Challenger Gold Limited (ASX: CEL) ('CEL', or the 'Company') is pleased to report that the final phase of metallurgical testwork required for the full-scale PFS at the Hualilan Gold Project is now underway, following the completion of a highly successful column leach test program.
This involves Sequential Flotation grind optimisation tests and associated flotation tails leach ('FTL') testing at various grind sizes, a PFS level comminution testing program, and large diameter Column Leach testing to allow final scale-up of the recent column tests results to PFS level. The entire program is on track for completion early in Q4 this year. The column leach testwork program produced outstanding results. Average recoveries of 75% (gold) and 41% (silver) compare favorably on the world stage. Additionally, these recoveries were achieved at a half inch crush size and relatively low cyanide consumption. The testwork confirms the potential of a heap leach processing route for the low-grade mineralization at Hualilan, offering a transformative opportunity to significantly expand the scale and economics of the Hualilan Project.
Managing Director, Kris Knauer commented: 'These final stages of metallurgical testwork mark a major milestone as we move toward delivery of a full-scale PFS for Hualilan. The outstanding heap leach results confirm the viability of processing low-grade material that was previously excluded from economic evaluation. This could materially enhance the scale, economics and development pathway for Hualilan, positioning it as a standout gold project in Argentina.'
Challenger Gold Limited (ASX: CEL) ('CEL', or the 'Company') is pleased to report that the final phase of metallurgical testwork required for the full-scale PFS at the Hualilan Gold Project is now underway, following the completion of a highly successful column leach test program. This involves Sequential Flotation grind optimisation tests and associated flotation tails leach ('FTL') testing at various grind sizes, a PFS level comminution testing program, and large diameter Column Leach testing to allow final scale-up of the recent column tests results to PFS level. The entire program is on track for completion early in Q4 this year. The column leach testwork program produced outstanding results. Average recoveries of 75% (gold) and 41% (silver) compare favorably on the world stage. Additionally, these recoveries were achieved at a half inch crush size and relatively low cyanide consumption. The testwork confirms the potential of a heap leach processing route for the low-grade mineralization at Hualilan, offering a transformative opportunity to significantly expand the scale and economics of the Hualilan Project.
Column Testwork Program
Challenger initiated a phased column leach testwork program to assess the viability of heap leaching for low-grade mineralization at the Hualilan Gold Project in San Juan, Argentina. This material - primarily located in the broad mineralized halo surrounding the high-grade core - had not been evaluated for inclusion in the high-grade Scoping Study released in November 2023. The goal was to determine whether the low-grade envelope could support an economically viable recovery pathway through lowcapex, large-scale heap leaching. The initial program, Panel 1, involved two composite samples crushed to 1/4 inch and subjected to standard 90-day column leach protocols. The tests returned encouraging gold recoveries of 64.6% and 48.9%, with silver recoveries of 61.4% and 57.5%, respectively. These results demonstrated sufficient promise to expand the metallurgical program and proceed with detailed follow-up testing.
Following receipt of the Panel 1 results, CEL commenced Panel 2, comprising 11 column tests focused on understanding the impact of lithology (dacite, lutite, and calcite) and gold grade on recovery. All samples were crushed to 1/4 inch and run for 90 days. Extensive assay-by-size testwork was also completed in parallel to determine gold deportment across particle size fractions. The results showed that both dacite and lutite returned strong recoveries, even at low head grades. The calcite-rich material showed weaker performance, particularly at lower grades, however the calcite hosted mineralisation only represents a small component (10%) of the overall lower-grade mineralization. Gold recoveries in dacite ranged from 66.0% to 86.5% across grades of 0.15-0.94 g/t Au, while lutite returned recoveries of 64.1% to 91.1% across grades of 0.18-0.81 g/t Au. Significantly, even at grades below 0.2 g/t Au, recoveries exceeded 60%, confirming the leachability of these material types at grades previously considered uneconomic.
Column Leach Tests
Column leach testing is an industry-standard methodology used to simulate full-scale heap leach operations. Typically conducted over a 90-day period, the test involves stacking ore in vertical columns and percolating a leaching solution through the material to estimate gold and silver recoveries. These tests provide essential data on ore leachability, metal recovery rates, and the efficiency of the leaching process, supporting the design of large-scale, economically viable heap leach pads
Heap Leaching in Argentina Heap leaching is a well-established and widely accepted processing method in Argentina, and particularly in San Juan Province. Existing operations such as Veladero (Barrick Gold) and Gualcamayo (Minas Argentinas S.A.) successfully use heap leaching for gold recovery. The recently submitted Environmental Impact Assessment for McEwen Copper's Los Azules project also includes a copper heap leach component. Additional heap leach operations include Fortuna Silver's Lindero mine in Salta and Cerrado Gold's Minera Don Nicolas in Santa Cruz, highlighting the regulatory and operational acceptance of this technology across Argentina's key mining jurisdictions.
Contact:
Kris Knauer
Chairman
Tel: +61 411 885 979
Email: kris.knauer@challengergold.com
FORWARD LOOKING STATEMENTS
The announcement may contain certain forward-looking statements. Words 'anticipate', 'believe', 'expect', 'forecast', 'estimate', 'likely', 'intend', 'should', 'could', 'may', 'target', 'plan', 'potential' and other similar expressions are intended to identify forward-looking statements. Indication of, and guidance on, future costings, earnings and financial position and performance are also forward-looking statements. Such forward looking statements are not guarantees of future performance, and involve known and unknown risks, uncertainties and other factors, many of which are beyond the control of Challenger Gold Ltd, its officers, employees, agents and associates, which may cause actual results to differ materially from those expressed of implied in such forward-looking statements. Actual results, performance, or outcomes may differ materially from any projections or forward-looking statements or the assumptions on which those statements are based. You should not place any undue reliance on forward-looking statements and neither. Challenger nor its directors, officers, employees, servants or agents assume any responsibility to update such information. The stated Production Targets are based on the Company's current expectations of future results or events and should not be relied upon by investors when making investment decisions. Further evaluation work and appropriate studies are required to establish sufficient confidence that this target will be met. Financial numbers, unless stated as final, are provisional and subject to change when final grades, weight and pricing are agreed under the terms of the offtake agreement.
The Company confirms that the form and context in which the Competent Person's findings are presented have not been materially modified from the original market announcements.
(C) 2025 Electronic News Publishing, source ENP Newswire