Saturday, September 26, 2026
MiningNewsTerminal
Saturday, September 26, 2026 Admin

SLI.V ·

Standard Lithium Announces Positive Preliminary Economic Assessment and Upgrading of Mineral Resource at Its Southern Arkansas Lithium Brine Project

Resource Estimates Economic Studies

STANDARD LITHIUM ANNOUNCES POSITIVE PRELIMINARY ECONOMIC ASSESSMENT

AND UPGRADING OF MINERAL RESOURCE AT ITS SOUTHERN ARKANSAS LITHIUM

BRINE PROJECT

19th June 2019 – Vancouver, BC – Standard Lithium Ltd. (“Standard Lithium” or the

“Company”) (TSXV: SLL) (OTCQX: STLHF) (FRA: S5L), is pleased to announce the results of a

Preliminary Economic Assessment (PEA) of its 150,000 acre project in the south-central region

of Arkansas, USA (the “Property”). The PEA considers the production of battery -quality lithium

carbonate through a phased build -out to a total 20,900 tonnes per annum (tpa) from the

contemplated joint venture with Lanxess Corp. (see press release dated November 12, 2018) at

their three-operating bromine-processing plants. The PEA also includes the reclassification of

the existing mineral resource to an Indicated category. The PEA was prepared by Advisian, the

consulting arm of WorleyParsons Canada Services Ltd (Worley) , a world -leading integrated

engineering firm with extensive experience in the design and construction of chemical plants and

lithium brine processing projects around the globe.

Key Points:

• Pre-tax US$1.3 Billion NPV at 8% discount rate and IRR of 42%;

Total CAPEX estimate of US$437 Million including 25% contingency of both direct and

indirect capital costs , completed in accordance with American Associ ation of Cost

Engineers (AACE) International Class 5 standard for estimates in process industries;

• 25 year mine -life producing 20,900 tpa battery -quality lithium carbonate when all three

plants are operational (production ramped up to full capacity over 5 years);

• Non-optimised reagent cost per tonne lithium carbonate of US$3,107

• All-in operating costs, including all direct and indirect costs, sustaining capital, insurance

and mine-closure costs of US$4,319 per tonne of lithium carbonate; and

• Lanxess resource upgraded to 3,140,000 tonnes Lithium Carbonate Equivalent (LCE) at

the Indicated Category.

Dr. Andy Robinson, President and COO of Standard Lithium commented “We are delighted that

we have been able, through close partnerships and access to large amounts of data, to bring our

Lanxess project to the stage of successful completion of the PEA in such a short period of time.

We were able to provide to Worley a huge amount of process testing and actual operational data

from the current brine-processing plants in southern Arkansas, and as a result, we feel that we

have produced a realistic view of the potential there, as well as a picture of the robustness of the

project. We are progressing the deployment of the demonstration plant, and are scheduled to

have it deployed to the project site in southern Arkansas in Q3 of this year. Real -world process

optimisation from the demonstration plant, combined with the advanced nature of this PEA, mean

that we are well positioned to release a robust feasibility study in early 2020.”

PEA Highlights:

Units Values

Production tpa 20,900[1]

Plant Operation years 25[2]

Total Capital Cost (CAPEX) US$ 437,162,000[3]

Operating Cost (OPEX) US$/yr 90,259,000[4]

Average Selling Price US$/t 13,550[5]

Annual Revenue US$ 283,195,000

Discount Rate % 8

Net Present Value (NPV) Pre-Tax US$ 1,304,766,000

Net Present Value (NPV) Post-Tax US$ 989,432,000

Internal Rate of Return (IRR) Pre-Tax

%

% 41.8

Internal Rate of Return (IRR) Post-Tax % 36.0

Notes:

All model outputs are expressed on a 100% project ownership basis

[1] Total production, using existing brine supply rates at the completion of Phase 3

[2] Plant operation commences upon completion of Phase 1

[3] Includes 25% contingency of both direct and indirect capital costs

[4] Includes all operating expenditures, including sustaining capital and allowance for mine closure

[5] Selling prices ranging between US$10,840-16,260/tonne were modelled as part of sensitivity analysis

Capital Costs

The project is envisaged to be implemented in three stages, corresponding with build -out at the

existing brine processing fa cilities. At full build -out, with estimated production of 20,900 tpa of

lithium carbonate, the direct capital costs are estimated at US$204 Million, with indirect costs of

US$146 Million. A contingency of 25% was applied to both direct and indirect costs.

Project

Phase Item Direct Cost

US$

Indirect

Cost US$

Contingency

US$ CAPEX US$

Phase 1

South

Plant

South Lithium Extraction Plant,

Train 1 Carbonate Plant and

Ancillary Infrastructure

$79,959,000 $56,978,000 $34,234,000 $171,171,000

Phase 2

West

Plant

West Lithium Extraction Plant,

Train 2 Carbonate Plant and

Ancillary Infrastructure

$74,355,000 $54,587,000 $32,236,000 $161,178,000

Phase 3

Central

Plant

Central Lithium Extraction

Plant, Train 3 Carbonate Plant

and Ancillary Infrastructure

$49,812,000 $34,038,000 $20,963,000 $104,813,000

TOTAL $204,126,000 $145,603,000 $87,433,000 $437,162,000

Operating Costs

The operating cost estimate included both direct costs and indirect costs, as well as sustaining

capital and allowances for mine closure. The majority of the operating cost is based on reagent

usage required to extract the lithium from the tailbrine, as well as conversion to lithium carbonate.

Out of this, the greatest amount is related to acid and base consumption (hydrochloric acid and

caustic soda), and was estimated using information from the mini-pilot studies completed to date;

it should be noted that optimisation of reagent usage during the mini -pilot studies was not

conducted, and hence, it can be reasonably assumed that future reagent consumption can be

optimised. As such, the estimates provided are considered to be at the upper end of likely future

costs. One of the key assessments that will be made during operation of the demonstration plant

will be studying reagent optimisation and acid/base recovery.

Resource Assessment

The resource present in the Smackover Formation below the Lanxes s property was reclassified

based on completion of additional brine sampling/geochemistry and advances in the lithium

recovery process development work. Using a cut-off criteria of 100 mg/L, t he Lanxess lithium

brine resource estimate is classified as ‘Indicated’ according to the CIM definition standards. The

total Indicated Lanxess lithium brine resource is estimated at 590,000 tonnes of elemental lithium,

or 3,140,000 tonnes LCE; see below for more detail.

South Arkansas Lithium Brine Project Indicated Resource Statement

Parameter South Unit Central Unit West Unit Total

Aquifer Volume (km3) 5.83 8.29 16.31 30.43

Brine Volume (km3) 0.689 0.995 1.84 3.52

Average Li concentration

Milligrams per litre (mg/L) 168 mg/L

Average Porosity 11.8 % 12.0 % 11.2 % 11.6 %

Total Li resource (as

metal) metric tonnes

(see notes [4] & [5] below)

116,000 167,000 308,000 590,000

Total LCE resource

(metric tonnes)

(see notes [4] & [5] below)

615,000 889,000 1,639,000 3,140,000

Notes:

[1] Mineral resources are not mineral reserves and do not have demonstrated economic viability.

There is no guarantee that all or any part of the mineral resource will be converted into a mineral reserve.

[2] Numbers may not add up due to rounding.

[3] The resource estimate was completed and reported using a cut-off of 100 mg/L lithium.

[4] The resource estimate was developed and classified in accordance with guidelines established

by the Canadian Institute of Mining and Metallurgy. The associated Technical Report was completed in

accordance with the Canadian Securities Administration’s National Instrument 43 -101 and all associated

documents and amendments. As per these guidelines, the resource was estimated in terms of metallic

(or elemental) lithium. The Qualified Person for the Mineral Resource estimate is Roy Eccles, P. Geol.

[5] In order to describe the resource in terms of ‘industry standard’ lithium carbonate equivalent, a

conversion factor of 5.323 was used to convert elemental lithium to LCE.

Lithium Pricing and Production

A detailed future pricing study for lithium chemicals was not completed for this PEA. The average

price used for future sales of battery -quality lithium carbonate was developed by calculating the

three-year rolling average from USGS-compiled sales figures. This future average sales price of

US$13,550/tonne is consistent with those used for publicly-released economic assessments of

other lithium brine projects in the previous 12 months. Future selling prices ranging between

US$10,840 to US$16,260/tonne were modelled as part of a sensitivity analysis exercise.

The total production of 20,900 tpa lithium carbonate is based on recovery of lithium from the tail-

brine stream already being produced at the three operational brine processing facili ties in

southern Arkansas. It does not take into account possible future increases in pumping volumes

at the plants ; possible optimisation by using selected brine supply wells to increase lithium

concentrations in the tail-brine stream; nor possible expansion to include brine streams from other

brine leases that the Company has access to in the region (e.g. the Company’s Tetra lithium -

brine property).

Processing

The PEA is based on a flowsheet that contemplates use of the lithium extraction technology that

has been tested by the Company through independent bench-scale and mini-pilot stage testing,

and will be tested further in the Company’s Demonstration plant, scheduled for delivery to the

South Plant location in Q3 of 2019. The conversion of the resulting lithium chloride solution to a

final battery quality lithium carbonate product is based on existing technology as used

commercially at several facilities.

Quality Assurance

The PEA was completed by Worley, with Stanislaw Kotowski P.Eng. as the lead author. Roy

Eccles P. Geol. of APEX Geoscience Ltd. was the QP responsible for the reclassified mineral

resource estimate. Stanislaw Kotowski P.Eng., is a qualified person as defined by NI 43-101, and

has supervised and approved the preparation of the scientific and technical information that forms

the basis for this news release. Mr. Kotowski is independent of the Company. A National

Instrument 43-101 report is required to be filed, in conjunction with the disclosure of the PEA in

this news release, within 45 days.

About Standard Lithium Ltd.

Standard Lithium (TSXV: SLL) is a specialty chemical company focused on unlocking the value

of existing large -scale US based lithium -brine resources. The Company believes new lithium

production can be brought on stream rapidly by minimizing project risks at selection stage

(resource, political, geographic, regulatory and permitting), and by leveraging advances in lithium

extraction technologies and processes. The Company’s flagship project is located in southern

Arkansas, where it is engaged in the testing and proving of the commercial viability of lithium

extraction from over 150,000 acres of permitted brine operations utilizing the Company’s

proprietary selective extraction technology. The Company is also pursuing the resource

development of over 30,000 acres of separate brine leases located in southwestern Arkansas

and approximately 45,000 acres of mineral leases located in the Mojave Desert in San Bernardino

County, California.

Standard Lithium is listed on the TSX Venture Exchange under the trading symbol “SLL”; quoted

on the OTC - Nasdaq Intl Designation under the symbol “STLHF”; and on the Frankfurt Stock

Exchange under the symbol “S5L”. Please visit the Company’s website at

www.standardlithium.com.

Contact Information:

LHA Investor Relations, Mary Magnani, (415) 433-3777

On behalf of the Board,

Standard Lithium Ltd.

Robert Mintak, CEO & Director

Neither TSX Venture Exchange nor its Reg ulation Services Provider (as that term is defined in policies of

the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release. This news

release may contain certain “Forward-Looking Statements” within the meaning of the United States Private

Securities Litigation Reform Act of 1995 and applicable Canadian securities laws. When used in this news

release, the words “anticipate”, “believe”, “estimate”, “expect”, “target, “plan”, “forecast”, “may”, “schedule”

and other similar words or expressions identify forward-looking statements or information. These forward-

looking statements or information may relate to future prices of commodities, accuracy of mineral or

resource exploration activity, reserves or resources, regulatory o r government requirements or approvals,

the reliability of third party information, continued access to mineral properties or infrastructure, fluctuations

in the market for lithium and its derivatives, changes in exploration costs and government regulation in

Canada and the United States, and other factors or information. Such statements represent the Company’s

current views with respect to future events and are necessarily based upon a number of assumptions and

estimates that, while considered reasonable by the Company, are inherently subject to significant business,

economic, competitive, political and social risks, contingencies and uncertainties. Many factors, both known

and unknown, could cause results, performance or achievements to be materially different from the results,

performance or achievements that are or may be expressed or implied by such forward-looking statements.

The Company does not intend, and does not assume any obligation, to update these forward -looking

statements or information to reflect changes in assumptions or changes in circumstances or any other

events affections such statements and information other than as required by applicable laws, rules and

regulations.