Mineral Processing Circuit

This NI 43-101 Technical Report outlines the recovery methods for the Churchrock Uranium Project, focusing on a Preliminary Economic Assessment (PEA). The project utilizes an In-Situ Recovery (ISR) method where lixiviant is circulated through a wellfield to extract uranium underground. The process involves a two-site operation: a Satellite Plant at Churchrock for ion exchange recovery and a Central Processing Plant (CPP) at Crownpoint for elution, precipitation, and drying.

This report outlines the recovery methods for the De Bron Merriespruit (DBM) Project, focusing on gold recovery. Uranium recovery was evaluated as a potential byproduct but excluded due to marginal economics and additional capital costs. The processing plant is designed for a throughput of 80,000 tonnes per month, utilizing direct SAG milling followed by a Carbon-in-Leach (CIL) circuit. The CIL circuit is optimized at eight stages to minimize carbon inventory and gold lock-up, with a target recovery of 96.2%.

This NI 43-101 Technical Report details the operational status and life-of-mine plan for the Greens Creek Polymetallic Mine in Alaska, operated by Hecla Mining. The mine has been operational for 30 years, with continuous operation for the last 23 years. It is an underground mine targeting massive sulfide mineralization in a temperate rainforest environment. The current mine life extends to 2030, with infrastructure primarily located at the 920/860 mine area and the Hawk Inlet camp.

The 2021 production data for the Bolañitos plant indicates a throughput of 418,514 tonnes of ore, grading 42 g/t silver and 2.02 g/t gold. Recoveries averaged 87% for silver and 90.7% for gold, resulting in 483,507 oz of silver and 24,730 oz of gold recovered. The plant operated at an average throughput of 1,163 tonnes per operating day, slightly exceeding the planned rate of 1,100 t/d, with only 4 days of maintenance downtime recorded.

The Red Mountain Gold Project Preliminary Economic Assessment Report outlines the proposed recovery methods for extracting gold and silver from mine feed. The process involves stage crushing using a jaw and cone crusher, followed by grinding in a rod and ball mill circuit to a target grind size of 95% passing 38 µm. The crushed feed is processed at a nominal rate of 1000 t/d.

This report outlines the conceptual flowsheet for the Romero Project Preliminary Economic Assessment (PEA). The process is designed to treat 1,400,000 tonnes per year of ore, with a daily throughput of 4,000 tonnes. The metallurgical strategy focuses on recovering copper into a concentrate containing approximately 20% copper, along with gold and silver credits.

The Sheep Mountain Project is a uranium recovery facility utilizing conventional heap leaching technology, a process established globally for oxidized ores. The operation involves stacking mined material on a double-lined heap leach pad, applying an acidic leaching solution containing sulfuric acid and an oxidant, and collecting the pregnant leach solution (PLS) for processing. Over a 12-year mine life, the project is designed to recover an average of 1.4 million pounds of U3O8 annually.