Smackover Lithium Files Definitive Feasibility Study for Its South West Arkansas Project, North America's Highest-Grade Reported Lithium Brine Reserve

Original announcement by tmx on

Company
Standard Lithium Ltd.
Ticker
SLI
Exchange
TSX
Region
Arkansas
Primary commodity
Lithium
Secondary commodities
None reported
Document categories
Resource update, Economic study
Extracted
2026-09-16 23:02:17 UTC

Analysis by Minestarters Atlas

Minestarters Atlas analysis

Summary

Standard Lithium has filed a Definitive Feasibility Study (DFS) for its South West Arkansas lithium brine project. The study outlines a 20-year mine life with 447,000 tonnes of LCE in Proven Reserves and a projected 20.2% unlevered pre-tax IRR.

Reasoning: The announcement of a DFS for a high-grade lithium project with a solid 20.2% IRR and significant reserves is a major de-risking milestone for the company.

Positive factors

  • Definitive Feasibility Study (DFS) filed
  • High-grade lithium brine reserves reported
  • Strong IRR of 20.2%
  • First commercial DLE operation in the US

Negative factors

  • Qualified Person is not independent

Facts used in scoring: 3

Classification and evidence

DFS Completepositive · Story-specific tag

No canonical definition is currently available.

Why it applies: The company has filed a Definitive Feasibility Study for the South West Arkansas project.

Evidence · text

“announced today that the Definitive Feasibility Study (“DFS” or the “Report”) for its South West Arkansas (“SWA”) project (the “Project” or “SWA Project”) has been filed.”

Proven Reservepositive

Measured Resource with demonstrated economic viability after applying modifying factors.

Why it applies: The DFS reports 447,000 tonnes of Proven Reserves of LCE.

Evidence · text

“producing 447,000 tonnes (Proven Reserves) of lithium carbonate equivalent (“LCE”)”

NI 43-101 Compliantpositive

Resource estimate prepared in compliance with NI 43-101 (Canada) — high reporting standard.

Why it applies: The disclosure is reviewed and approved by a Qualified Person under NI 43-101 standards.

Evidence · text

“reviewed and approved by Mr. Stephen Ross, P.Geo... for purposes of, and as that term is defined in, National Instrument 43-101”

Extracted facts

Stored fact records: 2. Some facts used in scoring do not have a stored record.

Resource Estimates (2)

indicatedSouth West Arkansas · lithiumTonnes: 1177000Contained Metal: 1177000Contained Unit: tonnes lceView all details
Link to this fact

Identity

Project
South West Arkansas
Commodity
lithium
Region
arkansas
Reported Region
Arkansas
Ticker
SLI

Resource scope

Estimate type
resource
Reporting standards
ni_43_101
Resource group id
resource:58eb2edbf6f0577655d5
Resource basis
gross

Resource Data

Category
indicated
Tonnes
1177000
Contained Metal
1177000
Contained Unit
tonnes lce

Review

Needs Review
No
Historical
No

Dates

Event date
2025-10-14T00:00:00.000Z

Reasoning: The resource scale is substantial for a lithium brine project.

Positive factors

  • Significant M&I resource

Evidence · text

“38% of the in-situ Measured and Indicated Resources of 1,177,000 tonnes LCE.”

Tags used in scoring

Indicated Resourcepositive

Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves.

Why it applies: category is "indicated"

Cut-off Undisclosednegative

High-grade interval reported without stating the cut-off grade used for compositing.

Why it applies: no cutoff_grade was stated

NI 43-101 Compliantpositive

Resource estimate prepared in compliance with NI 43-101 (Canada) — high reporting standard.

Why it applies: reporting_standards includes ni_43_101

DFS-Supportingneutral

Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence.

Why it applies: the release names the study this estimate supports

provenSouth West Arkansas · lithiumTonnes: 447000Contained Metal: 447000Contained Unit: tonnes lceView all details
Link to this fact

Identity

Project
South West Arkansas
Commodity
lithium
Region
arkansas
Reported Region
Arkansas
Ticker
SLI

Resource scope

Estimate type
reserve
Reporting standards
ni_43_101
Resource group id
resource:9547e8afe71141344ecb
Resource basis
gross

Resource Data

Category
proven
Tonnes
447000
Contained Metal
447000
Contained Unit
tonnes lce

Review

Needs Review
No
Historical
No

Dates

Event date
2025-10-14T00:00:00.000Z

Reasoning: The reserve grade is high for the region.

Positive factors

  • High grade brine

Evidence · text

“producing 447,000 tonnes (Proven Reserves) of lithium carbonate equivalent (“LCE”)”

Tags used in scoring

Proven Reservepositive

Measured Resource with demonstrated economic viability after applying modifying factors.

Why it applies: category is "proven"

Cut-off Undisclosednegative

High-grade interval reported without stating the cut-off grade used for compositing.

Why it applies: no cutoff_grade was stated

NI 43-101 Compliantpositive

Resource estimate prepared in compliance with NI 43-101 (Canada) — high reporting standard.

Why it applies: reporting_standards includes ni_43_101

DFS-Supportingneutral

Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence.

Why it applies: the release names the study this estimate supports

How Atlas produces this analysis

Minestarters Atlas uses automated extraction to summarize mining announcements, identify reported measurements, and classify supporting evidence. Sentiment reflects the extracted narrative and classification rules; it is an interpretation, not a reported measurement. Evidence quotes and context are provided where available. Missing data, low-confidence results, and review flags indicate limitations. Check the original publisher announcement before relying on an interpretation.