Collective Mining Ltd. (Nasdaq: CNL; TSX: CNL) is advancing a two-route processing flowsheet for the Apollo deposit at its Guayabales Project in Caldas, Colombia. Most of the material would go through a conventional gravity and cyanidation plant producing gold-silver doré. Copper-rich and tungsten-rich material from two defined sub-domains would be routed to separate flotation circuits producing their own concentrates. The company outlined the design in a September 21, 2026, release that also reported new Copper Sub-Domain test results and head grades for the Tungsten Sub-Domain samples. Collective is working toward an environmental license application in the second half of 2027.

The flowsheet follows the company’s maiden Mineral Resource, published September 8, 2026. That estimate put Apollo at 37.0 million tons Indicated grading 2.17 grams per ton (g/t) gold equivalent (AuEq), or 2.58 million ounces AuEq, plus 48.2 million tons Inferred at 1.83 g/t AuEq, or 2.83 million ounces AuEq. The new work addresses how gold, silver, copper and tungsten would be recovered from different parts of the deposit.

Why Two Routes

According to the company, the broader deposit is predominantly gold and silver with low copper and tungsten grades, while higher-grade copper and tungsten mineralization is concentrated in two defined sub-domains. Outside the Copper Sub-Domain, copper averages 0.04% in the Indicated portion of the Mineral Resource and 0.02% in the Inferred portion. Material with low copper and low tungsten grades would go through gravity recovery and cyanidation to produce doré.

The Copper Sub-Domain holds 10.2 million tons of Indicated material grading 0.41% copper, 1.25 g/t gold, 56.0 g/t silver and 0.022% tungsten trioxide (WO₃), or about 27.6% of total Indicated tonnage. It also contains 0.81 million tons of Inferred material at 0.37% copper, 1.7% of the Inferred category. Higher-grade Copper Sub-Domain material would feed a copper flotation circuit making a concentrate with gold and silver credits. The flotation tailings would then be sent to cyanidation to recover the remaining gold and silver.

The Tungsten Sub-Domain is much smaller. It holds 2.57 million tons Indicated grading 0.10% WO₃, 1.38 g/t gold, 39.1 g/t silver and 0.39% copper, or 6.9% of Indicated tonnage, plus 0.05 million tons Inferred at 0.20% WO₃. A front-end gravity stage would separate tungsten-rich material for treatment in what the company calls a “small, dedicated” circuit using gravity concentration and flotation. Gold, silver and copper in that material would be separated and directed to the main processing circuit.

The two sub-domains are not mutually exclusive and may overlap, and Collective says their tonnages should not be added to each other or to the overall Mineral Resource because doing so could double-count material. The company describes both as subsets of the open-pit Mineral Resource and says it expects copper and tungsten production to come mainly from them.

Cross-section of the Apollo Mineral Resource open pit showing the higher-grade Copper Sub-Domain. (Figure courtesy Collective Mining)

The Test Results

All metallurgical samples were prepared and analyzed at the Kamloops, British Columbia, laboratory of ALS Canada Ltd. Composites came from the remaining half drill core of 32 Apollo holes. According to the company, ALS Canada conforms to ISO/IEC 17025, and the Kamloops laboratory is accredited by the Standards Council of Canada for the specific tests in the program.

The master composite results were first reported on August 25, 2026. That composite was built from drill core taken across roughly the top 1,000 meters of the deposit. The copper composite and the tungsten test samples were sourced specifically from their respective sub-domains. Earlier gold recovery work on the Apollo system, done before the deposit had a formal resource estimate, was covered by Finance Colombia.

The resource estimate’s gold-equivalent calculation assumes recoveries of 95% for gold, 92% for silver, 85% for copper and 70% for WO₃. The Copper Sub-Domain figures come from open-circuit testing. Locked-cycle testing of that material is the next step in the company’s metallurgical program.

“The higher-grade copper and tungsten sub-domains which are contained mostly within the Open Pit portion of the mineral resource will be selectively routed through dedicated flotation concentrate circuits designed to recover those metals.”

— Ned Jalil, chief executive officer, Collective Mining

Chief Executive Officer Ned Jalil, who approved the release’s technical information as a Qualified Person under Canada’s National Instrument 43-101, said the majority of the Mineral Resource “will be processed through a conventional cyanidation circuit with low reagent consumption to produce gold and silver doré.” He added: “The test work completed to date strongly supports this approach, and we are now optimizing the integrated flowsheet as we advance toward our planned 2027 licensing submission in Colombia.” Collective named Jalil chief executive in April 2025, with Omar Ossma remaining president.

What Comes Next

The next phase of metallurgical work will include locked-cycle testing of higher-grade Copper Sub-Domain material, variability testing and optimization of the tungsten circuit. The goal is to confirm circuit configuration, recoveries, reagent requirements and concentrate specifications. Collective says the final flowsheet design and performance parameters depend on completing the metallurgical and engineering programs.

Collective laid out the following milestones, among others, with the resource estimate:

• construction of an underground exploration adit starting in the fourth quarter of 2026
• an environmental license application in the second half of 2027
• an updated resource estimate in the first quarter of 2028
• a Preliminary Economic Assessment and an expected license decision in the second half of 2028
• a Feasibility Study by mid-2029
• the start of early works and construction in the second half of 2029

Executive Chairman Ari Sussman said at the time that the company was accelerating environmental baseline, engineering and permitting studies alongside exploration. In the same release, he stated: “Our priority is to grow the resource and establish the technical and environmental basis for development, subject to study results, financing and the required approvals.”

Collective says it has drilled more than 42,000 meters at Apollo since the March 31, 2026, database cut-off used for the maiden estimate, and none of that drilling is included in the current Mineral Resource. The September 8 release lists hole APC-162, announced on June 29, 2026, among selected drill results not included in the Mineral Resource. APC-162 returned 27.35 meters grading 1.68% WO₃, 11.62 g/t gold, 54 g/t silver and 0.43% copper from 336.40 meters downhole, which the company expresses as 2.51% WO₃ equivalent. Finance Colombia reported the intercept at the time. The company’s tungsten cross-section places the intercept below the modeled Tungsten Sub-Domain and labels it “Not included in MR.”

Cross-section of the Apollo Mineral Resource open pit showing the higher-grade Tungsten Sub-Domain and the APC-162 intercept, which is not included in the Mineral Resource. (Figure courtesy Collective Mining)

Resource Context and Caveats

The Indicated Mineral Resource contains 1.64 million ounces of gold, 29.0 million ounces of silver, 115 million pounds of copper and 3,887 tons of WO₃. The Inferred Mineral Resource adds 2.47 million ounces of gold, 13.0 million ounces of silver, 32 million pounds of copper and 1,081 tons of WO₃. The gold-equivalent calculation assumes gold at $3,000 USD per ounce, silver at $60 USD per ounce, copper at $5.25 USD per pound and WO₃ at $93.31 USD per pound.

The estimate is classified under the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Definition Standards. The company notes that Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability, and that the conceptual pit shell and underground shapes used to constrain the estimate are not engineered mine designs or an economic study.

Location and Background

The Apollo deposit lies about 1.75 kilometers northwest of the Marmato mine operated by Aris Mining (NYSE: ARIS; TSX: ARIS). Collective has secured additional mining titles at the project following public hearings in Supía and Marmato. According to the company, its founding team previously developed Continental Gold, which Sussman says discovered the Buriticá deposit in Antioquia. Zijin Mining Group (SSE: 601899; HKEX: 2899) agreed to acquire Continental Gold in a transaction announced December 2, 2019, with a total equity value of approximately $1.4 billion CAD on a fully diluted basis.

Headline photo: A Collective Mining team member examines a rock sample with a hand lens as two others look on. (Photo courtesy Collective Mining)