82.6% Copper Recovery Backs Fitzroy's Heap Leach Plan for Buen Retiro

• Mini-column testing of Buen Retiro's 3 principal ore types returned total copper recoveries of 71.8% for high-grade oxide, 59.9% for low-grade oxide and 82.6% for mixed material after 21 days of leaching.
• Net acid use ran from 3.4 to 11.2 kilograms of acid for each kilogram of copper recovered.
• Preliminary results from the ongoing 1-meter column tests are running above the mini-column figures and point to recoveries after 70 days of approximately 95% for mixed material, 85% for high-grade oxide and 74% for low-grade oxide.
• Industrial recovery is typically derived by multiplying those column figures by a scaling factor between 0.8 and 0.9.
• Adding chloride, both to the ore before leaching and to the leach solution, lifted copper recoveries by 3 to 5 percentage points in both oxide types at similar acid consumption.
• Hardness testing returned Bond Work Indices below 8 kilowatt hours per metric ton, which indicates soft material, with medium-to-moderate abrasivity.

Company Overview

Fitzroy Minerals (TSXV: FTZ | OTCQX: FTZFF | FSE: C3Y) is a copper-focused exploration and development company with assets in the Americas. Its portfolio includes the Buen Retiro Copper Project near Copiapó, Chile; the Caballos Copper and Polimet Gold-Copper-Silver projects in Valparaiso, Chile; the Taquetren Gold Project in Rio Negro, Argentina; and the Caribou Project in British Columbia, Canada.

The Test Program at Buen Retiro

SGS Laboratories is running the first phase of metallurgical test work at Buen Retiro in Chile, to establish how the deposit responds to heap leaching. The work supports the heap leach development plan Fitzroy is preparing.

Buen Retiro's mineralization is split into 3 principal ore types by grade and mineralogy: high-grade oxide, carrying total copper of 0.5% or more; low-grade oxide, between 0.2% and 0.5%; and mixed material, marked by tenorite, cuprite, native copper, chalcocite and green oxides. Composites of the 3 types went to the laboratory in Santiago, part of 3,341 kilograms submitted for 208 tests.

The program proceeds in stages, narrowing the variables carried forward at each one: 45 tests holding acidity constant, 66 tests of acid pretreatment, 55 mini-column tests, 30 in 1-meter columns and 12 in 3-meter columns. Ten mini-column tests are complete, alongside hardness, abrasivity and mineralogical testing.

Mini-Column Results

The mini-column campaign is complete, with a closed metallurgical balance: the copper going into each test is fully accounted for against the copper coming out. Head grades were 0.95% total copper for the high-grade oxide, 0.35% for the low-grade oxide and 1.24% for the mixed material. Carbonate content was relatively low across all 3, at 0.13%, below 0.05% and 0.44%.

At 21 days of leaching, under the best conditions tested for each ore type, total copper recoveries reached 71.8%, 59.9% and 82.6% respectively, at acid consumptions of 4.9, 11.2 and 3.4 kilograms for each kilogram of copper recovered. Duplicate tests returned copper extractions within 1 percentage point of one another, with no duplicate yet for the mixed material. Recovery followed 2 stages in all 3 ore types: a fast stage from the more soluble oxidized copper minerals, then a slower stage from more stubborn forms such as copper in iron oxides. Curves were still rising at 21 days, and the company is targeting further gains from a longer leach.

President and Chief Executive Officer of Fitzroy Minerals, Merlin Marr-Johnson, puts the recovery figures against the acid the tests consumed to reach them:

"These results exceed what we were hoping for from our first phase of metallurgical testing at Buen Retiro. Final copper recoveries of up to 82.6%, achieved with low acid consumption and excellent reproducibility across three separate Units in just 21 days, give us real confidence in the heap-leach case for the Project."

Acid use also shapes which ore types gain most from a longer leach.

Chloride Addition & Acid Consumption

Acid consumption leaves room to extend the leach cycle and potentially lift copper recovery above 75% for the high-grade oxide and mixed types, which are most of the resource. The low-grade oxide type showed a higher specific acid consumption, which limits the benefit of a longer leach there.

Adding chloride, as salt during agglomeration, the stage where crushed ore is bound into clumps, and in the leach solution, improved copper recoveries by 3 to 5 percentage points in both oxide types at similar acid consumption. Fitzroy has identified it as a way to optimize the flowsheet.

For the mixed material, raising the agglomeration acid dose from 15 to 30 kilograms for each metric ton of ore lifted recovery by 2 to 4.5 percentage points, at the cost of higher acid use. At a constant acid dose, raising the chloride concentration in the leach solution from 60 to 90 grams per liter improved extraction by a further 3 percentage points, from 79% to 82%.

The 1-Meter Column Tests

Six 1-meter columns are in leach, 2 of each ore type, at a coarser crush than the mini-columns. As of September 23, 2026 the oxide columns had 68 days of cumulative leaching and the mixed columns 53 days. The metallurgical balance for these tests is not yet closed, so the results are preliminary.

The best-performing column of each ore type uses the salt-in-agglomeration and chloride-in-leach conditions intended for plant scale. On that basis, chloride leaching is trending toward preliminary recoveries of 85% for high-grade oxide, 74% for low-grade oxide and approximately 95% for mixed material. Reaching an expected industrial recovery means multiplying those figures by a scaling factor between 0.8 and 0.9.

At the same 21-day leach time and equivalent conditions, the 1-meter columns are modestly below the mini-column figures, consistent with their coarser crush and the smaller volume of solution applied to each metric ton of ore. Once leaching runs well past 21 days, they already exceed the mini-columns' final 21-day recoveries. For copper oxide, leach time appears to count for more than solution volume, so the plant will be designed for enough residence time on the heap to reach the target recovery.

Hardness & Abrasivity

Hardness testing on samples from the Buen Retiro pit returned Bond Work Indices below 8 kilowatt hours per metric ton, a measure of the energy needed to crush rock. Those values indicate soft material. That implies lower energy use at the crushing stage and less demand on crushing equipment.

Abrasivity indices for the same rock types fall in a medium-to-moderate range, which suggests wear on crusher liners, screens and conveyors should be manageable under standard maintenance. Measured densities came in above industry norms for comparable deposits, the massive-iron rock type averaging 3.67 grams per cubic centimeter.

Next Steps

Leaching continues on those 6 columns, with metallurgical balances due at the end of September 2026. Fitzroy is targeting mid-December 2026 for the full 1-meter column campaign, 30 columns in total. Testing in 3-meter columns, representative of industrial-scale operation, and run-of-mine column testing are due to begin in early November 2026 or earlier.

The overall test campaign and final report are targeted for completion by March 1, 2027. Those results feed into the pre-feasibility study (PFS) for Buen Retiro, planned for release in the second quarter of 2027.

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