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

LCE.V ·

Cypress Development Studies Chloride Leaching for Clayton Valley Lithium Project in Nevada

Metallurgy & Processing

Suite 1610 - 777 Dunsmuir Street, Vancouver, BC, Canada, V7Y 1K4

www.cypressdevelopmentcorp.com

TSX Venture Exchange Symbol: CYP

Email: [email protected]

Telephone: (604) 687-3376

Facsimile: (604) 687-3119

NEWS RELEASE

December 3, 2020

Cypress Development Studies Chloride Leaching for Clayton Valley

Lithium Project in Nevada

Vancouver, BC - Cypress Development Corp. (TSX-V: CYP) (OTCQB: CYDVF)

(Frankfurt: C1Z1) (“Cypress” or “the Company”) reports it is initiating a scoping level

study into the extraction of lithium using chloride-based leaching. This decision follows

the test results reported in the Company’s November 24, 2020 news release. The data

indicates a higher rate of lithium extraction in leaching claystone with hydrochloric acid

than with sulfuric acid when in the presence of high chloride levels. The Company has

engaged NORAM Engineering and Constructors Ltd. (NORAM) and Continental

Metallurgical Services Inc. (CMS) for the study which is expected to be completed in

January 2021.

“The purpose of this study is to quickly determine if a change in direction is warranted,”

said Cypress CEO Bill Willoughby. “Cypress is a leader in the development of acid

leaching of lithium claystone. When presented with new information suggesting a way

to improve the project, we respond with evaluating the new data to bring the best value

to our shareholders. The work by NORAM and CMS will determine if this is an

alternative that should be pursued and whether it replaces or augments the use of

sulfuric acid in our extraction process.”

Study Outlined

Cypress continues to work on the pilot plant as recommended in the Company’s

positive May 19, 2020 Prefeasibility Study (PFS). The project is based on a surface

mine producing 15,000 tonnes per day (tpd) of lithium-bearing claystone to a leach

plant yielding 27,400 tonnes per year of lithium carbonate equivalent (LCE) over a 40-

year mine life. Features including favorable location, low strip ratio and low acid

consumption result in an estimated cash cost of $3,329 per tonne LCE. A basic PFS

assumption is the construction of a 2 ,500 tpd acid plant to support the leaching and

power needs of the project.

The Company reported in its November 24, 2020 news release t esting resulted in

85.3% total extraction when using hydrochloric acid to leach lithium-bearing claystone

from the project. This result was higher than the 80.2% lithium extraction obtained

2

when using sulfuric acid under the same conditions. Conditions included using a high

sodium chloride solution instead of distilled water in leaching. The results were

important in demonstrating the ability to tolerate high chloride levels in the process and

flexibility in the water supply that could include geothermal solutions and lithium -

bearing brine. The higher level of lithium extraction was confirmed in a subsequent

test by CMS and with multi-element analyses performed by ALS Global.

In the analyses to date, hydrochloric acid digests significantly more of the clay .

However, t he processing steps to purify and concentrate the leach solution are

potentially easier and lower cost. The scoping study will include a larger test to provide

more solution to confirm these steps. The study deliverables will include mass

balances and finalized flowshee ts for sulfate and chloride leaching in a high saline

system. Also, i ncluded will be scoping level estimates for power and other

consumables, and potential changes in project capital and operating costs.

Pilot Plant Progress

Work toward the pilot plant program is the next stage in the project’s development .

The Company has reviewed several locations for the testing and has narrowed its

consideration to two. Discussions are ongoing. Permit applications are being prepared

as required for the site and bulk sample locations.

The Company reports nine months of baseline environmental related studies were

completed and are in the reporting stage on Cypress’ property . No major

environmental issues were encountered by the Company’s consultants.

Newly received test results from NORAM confirmed a high level of recovery of sulfuric

acid from the process leach solution. Results from this key step showed greater than

90% of the free sulfuric acid in the solution after leaching, was successfully recovered

and available for recycling. The ability to recover and recycle sulfuric acid in the

process is a critical step. The PFS has an allowance for minor losses of sulfuric acid.

The results from NORAM are within the PFS allowance and provide the information

needed for the acid recovery portion of the pilot plant.

The results of the scoping study may require the revaluation of the recommendation

in the PFS to include the use of hydrochloric acid in place of, or in addition to sulfuric

acid in the pilot plant. The Company anticipates the purchasing and assembling of the

pilot plant will proceed upon completion of the scoping study and its outcome. The

Company anticipates completing the pilot plant as planned.

Qualified Person:

Todd Fayram, MMSA-QP, is the qualified person as defined by National Instrument

43-101 and has approved the technical information in this release.

About Cypress Development Corp.:

Cypress Development Corp. is a publicly traded exploration company focused on

developing the Company’s 100% -owned Clayton Valley Lithium Project in Nevada.

Exploration and development by Cypress discovered a world-class resource of lithium-

bearing claystone adjacent to the Albemarle Silver Peak mine, North America's only

lithium brine operation. The size of the resource makes the Clayton Valley Project a

3

premier source that has the potential to impact the supply of lithium for the fast-growing

global energy storage battery market.

Clayton Valley Lithium Project, Nevada claims map:

https://www.cypressdevelopmentcorp.com/site/assets/files/3573/cyp_cm_series_drill

_hole_map_2020.jpg

Cypress Development Corp. has approximate ly 9 8.7 million shares issued and

outstanding.

To find out more about Cypress Development Corp. (TSX-V: CYP), visit our website

at www.cypressdevelopmentcorp.com.

CYPRESS DEVELOPMENT CORP.

“Dr. Bill Willoughby”

WILLIAM WILLOUGHBY, PhD., PE

Chief Executive Officer

For further information contact myself or:

Don Myers

Cypress Development Corp.

Director, Corporate Communications

Telephone: 604-639-3851

Toll Free: 800-567-8181

Facsimile: 604-687-3119

Email: [email protected]

NEITHER THE TSX VENTURE EXCHANGE NOR ITS REGULATION SERVICES

PROVIDER ACCEPTS RESPONSIBILITY FOR THE ADEQUACY OR ACCURACY OF THE

CONTENT OF THIS NEWS RELEASE.

This release includes certain statements that may be deemed to be "fo rward-looking

statements". All statements in this release, other than statements of historical facts, that

address events or developments that management of the Company expects, are forward -

looking statements. Although management believes the expectations expressed in such

forward-looking statements are based on reasonable assumptions, such statements are not

guarantees of future performance, and actual results or developments may differ materially

from those in the forward-looking statements. The Company undertakes no obligation to update

these forward -looking statements if management's beliefs, estimates or opinions, or other

factors, should change. Factors that could cause actual results to differ materially from those

in forward-looking statements, include market prices, exploration and development successes,

continued availability of capital and financing, and general economic, market or business

conditions. Please see the public filings of the Company at www.sedar.com for further

information.