Eau Claire Project — 2025 Preliminary Economic Assessment

The 2025 PEA for the Eau Claire gold project describes a processing facility designed to treat 1,500 tpd of ore through crushing, grinding, gravity separation, and cyanidation circuits incorporating an In-Line Leach Reactor and Carbon-in-Leach system.

Report context

This NI 43-101 technical report, dated 2025, presents a Preliminary Economic Assessment for the Eau Claire property, operated by Fury Gold Mines Limited, located in Quebec, Canada. The property was initially known as the Clearwater Project. The report documents the design of a processing facility calibrated to process 1,500 tons of ore daily, based on extensive metallurgical test work and detailed analyses. The operation plan anticipates processing approximately 525,000 tons of gold-bearing ore annually over 350 operational days per year.

Processing route

Crushing

Ore is transported by truck from the mine complex to the crusher dump pocket, which is equipped with a static grizzly and a Rock Breaker designed to break down oversized material. Ore passing through the grizzly falls onto an apron feeder that conveys it to the jaw crusher. The crushed ore is then conveyed to the ore storage bin.

Grinding

Ore from the storage bin feeds the semi-autogenous (SAG) mill. Pebble lime is added onto the SAG mill feed conveyor to manage pulp pH. The SAG mill operates in closed circuit with the SAG screen; oversized material returns to the SAG mill and undersize flows to the primary cyclone pump box. The ball mill operates in closed circuit with primary and secondary hydrocyclones. Primary cyclone underflow is directed to the gravity circuit. Overflow from the secondary cyclones, with particle size P80 around 48 microns, reports to a trash screen before proceeding to the leach feed thickener. Undersize from the trash screen is routed to the leach feed thickener.

Gravity Circuit

The gravity circuit utilizes underflow from the primary cyclone, bifurcated to service two parallel circuits. Each circuit comprises a vibrating screen and a gravity concentrator. Concentrate from the gravity circuits undergoes intensive cyanidation within an In-Line Leach Reactor (ILR). Oxygen, cyanide, and caustic soda are introduced from designated storage tanks through dosing pumps. The high-grade pregnant gold solution generated in the ILR is pumped to electrowinning buffer tanks; spent tailings are directed back to the ball mill.

Initial Leach (IL) Circuit

The leach feed thickener receives milled ore pulp from the trash screen. Underflow from the thickener is pumped to the first leach tank, where cyanide is introduced. Pulp flows from the first tank to the second tank and then into the Carbon-in-Leach (CIL) circuit.

Carbon-in-Leach (CIL) Circuit

The CIL circuit consists of six interconnected tanks. Cyanide solution is introduced into the first tank; compressed air is supplied to each tank. Activated carbon is added to the sixth CIL tank and pumped counter-currently toward the first tank. Screens at discharge points prevent carbon from overflowing between tanks. CIL tailings report to a tailings thickener; underflow is pumped to the cyanide destruction tank, where sulfur dioxide and compressed air destroy residual cyanide. Ferrous sulfate is added to reduce arsenic content.

Carbon Circuit

Loaded carbon is periodically extracted from the first CIL tank and transferred to a washing screen. Washed carbon descends to the loaded carbon tank; residual pulp is returned to the CIL tanks. Loaded carbon moves to the acid washing tank, where hydrochloric acid is introduced for two hours. After rinsing, carbon undergoes elution for desorption of gold. Eluted carbon is screened; undersize reports to a carbon fines thickener. Carbon fines are filtered, pressed, and bagged. Regeneration kiln thermally treats carbon; output is quenched and returned to the calibration screen. Makeup carbon is pumped back into the CIL circuit.

Elution and Electrowinning Circuits

The elution circuit operates using the ZADRA process. A combination of caustic soda and cyanide in process water is pumped through a heat exchanger and water heater before entering the elution vessel. Pregnant solution flows from the top of the vessel through the heat exchanger and a cooling battery. In the electrowinning cell, gold ions are deposited onto cathode plates, forming a gold sludge. Barren solution is recycled to the barren solution tank. Gold sludge is filtered, dried, and smelted in an induction furnace to produce gold doré bullion bars.

Energy Management

Natural gas powers the carbon regeneration kiln, the water heater at the biological treatment plant, and provides heating for the processing plant. Electricity powers machinery and systems across the facility.

Water Management

Fresh water is obtained from wells at a rate of 40 m³/hr (960 m³/day) and is used primarily for preparation of chemical solutions and paste fill. Process water originates from the thickening process prior to leaching and is recirculated to the grinding circuit.

Key reported parameters

Technical qualifications

A portion of the contained metal of the Eau Claire deposit and all of the contained metal in the Percival deposit are in the Inferred Mineral Resource classification. It is reasonably expected that the majority of Inferred Mineral Resources could be upgraded to Indicated Mineral Resources with continued exploration. Different interpretation from the current mineralization models may adversely affect the current mineral resource estimates. Continued drilling may help define with more precision the shapes of the zones and confirm geological and grade continuities along strike or down dip/plunge.

Source: Technical Report – 2025 Preliminary Economic Assessment-Eau Claire Project, Quebec, Canada, SGS Geological Services.