Arizona Gold & Silver reports up to 99% gold recovery at Philadelphia project

Jul 2, 2026

Arizona Gold and Silver CEO Mike Stark joined Steve Darling from Proactive to discuss encouraging metallurgical test results from the Philadelphia gold-silver project in Mohave County, Arizona, highlighting strong gold recoveries through both agitation and heap leach processing.

Stark said agitation leach cyanidation achieved gold recoveries of 91% to 99% using modest grind sizes of 0.40 to 0.136 mm (40–110 mesh). More than 50% of the total gold was recovered within the first 10 days of column leaching, demonstrating rapid extraction characteristics.

Heap leach testing also delivered positive results, with 84% gold recovery from bulk material crushed to -6.3 mm using high-pressure grinding rolls (HPGR) over a 177-day leach cycle. Regression analysis indicates recoveries could increase to approximately 86% over 360 days.

Silver recoveries ranged from 49% to 72% through agitation leaching, while heap leach processing achieved 37% silver recovery. Testing also showed that HPGR crushing improved gold recovery by 12% compared with conventional crushing methods, while silver recovery improved by approximately 3%.

Agglomeration and compaction testing demonstrated that the crushed material is suitable for heap stacking heights of 10 to more than 30 metres with the addition of only 2 to 4 kilograms of cement per tonne, supporting the project’s heap leach potential.

Based on the results, management believes higher-grade material could be processed through agitation cyanide leaching to maximize gold and silver recovery, while lower-grade ore could be treated economically through HPGR-assisted heap leaching.

The metallurgical work was conducted on a 415.5-kilogram bulk sample collected from the current surface operation. Head assays returned 1.929 to 1.988 g/t gold and 2.82 to 3.34 g/t silver, exceeding the original target grade of 1.0 to 1.2 g/t gold. The company said the higher grades are consistent with previous sampling, reflecting the presence of fine and wire gold within the deposit.

https://arizonagoldsilver.com/