The plan involves increasing the combined design processing capacity of the Phase 1 and Phase 2 concentrator plants by approximately 21%, to 9.2 million tonnes per year (t/y) of ore, up from 7.6 million, once steady-state production is achieved at both concentrators.
Upon completion of the de-bottlenecking initiative, annual copper output at Kamoa-Kakula’s Phase 1 and Phase 2 plants is expected to reach 450,000 tonnes by the second quarter 2023 –positioning Kamoa-Kakula as the world’s fourth largest copper producer.
The de-bottlenecking project has an estimated cost of approximately $50 million and is expected to take about 12 months to complete.
“Kamoa-Kakula is blessed with an incredible endowment of high-grade copper resources. Given that our underground mine development and ore production are both progressing well ahead of schedule, the plant expansion will allow the operations team to process significantly more high-grade copper ore directly from the Kakula mine in the years ahead,” Mark Farren, CEO of Ivanhoe’s Kamoa Copper unit, said in a press release.
“Our orebody has a huge advantage in allowing us to adapt our mining cut-off to mine larger tonnages very efficiently, while maintaining grades above a desired level. The expansion also provides the team with the flexibility to utilize our surface stockpiles, for which the mining is already paid for, that totalled more than 4.4 million tonnes grading 4.61% copper at the end of January,” Farren added.
Meanwhile, Ivanhoe has also confirmed that construction of Kamoa-Kakula’s Phase 2, 3.8 million t/y concentrator plant is almost complete, with early-stage commissioning activities now underway. Hot commissioning of the concentrator with first ore and initial copper concentrate production are both on track for April 2022.
Engineering and early works for the Phase 3 expansion, including a new box cut and twin declines to access new mining areas, is also progressing quickly. A third, significantly larger concentrator is being designed and is expected to commissioned in the fourth quarter of 2024.
An updated pre-feasibility study, including the Phase 3 expansion, is expected in the third quarter of 2022. Also underway are early works on a direct-to-blister flash smelter at Kamoa-Kakula that will incorporate technology supplied by Metso Outotec of Finland, and have a nameplate capacity of 500,000 t/y of approximately 99%-pure blister copper.
The Phase 1 concentrator is currently running at a throughput that is in excess of its 3.8 million t/y design capacity by more than 22%, with 112% of design throughput achieved in January. Copper recoveries of above 87% also are consistently being achieved that are in excess of design recovery of 85.6%.
However, despite the Phase 1 concentrator incurring significant downtime for critical tie ins and changes required for the commissioning of the Phase 2 concentrator, the copper in concentrate produced in January still totalled 18,824 tonnes ─ almost the same as December’s record of 18,853 tonnes.
“After successfully operating the Phase 1 concentrator for more than eight months, we’ve identified a number of relatively minor modifications to the concentrator that should increase ore throughput from the current design of 475 t/h to 580 t/h,” Steve Amos, Ivanhoe Mines’ head of projects, DRC, explained.
According to Amos, modifications made through the de-bottlenecking initiative “will allow the team to consistently operate the concentrator plant at the increased throughput without compromising plant availability, copper recovery or copper concentrate grade.”
Last year, the Kamoa-Kakula project outputted more than 100,000 tonnes of copper concentrate, exceeding the upper end of Ivanhoe’s annual production guidance. This year, the company has set its guidance at between 290,000 and 340,000 tonnes.