Kay Mine Project: Cu-Pb-Zn Flotation & Albion Gold Leach

Source: Arizona Metals Corp (2026)
Website: https://www.arizonametalscorp.com/kay-mine

Critical Data

Overview

Arizona Metals Corp. is advancing the Kay Mine Project in Arizona, USA, with a robust recovery methods section detailed in the Preliminary Economic Assessment (PEA) NI 43-101 Technical Report effective April 30, 2026. The proposed process plant is designed to nominally treat 0.7 Mtpa of underground fresh rock, employing a standard metallurgical flowsheet tailored for Cu-Pb-Zn mineralized material. This facility integrates conventional comminution, selective flotation, and advanced oxidative leaching to maximize metal recovery. The comminution circuit—primary jaw crusher, secondary cone crusher, and ball mill—delivers a primary grind size of P80 60 μm, optimizing liberation for subsequent flotation. Three distinct concentrate streams (copper-lead, zinc, and pyrite) are produced, with the pyrite concentrate subjected to Albion oxidative leaching at a 72-hour residence time to unlock refractory gold. A Carbon-in-Leach (CIL) circuit with 48-hour retention further recovers gold via cyanide leaching and carbon adsorption, followed by a Split Pressure Zadra elution, electrowinning, and smelting to produce doré. The flowsheet also includes cyanide destruction using the SO₂/O₂ process to achieve weak acid dissociable (WAD) cyanide levels below 5 ppm, demonstrating a commitment to environmental compliance. Located in a historic mining district, this project capitalizes on established infrastructure and metallurgical expertise, positioning itself as a significant copper-lead-zinc-gold producer in the region. The recovery methods outlined in this PEA reflect industry best practices and are underpinned by rigorous metallurgical test work. This article explores each process stage in detail, highlighting key equipment, parameters, and performance metrics critical to the project’s economic viability.

Key Process Stages

• Stage 1: Comminution Circuit – Primary jaw crusher, secondary cone crusher, and ball mill reduce underground fresh rock to a target primary grind size of P80 60 μm. This fine grind ensures adequate liberation of valuable minerals for effective flotation. The circuit operates at a nominal throughput of 0.7 Mtpa, balanced by surge bins and conveyors.
• Stage 2: Flotation Circuit – Rougher and cleaner flotation stages produce separate copper-lead (Cu-Pb) and zinc concentrates. The pyrite concentrate is recovered via a dedicated rougher flotation line. All flotation cells are conventional mechanical units sized for the design tonnage, with regrind mills for cleaner feed to enhance concentrate grades.
• Stage 3: Albion Oxidative Leaching – The pyrite concentrate undergoes Albion leaching at a residence time of 72 hours. This process oxidizes sulfide minerals, liberating refractory gold locked in the pyrite matrix. The circuit includes pre-leach thickening, oxygen injection, and temperature control to optimize oxidation kinetics.
• Stage 4: Carbon-in-Leach (CIL) – After Albion treatment, the leach slurry enters a CIL circuit with a 48-hour residence time. Cyanide leaching dissolves gold, which is adsorbed onto activated carbon in a Leach-CIP carousel configuration. Carbon loadings and solution grades are monitored to maximize gold extraction.
• Stage 5: Carbon Elution, Electrowinning & Cyanide Destruction – Loaded carbon is stripped using a 10-tonne Split Pressure Zadra circuit, producing a pregnant solution for electrowinning and smelting into doré. Tailings from the CIL circuit undergo cyanide destruction via the SO₂/O₂ process to reduce WAD cyanide to <5 ppm before pumping to the tailings storage facility.

Additional Interesting Data and Summary

Beyond the core recovery methods, the Kay Mine Project incorporates several technical and environmental aspects that enhance its overall sustainability and economic profile. The Albion oxidative leaching stage operates at a 72-hour residence time, a critical parameter for processing the refractory pyrite concentrate, while the subsequent CIL circuit holds a 48-hour residence time to ensure optimal gold dissolution and adsorption. The cyanide destruction circuit using the SO₂/O₂ process is designed to reduce WAD cyanide to less than 5 ppm, meeting stringent environmental discharge standards and demonstrating proactive stewardship. The process plant also includes air and oxygen circuits, water systems (domestic, raw, gland seal, and process water), and a tailings pumping system to a designated storage facility. From an economic perspective, the PEA (effective April 30, 2026) evaluates capital and operating costs for this 0.7 Mtpa facility, with the flowsheet selected based on extensive metallurgical test work that confirms the viability of producing separate Cu-Pb and zinc concentrates plus a gold-bearing doré. The project benefits from its location in Arizona, a mining-friendly jurisdiction with established infrastructure, skilled labor, and access to power and water. Forward-looking initiatives may include optimization of grind size to reduce energy consumption, evaluation of alternative reagents for flotation selectivity, and potential expansion of throughput capacity. The combination of conventional flotation with Albion leaching and CIL positions the Kay Mine Project as a technically robust and environmentally responsible operation, capable of delivering copper, lead, zinc, and gold to the market while adhering to best practices in water management and cyanide detoxification. As the project moves toward feasibility and permitting, these recovery methods will continue to be refined to maximize metal recoveries and minimize environmental footprint, underscoring Arizona Metals Corp.’s commitment to sustainable mining.

Key Processes: Flotation, CIP/CIL, Cyanidation, Ball Mill, Crushing

Target Commodities: Gold