Reported Earlier: Standard Lithium Reports Milestones Achieved, 1M Barrels Processed, 15,000 DLE Cycles, 6 Years Of Zero Safety Incidents

• Processed 1 million barrels of brine, pumped in real-time from the Smackover Formation
• Completed 15,000 cycles of DLE using the same process to be implemented at the South West Arkansas Project
• 6 years and 340,000 man hours of operation without a safety incident
  
  
  
   

VANCOUVER, British Columbia, April 22, 2026 (GLOBE NEWSWIRE) -- Standard Lithium Ltd. ("Standard Lithium" or the "Company") (TSXV:SLI) (NYSE.A: SLI), a leading near-commercial lithium company, is pleased to announce the achievement of several meaningful operational milestones at its large-scale Demonstration Plant (the "demo plant" or "facility") in El Dorado, Arkansas. The demo plant contains a fully operational brine-to-lithium carbonate flowsheet, and at its core is a commercial-scale direct lithium extraction ("DLE") unit supplied by Aquatech.

Since its initial commissioning in 2020, the facility has now reached three significant milestones:

• Standard Lithium has processed 1 million barrels (42 million gallons, or 160 million litres) of real brine, pumped in real-time from the Smackover Formation;
• The core DLE technology to be used at the South West Arkansas Project (the "SWA Project") (with initial capacity of 22,500 tonnes of annual battery-quality lithium carbonate) has now successfully completed over 15,000 cycles, demonstrating the fundamental performance targets of 95%+ lithium recovery and 99%+ rejection of key contaminants; and
• The experienced team of operators, technicians, laboratory specialists and engineers have completed roughly 340,000 man hours during the six years of operation, and have done so with zero incidents, underscoring Standard Lithium's strong commitment to operational safety and best practices.