Chesapeake Gold Reduces Metates Oxidation Time While Maintaining Precious Metal Recoveries

• The Massive Intrusive domain achieved 70% gold and 61% silver recovery over 90 days of oxidation, compared with 240 days in Phase II.
• The Intrusive Breccia domain reached 57% gold and 60% silver recovery over 180 days, nearly double Phase I results over the same period.
• High Pressure Grinding Roll (HPGR) crushing increased gold recovery by 16% to 47% and silver by 23% to 65% compared with conventional crushing.
• Silver recovery rose from 50% to 55% in Phase II to approximately 60% under the new test procedures.
• The number of projects taking part in the heap oxidation technology testwork has increased to six.

Chesapeake Gold Corp. (TSXV:CKG) is a Canada-based company whose flagship asset is the Metates Project in Durango State, Mexico, one of the largest undeveloped gold-silver deposits in the Americas. Metates contains 16.77 million ounces of gold at 0.57 grams per tonne (g/t) and 423.2 million ounces of silver at 14.3 g/t in the Measured and Indicated categories (the higher-confidence resource classifications), with a further 2.13 million ounces of gold and 59.0 million ounces of silver in the Inferred category. Chesapeake is also developing a proprietary heap oxidation technology, a process that breaks down the sulphide minerals holding the gold and silver while the ore sits on a leach pad, so the metals can then be recovered.

Phase III Testwork Delivers Faster Oxidation With Comparable Recoveries

The Phase III variability programme introduced new procedures designed to better simulate actual mine operations. The Massive Intrusive domain, which represents the majority of the future mine plan, returned 70% gold and 61% silver recovery over a 90-day oxidation phase, compared with 240 days in Phase II and 180 days in Phase I. These recoveries were broadly similar to Phase II but were achieved in nearly a third of the time, while silver recovery doubled compared with Phase I.

The same procedure was applied to the Intrusive Breccia domain, a smaller zone above the Massive Intrusive that hosts similar grades. Over a 180-day oxidation phase, recoveries reached 57% for gold and 60% for silver, nearly doubling Phase I results over the same period and exceeding Phase II results over a shorter time frame.

Chief Executive Officer Jean-Paul Tsotsos said:

"The first results from the third phase of Metates' metallurgical testing highlight several significant advances through our variability program, including the ability to maintain and improve precious metals recoveries while reducing oxidation times."

A shorter oxidation phase is expected to reduce Metates' capital and operating costs and lower working capital requirements during mine ramp-up.

HPGR Crushing Shows Potential to Lift Baseline Recoveries

Chesapeake compared conventional crushing with an HPGR system, which crushes rock by pressing it between two rollers under high pressure. Using direct cyanidation (leaching without the oxidation step), HPGR-crushed material increased gold recovery by 16% to 47% and silver recovery by 23% to 65%.

The results indicate the potential to raise baseline recoveries before heap oxidation is applied. Silver was a particular focus of Phase III, and a potential 15% increase in silver recovery is expected to have a significant positive impact on Metates' project economics.

Chief Executive Officer Jean-Paul Tsotsos said:

"In addition, the preliminary High Pressure Grinding Roll ("HPGR") testwork underway offers another opportunity to further enhance recoveries."

An optimisation phase of metallurgical testwork, to be carried out ahead of the planned prefeasibility study (PFS), a detailed technical and economic assessment of the project, will test HPGR crushing combined with the heap oxidation technology to shorten oxidation further and increase final recoveries.

Third-Party Testwork Pipeline Expands to Six Projects

The first round of third-party testwork on the heap oxidation technology is nearing completion, with results to be released when available.

Chesapeake has received samples from three new projects, bringing the total number of projects participating in the testwork to six.

Chief Executive Officer Jean-Paul Tsotsos said:

"Industry interest in our Technology is growing, with several third-party projects participating in the testwork program as we execute on our commercialization strategy."

This work runs in parallel with the Metates programme and is intended to demonstrate the technology's applicability across a wide range of deposits, supporting Chesapeake's strategy to commercialise the process.

Milestones and Next Steps

The two large-diameter columns at Metates have completed the oxidation and cyanidation phases and, along with the long-residence variability columns covering the future mine plan, are being validated and reconciled with data collected during the programme. These results will be incorporated into the planned PFS to determine oxidation rates, input costs, capital estimates, and recoverable gold and silver ounces. Testwork will continue to build on Phase III results, expand the HPGR programme with heap oxidation, and develop plans for a pilot plant demonstration facility. Chesapeake is advancing several PFS workstreams, with the study's timing contingent on the recovery of the San Vicente 3 concession. Remaining Phase III and third-party results will be released as they become available.

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