Phoenix, Arizona--(Newsfile Corp. - November 10, 2020) - Excelsior Mining Corp. (TSX: MIN) (FSE: 3XS) (OTCQX: EXMGF) ("Excelsior" or the "Company") is pleased to provide the following update for the Gunnison Copper Project in Arizona.

Limited operations in response to the COVID-19 pandemic have been implemented in order to optimize many aspects of the production wellfield. Highlights from the wellfield optimization program include:

  • The issue of copper precipitates and other precipitates blocking wells has been solved; the upgrades to the wellfield implemented earlier in the year have proven effective;
  • Copper grades in the wells that have been consistently operated are in-line with expectations;
  • These activities have generated sufficient copper in solution to commence operation of the Solvent Extraction-Electrowinning (SX-EW) production facility, which has been turned on;
  • Copper cathode production is expected to commence within 30 days;
  • Staffing levels remain reduced and restricted due to the COVID-19 Pandemic. Operations have been conducted in a safe manner with only one COVID-19 case at Gunnison reported. In response, successful contact tracing and isolation measures were implemented without any requirement to shut-down operations;
  • Expansion of activities to surrounding wells is occurring, with a view to ramping-up to full, nameplate, capacity through 2021; and
  • It is expected that additional time will be required during this ramp-up to optimize the wells and resolve any challenges as they occur.

Stephen Twyerould, President and CEO, said, "We are encouraged by the results of our wellfield optimization program and the team's ability to identify and resolve issues as they arise. The upgrades to the wellfield have proven successful; we can easily and efficiently switch back and forth between injection and recovery for backflushing and flow reversals, and this system has shown substantial improvement in well efficiency. After only three-months of acid injection, we have collected enough copper to start initial production; this will allow us to commission and evaluate SX-EW capabilities. Optimization programs are being rolled out to additional wells and we are confident that production will be expanded over the coming months."

Excelsior previously announced the commencement of acid injection and solution recovery through a limited number of wells. The purpose of these activities was to test the modified (retro-fit) wells under small-scale operating conditions and to gain knowledge on the new "Push-Pull" operating procedures (see Excelsior news release dated August 12, 2020). The smaller scale operation also allowed Excelsior to confirm that it could establish operations that minimized health and safety risks from the transmission of COVID-19. Results from current testing confirms that several wells have achieved partial acid breakthrough; these wells have shown no signs of precipitates blocking or restricting recovery flow. Therefore, Excelsior has confirmed that the need to backflush in order to remove precipitates diminishes or goes away entirely once breakthrough has occurred. Wells that have not broken through still require intermittent back flushing using the modified infrastructure, which has proven very effective.

Twyerould added, "The management team is rapidly gaining the knowledge and expertise necessary to optimize wellfield performance. A variety of issues still need to be worked through, such as how to minimize the impact of carbon-dioxide on fluid flows and how best to maximize flow rates in general; however, we believe that all of these challenges are temporary and will not impact long-term copper production. We expect to be able to expand operations to include the entire wellfield in the very near future."

Excelsior is confident that a gradual expansion of wellfield operations will allow for operations that minimizes the risks of COVID-19 transmission. The ability of Excelsior to optimize the entire wellfield may be impacted by supply chain disruptions related to the on-going pandemic.

About Excelsior Mining

Excelsior "The Copper Solution Company" is a mineral exploration and production company that owns 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. The Feasibility Study projected an after-tax NPV of US$ 807 million and an IRR of 40% using a US$ 2.75 per pound copper price and a 7.5% discount rate.

Excelsior's technical work on the Gunnison Copper Project is supervised by Stephen Twyerould, Fellow of AUSIMM, President & CEO of Excelsior and a Qualified Person as defined by National Instrument 43-101. Mr. Twyerould has reviewed and approved the technical information contained in this news release.

Additional information about the Gunnison Copper Project can be found in the technical report filed on SEDAR at www.sedar.com entitled: "Gunnison Copper Project, NI 43-101 Technical Report, Feasibility Study" dated effective December 17, 2016.

For more information on Excelsior, please visit our website at www.excelsiormining.com.

For further information regarding this press release, please contact:

Excelsior Mining Corp.
Concord Place, Suite 300, 2999 North 44th Street, Phoenix, AZ, 85018.

JJ Jennex, Vice President, Corporate Affairs
T: 604 723 1433
E: info@excelsiormining.com
www.excelsiormining.com

Cautionary Note Regarding Forward-Looking Information

This news release contains "forward-looking information" concerning anticipated developments and events that may occur in the future. Forward looking information contained in this news release includes, but is not limited to, statements with respect to: (i) the results of the Feasibility Study, including operating and capital cost estimates and the economic benefits from the Gunnison Copper Project; (ii) the details of the operations plan; (iii) the timeline to initial production; (iv) plans to expand wellfield operations; (v) health and safety matters; and (vi) the ability to mine the Gunnison Copper Project using in-situ recovery mining techniques.

In certain cases, forward-looking information can be identified by the use of words such as "plans", "expects" or "does not expect", "budget", "scheduled", "estimates", "forecasts", "intends", "anticipates" or "does not anticipate", or "believes", or variations of such words and phrases or state that certain actions, events or results "may", "could", "would", "might", "occur" or "be achieved" suggesting future outcomes, or other expectations, beliefs, plans, objectives, assumptions, intentions or statements about future events or performance. Forward-looking information contained in this news release is based on certain factors and assumptions regarding, among other things, the estimation of mineral resources and mineral reserves, the realization of resource and reserve estimates, expectations and anticipated impact of the COVID-19 outbreak, copper and other metal prices, the timing and amount of future development expenditures, the estimation of initial and sustaining capital requirements, the estimation of labour and operating costs (including the price of acid), the availability of labour, material and acid supply, receipt of and compliance with necessary regulatory approvals, the estimation of insurance coverage, and assumptions with respect to currency fluctuations, environmental risks, title disputes or claims, and other similar matters. While the Company considers these assumptions to be reasonable based on information currently available to it, they may prove to be incorrect.

Forward looking information involves known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of the Company to be materially different from any future results, performance or achievements expressed or implied by the forward-looking information. Such factors include risks inherent in the construction of mineral deposits, including risks relating to changes in project parameters as plans continue to be redefined including the possibility that mining operations may not be sustained at the Gunnison Copper Project, risks relating to variations in mineral resources and reserves, grade or recovery rates, risks relating to the ability to access infrastructure, risks relating to changes in copper and other commodity prices and the worldwide demand for and supply of copper and related products, risks related to increased competition in the market for copper and related products, risks related to current global financial conditions, risks related to current global financial conditions and the impact of COVID-19 on the Company's business, uncertainties inherent in the estimation of mineral resources, access and supply risks, risks related to the ability to access acid supply on commercially reasonable terms, reliance on key personnel, operational risks inherent in the conduct of mining activities, including the risk of accidents, labour disputes, increases in capital and operating costs and the risk of delays or increased costs that might be encountered during the construction process, regulatory risks, financing, capitalization and liquidity risks, risks related to disputes concerning property titles and interests, environmental risks and the additional risks identified in the "Risk Factors" section of the Company's reports and filings with applicable Canadian securities regulators.

Although the Company has attempted to identify important factors that could cause actual actions, events or results to differ materially from those described in forward-looking information, there may be other factors that cause actions, events or results not to be as anticipated, estimated or intended. Accordingly, readers should not place undue reliance on forward-looking information. The forward-looking information is made as of the date of this news release. Except as required by applicable securities laws, the Company does not undertake any obligation to publicly update or revise any forward-looking information.

To view the source version of this press release, please visit https://www.newsfilecorp.com/release/67862