Kakula underground mine development has reached the edge of the high-grade ore as mining advances toward zones in excess of 8% copper Mine surpasses 16 million hours, or more than 7.5 years, worked without a lost-time injury
September 8, 2019
Kakula underground mine development has reached the edge
of the high-grade ore as mining advances toward zones in excess
of 8% copper
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
KOLWEZI, DEMOCRATIC REPUBLIC OF CONGO – 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
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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.
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Figure 1: The 13.3-kilometre-long Kakula Deposit showing the first five years of
underground development and production focused on the pink area containing
copper grades greater than 8% copper. Zoomed-in area is shown in Figure 2.
Figure 2: The first tunnel (blue) to reach the high-grade Kakula orebody (brown)
with copper grades between 3% and 8%. The tunnels will advance toward the
ultra-high-grade copper zone (pink) with copper grades greater than 8%.
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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.
Figure 3: Projected increasing copper grades across the initial orebody crossing,
from hole DD1039 progressing through to hole DD1026, highlighted by the high-
grade footwall loading in the siltstone unit above the sandstone contact.
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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.
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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).
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Kakula’s main box cut/portal and northern declines, the conveyor belt transfer
foundations and portal electrical substation.
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Installing high-capacity fans at Kakula’s 5.5-metre-diameter ventilation shaft 1
that will supply fresh air from surface to the northern side of the underground
Kakula orebody.
Kamoa-Kakula’s mine development team and geologists celebrating another
impressive safety milestone. Ivanhoe Mines is very proud of the team’s safety
record that now exceeds 7.5 years with zero lost-time injuries.