Exploration and Reutilization Progress of the Limon Gold-Antimony Ore Mine in the US

According to Miningweekly, NevGold, listed on the Toronto, Frankfurt, and OTCQB exchanges, has reported favorable results from the first phase of pit sampling at its Limon Butte project in Nevada, US, confirming the continuity of antimony and gold grades in the old heap leach pads and presenting an opportunity for near-term antimony production.

The old heap leach pads were constructed during the mine's production period from 1989 to 1990, when the gold price was below $400 per ounce and antimony was not a target mineral for mining and processing.

Historical records indicate that the heap leach pads may contain 2.4 million to 3 million mt of previously mined ore, now exposed on the surface. Surface sampling conducted by NevGold on two heap leach pads shows continuous and high-grade distributions of antimony and gold.

These tailings can be categorized into crushed ore and run-of-mine heap leach pads. According to historical data, the crushed ore heap leach pad contains 1.4 million to 1.7 million mt of tailings, with an average antimony grade of 0.72% and gold grade of 0.43 g/mt. The particle size is 1/3 inch. The run-of-mine heap leach material amounts to 1 million to 1.3 million mt, with an average antimony grade of 0.31%, gold grade of 0.81 g/mt, and variable particle sizes.

The company stated that both types of old heap leach pads exhibit very consistent antimony and gold grades, with all sampled pits showing significant mineralization. Local antimony grades in the heap leach pads range from 0.47% to 0.81%, varying by sample.

NevGold indicated that there is a high likelihood of recovering residual gold and antimony from the old heap leach pads in the future. Metallurgical testing conducted at Limon Butte also demonstrated favorable processing performance, with heap leaching of antimony being a preferred option.

Tests completed last year showed that antimony recovery via acid leaching can reach up to 92%, with almost no impact on gold recovery.

The company noted that residual gold from the heap leach pads can be recovered after future antimony treatment. Acid leaching is considered the preferred metallurgical method for antimony, eliminating the need for downstream processing at third-party smelters.

In this scenario, antimony metal would be produced on-site using conventional leaching and electrodeposition processes, similar to the solvent extraction and electrowinning (SX/EW) method commonly used in the copper oxide industry.

Due to its strategic importance and military applications, antimony is classified as a highest-risk critical mineral. Limon Butte is a historic mine in Nevada hosting near-surface, high-grade antimony ore.

NevGold stated that the old heap leach pads make it possible to commence antimony production in the near term, while simultaneously advancing large-scale gold/antimony production.

In addition to the heap leach pads, the company is progressing with drilling, metallurgical testing, and resource estimation preparations at Resurrection Ridge, Cadillac Valley, and the newly discovered high-grade Bullet Zone gold target in 2025.

Nifu Company stated that phased development could create multiple development scenarios within the next 12 to 24 months, with the potential for near-term commissioning and cash flow generation.

As part of the Limon Peak 2025-2026 work plan, Nifu Company has completed an assessment of the historical geological database, focusing on gold and antimony, and has advanced to the second phase of metallurgical testing.

To date, 30 holes have been completed in the gold/antimony target area. The company is also advancing near-term antimony production from the crushing and raw ore heap leach pads. Sonic drilling has commenced following the completion of the first phase of sampling and metallurgical testing, and preliminary gold-antimony resource estimation is underway.

"These results have rapidly de-risked the project and enhanced the potential for near-term production at Limon Peak. The mine is also a key brownfield site with potential for near-term commissioning. The historical Limon Peak mine, which previously focused solely on gold, benefits from a large amount of mined ore exposed on the surface of the heap leach pads."

"The addition of antimony enables multiple development scenarios, which are currently under evaluation. We believe this represents one of the options for building an integrated upstream-downstream antimony supply chain in the US in the near term."

"While advancing the development of the old heap leach pads, we are also progressing toward the construction of a larger-scale commercial gold-antimony mine through drilling, metallurgical testing, and resource estimation at Resurrection Ridge, Cadillac Gulch, and Bretton. This provides the company with significant optionality for advancing Limon Peak's gold production and cash flow generation," said Brandon Bonifacio, CEO of Nifu Gold.