Arizona Gold & Silver Inc (TSX-V:AZS, OTCQB:AZASF) announced that it has launched Phase 2 of its metallurgical testing program at the Philadelphia gold-silver project in northwestern Arizona.
The company said that this second testing phase follows encouraging results from Phase 1, where column leach tests demonstrated gold recoveries ranging from 61% to 73% over a 177-day cycle.
Regression analysis suggested potential recoveries of up to 80% over a 360-day period, supporting the potential of heap leaching for the project.
The Phase 2 testing involves a 415-kilogram bulk sample and will include four parallel column tests.
These will compare two conventional crush sizes (-6.3mm and -12.5mm) against the same sizes processed using High Pressure Grinding Roll (HPGR) technology. The goal of the test is to determine whether HPGR improves gold recovery rates and speeds up extraction by generating finer particles and microfractures in the ore.
Power usage, cement requirements for agglomeration, and compaction permeability will also be assessed, informing future economic and engineering studies.
The head grade of the sample is 2 grams per ton (g/t) gold, which Arizona Gold & Silver highlighted is significantly higher than the previously estimated 1.24 g/t from earlier channel samples.
Further, ongoing drilling at Philadelphia continues to demonstrate widths and grades of mineralization consistent with other commercial heap leach operations in the Oatman District, the company said.