Northmin Reports Positive Metallurgical Test Results for Tynagh Project

Northmin Corporation, a Toronto-based exploration and development company, has announced positive results from metallurgical test work on material from the West Pond tailings resource at its 100%-owned Tynagh Project in the Republic of Ireland. The tests, conducted by Loop Hydrometallurgy Operations Pty Ltd., showed high levels of metals leaching, with silver achieving a recovery rate of 93%, zinc at 97%, lead at 89%, and copper at 81%.

The test results indicate that the metals can be recovered from the solution to produce saleable products. The process, based on tank leaching at less than 100°C using an aqueous solution of simple salts, simplifies the overall flow sheet and potentially reduces the need for reagent acid.

The test program involved seven leach test runs, covering both standard and enhanced leach conditions. The primary objective was to investigate the conditions required to achieve high levels of metals value dissolution. Secondary objectives included investigating the possibilities for reduced reagent costs and demonstrating the production of saleable metals products. The process, known as the Halion Loop™, operates at atmospheric pressure and below 100°C, producing high purity metals directly at the mine site. It also eliminates the risk of acid mine drainage and minimizes environmental impact.

Dr. Evan Kirby, a Consulting Metallurgist and Director of Northmin, stated, "The metallurgical test results confirm the potential for significant revenue from the Tynagh tailings resource. The recoveries of silver are excellent at 93%, and the high recoveries of other metals will provide additional revenue. The operating costs appear favorable, suggesting potential for high operating margins."

Northmin plans to move forward with further techno-economic and environmental studies to advance the project towards production. The company has also asked Loop Hydrometallurgy to carry out a study to determine the likely economics of the proposed flowsheet, taking into account expected revenues, operating costs, and capital expenditures. The company will also consider different capacity options to inform the optimal ramp-up strategy.

The Tynagh Project includes a NI 43-101 compliant resource with high-grade silver, zinc, lead, and copper values. The West Pond contains 2.69 million tonnes (Mt) of Inferred mineral resources at 21.6% barium oxide (BaO), 49 grams per tonne (g/t) silver (Ag), 3.56% zinc (Zn), 2.68% lead (Pb), and 0.23% copper (Cu). The East Pond has 1.26 Mt of Indicated mineral resources at 13.2% BaO, 34 g/t Ag, 3.63% Zn, 2.16% Pb, and 0.15% Cu, and 2.7 Mt of Indicated mineral resources at 9.5% BaO, 13 g/t Ag, 1.02% Zn, and 0.65% Pb.

Northmin is also assessing the overburden and low-grade ore stockpile on the site and has previously announced high-grade silver results from first-pass sampling. The company has also reported high-grade copper drill results from below the historic zinc-lead-silver mine at Tynagh, including 6.4 meters grading 4.92% copper (Cu), 0.98% antimony (Sb), and 62.04 grams per tonne (g/t) silver (Ag) from 149.0 meters in hole 3615-26-07.

With these positive results, Northmin is excited to move forward with further optimization and confirmation of process performance and product recoveries. The company plans to carry out additional test work with Loop Hydrometallurgy to refine the product strategy and further define the expected economics. Environmental studies will also commence in parallel to support the permitting process.