Underground development at TSX-listed Ivanhoe Mines’ Kamoa-Kakula copper project, in the Democratic Republic of Congo (DRC), totalled 2 069 m in September, setting a new monthly record for the project by bringing the total underground development to more than 22.6 km – 7 km, or 44%, ahead of schedule.
The underground development comprises 1 694 m at the Kakula mine and 373 m at the Kansoko mine.
Several underground development headings at the Kakula mine have now transitioned into the higher-grade ore zones near the centre of the deposit, with grading between about +5% copper and +8% copper.
October will be the first month of mining in Kakula’s high-grade ore from the southern access drives and this ore will be stored on a separate high-grade surface stockpile near the southern decline.
Mining on the northern side of the orebody will also soon intersect the higher-grade ore.
In addition to driving the main connecting access drives, underground mining crews at Kakula are focused on preparation work for developing the high-grade drift-and-drill stoping blocks in the centre of the orebody, where the average grade is up to +8% copper.
Opening up of the mining footprint for these high-grade stoping areas entails development work in areas of low-, medium- and high-grade ore, and is designed to coincide with the startup of the processing plant next year.
This will allow mining crews to deliver high-grade stoping ore directly from the underground to the processing plant, Ivanhoe says.
Underground development at the Kansoko mine is in low-to-medium-grade orezones, grading between about +2% and +3% copper. Kansoko is being developed by training crews and will be a supplemental source of ore when the Kakula concentrator processing capacity doubles to 7.6-million tonnes a year, which is currently planned to be commissioned in the second quarter of 2022.
Pre-production surface ore stockpiles now total more than 803 000 t.
“The new underground record achieved in September puts development progress months ahead of plan,” says Ivanhoe CEO Mark Farren, who adds that the next major milestone in the mine’s development will be the joining of the northern and southern access drives, which is expected to occur in November.
Once this is achieved, the opening up and ledging of the drift-and-fill blocks can start in the high-grade core of the deposit, where the average grade is up to +8% copper.
In terms of production, initial production at the Kakula mine processing plant is scheduled for the third quarter of 2021.
Kakula is projected to be the world’s highest-grade major copper mine, with an initial mining rate of 3.8-million tonnes a year at an estimated average feed grade of more than 6% copper over the first five years of operation.
Kakula is also the first of multiple, planned, high-grade mining areas on the 400 km2 Kamoa-Kakula mining licence.