Metallurgical Test Work Improves Gold Recovery At The Whistler Gold-Copper Project

ANCHORAGE, AK – U.S. GoldMining Inc. reported on the metallurgical test work program which commenced earlier this year, located 105 miles northwest of Anchorage, Alaska. Recovery of up to 85.3% gold (Au), 79.1% copper (Cu) and 55.3% silver (Ag) from the combined sulphide flotation and leaching test work using a master composite derived from Whistler Deposit drill core that is representative of the average metal grade within the Project’s mineral resource estimate (MRE). Sulphide flotation locked cycle tests (LCT) produced a copper concentrate grading 23.7% Cu with a 0.6% mass pull at a P80 grind size of 120µm (rougher circuit) and a regrind of 16µm (cleaner circuit). The initial concentrate metal recoveries include 54.1% Au, 79.1% Cu and 55.3% Ag.
Leach testing of the rougher sulphide flotation circuit tails recovered an additional 31.2% Au, for the combined overall recovery of 85.3% Au. A total of 28 flotation tests were completed together with four leach tests on a combination of master composites and variability samples. The Program results provide key metallurgical recovery and process flowsheet inputs to the initial economic assessment (the PEA).
Tim Smith, Chief Executive Officer, said, “The Company is delighted with the 2025 metallurgical test work results which have confirmed that high gold recoveries in excess of 85% may be achievable at the Project. Previous metallurgical test work only included sulphide flotation, resulting in gold recovery of approximately 70%. However, the combination of a conventional flotation and a sequential leach process has been key to improving gold metallurgical recovery at the Whistler Deposit, with gold recoveries achieving 85.3% overall, an increase of 22% over previous test work. The process flowsheet used in these tests employs proven and demonstrated technology to produce a marketable copper concentrate, as well as direct production of gold doré through leaching. This simple but effective process flowsheet will be a key component of the on-going PEA.”