Mr. Ernest Mast reports

DORE COPPER REPORTS EXCELLENT CONCENTRATE GRADES AND RECOVERIES WITH LOW IMPURITY ELEMENT CONCENTRATIONS FROM FLOTATION TESTS AT ITS CORNER BAY PROJECT

Dore Copper Mining Corp. has released positive flotation test results at its flagship Corner Bay high-grade copper-gold project located approximately 55 kilometres by road from the corporation's Copper Rand mill, near Chibougamau, Que. This metallurgical test program is part of the work that is designed to support completion of a feasibility study for the implementation of a hub-and-spoke operation model.

Key highlights from lock cycle flotation tests:

• Excellent copper recoveries of 98.2 per cent and 96.8 per cent from a representative composite sample;
• High-quality copper concentrate grades results of 27 per cent and 29.6 per cent.

The results are an improvement over the figures included in the May, 2022, preliminary economic assessment (PEA), where the flotation recoveries for copper were 96.7 per cent and the copper concentrate grade was 23.7 per cent. All metallurgical tests completed to date support the effectiveness of utilizing ore sorting technology to improve the mill feed grade and reduce the mill feed tonnage resulting in a high-quality salable copper concentrate.

Ernest Mast, president and chief executive officer, stated: "These flotation test results validate the favourable mineralogy of the Corner Bay deposit for high-performance ore sorting technology and conventional flotation to produce a high-quality copper concentrate containing low levels of deleterious metals. These figures demonstrate the robust nature of the processing plant flowsheet that will be used in the feasibility study."

Metallurgical test work program summary

Base Metallurgical Laboratories Ltd. in Kamloops, B.C., was commissioned to complete Corner Bay metallurgical development and locked cycle flotation testing in support of the feasibility study.

A total of 34 diamond drill holes were used to create a spatially diverse composite sample (the CBSP composite) that intersected copper mineralized zones within the Corner Bay mineral resource estimate. The core material selected represented different rock types: semi- and massive sulphides, quartz veins, diorite dike, and fresh and altered anorthosite. The drill core was sampled by cutting a quarter split NQ core.

The CBSP composite was firstly compiled into a 202-kilogram sample with a grade of 2.20 per cent Cu. The CBSP composite was then processed through the Steinert ore sorter and mixed with 26 per cent of the unsorted underflow bypassed mineralized material to represent an overall sorted preconcentrate mineralized material product. The CBSP composite resulted in a 123-kilogram sample with a grade of 3.31 per cent Cu.

The composite sample was evaluated through lock cycle tests to determine the flotation metallurgical performance. The sample was prepared to a nominal grind size of 140 microns K80 in the rougher testing and then processed through a regrind size of approximately 37 microns K80 in the cleaner tests. The sample responded consistently throughout the test work with excellent performance to conventional flotation processing methods and reagents. Two locked cycle tests were completed with varying retention times to determine the concentrate grade versus recovery. The tests resulted in concentrate grades of 27 per cent Cu and 29.6 per cent Cu and recoveries 98.2 per cent and 96.8 per cent, respectively.

Minimal amounts of deleterious elements (such as arsenic, antimony, bismuth, cadmium etc.) were present in the concentrate, indicative of the clean nature of the concentrate. These results showed the highly commercial quality of the concentrate in terms of salability and payment terms of smelters.

Technical disclosure

All metallurgical test work referenced in this news release was completed by Base Metallurgical Laboratories, based in Kamloops, B.C., Canada.

Commercial certified standard material and blanks were inserted by BML into the sample chain accounting for 10 per cent of the samples as part of the quality assurance and quality control (QA/QC) program.

Qualified person

Mr. Mast, PEng, president and CEO of the corporation, and a qualified person within the meaning of National Instrument 43-101 -- Standards of Disclosure for Mineral Projects, has reviewed and approved the scientific and technical information contained in this news release.

About Dore Copper Mining Corp.

Dore Copper Mining aims to be the next copper producer in Quebec with an initial production target of over 50 million pounds of copper equivalent annually by implementing a hub-and-spoke operation model with multiple high-grade copper-gold assets feeding its centralized Copper Rand mill1. The company delivered its PEA in May, 2022, and is proceeding with a feasibility study.

The company has consolidated a large land package in the prolific Lac Dore/Chibougamau and Joe Mann mining camps that has historically produced 1.6 billion pounds of copper and 4.4 million ounces of gold. The land package includes 13 former0producing mines, deposits and resource target areas within a 60-kilometre radius of the company's Copper Rand mill.

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