Kamoa-Kakula Copper Recovery: High-Grade Concentrator & DBF Smelter
Source: Ivanhoe Mines Ltd (2026)
Website: https://www.kamoacopper.com/en/
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Throughput | 10.5 | Mtpa | Kakula concentrator combined capacity (Phase 1 and 2) |
| Throughput | 6.5 | Mtpa | Kamoa concentrator effective capacity (above design 5.0 Mtpa) |
| Mill Power | 10,000 | kW | Kamoa primary ball mill: dual 5,000 kW VSD drives |
| Mill Power | 5,500 | kW | Kakula regrind HIGMill per module (two per module) |
| Target Grind Size | 53 | µm | P80 in ball mill cyclone overflow |
| Head Grade | 3.34 | % Cu | Kakula concentrator design ROM grade |
| Head Grade | 2.46 | % Cu | Kamoa concentrator upgrade design ROM grade |
| Recovery % | 90.6 | % | Kakula concentrator design recovery (P95) |
| Recovery % | 83.0 | % | Kamoa concentrator upgrade design recovery |
| Processing Capacity | 17 | Mtpa | Combined total concentrator capacity |
| Energy Consumption | 8 | MW | Electrical power generated from waste heat recovery at smelter |
| Operating Hours | 7,998 | hours/year | Kakula milling circuit operating time |
| Operating Hours | 7,709 | hours/year | Kamoa milling circuit operating time |
Overview
The Kamoa-Kakula Copper Complex, operated by Kamoa Copper SA (a joint venture between Ivanhoe Mines, Zijin Mining Group, Crystal River Global Limited, and the DRC government), represents one of the world’s largest and highest-grade copper mining operations. Located in the Democratic Republic of Congo’s Central African Copperbelt, the complex integrates two concentrators and a state-of-the-art copper smelter to produce blister copper anode grading >99.66% Cu. The 2026 Mineral Resource and Mineral Reserve Update considers a total concentrator production capacity of approximately 17 Mtpa, combining the Kakula Phase 1 and Phase 2 concentrators (10.5 Mtpa) with the Kamoa Phase 3 concentrator (6.5 Mtpa). Recovery methods are designed to maximize copper extraction from high-bornite chalcocite and chalcopyrite ores through conventional comminution, flotation, and Direct-to-Blister Flash (DBF) smelting. The Kakula concentrator is undergoing optimization (Project P95) to achieve 90.6% copper recovery, while the Kamoa concentrator operates above design capacity with recoveries exceeding 86% at a head grade of approximately 2.3% Cu. The onsite Kakula copper smelter, commissioned in December 2025, employs Metso-licensed DBF technology to treat 1.2 Mtpa of blended concentrate, producing 500 ktpa of copper anode and 783 ktpa of sulphuric acid as a co-product. This integrated recovery flowsheet—from run-of-mine ore through crushing, HPGR, ball milling, flotation, regrind, and smelting—minimizes concentrate transport costs, reduces carbon footprint via waste heat recovery (8 MW electrical power), and ensures high metal recovery. As of early 2026, the smelter is ramping up to nameplate capacity, with ongoing infrastructure upgrades to resolve early operational challenges including oxygen plant capacity and ladle heat loss.
Key Process Stages
- Stage 1: Crushing and Screening – ROM ore (F100 450 mm) is crushed via cone crushers in closed circuit with vibrating screens to 100% passing 50 mm. At Kamoa, two CS660 cone crushers (315 kW each) reduce material from F80 195 mm to P80 52 mm. Primary screen undersize is conveyed to HPGR feed stockpile.
- Stage 2: HPGR and Ball Milling – Crushed ore is fed to High-Pressure Grinding Rolls (HPGR; e.g., Polycom 17/12-5 with dual 1,200 kW drives) operating in closed circuit with wet screening to produce P80 of 4.5 mm. HPGR product is gravity-fed to a two-stage ball milling circuit (dual 5,000 kW drives at Kamoa) in closed circuit with cyclone clusters, achieving target grind size P80 53 µm. Flash flotation in the milling circuit recovers liberated chalcocite.
- Stage 3: Rougher and Scavenger Flotation – Milled slurry is classified into coarse and fine fractions for separate rougher flotation circuits. High-grade (fast-floating) rougher concentrate and medium-grade (slow-floating) scavenger concentrate are produced. Rougher concentrate reports to low-entrainment high-grade cleaner circuit. Scavenger concentrate and cleaner tailings undergo regrind.
- Stage 4: Concentrate Regrind and Cleaning – Scavenger concentrate and coarse rougher tailings are reground to P80 ~10 µm in a regrind circuit (vertical tower HIGMills with 5.5 MW per module at Kakula). The regrind product is upgraded through a three-stage scavenger cleaning circuit. Final concentrate combines high-grade cleaner concentrate, scavenger recleaner concentrate, and optional medium-grade scavenger cleaner concentrate.
- Stage 5: Direct-to-Blister Flash Smelting – Blended concentrates from both concentrators are dried and fed to a Metso-licensed DBF furnace operating at ~1200°C. Blister copper (99.66% Cu) is transferred via launder to three 660-tonne anode refining furnaces with twin casting machines. Slag is cleaned in a 30 MVA electric furnace, and off-gas feeds a DCDA sulphuric acid plant (783 ktpa H2SO4). Waste heat recovery generates 8 MW electricity.
Additional Interesting Data and Summary
The Kamoa-Kakula recovery system is underpinned by rigorous testwork and trade-off studies (Section 13 of the technical report) that optimized flowsheet configuration for the unique mineralogy—high-bornite and chalcocite at Kakula versus chalcopyrite-dominant ore at Kamoa. The Kakula concentrator achieves a mass pull to final concentrate of 6.4% of mill feed, producing a final concentrate grade of 47% Cu. At Kamoa, the mass pull is 5.83% at a concentrate grade of 35.1% Cu, reflecting the higher energy requirements of chalcopyrite flotation. The regrind circuit at Kakula uses two new 5.5 MW HIGMills per module for ultra-fine grinding to 10 µm, enabling additional liberation of locked copper minerals. Four Larox PF 72/72 M60 filter presses dewater concentrate to 8% moisture (w/w). Tailings management includes thickening, with existing thickeners converted to clarifiers to improve water recovery, and a dedicated backfill plant for underground support. The smelter operates 7,400 hours per annum (84.5% availability) and can treat a Kamoa:Kakula concentrate blend ratio up to 70:30; beyond this ratio, the DBF heat balance becomes unmanageable and acid plant capacity is exceeded. Early ramp-up challenges—VPSA oxygen plant underperformance, launder blockages at Anode Furnace No. 3, and skull formation in cast iron ladles—are being addressed with additional oxygen modules, burner installations, and procurement of insulated ladles. As of the effective date (March 2026), the smelter operates at approximately 70% of nameplate capacity. Sustainability initiatives include waste heat recovery generating 8 MW of electrical power and a DCDA sulphuric acid plant that captures SO₂ emissions, producing 783 ktpa of acid for sale or reagent use. The concentrators achieve high water recirculation via thickener overflow and clarifiers, minimizing fresh water intake. The Kamoa-Kakula complex is a benchmark for modern copper recovery in the DRC, with future outlook including further debottlenecking of the Kamoa concentrator to its original 10 Mtpa modular design and complete smelter ramp-up to 500 ktpa copper anode, strengthening its position as a top-tier global copper producer.
Key Processes: Flotation, Gravity Separation, SAG Mill, Ball Mill, Crushing
Target Commodities: Copper, Zinc, Lead
