Kibali Gold Mine Recovery: Dual Oxide & Sulphide Circuits

Source: Barrick Mining Corporation (2026)
Website: https://www.barrick.com/English/operations/kibali/default.aspx

Critical Data

Overview

The Kibali Gold Mine, operated by Barrick Mining Corporation, is one of Africa’s largest gold mining operations, located in the Neoarchean Moto Greenstone Belt in northeastern Democratic Republic of the Congo. The mine’s processing facility, commissioned in 2013 and steadily optimized since, employs a unique dual-circuit configuration designed to handle both oxide/free-milling ores and sulphide refractory ores, ensuring optimal gold recovery from geometallurgically variable feed sources. This innovative approach allows the plant to process up to 8.32 million tonnes annually (2025 throughput), exceeding its design capacity of 7.2 Mtpa for sulphide-only operation. The oxide circuit utilizes standard crushing, ball milling, gravity concentration via Knelson concentrators, and conventional carbon-in-leach (CIL) technology, while the sulphide refractory circuit incorporates primary and secondary crushing, flash and conventional flotation, ultrafine grinding (UFG) to a P80 of 23 μm, pre-oxidation, and a Pumpcell carbon-in-pulp (CIP) circuit for enhanced gold recovery from difficult-to-treat ores. The significance of Kibali’s recovery methods lies in their operational flexibility—both circuits can process sulphide ore, enabling a progressive transition from oxide to full sulphide treatment as oxide reserves deplete—and in the integration of advanced technologies such as the AARL elution circuit, the AZ-CRP® cyanide removal plant, and an Inline Leach Reactor (ILR) for coarse gold. This dual-stream configuration, combined with rigorous ore blending and stockpile management, has delivered plant availability exceeding 95% and utilization over 99% since 2017, making Kibali a benchmark for gold processing innovation.

Key Process Stages

• Stage 1: Primary and Secondary Crushing – ROM ore from underground (KCD) and open pits undergoes primary crushing via two Sandvik CJ815 jaw crushers and secondary crushing via two Sandvik CS660 cone crushers, reducing sulphide ore to a P80 of 45 mm. Oxide ore bypasses secondary crushing, feeding directly to the mill via a 5,000 t live stockpile. The fine ore stockpile (FOS) with 11,700 t live capacity ensures smooth feed to both circuits.
• Stage 2: Grinding, Classification, and Gravity Recovery – Both circuits utilize ball mills in closed circuit with cyclones. The oxide circuit targets a P80 of 80 μm, while the sulphide circuit targets P80 75 μm. Cyclone underflow is directed to Knelson gravity concentrators and flash flotation cells to recover coarse free gold, which is leached in a Gekko Inline Leach Reactor (ILR) before reporting to the gold room.
• Stage 3: Flotation and Concentrate Handling – Sulphide circuit cyclone overflow reports to rougher flotation via two parallel banks of six 70 m³ Outotec forced air cells. Rougher concentrate and flash flotation concentrate are thickened before undergoing ultrafine grinding. Oxide circuit cyclone overflow reports directly to CIL, with flash flotation used optionally when treating free-milling fresh ore.
• Stage 4: Ultrafine Grinding and Pre-Oxidation – The sulphide concentrate is ground to a P80 of 23 μm using eight FLSmidth VXP2500 ceramic bead mills (expanded in 2017). The ultrafine product then enters a two-tank pre-oxidation circuit fitted with Aachen reactors, where lime, oxygen, and lead nitrate are added to enhance subsequent cyanidation. A pre-leach tank with Aachen reactor follows before the extended leach circuit.
• Stage 5: Cyanidation, Carbon Recovery, and Cyanide Detoxification – Pre-oxidized slurry enters two 2,100 m³ leach tanks for extended residence, then overflows to eight Kemix Pumpcell tanks in carousel mode for counter-current CIP adsorption. Loaded carbon from both CIL and Pumpcell circuits is eluted in parallel 12-tonne AARL elution circuits, with electrowinning and smelting producing doré bars. CIL tails are detoxified in a 4.8 Mtpa AZ-CRP® cyanide removal plant, which also recovers additional gold and copper.

Additional Interesting Data and Summary

The Kibali processing plant’s dual-circuit design has demonstrated exceptional operational performance, with plant availability reaching 95.03% and utilization 99.27% in 2025, driven by rigorous planned maintenance and process optimization. Reagent consumption in 2025 reflects efficient operations: cyanide averaged 0.658 kg/t (actual Q4 0.638 kg/t), lime 1.253 kg/t, grinding media 0.539 kg/t, and caustic soda 0.363 kg/t. The AZ-CRP® plant, installed to meet ICMI cyanide standards, processes 4.8 Mtpa of CIL tails, recovering additional gold and copper through adsorption, elution, acidification, and HCN scrubbing. The Kibali hydropower system provides up to 42.8 MW peak capacity, supplemented by 43 MW thermal generation, with total mine load averaging 41 MW. Specific energy consumption has steadily declined from 28.5 kWh/t in 2015 to 26.9 kWh/t in 2025, thanks to finer underground crushing (P80 <50 mm). Water demand has stabilized at 11.5 Mm³ per annum (1.38 m³/t), with forecasts to continue at these levels for the remaining life of mine. The processing plant workforce totals 570 employees and 245 contractors, supporting operations including TSF management, plant cleaning, and oxygen production. Economic significance is underscored by the mine’s ability to process both oxide and refractory sulphide ores, extending mine life as higher-grade oxide sources deplete. The circuit interoperability also allows partial retreatment of tailings and intermediate products, improving overall recovery. Future outlook includes conversion of the oxide plant to a parallel sulphide circuit once oxide sources are exhausted, requiring expansion of concentrate handling and Pumpcell circuits. The qualified person (QP) confirms that current facilities are suitable for processing all ores envisaged in the life-of-mine plan, with sustained high availability and cost-effective reagent and energy use positioning Kibali as a leading gold recovery operation globally.

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

Target Commodities: Gold, Copper, Lead