Kandiolé Gold Recovery: Crushing, Grinding & CIL Process

Source: Roscan Gold Corporation – formerly, Roscan Minerals Corporation (2026)
Website: https://roscan.ca/projects/kandiole-project/

Critical Data

Overview

The Kandiolé Project, operated by Roscan Gold Corporation (formerly Roscan Minerals Corporation), is a proposed gold mining development situated in southwestern Mali, West Africa, near the village of Dabia. The Preliminary Economic Assessment (PEA), effective 27 February 2026, outlines a conventional recovery approach comprising crushing, grinding, gravity concentration, and carbon-in-leach (CIL) cyanidation. ROM ore will be sourced from multiple deposits including Mankouke South main pit, Mankouke Central, Kabata, and satellite pits KN1 and KN2, then hauled by 200-tonne trucks to a processing plant near Kabaya. The flowsheet integrates a primary jaw crusher, a semi-autogenous grinding (SAG) mill and ball mill in closed circuit with hydrocyclones to achieve a target grind of P80 100 µm. A gravity concentrator treats a portion of the cyclone underflow to recover free gold, while the balance undergoes cyanide leaching in a CIL circuit. Gold is stripped from loaded carbon using the Zadra process, followed by electrowinning and smelting in an on-site induction furnace to produce doré bars. Overall gold recoveries are expected between 90 wt% and 94 wt%, though gravity-only recovery shows high variability (4 wt% to 75 wt% based on testwork). This conceptual PEA-level design provides the foundation for future prefeasibility and feasibility studies, with process parameters subject to further optimisation. The project benefits from existing road access via Route Nationale 24 and nearby regional infrastructure, positioning Kandiolé as a strategic gold development in the prolific West African Birimian greenstone belt.

Key Process Stages

• Stage 1: Primary Crushing and Stockpiling – ROM ore is fed from the ROM pad using a CAT 992 loader into a primary jaw crusher. Crushed ore is conveyed to a nominal 20,000‑tonne crushed ore stockpile, from which vibrating feeders reclaim material for the grinding circuit.
• Stage 2: Grinding Circuit – Ore is ground in a SAG mill followed by a ball mill operating in closed circuit with hydrocyclones. The target grind size is P80 100 µm to achieve optimal liberation for leaching. This conventional SAG/ball mill configuration ensures efficient size reduction for downstream processing.
• Stage 3: Gravity Gold Recovery – A portion of the cyclone underflow is directed to a gravity concentrator to capture free gold. This step reduces the load on the CIL circuit and improves overall recovery, although gravity recovery is highly variable (4 wt% to 75 wt% based on metallurgical testwork).
• Stage 4: Cyanide Leaching and Carbon-in-Leach (CIL) – The ground ore is leached with cyanide in a CIL circuit, chosen due to the minor residual carbon content of the ore. Gold is adsorbed onto activated carbon as it passes through the leach tanks, ensuring high recovery efficiency.
• Stage 5: Gold Recovery and Smelting – Loaded carbon undergoes Zadra stripping to elute gold into solution, followed by electrowinning to deposit gold onto cathodes. The electrowon gold is smelted in an on-site induction furnace to produce doré bars for final sale.

Additional Interesting Data and Summary

The recovery methods outlined for the Kandiolé Project are based on conventional, well-proven technologies—crushing, SAG/ball mill grinding, gravity concentration, and CIL cyanidation—that are widely adopted in West African gold operations. The conceptual flowsheet supports a PEA-level evaluation, with key parameters such as throughput, mill power, and energy consumption not yet defined. The target grind size of P80 100 µm is typical for free-milling oxide and fresh ores, and the overall gold recovery of 90 wt% to 94 wt% reflects the favourable metallurgical characteristics of the Kandiolé ore. However, gravity gold recovery shows significant variability (4 wt% to 75 wt%), indicating that further testwork is needed to optimise the gravity circuit and reduce reliance on cyanide. Environmental considerations at this stage are conceptual; the use of cyanide requires responsible management and tailings containment, though no specific water or energy consumption metrics are available. Economically, the proposed processing route aligns with regional benchmarks, leveraging existing road infrastructure (RN24 highway) and proximity to Kéniéba town. The project also benefits from a local Roscan exploration office and core-logging facilities near Diabarou. Sustainability initiatives have not been detailed in the provided section, but future studies (prefeasibility and feasibility) will refine the flowsheet, incorporate energy efficiency measures, and assess water recycling opportunities. The Kandiolé Project represents a significant gold exploration-to-development opportunity in Mali, a country with a long mining history and supportive mining code. Forward-looking statements in the PEA emphasise that the process design remains subject to optimisation; the variability in gravity recovery underscores the need for additional metallurgical testwork to derisk the project. The planned on-site induction furnace for smelting underscores a self-sufficient gold recovery philosophy. Overall, the recovery methods described provide a robust yet flexible foundation for advancing the Kandiolé Project toward production, contingent on successful future engineering studies and economic validation.

Key Processes: CIP/CIL, Cyanidation, Gravity Separation, SAG Mill, Ball Mill, Crushing

Target Commodities: Gold