Resumption of Underground Mining in the Western Section of the Kakula Mine

According to Ivanhoe Mines: Robert Friedland, Executive Co-Chairman of Ivanhoe Mines (TSX: IVN; OTCQX: IVPAF), Weibao Hao, Co-Chairman, and Marna Cloete, President and Chief Executive Officer, announced today the latest operational updates for the Kamoa-Kakula copper mine project, as well as the preliminary findings of the geotechnical investigation following the seismic event at the Kakula mine announced on May 20, 2025.

Mining operations in the western section of the Kakula mine were safely and prudently restarted on June 7, 2025, with equipment and mining crews returning underground to resume production. The short-term mining plan for the western section of the Kakula mine has been updated to incorporate the recommendations summarized in the preliminary investigation report.

It is expected that mining operations in the far eastern section of the Kakula mine will also resume as soon as possible, with a focus on development work to open up access to new mining areas east of the existing mining zones. The development work in the new mining areas of the far eastern section of the Kakula mine will be carried out in a spatially isolated manner from the pumping work areas and is expected to be completed in the second quarter of 2026.

On June 2, 2025, the company announced that additional pumping equipment had been installed at the Kakula mine to maintain stable water levels. Since the initial announcement on May 18, 2025, the frequency of seismic events has also decreased. Pumping operations are expected to commence in the eastern section of the Kakula mine in August 2025 and be completed in the fourth quarter.

The recommendations made by world-class geotechnical experts based on the preliminary investigation findings have been incorporated into the short-term mining plan for the Kakula mine to ensure the safe restart of mining operations. Meanwhile, the management and technical advisors of Kamoa-Kakula are developing and reviewing the medium- and long-term mining plans for the mine.

The Phase 1 and Phase 2 beneficiation plants continue to operate at approximately 50% of their combined capacity, processing ore from surface stockpiles. With the resumption of mining operations in the western section of the Kakula mine, ore supply to the beneficiation plants will increase, and the Phase 1 and Phase 2 beneficiation plants will gradually ramp up production over the remainder of 2025, with ore supply supplemented by ore mined from the western section of Kakula. Mining activities at the Kamoa underground mine and the adjacent Phase 3 beneficiation plant continue to operate normally without any disruptions.

It is expected that the smelter located on the mine site will commence operations in September 2025 and produce its first copper anodes in October, once copper concentrate production and inventory levels meet the required conditions.

Robert Friedland, Executive Co-Chairman of Ivanhoe Mines, commented, "We are grateful and deeply appreciate the swift response of the on-site team in stabilizing the groundwater levels at the Kakula mine and resuming mining operations in the western section. Critical dewatering equipment required to ensure the safety of the entire mine was rapidly deployed, while preparations were actively underway to advance as quickly as possible into the Kakula Far East zone to open up new high-grade mining areas."

"Although it is still too early to outline detailed plans for 2026 and 2027, the prospects for the Kamoa-Kakula copper mine and the adjacent Western Foreland exploration project remain bright. Kamoa-Kakula is, and will continue to be, a world-class mine, maintaining its leading position among the world's copper producers for decades to come."

President and CEO, Mark Cutifani, commented: "We are working tirelessly to safely and methodically restore full operations at the Kakula mine, with safety as our top priority! We would like to express our sincere gratitude to the mining team, engineering team, and our many long-standing contractors for their outstanding contributions in restoring dewatering capacity and restarting mining operations, all without any lost-time incidents."

"The resilience and operational strength demonstrated by our team underscore the extraordinary nature of this world-class copper district – and the bright future it will create for generations to come."

Following the seismic event, although the inflow of water into the Kakula mine's underground workings gradually increased, it has now stabilized at approximately 4,000 liters per second. Due to the impact of the seismic event on existing underground dewatering facilities, additional underground dewatering capacity totaling approximately 4,400 liters per second has been installed, helping to stabilize the groundwater level. The new pumping stations are connected to the existing central dewatering infrastructure and then discharge water to the surface through four locations near the bottom of the northern and southern twin declines, as shown in Figure 2.

With the stabilization of the water level, mining operations have resumed on the western side of the Kakula mine. Mobile equipment and mining crews, which were evacuated from underground on May 18, 2025, have now returned to the underground workings and conducted their first blast on June 7, 2025. The short-term mining plan has been updated to incorporate recommendations from the preliminary geotechnical investigation report. Based on underground conditions, Kamoa-Kakula's mining crews plan to increase mining volumes on the western side of the Kakula mine to approximately 300,000 mt per month (or 3.6 million mt per year on an annualized basis) in H2 2025.

In Q3, mining operations will ramp up the mining capacity in the Kakula West Zone to 3.6 million mt/year, with further adjustments to be made based on underground conditions.

In H2 2025, the underground mining team will focus on implementing three major projects: ramping up the mining capacity in the Kakula West Zone, constructing a new mining area in the Far East Zone of the Kakula Mine, and ramping up the mining capacity in the Kamoa Mining Area.

Additional operational personnel have been deployed to the Kamoa Mine, located approximately 10 kilometers north of the Kakula Mine, to assist the existing mining team in underground excavation works, as well as in the construction of newly designed box-cut and ramp development at the Kansoko Mine. The new ramp will help increase the mining capacity at Kansoko and further supplement the ore supply required by the Phase 1 and Phase 2 beneficiation plants.

The Far East Zone of the Kakula Mine will adopt a new mining plan, focusing on development works further east of the existing mining area. The new mining area and the existing mining area will be separated by a safety pillar to prevent the rock mechanics instability in the existing mining area from propagating to the new mining area.

The mining team is expected to soon commence construction of two new main access tunnels. The two main tunnels will be constructed simultaneously, advancing eastward from the existing underground infrastructure (see Figure 2). The construction of the new mining area will involve the extraction of ore and waste rock, and is expected to be completed by Q2 2026. The new access tunnels will be isolated from the mining faces currently being dewatered, and dewatering operations will also be conducted separately and independently.

Upon completion of dewatering in the East Zone of the Kakula Mine, in-situ geotechnical observations will be conducted in the existing mining area, followed by a comprehensive evaluation by geotechnical experts. The evaluation results will determine the future scope of production resumptions in the existing mining area.

Underground water inflow is mainly concentrated in the deepest part of the East Zone of the mine (see Figure 2). The Kamoa-Kakula engineering team has developed a phased plan for dewatering the Kakula Mine.

Phase 1: Install temporary pumping facilities underground to maintain the existing water level stable. Phase 1 was completed on June 2, 2025.

Phase 2: Install large-power pumps and a permanent pumping system that can be operated from the surface to conduct comprehensive dewatering operations throughout the Kakula Mine. Kamoa Copper has ordered five large-power pumping units, each with a dewatering capacity of 650 liters per second. The long-term plan also includes the procurement of additional pumping units, which will be deployed in pairs in the existing shafts to the bottom of the Kakula Mine (see Figure 2). Dewatering is expected to commence in August 2025. As water levels gradually decline, the engineering team will begin repairing the underground pumping, ventilation, and other systems, and complete the geotechnical engineering assessment. It is expected that the dewatering work in the eastern section of the Kakula Mine will be completed in Q4.

Following the first mine seismic event on May 18, 2025, the company promptly engaged two renowned and independent geotechnical consulting firms, Beck Engineering from Australia and Open House Management Solutions (hereinafter referred to as "Open House") from South Africa, to conduct an investigation at the Kamoa-Kakula Mine. With the support of Ivanhoe Mines, the two consulting firms worked closely with the Kamoa-Kakula engineering team.

The preliminary investigation results indicate that the mine seismicity originated from areas in the eastern section of the Kakula Mine with high ore extraction rates. It is currently believed that the secondary stope, originally planned for Step-2 mining, experienced subsidence-induced yielding deformation, leading to stress redistribution and transmission to the pillars in the area. This, in turn, caused the pillars to yield and deform due to excessive bearing stress. Although backfilling of the mined-out areas could not prevent stress redistribution to the regional pillars, it may have mitigated the effects in some cases. Meanwhile, it cannot be ruled out that adverse geological factors within the area exacerbated the yielding deformation of the pillars. Pillars are unmined ore or rock left in place to support the roof of underground voids; mined-out areas refer to spaces underground where mining has been completed. Backfilling is the operation of filling mined-out areas with a mixture of tailings and cement, which, after consolidation, can achieve the target strength.

The geotechnical evaluation has not yet been completed and will be further detailed in the eastern section of the Kakula Mine after the dewatering operations are finished.

The preliminary investigation results recommend changes to the short-term mining plan to increase the width of the pillars, thereby providing stronger structural support. The results also suggest adjusting the mining sequence to improve stress distribution and overall stability. Additionally, an enhanced rock mechanics monitoring system will be installed throughout the mine.

The management of Kamoa-Kakula, along with Beck Engineering, Open House, and other technical consultants, are making revisions to the short-term, medium-term, and long-term mining plans based on the geotechnical investigation findings.

Prior to the mine seismicity, the company was in the process of updating the comprehensive mine life-of-mine development plan, which has now been suspended until Ivanhoe Mines' engineering team and its panel of technical experts complete their review and agree to the relevant changes. After the update work resumes, Ivanhoe Mines will provide updates on the progress of the revised comprehensive development plan.

On June 7, 2025, mining operations in the western section of Kakula were safely and prudently resumed. It is planned to increase the underground mining capacity to 3.6 million mt per year in Q3. Combined with ore from surface stockpiles and supplementary ore from the northern Kamoa Mine, this will be sufficient to support over 80% of the combined designed capacity (9.2 million mt per year) of the Phase I and II beneficiation plants. It is expected that in the second half of the year (H2), the copper grade of raw ore in the Kakula West section will range between 3.0% and 4.0%.

Since the suspension of underground operations on May 18, 2025, the Phase I and Phase II beneficiation plants have been operating at approximately 50% of their combined capacity, processing ore from surface stockpiles.

The Phase III beneficiation plant adjacent to the Kamoa mine (see Figure 3) has maintained excellent operational performance since the beginning of this year. The plant's current average ore processing capacity is equivalent to an annualized capacity of 6 million mt, which is 30% higher than the designed capacity of 5 million mt per year. As of 2025, the average copper grade of ore processed by the Phase III beneficiation plant has been 2.84%. The mining output from the Kamoa and Kansoko mines has increased over the past two months, exceeding an annualized production of 6.8 million mt.

The short-term mining plans for the Kamoa and Kansoko mines have been updated to incorporate recommendations from preliminary geotechnical investigations. The long-term mining plans will be reviewed in conjunction with the overall review of the Kakula mine.

The updated 2025 production guidance for Kamoa-Kakula is based on assumptions and estimates as of June 10, 2025, and involves estimates of known and unknown risks, uncertainties, and other factors that may differ significantly from actual results.

The revision of the 2025 production guidance has taken into account the potential impacts of recent seismic events and the resulting disruptions to mining operations at the Kakula mine. Although mining operations have resumed in the Kakula West section, it is currently impossible to accurately predict potential further seismic events, the resulting disruptions, the integrity of underground infrastructure, the ability to ramp up production in underground operations, the ability to complete dewatering work, and the timing of the commissioning of new mining areas in the Far East section. The updated 2025 production guidance is based on the aforementioned factors, and the company's management believes these considerations and assumptions are reasonable given all currently available information. Figure 4 provides detailed information on the revision of the production guidance.

Senior management at Kamoa-Kakula has confirmed that the one-step copper smelter at the mine site will begin operations in early September 2025, with the first copper anodes expected to be produced in October. Smelters can operate at a minimum of 50% capacity, which is equivalent to an annualized copper production of approximately 250,000 mt.

As of May 31, 2025, there were 33,000 mt of copper in copper concentrates onsite at the mine that had not been sold. It is expected that the first batch of concentrates will be fed into the process approximately four to six weeks after production starts, and it is estimated that there will be a total of approximately 35,000 mt of copper in concentrates in inventory pending sale at that time.

In addition, the senior management of Kamoa-Kakula expects that the Inga II hydropower station's Unit 5 turbine (with a designed power of 178 MW) will be commissioned in October 2025, further increasing the hydropower capacity available to the Kamoa-Kakula copper mine through the domestic power grid.