Gunnison Copper Corp (TSX:GCU, OTCQB:GCUMF) announced new results from the ongoing High-Value-Add Work Program evaluating the commercial potential of limestone occurring within the planned Gunnison Open Pit mine plan in Arizona.
The sampling involved three historical drill holes and whole-rock analysis (XRF and ICP-MS) was completed on 883 feet of limestone core, representing about 39% of the total logged limestone in these holes.
The multi-asset, pure-play copper developer and producer said the evaluation indicates that a substantial portion of the limestone, material that is currently scheduled as waste in the mine plan, is suitable for a range of industrial end-use markets, including cement, agricultural lime, and premium paper filler/paint and coatings, which could create new by-product revenue for the company.
"These initial results suggest a significant opportunity to unlock value from material previously categorized as waste, with potential to supply cement, agricultural lime, and premium filler markets," Roland Goodgame, Gunnison Copper’s senior vice president, business development, said in a statement.
"As part of our High-Value-Add Work Program, this limestone evaluation could enhance project economics by diversifying revenue and reducing waste handling, and we intend to integrate these findings into our updated PEA (preliminary economic assessment) expected in Q1 2026, with PFS (pre-feasibility study) work already underway."
Gunnison Copper noted that 96% of the analyzed limestone meets industrial specifications for several saleable products.
The company added that about 21% of the analyzed material met indicative thresholds for premium paper filler/coating and high-brightness paint/coatings applications.
Going forward, Gunnison Copper said it will expand sampling coverage beyond the initial 883 feet to improve statistical confidence across the planned open pit area.
It will also conduct specification-based test work, for factors such as brightness/whiteness indices and grindability, aligned to cement, agricultural-lime, and premium filler/paint product standards.
In addition, Gunnison will develop an advance mine plan and materials-handling trade-offs (selective mining, in-pit stockpiling, on-site sizing) to define practical pathways to market.
The company said it will also evaluate logistics, permitting, and commercialization options, including potential marketing partnerships and offtake discussions, for incorporation into the updated PEA and the PFS scope.
Investors reacted positively, sending Gunnison's Canadian-listed stock over 5% higher on Friday morning in Toronto.