Mr. Darren Pylot reports

CAPSTONE TO EXPAND LEACHING AT PINTO VALLEY; 300 TO 350 MIBS OF LOW-COST, COPPER CATHODE PRODUCTION POTENTIAL

Capstone Mining Corp.'s Pinto Valley mine has successfully demonstrated positive economics from enhanced dump leach performance by partnering with Jetti Resources LLC to apply its novel patented catalytic technology at Pinto Valley's existing dump leach operation.

Highlights

During the first year of Capstone's partnership with Jetti, cathode production per area irrigated has doubled. A plan to increase activity is being implemented with the goal of generating strong cash flow from Pinto Valley's underutilized 25-million-pound-per-year solvent extraction and electrowinning (SX-EW) plant, which is currently operating at only 20 per cent of capacity. The plan is to increase cathode production to 300 million to 350 million pounds from residual and high-grade waste over the next two decades, creating 30 new jobs at Pinto Valley.

Darren Pylot, Capstone's president and chief executive officer, said: "The mining industry has long been pursuing a viable technology to leach low-grade chalcopyrite ores. The results after year one of our partnership with Jetti Resources are exciting because it means we can generate high margin from material that would have been waste. This project represents an opportunity to position Pinto Valley more competitively, which will create and sustain jobs, and economic benefits in a socially and environmentally responsible manner."

The engagement of Jetti and utilization of its proprietary technology was an extension of Pinto Valley's existing phase 3 optimization study, which is focused on several low-capital-expenditure, high-impact projects aimed at having a material increase to the net present value of the operation. The PV3 optimization study is scheduled for release in fourth quarter 2020.

Jetti novel catalyst technology

Jetti's patented technology makes it possible to extract copper from low-grade primary sulphides, such as chalcopyrite, the world's most abundant copper mineral ore. Jetti has developed and commercially deployed a catalytic technology that allows for the efficient and effective heap and stockpile leach extraction of copper trapped in these challenging mineral ores. Jetti's catalysts enable the disruption of the sulphur metal bond of the mineral, allowing copper extraction to take place unimpeded. As a result, Jetti is now increasing profitability at operations and extending project life, while also converting uneconomic waste rock into valuable assets.

Mike Outwin, Jetti Resources co-founder and chief executive officer, said: "Pinto Valley was a perfect candidate to pioneer our breakthrough technology given the abundance of copper resources available for leaching and the underutilized plant and infrastructure in place. Our technology has integrated seamlessly with the existing infrastructure on site, and we have doubled the production of copper cathode per area irrigated within one year of our partnership. We are excited to partner with Capstone to realize more economic value from their vast copper resource in Arizona and possibly other projects in the Americas."

In 2019, Jetti started deploying its novel catalytic technology at Pinto Valley's leach operation and, one year later, has now doubled copper cathode production per area irrigated.

Pinto Valley's cathode production history

Pinto Valley started producing copper cathode in 1981 from material below the cut-off grade of its mill that had been stockpiled since the early 1970s. This provided a 12-per-cent to 15-per-cent boost to total copper production as cathode accounted for an average of 16 million pounds per annum through to the early 2000s. Since then, the production of copper cathode has decreased consistently to under four million pounds per annum due to the impact of reduced leach kinetics as chalcopyrite is subjected to a passivation layer inhibiting further breakdown.

Next steps

As a result of the positive commercial demonstration phase, Pinto Valley intends to significantly expand leaching activity, targeting approximately 280 million to 300 million tonnes of historic leach stockpile and 175 million to 185 million tonnes of high-grade waste already scheduled for removal over the remaining 19 years of mine life. Potential to increase the mill cut-off grade to bolster copper concentrate production, thereby increasing the tonnage of high-grade waste available for leaching, will be studied during the second half of 2020. An updated National Instrument 43-101 technical report is expected in 2021.

The solvent-extraction-electrowinning (SX-EW) plant is currently only 20 per cent utilized.

A total of 11 million to 12 million tonnes of high-grade waste have been placed since early 2019 and by the end of 2022, approximately 48 million to 52 million tonnes are expected to be under irrigation.

About Capstone Mining Corp.

Capstone Mining is a Canadian base metals mining company, focused on copper. The company's two producing mines are the Pinto Valley copper mine located in Arizona, United States, and the Cozamin copper-silver mine in Zacatecas state, Mexico. In addition, Capstone has a large-scale, fully permitted, 70-per-cent-owned copper-iron-gold Santo Domingo project in Region III, Chile, in partnership with Korea Resources Corp., as well as a portfolio of exploration properties. Capstone's strategy is to focus on the optimization of operations and assets in politically stable, mining-friendly regions, centred in the Americas.

Compliance with NI 43-101

Unless otherwise indicated, Capstone has prepared the technical information in this news release based on information contained in the technical reports and news releases available under Capstone Mining's company profile on SEDAR. Each disclosure document was prepared by or under the supervision of a qualified person as defined in National Instrument 43-101 -- Standards of Disclosure for Mineral Projects of the Canadian Securities Administrators. For readers to fully understand the information in this news release, they should read the technical reports in their entirety, including all qualifications, assumptions and exclusions that relate to the information set out in this presentation which qualifies the technical information. Readers are advised that mineral resources that are not mineral reserves do not have demonstrated economic viability. The disclosure documents are each intended to be read as a whole, and sections should not be read or relied upon out of context. The technical information is subject to the assumptions and qualifications contained in the disclosure documents. For further details refer to the company's NI 43-101 technical reports for Pinto Valley mine life extension -- phase 3 (PV3) prefeasibility study, Miami, Ariz., published Feb. 23, 2016, effective Jan. 1, 2016.

The technical information in this presentation has been prepared in accordance with NI 43-101 and reviewed and approved by Colleen Roche, Capstone Pinto Valley's manager, operations support, a qualified person as defined in NI 43-101.

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