Updated Mineral Resource Estimates At Guanajuato Mine Complex

VANCOUVER, - Great Panther Mining Limited has completed updated Mineral Resource estimates for its 100%-owned Guanajuato Mine Complex (GMC) in Mexico. These estimates have an effective date of July 31, 2020 and are based on 199 holes totaling 19,913 meters of drilling since the previous Mineral Resource estimate.

GMC is comprised of the Guanajuato and San Ignacio underground mines and the 1,000 tonne-per-day Cata processing plant, located in the prolific Guanajuato mining district.

Highlights: Measured and Indicated (M&I) Mineral Resources contain 10.2 million (M) silver equivalent ounces (Ag eq oz), a 17% increase over the previous 2019 estimate; M&I Mineral Resource grade increased 10% from 180 to 199 grams per tonne silver (g/t Ag); Inferred Mineral Resources contain 18.1M Ag eq oz, more than double the previous estimate; At Guanajuato, Inferred Mineral Resources increased from 2.3M to 6.0M Ag eq oz, reflecting successful exploration efforts in the Los Pozos area; and At San Ignacio, Inferred Mineral Resources increased from 5.9M to 12.1M Ag eq oz, reflecting successful exploration efforts in the Purisima area.

President and CEO Rob Henderson, said, "We are pleased to have completed another productive drilling campaign at GMC, successfully outlining new resources and demonstrating the quality of the orebody. GMC has been in our portfolio since 2005 and has cumulatively produced nearly 30 million silver equivalent ounces for Great Panther. We also expect to report updated reserve and resource estimates at Tucano before year end.”

At San Ignacio, compared to the previous Mineral Resource estimate, inferred tonnage increased 98%, silver grades increased 14%, and Ag eq oz increased 106%. These changes reflect the use of higher metal prices, mine depletion, and expansion and addition of zones in the Purisima vein area due to successful exploration drilling.

Compared to the previous Mineral Resource estimate at Guanajuato, M&I tonnage increased 26%, silver grades increased 22%, and Ag eq oz increased 47%. Inferred tonnage increased 121%, silver grades increased 31%, and Ag eq oz increased 154%. These changes reflect the use of higher metal prices, minor mine depletion, significant changes (up and down) in total operating costs in several mining areas, and expansion of zones at Los Pozos due to successful exploration drilling.

Between August 1, 2019 and July 31, 2020, a total of 23,175 tonnes were mined at Guanajuato.

Since the cut-off date of July 31, 2020 for this Mineral Resource estimate, Great Panther has drilled an additional 63 holes totaling 9,560 meters. Drilling at Guanajuato and San Ignacio is continuing with three underground rigs at Guanajuato (two in the Los Pozos area and one in the Valenciana area), and one surface rig at San Ignacio continuing in-fill and step out drilling along the Purisima vein system.

Great Panther has been working with permitting authorities to expand the capacity of its existing GMC tailings storage facilities (TSF) beyond January 2021. Approval from the environmental permitting authority Secretaría del Medio Ambiente y Recursos Naturales (SEMANART) for expansion of the GMC TSF (lifts 18 and 19) has been received, subject to also receiving approval by the national water authority, Comisión Nacional del Agua (CONAGUA) which is outstanding. In parallel, the Company has been pursuing a permit from SEMANART for a one-meter high center-line raise of the existing embankment of the TSF (lift 17) to extend tailings capacity until April 2021 and provide more time for the receipt of approval from CONAGUA of the lift 18 and 19 expansion. SEMANART has advised Great Panther that its permit application for the one-meter raise on lift 17 will not be approved.

The Company has also been exploring alternatives with its technical consultants and legal advisors for tailings storage to continue processing beyond January 2021, including a review of technical alternatives which utilize existing permits. The technical alternatives under consideration have the potential to extend tailings capacity for two to five months and provide more time for receipt of the pending CONAGUA expansion approval. If the CONAGUA approval of expansion of the TSF has not been received and an alternative tailing storage solution does not get resolved prior to January 2021, the Company may need to cease milling operations at the GMC until receipt of the CONAGUA expansion approval.