Ivanhoe Mines announces restart of underground mining
June 11, 2025
Ivanhoe Mines announces restart of underground mining
operations on western side of Kakula Mine on June 7, 2025
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Underground water levels in Kakula Mine stabilized;
dewatering to commence in Q3 2025
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Kamoa-Kakula revises 2025 production guidance to between
370,000 and 420,000 tonnes of copper
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Smelter start-up expected to commence in September 2025,
with first anode anticipated in October 2025
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Ivanhoe Mines to host a conference call for investors before
market open on June 12, 2025
KOLWEZI, DEMOCRATIC REPUBLIC OF THE CONGO – Ivanhoe Mines (TSX: IVN;
OTCQX: IVPAF) Executive Co-Chairman Robert Friedland and President & Chief
Executive Officer Marna Cloete announce today an update on operational activities
at the Kamoa-Kakula Copper Complex, including preliminary geotechnical findings
relating to underground seismic activity experienced at the Kakula Mine, as first
announced on May 20, 2025.
Underground mining on the western side of the Kakula Mine has resumed in a safe
and conservative manner, with equipment and mining crews returning
underground on June 7, 2025. The short-term mine plan for the western side of
Kakula has been updated to include recommendations from the preliminary
findings.
Mining activities in the eastern side of the Kakula Mine are expected to start
imminently, with activities solely focused on developing access drives to a new
mining area east of the existing mine workings. Development to the new mining
area will be isolated from the dewatering activities on the same side of the mine.
As announced on June 2, 2025, additional underground pumping capacity was
installed at the Kakula Mine, stabilizing underground water levels. The frequency
of seismic activity has decreased since first reported on May 18, 2025. Dewatering
the eastern side of the Kakula Mine is expected to commence in August 2025 and
be complete during the fourth quarter.
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Recommendations from the preliminary geotechnical findings from world-leading
experts have been included in the short-term mine plans for the Kakula Mine to
ensure a safe restart of underground operations. Concurrently, medium- and long-
term mine plans are under review by Kamoa-Kakula management, together with
technical consultants.
The Phase 1 and 2 concentrators continue to operate at approximately 50% of their
combined operating capacity, processing ore from surface stockpiles. The
processing rate of the concentrators will ramp up throughout the remainder of
2025, as mining on the western side of the Kakula Mine increases, supplemented
by feed from ore stockpiles. Mining operations at the Kamoa underground mine,
as well as ore processing at the adjacent Phase 3 concentrator, continue to
outperform.
With the necessary copper concentrate expected to be available, the on-site
copper smelter is anticipated to start up in September, with first anode expected in
October 2025.
Ivanhoe Mines Executive Co-Chair, Robert Friedland commented:
“We are thankful and deeply appreciate our team’s swift response to stabilize
underground water levels in the Kakula Mine and resume mining on the western
side. The team has quickly secured the critical equipment needed to safely
dewater the entirety of the mine, while preparing to access a new high-grade
mining area in the east.
“While it’s still too early to outline our detailed plans for 2026 and 2027, the future
remains bright across the Kamoa-Kakula Copper Complex and adjacent Western
Forelands Exploration Project. Kamoa-Kakula is, and will continue to be, a world-
class Tier One operation, with decades ahead of us as one of the world’s leading
copper producers.”
President & Chief Executive Officer, Marna Cloete, commented:
“We are working tirelessly to safely and systematically restore full operations at
the Kakula Mine. Safety has always been, and will always remain, our highest
priority. We want to extend our sincere thanks to the mining crews, the
engineering teams and our long-term contractors for their extraordinary efforts in
restoring pumping capacity and restarting operations, all without any lost time
injuries.
“The resilience of our team and the strength of our operations reflect the
extraordinary nature of this world-class copper district—and the future it holds for
generations to come.”
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Figure 1. Outline of the Kakula and Kakula West orebody, overlaid with the
underground development since mining commenced in 2021. A significant
portion of the original Kakula deposit remains unmined as of May 2025.
Notes: Existing underground development as at May 2025. Illustration is based on the 2023 Kamoa-Kakula
IDP showing the estimated average grade of each vertical stack of blocks above a 2% total copper cut -off.
A minimum 3-metre thickness is applied.
Underground water levels in Kakula Mine have stabilized; underground
mining recommences on the western side of Kakula
Although water inflow rates into the Kakula Mine modestly increased following the
initial seismic activity, they have since stabilized at approximately 4,000 litres per
second. With existing underground pumping infrastructure impacted by the
seismic activity, a total of approximately 4,400 litres per second of additional
underground pumping capacity was installed, stabilizing underground water
levels. The new pump stations feed into the existing central pumping
infrastructure, where the water is then pumped to surface at four locations near
the bottom of the north and south twin declines, as shown in Figure 2.
With water levels stabilized, mining in the western side of the Kakula Mine has
restarted. Mobile equipment and mining crews, which were evacuated from the
mine on May 18, 2025, are returning underground, with the first blast having
occurred on June 7, 2025. Short-term mine plans have been updated to include the
recommendations from the preliminary geotechnical findings. Kamoa-Kakula’s
mining crews aim to ramp up mining from the western side of the Kakula Mine to
approximately 300,000 tonnes per month (3.6 million tonnes per year on an
annualized basis) during the second half of 2025, subject to underground
conditions.
For the remainder of 2025, Kakula’s underground mining crews will focus on three
activities: ramping up mining on the western side of the Kakula Mine; developing a
new mining area on the eastern side of the Kakula Mine; and ramping up
production from the Kamoa mining area.
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Figure 2: Overview of Kakula Mine’s existing underground infrastructure,
showing current pumping rates, future pumping capacity and depth of mine
workings.
The additional mining crews deployed to the Kamoa mining area, approximately 10
kilometres north of Kakula, will assist the existing teams with underground
development, as well as decline development from the construction of a new box
cut planned at the Kansoko Mine. The new box cut will enable increased
production from Kansoko, providing an additional source of ore for the Phase 1
and Phase 2 concentrators.
Mining crews to focus on new mining area in eastern side of Kakula;
development to commence imminently, isolated from dewatering
activities
Mining in the eastern side of the Kakula Mine will follow a new mine plan,
prioritizing development to a new mining area further east, beyond the existing
mine workings. The new mining area will be separated from the existing mine
workings by a barrier pillar. The barrier pillar is designed to protect the new
mining area from any potential spread of geotechnical instability from the existing
mining area.
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Mining crews will construct two new access drives to the new mining area, which
are expected to start imminently. The new access drives will be developed
simultaneously, advancing east from existing underground infrastructure, as
shown in Figure 2. Development to the new mining area is expected to be
conducted in both ore and waste and be completed in the second quarter of 2026.
The new development drives will be isolated from the mine workings that being
dewatered and will advance independently of dewatering activities.
Following the completion of dewatering activities on the eastern side of Kakula, a
physical geotechnical inspection of the mine's existing workings will be
conducted, concluding the full assessment by the geotechnical experts. The
results of this assessment will determine the approach and extent of mining in this
area.
As shown in Figure 2, the mine workings are at their deepest on the eastern side
of the mine and therefore underground flooding is predominantly concentrated
around this area. The Kamoa-Kakula engineering team has a two-stage plan to
dewater the entire Kakula Mine.
Stage One involves the installation of additional temporary underground pumping
infrastructure to stabilize and maintain current water levels. Stage One was
completed as announced on June 2, 2025.
Stage Two involves the installation of high-capacity, submersible pumps, and new
permanent infrastructure to fully dewater the entire Kakula Mine from surface.
Kamoa Copper has ordered five high-capacity pumps, each rated at 650 litres per
second. Additional pumps will also be ordered as part of the long-term pumping
infrastructure plan. These pumps will be deployed in pairs down existing shaft
infrastructure, accessing the deepest sections of the Kakula Mine as shown in
Figure 2. Dewatering activities are expected to commence in August 2025.
Engineering crews will refurbish underground pumping and ventilation
infrastructure, as well as complete geotechnical assessments, as water levels
subside. Dewatering of the entire Kakula Mine is expected to be complete during
the fourth quarter.
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Looking south: The two existing shaft locations where the “Stage Two”
dewatering surface pumping infrastructure will be installed to dewater the
eastern side of the Kakula Mine. Water will be discharged into existing
surface water channels (right of picture).
Looking north with the Phase 1 and 2 concentrators in the background: One
of the two shaft locations shown in the foreground that will be used for the
“Stage Two” dewatering of the deepest area of the Kakula Mine.
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A high-capacity submersible pump, similar to those being procured by
Kamoa Copper for dewatering the Kakula Mine, prior to being lowered down
a shaft at the Luansha Copper Mine, Zambia in September 2024. Photo
source: CNMC (China Nonferrous Metal Mining Group Co., Ltd).
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Preliminary geotechnical findings on the cause of recent seismic
activity
Two prominent, independent geotechnical engineering organizations, Beck
Engineering of New South Wales, Australia (Beck Engineering) and Open House
Management Solutions of Potchefstroom, South Africa (Open House), were
engaged and mobilized to Kamoa-Kakula shortly after seismic activity was first
detected on May 18, 2025. Both consulting engineering firms have been working
diligently with Kamoa-Kakula’s engineering team, with support from Ivanhoe
Mines.
Preliminary findings indicate that the seismic activity originated in an area within
the eastern side of the Kakula Mine with a mature percentage of extraction.
Current thinking postulates that blocks of ore, earmarked for secondary
extraction, started to yield in a cascading fashion, which resulted in stress
redistribution onto regional pillars. As a consequence, the regional pillars became
over-stressed and started to yield. The backfill, placed in mined-out stopes, was
not capable of preventing the stress redistribution onto regional support pillars,
but may have been a mitigant. The possibility that adverse regional geological
features may have exacerbated the yielding of regional pillars cannot be excluded
at this time. Pillars are sections of untouched ore or rock left in place to support
the roof of the mine, while stopes are mined-out areas. Backfill is the process
whereby mined-out stopes are filled with a mixture of concentrator tailings and
cement, which cures to achieve a targeted strength.
The geotechnical assessment has not yet been finalized as it relies on physical
access to the eastern section of the Kakula Mine once dewatering is completed.
The preliminary findings recommend modifying the short-term mine plans to
increase pillar widths for additional structural support. The findings also advise
changes to the mining sequence to improve stress distribution and overall
stability. Furthermore, enhanced geotechnical monitoring will be installed
throughout the mine.
Kamoa-Kakula’s management, together with Beck Engineering, Open House and
other technical consultants, are evaluating any changes to the short-, medium-
and long-term mine plans in light of these preliminary geotechnical findings.
Work on an updated life-of-mine integrated development plan, which was
underway before the seismic activity occurred, has been paused until Ivanhoe
Mines’ engineering team and its panel of technical experts have reviewed and
agreed on any updated assumptions. Ivanhoe Mines will provide a timing update
on the delivery of an updated IDP once work recommences.