Ivanhoe Mines: Kakula Underground Mine Development Has Reached the Edge of the High-Grade Ore as Mining Advances Toward Zones in Excess of 8% Copper
Monday, September 9th, 2019
Mine surpasses 16 million hours, or more than 7.5 years, worked without a lost-time injury
Mine and processing plant construction progressing well – On track for first copper concentrate production in Q3 2021
Robert Friedland and Yufeng “Miles” Sun, Co-Chairmen of Ivanhoe Mines (TSX: IVN) (OTCQX: IVPAF) are pleased to report that underground development at the Kakula Copper Mine now has reached the high-grade ore within the deposit.
The advancement of the first connecting underground drift, designed to tunnel through the centre of the high-grade orebody and open up the mine’s initial mineral reserves, has reached the edge of the high-grade ore. Grades of approximately 4% copper have been returned from sampling, and grades are expected to significantly increase as the development crews advance the drifts toward the deposit’s central mining zones that are in excess of 8% copper.
“This intersection marks a significant milestone in the context of our exploration and development efforts at Kamoa-Kakula that began more than 13 years ago,” said David Edwards, Geology Manager, Kamoa-Kakula Copper Project. “Now that you can see and touch Kakula’s high-grade copper ore, it really hits home that we are well underway toward building the first of multiple high-grade copper mines in the area.”
The Kakula connection drift is being developed to rapidly gain access to the highest grades in the centre of the deposit, and also connect with the Kakula South ventilation decline to increase the air flow to the underground working areas in the large-scale mechanized Kakula mining operation, allowing for more development and production mining crews.
The copper grades in the underground connection drift have been steadily increasing as the development approaches Kakula’s siltstone unit (fine-grained sedimentary rocks). The siltstone at Kakula is instrumental in the formation of the highest copper grades and is key to the bottom-loaded nature of copper mineralization in the deposit. The thick, ultra-high-grade mining zones in the centre of the Kakula Deposit, with grades greater than 8% copper, are expected to be intersected in the second half of 2020 (see figures 1 and 2).
Mine geologist Micheline Kyenge examining the initial high-grade copper ore intersected by underground tunneling at the Kakula Mine. Copper mineralization at the mining face is predominantly bornite (63% copper by weight) and chalcocite (nearly 80% copper by weight).
The high-grade ore is being stored on a dedicated run-of-mine stockpile on surface near the planned processing plant to ensure that there is plenty of ore to feed the processing plant during commissioning and ramp up.
The project currently is on schedule to produce first copper concentrate in Q3 2021, with the construction of the Kakula Mine continuing at a rapid pace. Underground development is being performed by mining crews operating large-capacity, semi-autonomous mining equipment, such as jumbo drilling rigs, load haul dumpers and 50-tonne trucks.
Note: The contours in Figure 2 represent the copper grade for the initial development drives, which will follow the bottom contact of the Kakula resource. These grades have not taken into consideration expected dilution and ore loss. As the copper grade is generally richer at the base of the Kakula resource, these contours show higher grades than the overall resource grade.
The grade calculations for Figure 2 are based on a six-metre thickness and 3% copper cut-off grade for the proposed bottom cut for the cut-and-fill areas of the resource and on a 4.5-metre thickness and 2% copper cut-off grade for the proposed room-and-pillar areas of the resource.
Copper-rich bornite and chalcocite mineralization at the face of the underground connection drift at the Kakula Mine.
Project construction progressing well – On track for first concentrate in Q3 2021
Work on the decline rock handling system that will be used to transport copper ore from Kakula’s underground workings to the surface processing plant is progressing very well. The concrete foundations for the head end of the conveyor belt have been completed and work on the portal electrical substation is nearing completion. The expected date for the first ore to surface using the decline conveyor system is March 2020.
Construction of the permanent underground dewatering system is well advanced with the initial water storage dam and pumping station complete. The excavation for the main decline’s bottom water storage dam has been completed and work is underway on the second pumping system.
Ventilation shaft number 1 will be commissioned shortly and work on ventilation shafts 2 and 3 has started. The vertical, 5.5-metre diameter shafts will supply fresh air from surface to the northern side of the underground Kakula orebody and allow the mine to double its underground mining crews to six. More than 5,000 metres of underground development has been completed to date, which is consistent with the schedule laid out in the February 2019 Kakula pre-feasibility study.
Basic engineering design and costing for the underground mine at Kakula recently has been completed. Detailed design is ongoing and the bulk of the procurement packages are scheduled to be placed by the end of 2019.
Engineering design, procurement and construction for the processing plant is fully underway. Orders for all of the long-lead items have been placed, including the ball mills, crushers, high-pressure grinding rolls, flotation cells, re-grind mills, thickeners and concentrate filter. Surface earthworks and terracing for the concentrator and surface infrastructure is well advanced, and the civil contract for the processing plant now has been signed. The tender for the structural, mechanical, piping and plate-work erection contract has been issued.
Energizing of the permanent 220-kilovolt overhead hydropower lines to the substation is expected by the end of 2020, well in advance of plant commissioning.
Construction of the new highway connecting the Kakula Mine with Kolwezi airport is more than 50% complete and remains on schedule to be fully operational by the end of this year. Once completed, the new highway will provide Kamoa-Kakula with important new transportation connections for the import of construction materials and export of copper concentrates. The Kakula permanent village construction also is progressing to plan with some accommodation units ready for occupation.
View of Kakula’s permanent village under construction, with the Kakula’s main box cut/portal and twin declines (in red) illustrated in Figure 2, and processing plant under construction (in yellow).https://www.ivanhoemines.com