CENTURY LITHIUM HIGHLIGHTS RARE EARTH POTENTIAL AT ANGEL ISLAND, NEVADA

Rhea-AI Summary

Century Lithium (OTCQX: CYDVF) reported December 11, 2025 lab results showing rare earth element (REE) recovery from Angel Island claystone using a chloride-based leach plus ion-exchange process. A 500-tonne bulk sample assayed 1,101 ppm Li and 239 ppm TREO (0.024%). Chloride leach produced solutions with 210 mg/L Li and 36 mg/L TREO, and ion-exchange recovered REEs at an aggregate ~99.6%. The sample’s REE mix was ~75% light REEs and ~25% yttrium/heavy REEs. Angel Island's planned processing of 2.75–5.5 million tonnes/year could generate 10–20 million tonnes of leach solution annually, suggesting meaningful by-product REE quantities, though economic evaluation and wider deposit representivity remain pending.

Positive

• Ion-exchange recovered REEs at ~99.6% aggregate
• Claystone assayed 1,101 ppm lithium
• Sample contained 239 ppm TREO (0.024%)
• Chloride leach produced 210 mg/L Li and 36 mg/L TREO
• Planned processing 2.75–5.5 million tonnes annually

Negative

• Company has not yet evaluated economic contribution of REE recovery
• Results from a 500-tonne bulk sample may not represent the whole deposit
• Ion-exchange showed 0% lithium recovery in IX stage

VANCOUVER, BC, Dec. 11, 2025 /PRNewswire/ - Century Lithium Corp. (TSXV: LCE) (OTCQX: CYDVF) (Frankfurt: C1Z) ("Century Lithium" or "the Company") is pleased to provide further details regarding its recent news release on the recovery of rare earth elements ("REEs") from its 100%-owned Angel Island Lithium Project in Nevada, USA. Testing using the Company's patent-pending chloride-based process combined with targeted ion-exchange demonstrated both potentially significant levels of REEs in solution and exceptionally high recoveries of REEs in ion-exchange. These results reinforce the opportunity for REEs to become a strategically important by-product alongside Angel Island's primary commodity, lithium carbonate and secondary revenue stream from the sales of sodium hydroxide.

"We are very encouraged by these findings," stated Bill Willoughby, President and CEO of Century Lithium. "From assays, the claystone sample used for testing contained 0.024% total rare earth oxides ("TREO"). Our ability to recover these elements efficiently from solution and in parallel with lithium is a significant accomplishment by our team. At the scale of our planned operations, these levels of REE would contribute meaningfully to North America's critical mineral supply chain and revenue streams from Angel Island."

The test work on the REEs was conducted using material taken from the 500-tonne bulk sample collected from Angel Island. The results listed below are representative of the bulk sample and should not be assumed representative of the Angel Island lithium claystone deposit as a whole.

The claystone material assayed 1101 ppm lithium and 239 ppm (0.024%) TREO. The REE distribution of the sample consists of approximately 75% light rare earth elements and 25% yttrium and heavy rare earth elements. Chloride leaching of the sample yielded solution concentrations of 210 mg/l lithium and 36 mg/l TREO, indicating that the REEs enter solution under the same conditions as used for lithium extraction.

Two ion-exchange ("IX") media were tested for recovery of REEs from the pregnant leach solution. Both media demonstrated high recovery of all REEs and yttrium. The table below summarizes the feed value, concentrations in the leach solution, and final IX recovery for selected elements.

Element *	Feed (ppm)	Solution (mg/l)	Recovery by IX (%)
Li	1,101	229.0	0.0 %
Nd + Pr	43.4	8.637	99.8 %
Dy	3.8	0.994	99.8 %
Tb	0.7	0.178	99.9 %
Y	24.9	6.645	99.8 %
Sc	14.4	0.307	97 %
Others	152.2	26.379	99.8 %
Total REO	239.4	35.700	99.6 %

* All elements with the exception of lithium reported as oxides.

Note: Representative samples for solids and liquids were delivered to ALS Canada Ltd. In Reno, Nevada, and analyses performed at their independent ISO/IEC 17035 accredited laboratory in Vancouver, B.C., using methods ME-MS14 and ME-ICP-15 on liquids and ME-MS61L with REE add-on for solids. Quality control in the form of duplicates, standards and blanks was provided by the laboratory. 

Globally, a significant amount of REE production comes from deposits that are large-scale and relatively low grade. Ion-adsorption clay deposits in southern China and Southeast Asia, for example, are long the world's dominant source of heavy rare earths and operate at 0.03–0.15% TREO. In the U.S., primary REE projects in Wyoming and Texas are under development with grades between 0.05% and 0.20% TREO. Together these illustrate that such deposits can achieve technical and strategic significance when supported by efficient extraction methods and substantial tonnage, underscoring the potential relevance of Angel Island's REE content as a by-product within a large-scale lithium operation.

Angel Island is expected to process 2.75 to 5.5 million tonnes of claystone annually across the Project's planned Phase 1 and Phase 2, generating 10 to 20 million tonnes of leach solution per year. At this scale, modest REE concentrations translate into strategically important quantities.

Century Lithium is not yet evaluating the economic contribution of REE recovery, as further reserve definition and metallurgical testing are required before such analysis is appropriate. But these results on REE recovery show Angel Island's strategic relevance to domestic critical-mineral supply, highlight a potential additional revenue source for the Company, and demonstrate the value of Century Lithium's processing technology. The Company remains fully committed to completing the updated feasibility study and advancing permitting for Angel Island, critical milestones that will drive Angel Island toward development.  

Qualified Person

Todd Fayram, MMSA-QP and Senior Vice President, Metallurgy of Century Lithium is the qualified person as defined by National Instrument 43-101 and has approved the technical information in this release.

ABOUT CENTURY LITHIUM CORP.

Century Lithium Corp. is an advanced-stage lithium company, focused on developing its 100%-owned lithium project Angel Island in Esmeralda County, Nevada, which hosts one of the largest sedimentary lithium deposits in the United States. The Company has utilized its patent-pending process for chloride leaching combined with direct lithium extraction to make battery-grade lithium carbonate. As part of the Company's chlor-alkali process, the planned sale of surplus sodium hydroxide produced at Angel Island is expected to contribute meaningfully to maintaining competitive operating costs for lithium carbonate production.

Angel Island is one of the few advanced lithium projects in development in the United States to provide an end-to-end process to produce battery-grade lithium carbonate for the growing electric vehicle and battery storage market. Angel Island is currently in the permitting stage for a three-phase feasibility-level production plan, expected to yield an estimated life-of-mine average of 34,000 tonnes per year of lithium carbonate over a 40-year mine-life.

Century Lithium trades on both the TSX Venture Exchange under the symbol "LCE" and the OTCQX under the symbol "CYDVF", and on the Frankfurt Stock Exchange under the symbol "C1Z".

To learn more, please visit centurylithium.com. 

ON BEHALF OF CENTURY LITHIUM CORP.

WILLIAM WILLOUGHBY, PhD., PE
President & Chief Executive Officer

NEITHER THE TSX VENTURE EXCHANGE NOR ITS REGULATION SERVICES PROVIDER ACCEPTS RESPONSIBILITY FOR THE ADEQUACY OR ACCURACY OF THE CONTENT OF THIS NEWS RELEASE.

Cautionary Note Regarding Forward-Looking Statements

This release contains certain forward-looking statements within the meaning of applicable Canadian securities legislation. In certain cases, forward-looking statements can be identified by the use of words such as "plans", "expects" or "does not anticipate", or "believes", or variations of such words and phrases or statements that certain actions, events or results "may", "could", "would", "might" or "will be taken", "occur" or "be achieved" and similar expressions suggesting future outcomes or statements regarding an outlook.

Forward-looking statements relate to any matters that are not historical facts and statements of our beliefs, intentions and expectations about developments, results and events which will or may occur in the future, without limitation, statements with respect to the potential development and value of the Project and benefits associated therewith, statements with respect to the expected project economics for the Project, such as estimates of life of mine, lithium prices, production and recoveries, capital and operating costs, IRR, NPV and cash flows, any projections outlined in the Feasibility Study in respect of the Project, the permitting status of the Project and the Company's future development plans.

These and other forward-looking statements and information are subject to various known and unknown risks and uncertainties, many of which are beyond the ability of the Company to control or predict, that may cause their actual results, performance or achievements to be materially different from those expressed or implied thereby, and are developed based on assumptions about such risks, uncertainties and other factors set out herein. These risks include those described under the heading "Risk Factors" in the Company's most recent annual information form and its other public filings, copies of which can be under the Company's profile at www.sedarplus.com. The Company expressly disclaims any obligation to update-forward-looking information except as required by applicable law. No forward-looking statement can be guaranteed, and actual future results may vary materially. Accordingly, readers are advised not to place reliance on forward-looking statements or information. Furthermore, Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.

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SOURCE Century Lithium Corp.

FAQ

What did Century Lithium announce about REE recovery at Angel Island on December 11, 2025 (CYDVF)?

Century Lithium reported chloride leach plus ion-exchange tests on a 500-tonne bulk sample that produced ~99.6% aggregate REE recovery and 36 mg/L TREO in solution.

How much TREO and lithium did the Angel Island bulk sample assay (CYDVF)?

The bulk sample assayed 239 ppm TREO (0.024%) and 1,101 ppm lithium.

What processing scale did Century Lithium forecast for Angel Island and its impact on REE quantities (CYDVF)?

Planned Phase 1/2 processing is 2.75–5.5 million tonnes of claystone per year, producing 10–20 million tonnes of leach solution annually.

Do the reported REE results mean immediate revenue for shareholders of CYDVF?

No; the company said it has not yet evaluated the economic contribution of REE recovery and further testing is required.

What REE composition did the Angel Island sample show in Century Lithium's December 2025 tests (CYDVF)?

The sample consisted of approximately 75% light rare earth elements and 25% yttrium and heavy rare earth elements.