Patriot Resources has ticked an important technical box at its newly acquired Tassa project in southern Peru, confirming the silver appears highly amenable to conventional processing - a key component in the recipe for turning resources into profitable mines.
Historical cyanidation metallurgical test work has returned average silver recoveries of 85.05 per cent, providing early evidence that the mineralisation could respond well to standard leach processing methods.
For explorers and developers alike, recoveries in this range are an encouraging sign that the metal locked in the rock can be efficiently extracted.
ALS Chemex originally conducted the test work in Peru on six surface rock samples collected across the project area.
The usual process of separating silver from the host rock uses chemicals combined with the silver ore powder to make a slurry. Cyanide is added to the slurry, and down the track, silver then magically dissolves into the solution. The solution passes through a series of filter plates and presses, which collect and dry the silver precipitate.
During testing, a total free sodium cyanide concentration of 0.21 per cent was recorded at the end of the 12-hour leach cycle, indicating controlled leaching conditions and stable reagent consumption. Put simply, the silver behaved well in the lab.
Metallurgy can often prove just as important as grade in determining whether a project ultimately becomes a mine. Even high-grade deposits can struggle economically if the metal proves difficult to recover. In contrast, deposits with solid recoveries and simple processing routes can benefit from lower operating costs and reduced technical risk.
To strengthen confidence in the historical data, Patriot has now commissioned Northern Metallurgy in Queensland to undertake an independent review of the earlier test work.
Metallurgical validation is an important de-risking step as Patriot advances the project following its maiden resource announcement earlier this year.
The company’s initial JORC inferred mineral resource estimate outlined a sizeable silver system holding 18.53 million tonnes for 31.4 million silver-equivalent ounces at a grade of 52.68 grams per tonne (g/t).
Within that figure lies a hefty 25.5 million ounces of contained silver grading 42.73g/t silver, along with a small but notable gold component, giving Patriot immediate leverage to any increase in the precious metal price.
Running along a 2.8-kilometre structural corridor, the silver-rich system has seen only limited drilling, leaving open the tantalising possibility that the current resource is merely the first glimpse of a far larger epithermal prize.
Peru has a long mining history, stretching back to the Incas and hundreds of years of mining by the Spanish. It hosts some of the world’s most prolific epithermal deposits and has long ranked among the globe’s leading silver producers. Significantly, the country is estimated to hold the world’s largest silver reserves, at around 91,000 metric tonnes.
Epithermal deposits form when mineral-rich fluids rise through fractures in volcanic rocks and cool near the surface, leaving behind precious metals such as silver and gold.
Notably, mineralisation at Tassa begins mainly from surface. It remains open in all directions, a combination that implies strong potential for a range of low-strip development options, while also keeping the door wide open for resource expansion.
Patriot’s decision to bring in independent specialists to review the historical work is another step towards building confidence in the data as the project develops.
With metallurgy now showing positive signs and further technical work underway, Patriot is gradually tightening the screws on the technical fundamentals that underpin Tassa.
And with silver prices climbing on the back of booming demand from solar, electronics and the global energy transition, projects capable of delivering clean recoveries and scalable resources are attracting increasing attention.
If upcoming work continues to confirm the metallurgy and expand the resource footprint, Patriot’s Peruvian silver play could start to shine a little brighter on the development radar.
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