Ivanhoe Mines (39.6%) and Zijin Mining (39.6%) continue to make rapid progress at the Kamoa-Kakula copper mining complex in DRC. An expansion in the initial processing plant capacity from 3 Mt/y to 3.8 Mt/y is already factored in, which requires increasing the underground mining crews in 2020 from 11 to 14 to ensure sufficient mining operations to feed the expanded plant throughput. This would have the benefit of producing a larger surface stockpile of ore prior to the scheduled commissioning of the processing plant, as well as accelerating the mine development schedule, providing the opportunity to bring forward the commencement of the second phase of development at Kakula.
Construction of the initial 3.8 Mt/y process plant is in progress with over 9,000 cubic metres of concrete poured and numerous work areas under construction. Fabrication of structural steel, processing plant components, and the ball mills is underway. Initial copper concentrate production is scheduled for the third quarter of 2021.
The ball mill manufacturing is proceeding at leading Chinese processing equpiment OEM CITIC Heavy Industries Co Ltd (CITIC HIC) at its factory in Luoyang. The process plant long lead items have started to arrive on site, with the ball mills scheduled to arrive in mid-2020. The initial shipment for the first line includes a 7,800 kW primary ball mill 21 ft by 31.5 ft and a secondary ball mills of the same power rating and size. The final operation will include two modules so two of these lines (each of the two 3 Mt/y grinding lines having a primary and secondary ball mill).
The concentrate regrind milling circuit consists of a single module, comprising three high intensity 355 kW Metso Stirred Media Detritor (SMD) regrind mills, operating in open circuit with a cluster of 8 x 250 mm diameter cyclones.
The expanded plant will have a rougher flotation circuit consisting of two identical modules (with one used for now), each comprising of a single bank of seven 300 m3 mechanically agitated, forced air flotation tank cells in series, to produce two concentrate products. Space provision was made for an eighth cell at the head of the flotation bank, in order to process 7.6 Mt/y if required. The high-grade cleaner flotation circuit will consist of two identical modules (again one per process line), comprising of a single low entrainment Jameson flotation cell from Glencore Technology, to produce the final high-grade concentrate product. The scavenger cleaner flotation circuit will consist of two identical modules, one per line, each comprising of a single bank of 6 x 160 m3 mechanically agitated forced air flotation tank cells in series.
Basic engineering design for the detailed planned project expansion from 3.8 Mt/y to 7.6 Mt/y is also currently underway. The scope of facilities includes underground expansion at Kakula, the commencement of mining operations at Kansoko, the second 3.8 Mt/y concentrator module at Kakula as well as associated surface infrastructure to support the expansion at the various sites. The basic engineering is expected to be complete by mid-2020. The second 3.8 Mt/y plant module will be primarily fed from the Kakula mine at a planned full production mining rate of 6 Mtpa. Further study work will determine the amount of tonnes to be sourced from the Kansoko mine, or elsewhere, to maximise the full milling capacity of 7.6 Mt/y. Any plans to accelerate the second module of Kakula’s processing plant would be subject to securing the necessary project-level financing and an independent definitive feasibility study on increased production mining rates from 6 Mt/y to 7.6 Mt/y.
In the mine, underground development at the Kakula copper mine continues to advance ahead of schedule and more than 14.4 km of underground development now has been completed ─ 4.4 km ahead of plan. The pace of development is expected to continue to accelerate as additional mining crews are mobilised.
In April, crews at Kakula began mining ore in areas with a grade of greater than 8% copper. This ore is being stockpiled on a dedicated high-grade surface stockpile, which is forecast to contain 105,000 t grading 5.95% copper by the end of May, 2020. Kakula’s medium-grade ore stockpile is forecast to contain an additional 250,000 t at 3.01% copper. The high-grade stockpile is projected to significantly expand in the coming months as the majority of Kakula’s underground development will be in mining zones grading +5% copper.
Mine access drives 1 and 2 (interconnected, parallel tunnels that will provide access to ore zones) continue to progress well towards the southern portion of the orebody. Development also is well advanced on the eastern perimeter drives and the room-and-pillar mining area.
Development from the southern portal has reached south access drives 1 and 2, with mining crews working to establish the connection of these drives with mine access drives 1 and 2 from the north side of the orebody, which is scheduled to occur in September 2020.
Project engineering and procurement activities are advancing well. The current primary construction focus that runs through the project’s critical path is the installation of the underground rock handling system, the processing plant and the electrical high-voltage infrastructure installation. Construction of the underground rock handling system is almost complete, with certain commissioning activities underway. There have been some commissioning delays associated with the site lockdown due to the COVID-19 pandemic. This has affected delivery of commissioning equipment and the deployment of commissioning engineers. The revised date for the first ore delivered to surface on the conveyor system is June 2020.
The reaming of Ventilation Shaft 2 recently was finished in March 2020, bringing the number of 5.5-m diameter ventilation shafts completed at Kakula to three (Ventilation Shafts 1 & 2, and Ventilation Shaft North West). The raise bore machine has been moved to Ventilation Shaft North East to start drilling a pilot hole. Ventilation Shaft 1 was fully commissioned with high-capacity fans installed in 2019, while Ventilation Shaft North West and Ventilation Shaft 2 are expected to be commissioned later this year. Ventilation Shaft North East is scheduled to be commissioned in March 2021.