Fitzroy Minerals Inc. (TSXV: FTZ, OTCQX: FTZFF, FSE: C3Y) has released results from the initial phase of metallurgical test work at its Buen Retiro Copper Project near Copiapo, Chile. The testing, conducted by SGS Laboratories, evaluated the response of three principal geometallurgical units to heap-leach processing. The results indicate strong potential for heap-leach development, with copper recoveries reaching up to 82.6% in mini-column tests and preliminary larger-scale results trending higher.
The mini-column testing, which is the first stage of column-based testing, confirmed favorable heap-leach response across all three units: high-grade oxide, low-grade oxide, and mixed. Total copper recovery after 21 days reached 71.8% for high-grade oxide, 59.9% for low-grade oxide, and 82.6% for mixed material. Net acid consumption was low-to-moderate, ranging from 3.4 to 11.2 kg/kg, and test reproducibility was excellent, with duplicate tests returning copper extractions within 1 percentage point. The company provided detailed results in Table 1: Total Cu recovery and acid consumption by UGM, mini-columns, 21 days of leaching (closed data). and Table 2: Duplicate results of CuT extraction at 21 days of leaching, mini columns (closed).
More encouraging are the preliminary results from the ongoing 1-metre column tests, which are trending above the mini-column figures. Projections of the trend lines indicate column recoveries after 70 days of approximately 95% for mixed material, 85% for high-grade oxide, and 74% for low-grade oxide. To estimate industrial copper recovery, these results should typically be multiplied by a scaling factor between 0.8 and 0.9. The recovery trends are illustrated in Figure 2. Copper recovery of Chloride Leach Samples after 68 and 53 days (trends projected to 75 days), head analysis, and a comparison of mini-column and 1-metre column results is provided in Table 3: Comparison of CuT extraction at 21 days of leaching, mini-columns (closed) vs. 1-metre columns (in progress), under equivalent treatment conditions.
Merlin Marr-Johnson, President and CEO of Fitzroy, commented, “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. Even more encouraging is that the more representative, one-metre columns are trending higher, pointing towards a final recovery of 95% after 75 days of leaching, for the Mixed material.”
The addition of chloride during agglomeration and leaching was identified as an opportunity to optimize copper recovery and acid consumption, improving recoveries by 3 to 5 percentage points in both oxide units. Additionally, favorable rock hardness, with Bond Work Indices below 8 kWh/t, and medium-to-moderate abrasiveness suggest lower energy requirements and predictable wear on equipment, which will positively impact the design of the crushing circuit.
This news is significant for Fitzroy Minerals as it materially de-risks the path toward heap-leach production at Buen Retiro. The positive metallurgical results support the company’s planned Heap Leach Development Plan and provide a solid technical basis for advancing the project. The next steps include closing out the 1-metre column balances by the end of September 2026, starting 3-metre column testing in November 2026, and reporting final metallurgical results by March 1, 2027. These results will feed into the Pre-Feasibility Study (PFS) planned for release in Q2 2027. For the mining industry, these results highlight the potential of chloride-assisted heap leaching to enhance copper recoveries, which could be applicable to similar oxide and mixed deposits globally. The full release is available on www.newmediawire.com.
