any materials or equipment shortages, any labour or service provider outages or delays or any technicalissues. Although management believes that the assumptions and expectations reflected in the forward-looking information are reasonable,there can be no assurance that these assumptions and expectations will prove to be correct. Forward-looking information inherently involvesand is subject to risks and uncertainties, including but not limited to that the market prices for lithium may not remain at current levels;and the market for electric vehicles and other large format batteries currently has limited market share and no assurances can be givenfor the rate at which this market will develop, if at all, which could affect the success of the Company and its ability to develop lithiumoperations. There can be no assurance that such statements will prove to be accurate, as actual results and future events could differmaterially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking information.The Company disclaims any intention or obligation to update or revise any forward-looking information, whether because of new information,future events or otherwise, except as required by law. For more information on the risks, uncertainties and assumptions that could causeour actual results to differ from current expectations, please refer to the current annual information form of the Company and other publicfilings available under the Company’s profile atwww.sedarplus.com.

Neither the TSX Venture Exchangenor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility forthe adequacy or accuracy of this news release.