Doré Copper Announces its Preparation Plans to Dewater the Former Joe Mann Gold Mine and Cedar Bay Copper-Gold Mine

• First water sampling tests indicate good results
  

TORONTO, March 05, 2021 (GLOBE NEWSWIRE) -- Doré Copper Mining Corp. (the "Corporation" or "Doré Copper") (TSXV: DCMC; OTCQB: DRCMF; FRA: DCM) is pleased to announce its preparation plans for the dewatering of the former Joe Mann and Cedar Bay mines which closed in 2007 and 1990, respectively.

The Company recently conducted water sampling tests down each shaft which returned positive results:

Cedar Bay Mine Sampling (November 2020):
The Cedar Bay mine ceased operations in 1990 after having produced 3.9 million tonnes (Mt) of ore grading 1.63% Cu and 3.21 g/t Au.

Water was sampled down the shaft every 100 meters down to the deepest development level of 760 meters for a total of seven samples. Video inspection of the shaft indicated no deformation with rails intact and in place. The average pH was 6.52, mildly acidic or near neutral (pure water has a pH of 7.0). Heavy metals were low in concentration with many metals below detection limits. The characterization demonstrated the presence of dissolved solids that will also need to be considered in the selection of the water treatment system for dewatering.

Joe Mann Mine Sampling (February 2021):
The Joe Mann mine ceased operation in 2007 after having produced 1.2 million ounces of gold (4.75 Mt of ore grading 8.26 g/t Au and 0.25% Cu).

Water was sampled down the shaft every 100 meters down to the deepest development level of 1,150 meters for a total of 12 samples. Video inspection indicated that the shaft is in excellent condition. The average pH was 7.35, indicating a slightly basic water chemistry. Heavy metals were low in concentration with many metals below detection limits. Copper and zinc concentrations were below detection limits in the majority of the samples. The characterization also demonstrated the presence of dissolved solids in this shaft, which will have to be considered in the choice of the water treatment system.

Ernest Mast, President and CEO, stated: “We are greatly encouraged by the good condition of the shafts and benign water characteristics in both mines. Following completion of the dewatering assessment, we will be in a position to make a decision on the dewatering of these mines. The dewatering would provide Doré Copper underground access to the lowest levels of the mines and accelerate our exploration and development timeline while lowering our drilling costs and improving drilling accuracy.”