Mr. Robert Winton reports

EXCELSIOR MINING ANNOUNCES JOHNSON CAMP STAGE 1 DRILLING WITH NUTON, A RIO TINTO VENTURE

Excelsior Mining Corp. has commenced drilling at Johnson Camp with Nuton LLC, a Rio Tinto venture, to further evaluate the use of its Nuton copper heap leaching technologies at Excelsior's Johnson Camp mine in Cochise county, Arizona. The program consists of drilling 6,000 feet of PQ core for the purposes of further metallurgical evaluation. Once completed the samples will be processed for mineralogy and tested using the Nuton process. Results are expected late Q3 2023. The program is being financed by Nuton and carried out in connection with the previously announced option agreement.

"Excelsior is now aggressively moving the Johnson Camp mine forward with the next stages of the work program with Nuton. The sulphide potential at JCM is significant and we are pleased to be working with Nuton to realize that potential. In parallel we continue to progress Gunnison towards well stimulation trials later this year," comments Robert Winton, senior vice-president and general manager of operations of Excelsior.

Rio Tinto has developed the Nuton technologies, an extensive portfolio of advanced copper heap leaching technologies targeted at primary sulphide minerals (including lower-grade mineral deposits), which could not otherwise be processed using traditional leaching or sulphide processing technologies. These technologies offer the potential to produce additional copper in a cost-effective manner that has significant environmental benefits and reduces waste from new and continuing operations.

About the Johnson Camp mine

The Johnson Camp mine is a past-producing open-pit, heap leach operation. The operation includes two open pits, a two-stage crushing-agglomerating circuit, a fully functioning SX-EW (solvent extraction-electrowinning) plant capable of producing 25 million pounds of cathode copper per year, a complete set of PLS and raffinate ponds, and full infrastructure (ancillary facilities, access, power, water and communications).

An updated preliminary economic assessment (PEA) incorporating sulphide leaching technology was announced Feb. 22, 2023. Mining of JCM would be by traditional open pit. The highlights of the PEA financial model, using a copper price of $3.75/pound, show an after-tax net present value of $180-million (U.S.) (7.5-per-cent discount rate), and an after-tax internal rate of return of 30.4 per cent. The results are tabulated herein.

The PEA is preliminary in nature and includes inferred mineral resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves. There is no certainty that the conclusions reached in the PEA will be realized. Mineral resources that are not mineral reserves do not have demonstrated economic viability.

About Excelsior Mining Corp.

Excelsior, the copper solution company, is a mineral exploration and production company that owns and operates the Gunnison copper project in Cochise county, Arizona. The project is a low-cost, environmentally friendly in situ recovery copper extraction project that is permitted to 125 million pounds per year of copper cathode production. Excelsior also owns the past-producing Johnson Camp mine and a portfolio of exploration projects, including the Peabody sill and the Strong and Harris deposits.

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