The Kamoa Copper project is located in the Kolwezi District, Katanga, Democratic Republic of the Congo (DRC). The project includes an underground mine and a concentrator plant that produces blister copper and sulphuric acid.
With an indicated resource of approximately 740Mt, Kamoa is regarded as Africa’s largest, high-grade copper discovery and the world’s biggest, undeveloped high-grade copper discovery.
The mining licence for the project, valid for 30 years, was granted by the government of the DRC in August 2012. Construction of the box cut began in July 2014 and the mine is anticipated to start production in 2017. The Kamoa project is expected to have an operational lifetime of 30 years.
LOM production plan schedule recommends 125.2Mt to be mined at an average copper yield of 3.81%, producing 11.4Mt of high-quality copper concentrate, including about 9.2 billion pounds of copper.
Ivanhoe Mines, through its subsidiary African Minerals Barbados Limited (AMBL), holds a 95% interest in the project. The remaining 5% share was transferred to the DRC Government on 11 September 2012 as a non-dilutable interest in AMBL, pursuant to the DRC Mining Code.
Location, geology and mineralisation of Kamoa copper mine
The Kamoa copper project is a large stratiform copper deposit, located approximately 25km west of Kolwezi town, and approximately 270km west of the provincial capital of Lubumbashi. The deposit is located within the Central African Copper belt and forms a part of the interpreted extension of the Western Foreland unit of north-western Zambia.
Sediment-hosted stratiform type of mineralisation is identified at the Kamoa mine. The mineralisation is hosted in either marine or red-bed sediments.
Most of the additional copper resources of Kamoa were hosted in the ultra-high-grade Bonanza zone and the Far North area.
Kamoa project reserves
The Kamoa is estimated to contain indicated mineral resources of 760Mt graded at 2.73% Cu, containing 45.8 billion pounds of copper. Inferred mineral resources are estimated to be 235Mt grading at 1.7% Cu as of January 2020.
In multiple mining zones, a probable mineral reserve of approximately 125.2Mt grading at 3.81% copper was defined to support a 6Mtpa production over 26-year mine life.
Kamoa copper mine development phases
The Kamoa copper project will follow a two-staged development approach. The first phase is aimed at mining the high-grade copper mineralisation from shallow, underground resources to yield a high-value concentrate. The mine and the mill will be expanded in the second phase in addition to constructing a smelter to produce blister copper.
The copper mine and concentrator complex at Kamoa will initially operate at a rate of three million metric tonnes per annum (mmtpa). The concentrator will comprise an MF2 circuit configuration, designed to achieve 85.4% recovery at 32.8% Cu concentrate grade.
Mining and processing
The room-and-pillar mining method is proposed for the shallower mineralisation at the Kamoa project, while the drift-and-fill method is proposed for deeper sections. The underground mine will be accessed through two portals and the initial mining target will be the Kansoko Sud mineralised zone.
Ore from the mine will be processed in a three-stage crushing circuit, and the primary and secondary ball mills will operate in a closed circuit with hydrocyclones. Ore will then be delivered to the flotation circuit, which will consist of roughers and scavengers with a re-grind mill between the rougher and scavenger stages.
Material from the flotation circuit will be cleaned in a cleaner circuit comprising cleaners, scavenger cleaners and re-cleaners. The final concentrate will be thickened before pumping to the concentrate filter. It will be stored at the concentrate shed before being fed to the smelter.
The smelting process will include the use of direct to blister flash (DBF) smelting technology, wherein the copper concentrate will be processed by flash smelting to produce blister copper (98% Cu). The produced blister copper will be transferred for anode furnace treatment, which refines and casts them as saleable anodes.
The on-site smelter is estimated to annually produce 300,000t of blister copper, along with 1,600t of sulphuric acid a day as a by-product. The sulphuric acid is proposed to be sold to copper-oxide mining operations at the Central African Copper belt.
A full production schedule will be maintained by a 26-year LOM over 17 years.
Infrastructure facilities at Kamoa
Power supply for the copper mine will be provided by La Société Nationale d’Electricité (SNEL), DRC’s national electricity company, under a financing agreement made in March 2014. SNEL is proposed to supply power from the Mwadingusha, Koni and Nzilo 1 hydroelectric power plants.
Contractors involved with the Kamoa mine development
AMC Consultants, AMEC E&C Services, SRK Consulting, Stantec Consulting International, Hatch, and Golder Associates Africa participated in the preparation of the preliminary economic assessment (PEA) for the Kamoa project.
African Mining Consultants was engaged to conduct the regulatory environmental baseline study (EBS) and the corresponding report for the project.
AMEC E&C Services additionally prepared the mineral resource estimate report for the Kamoa copper project. Hatch was engaged to prepare a development study for the copper project.
Katanga SPRL (MCK) was engaged for the construction of the box cut for the initial decline portals at Kamoa.