Dr. Andy Robinson reports

SMACKOVER LITHIUM SUCCESSFULLY COMPLETES DERISKING OF DLE TECHNOLOGY WITH FINAL FIELD-TEST AT SOUTH WEST ARKANSAS PROJECT

Smackover Lithium, a joint venture (JV) between Standard Lithium Ltd. and Equinor, has achieved one of the last technical milestones in the development of the South West Arkansas (SWA) project located in Lafayette and Columbia counties, Arkansas. The JV, in partnership with Koch Technology Solutions (KTS), successfully completed the final direct lithium extraction (DLE) derisking step for the SWA project, a critical step toward commercialization. Over a three-month period, the JV and its partners operated an on-site DLE field pilot plant, where it surpassed key performance criteria (more details provided below). Additionally, large-volume samples of the concentrated and purified DLE product have been sent to third party vendors. These vendors will convert the DLE product into battery-quality lithium carbonate while also being assessed as potential equipment suppliers for the commercial project. The resulting samples will play a key role in the qualification process with prospective offtake partners.

Highlights of this final derisking pilot include:

• Lithium recovery far exceeded the design criteria. During sustained operation, the DLE field pilot plant recovered over 99 per cent of the lithium from brine sourced from the SWA project's International Paper Company (IPC-1) well, far exceeding the 95-per-cent recovery used in the current design (average lithium content of the incoming brine was 427 milligrams per litre).
• Rejections for key contaminants were within acceptable tolerance of (that is, just above or below) the design criteria.
• The field pilot plant processed over 2,385 barrels (100,170 gallons) of brine from the IPC-1 well.
• The field pilot plant completed over 497 DLE cycles.
• These recent data from the field pilot plant testing supplement the 28,367,185 gallons of brine processed and the 11,206 cycles of DLE completed at Standard Lithium's demonstration plant in El Dorado, Ark., operating since 2020.
• The heart of the plant is the same KTS Li-Pro lithium selective sorption (Li-Pro LSS) technology, as described in the company's recent news release (Oct. 28, 2024).
• The field pilot plant has produced approximately 970 gallons (3,672 litres) of concentrated and purified lithium chloride solution (6 per cent LiCl solution).
• The 970 gallons of 6 per cent LiCl solution is currently being sent off site to three separate potential carbonate equipment vendors.
• The three vendors are expected to produce, in total, approximately 27 kilograms of battery-quality lithium carbonate, anticipated in May, 2025.

Standard Lithium's president and chief operating officer, Dr. Andy Robinson, commented: "This field pilot is the final step in derisking DLE technology for Smackover brines; we're now ready to commercialize this technology. For five years, Standard Lithium has been operating a large-scale demonstration plant in Arkansas, and we've processed over 28 million gallons of real, live Smackover brine. This large demonstration plant has been invaluable in developing, streamlining and optimizing the flow sheet. The field pilot was the final step to demonstrate that we can reliably process brine from our SWA project, extract lithium in real time and convert to a battery-quality lithium carbonate product. Smackover Lithium has now completed the necessary testing of the flow sheet and can complete the FEED [front-end engineering design] work and feasibility study."

Qualified person

Marek Dworzanowski, EUR Ing, CEng, HonFSAIMM, FIMMM, a qualified person as defined by National Instrument 43-101 and a consulting metallurgical engineer who is independent of the company, has reviewed and approved the relevant scientific and technical information in this news release.

About Smackover Lithium

Smackover Lithium is a joint venture between Standard Lithium and Equinor. Formed in May, 2024, Smackover Lithium is developing two direct lithium extraction project companies in southwestern Arkansas and eastern Texas. Standard Lithium owns a 55-per-cent interest and Equinor holds the remaining 45-per-cent interest in the two project companies, with Standard Lithium retaining operatorship.

About Standard Lithium Ltd.

Standard Lithium is a leading near-commercial lithium development company focused on the sustainable development of a portfolio of large, high-grade lithium brine properties in the United States. The company prioritizes projects characterized by the highest-quality resources, robust infrastructure, skilled labour and streamlined permitting. Standard Lithium aims to achieve sustainable, commercial-scale lithium production through the application of a scalable and fully integrated direct lithium extraction and purification process. The company's flagship projects are located in the Smackover formation, a world-class lithium brine asset, focused in Arkansas and Texas. In partnership with global energy leader Equinor, Standard Lithium is advancing the South West Arkansas project, a greenfield project located in southern Arkansas, and actively exploring promising lithium brine prospects in eastern Texas. Additionally, the company is advancing the phase 1A project in partnership with Lanxess Corp., a brownfield development project located in southern Arkansas. Standard Lithium also holds an interest in certain mineral leases in the Mojave Desert in San Bernardino county, California.

Standard Lithium trades on both the TSX Venture Exchange and the NYSE American under the symbol SLI and on the Frankfurt Stock Exchange under the symbol S5L.

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