Moss Gold Project: Flotation and CIL Gold Recovery Process
Source: GOLD X2 MINING INC (2026)
Website: https://goldx2.com/moss-gold-project/
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Throughput | 11 | Mtpa | Nominal fresh rock processing capacity |
| Target Grind Size | 55 | μm | Primary grind P80; concentrate regrind to 15 μm |
| Concentrate Regrind Size | 15 | μm | P80 for flotation concentrate prior to CIL |
| Residence Time (Concentrate CIL) | 48 | hours | Cyanide leaching and carbon adsorption duration for concentrate |
| Residence Time (Tailings CIL) | 24 | hours | Cyanide leaching for combined flotation and concentrate CIL tailings |
| WAD Cyanide Limit | <1 | ppm | Weak acid dissociable cyanide after destruction using SO₂/air process |
Overview
The Moss Gold Project, located near Thunder Bay, Ontario, is a significant gold development owned and operated by Gold X2 Mining Inc. The project’s Preliminary Economic Assessment (PEA), effective January 26, 2026, outlines a robust gold recovery flowsheet based on conventional flotation and cyanide leaching via carbon-in-leach (CIL) technology. Designed to process 11 million tonnes per annum (Mtpa) of fresh rock, the plant will produce doré bars through a series of integrated unit operations. The significance of this project lies in its ability to achieve high gold recoveries by combining flotation to concentrate the gold-bearing material and CIL for intensive leaching and adsorption. The process begins with two-stage crushing and semi-autogenous grinding (SAG) and ball mills, reducing ore to a target P80 of 55 µm. Rougher flotation then upgrades the feed, with the concentrate reground to 15 µm before entering a dedicated CIL circuit with 48 hours residence time. Tailings from flotation and concentrate CIL undergo a separate 24-hour CIL circuit, ensuring maximum gold extraction. Cyanide destruction using the SO₂/air process reduces weak acid dissociable (WAD) cyanide to below 1 ppm, meeting strict environmental standards. This integrated approach positions the Moss Gold Project as a technically sound and environmentally responsible gold recovery operation, supporting Ontario’s mining sector.
Key Process Stages
- Stage 1: Comminution – Two-stage crushing followed by a SAG mill and ball mills in closed circuit with hydrocyclones produces a final grind size of P80 55 µm, ensuring optimal liberation for flotation.
- Stage 2: Rougher Flotation – The ground slurry undergoes rougher flotation to concentrate gold-bearing sulfides, rejecting barren gangue and reducing the mass flow to downstream leaching circuits.
- Stage 3: Concentrate Regrind – Flotation concentrate is reground to a target P80 of 15 µm using an IsaMill or similar technology, increasing surface area for efficient cyanide leaching.
- Stage 4: Concentrate Carbon-in-Leach (CIL) – The reground concentrate is thickened and then leached with cyanide in a CIL circuit with 48 hours residence time. Gold is adsorbed onto activated carbon, followed by carbon elution via a 6-tonne split pressure Zadra circuit, electrowinning, and smelting to produce doré.
- Stage 5: Tailings CIL and Cyanide Destruction – Combined flotation tailings and concentrate CIL tailings undergo a secondary 24-hour CIL circuit for residual gold recovery. The final tailings are treated in a cyanide destruction circuit using the SO₂/air process to reduce WAD cyanide below 1 ppm before pumping to a tailings storage facility.
Additional Interesting Data and Summary
The remaining technical data for the Moss Gold Project’s recovery methods emphasizes a holistic and environmentally conscious design. The process plant incorporates a 6-tonne split pressure Zadra circuit for carbon elution, ensuring efficient gold stripping from loaded carbon. Carbon handling and regeneration circuits extend carbon life, reducing operating costs. Electrowinning and smelting convert the gold-silver sludge into high-purity doré bars. A critical environmental feature is the cyanide destruction circuit, which employs the SO₂/air process to lower WAD cyanide to less than 1 ppm, exceeding typical regulatory requirements and mitigating long-term tailings management risks. The plant layout prioritizes operator safety and maintenance access, with sufficient automation to minimize continuous operator interface while allowing manual override. Equipment selection focuses on reliability and ease of maintenance, supporting the 11 Mtpa nominal throughput. Although specific energy and water consumption figures are not provided in the PEA, the flowsheet is designed with closed-loop water systems (potable, raw, gland seal, and process water) to minimize freshwater intake. The air and oxygen circuits support the leaching and cyanide destruction processes. Economically, this PEA-stage project demonstrates a technically robust gold recovery approach that leverages proven unit operations—flotation and CIL—adapted to the Moss deposit’s mineralogy. The combination of a coarse primary grind (55 µm) with fine regrind (15 µm) optimizes both liberation and leaching kinetics. Future outlook includes potential process optimization through piloting and detailed engineering, aiming to maximize recovery rates beyond the baseline design. The significance of this facility lies in its ability to process a large tonnage with low environmental impact, positioning Gold X2 Mining Inc. as a responsible developer in Ontario’s Thunder Bay mining district. Sustainability initiatives are embedded in the flowsheet, particularly the cyanide destruction step and water recycling, aligning with industry best practices for green mining.
Key Processes: Flotation, CIP/CIL, Cyanidation, SAG Mill, Ball Mill, Crushing
Target Commodities: Gold
