Ivanhoe Mines reports Mineral Resources for Makoko and Kiala discoveries in the Western Foreland
November 13, 2023
Ivanhoe Mines reports Mineral Resources for Makoko and Kiala discoveries in the Western Foreland ■ Makoko contains Indicated Mineral Resource of 16 million tonnes at 3.55% copper plus Inferred Mineral Resource of 154 million tonnes at 1.97% copper using a 1.5% copper cut-off ■ Kiala contains Indicated Mineral Resource of 5 million tonnes at 3.56% copper using a 1.5% copper cut-off ■ Makoko ranks as the world’s third-largest and highest-grade copper discovery since Kakula in 2016 ■ Ivanhoe has now discovered 38.7 million tonnes of contained copper in Measured & Indicated Resources and a further 9.4 million tonnes in Inferred Resources across the Western Foreland shelf, including Kamoa and Kakula ■ Mining rights covering Makoko and Kiala discoveries awarded for an initial period of 25 years ■ Western Foreland to benefit from improving DRC infrastructure, including power and the Lobito Rail Corridor, which passes through the licences ■ Western Foreland exploration update on new targets expected before year-end
KOLWEZI, DEMOCRATIC REPUBLIC OF CONGO – Ivanhoe Mines (TSX: IVN; OTCQX: IVPAF) Executive Co-Chair Robert Friedland and President Marna Cloete are pleased to announce the independently verified, maiden Mineral Resource estimates for the high-grade Makoko and Kiala deposits within Ivanhoe’s Western Foreland Exploration Project.
Makoko and Kiala are two distinct discoveries adjacent to the Kamoa-Kakula Copper Complex and continue Ivanhoe’s distinguished track record of making greenfield discoveries in this uniquely endowed geological terrain. The two deposits occur within the 2,407-square-kilometre Western Foreland Exploration Project, which lies adjacent to the 400-square-kilometre Kamoa-Kakula Copper Complex in the Democratic Republic of Congo (DRC). The Western Foreland licences are 80% to 100%-owned by Ivanhoe Mines.
Ivanhoe Founder and Executive Co-Chairman Robert Friedland commented: “These outstanding results are the culmination of over twenty years of effort, starting with grassroots, frontier exploration to define a previously unknown mineral horizon with the potential to host huge copper deposits with spectacular grades.
“The theory was proven to be correct, as our team of visionary geoscientists discovered Kamoa in 2008, followed by the monumental Kakula discovery in 2016. In little over five years, Kakula went from drill core samples to one of the five largest copper mines in the world, with by far the highest grade, thanks to the hard work of our outstanding project and operations teams.
“Ivanhoe Mines’ geologists are rarely quiet for long, and these Mineral Resource estimates for Makoko and Kiala are just the beginning of demonstrating the immense copper mineral potential of the entire Western Foreland basin.
Remarkably, this team is now responsible for the largest copper discovery of the last ten years, the ultra-high-grade giant Kakula discovery, as well as the giant Kamoa discovery and now the fourth largest discovery in Makoko.
“We will be looking into whether Makoko’s near surface mineralized zone is amenable to heap leaching, which if possible, would be both a very low capital intensive, as well as a very low carbon intensive way of producing copper cathode.
“There is much more to come as this story unfolds … we continue to perfect our knowledge of the geological controls of this globally significant copper district … and we are adding to our carefully chosen land position in the region.”
Ivanhoe President Marna Cloete added: “Makoko and Kiala will benefit from significant infrastructure advantages compared to when we developed Kakula, which was built in record time. We are working tirelessly to improve hydropower generation capacity in DRC through the refurbishment of Turbine #5 at the Inga II facility, which is expected to be supplying green hydroelectric power to the grid by the fourth quarter of 2024, as well as ongoing improvements to the grid transmission network.
“The redevelopment of the Lobito Rail Corridor, built with Chinese assistance and now supported by the United States, European Union and G7 nations, passes within a few kilometres of both the Makoko and Kiala deposits. The corridor will dramatically reduce turnaround times, both for inbound construction materials and equipment, as well as for outbound copper products, and will reduce development and operating costs, as well as carbon emissions.
“We look forward to advancing the development of Makoko and Kiala in partnership with our Congolese shareholders, and also to further exploration success from our major drill campaign this year across the Western Foreland land package.”
Figure 1: Top copper discoveries over the past 10 years, plus Kamoa (2008). Makoko and Kiala rank as the world’s third-largest copper discovery since Kamoa-Kakula, and the highest-grade.
30.0 4.0
Contained, M&I 25.0 Contained, Inferred Grade, M&I (%) 3.0 20.0 Grade, Inferred (%)
15.0 2.0
10.0 1.0 5.0
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*The Kamoa discovery, within the larger Kamoa-Kakula Copper Complex, was made in 2008. It has been inserted for reference.
Source: Company filings, S&P Global Market Intelligence. Based on public disclosure as of August 1, 2023. The Makoko and Kiala mineral resources (1.0% cut-off grade) have not been reviewed by S&P Global.. The mineral resource at La Huifa (Codelco) is stated in public disclosures as a geological resource, which is assumed to be an Inferred resource in this chart. Notes: Chart ranks the largest copper discoveries made globally in the last ten years (from January 1, 2013) based on contained copper in resources. Measured and indicated resources are inclusive of reserves and are on a 100% basis.
Figure 2. Map highlighting the Makoko and Kiala discoveries on the Western Foreland licences.
Makoko emerges as the world’s fourth-largest copper discovery over the past decade
Makoko, first discovered in 2018, is situated approximately 20 kilometres west of the Kakula deposit, along strike of the regional structure controlling high-grade copper mineralization at Kakula. Drilling at Makoko has defined a flat-lying, stratiform copper deposit that is geologically similar to the Kamoa and Kakula deposits. The primary mineralized zone at Makoko relates to an east-southeast trending growth fault structure that maintains the sulfur-rich host unit in close proximity to the underlying aquifer. These two key factors for mineralization are combined at Makoko over a width of 700 metres and strike extent of 3,800 metres. A second sub-parallel zone of shallower mineralization occurs up-dip across a strike extent of approximately 11 kilometres, where a stratigraphically higher, sulfur-rich host is in contact with the underlying aquifer. Both zones of mineralization remain open along strike.
Ivanhoe Mines’ exploration team with core from the 2023 Western Foreland drill campaign, which has generated 28,550 metres of diamond drill core through Q3 2023.
During the third quarter, contractor diamond drill rigs across Western Foreland increased to seven, in addition to the Ivanhoe Landcruiser diamond drill rig.
The highest-grade section of the Makoko deposit occurs between 300 and 600 metres in depth and coincides with the Indicated Resource area shown in Figure 5. Highlights of the maiden Makoko Mineral Resource estimate, prepared by Ivanhoe Mines under the direction of the MSA Group (MSA), of Johannesburg, South Africa, in accordance with the 2014 CIM Definition Standards for Mineral Resources and Mineral Reserves:
- Indicated Resources total 16 million tonnes at a grade of 3.52% copper, containing 1.3 billion pounds of copper at a 1% copper cut-off. At a higher 1.5% copper cut-off, Indicated Resources total 16 million tonnes at a 3.55% copper, containing 1.3 billion pounds of copper.
- Inferred Resources total 243 million tonnes at a grade of 1.71% copper, containing 9.2 billion pounds of copper at a 1% copper cut-off. At a higher 1.5% copper cut-off, Inferred Resources total 154 million tonnes at a 1.97% copper grade, containing 6.7 billion pounds of copper.
- The average vertical thickness of the selective mineralized zone at a 1.0% cut-off is 5.2 metres in the Indicated Resource area and 6.0 metres in the Inferred Resource area. At a higher 1.5% cut-off, the average vertical thickness of the selective mineralized zone is 5.2 metres in the Indicated Resource area and 6.6 metres in the Inferred Resource area.
The Makoko Mineral Resource has been defined by drilling covering a total area of 15.9 square kilometres within the much larger Makoko exploration area. The total area extent of Indicated Resource is 1.1 square kilometres at a 1.0% cut-off and 14.8 square kilometres for the Inferred Resource at a 1.0% cut-off. The average dip of the mineralized zone in the Mineral Resource area is 14 degrees.
The Mineral Resource estimate is based on the results from approximately 50,000 metres of drilling in 148 holes. An additional 20 holes totaling more than 2,800 metres have been completed since the closure of the database for resource estimation purposes.
Following the closure of the database for resource estimation, further drilling was completed to test shallow mineralization and to join the two Inferred zones. This drilling, and results available thus far, are shown in Figure 3 and Figure 5. There is currently one active rig drilling the western extension of Makoko, while other exploration has shifted to test other targets in the broader Western Foreland Exploration Project during the remainder of the dry season, which typically ends in mid-to-late November.
The Makoko Mineral Resource estimate was prepared by Ivanhoe Mines under the direction of Jeremy Witley of the MSA Group. Mr. Witley is the Qualified Person for the estimate and is considered independent of Ivanhoe for purpose of NI 43-101. The Makoko Mineral Resource estimate has an effective date of September 4, 2023.
The Makoko Mineral Resources, along with sensitivities at various cut-offs, are shown in Tables 1 and 2.
Table 1. Makoko Discovery Indicated and Inferred Mineral Resources at a 1.0% cut-off grade.
| Category | Tonnage (millions) | Area (km2) | Copper Grade (%) | Vertical Thickness (m) | Contained Copper (ktonnes) | Contained Copper (billion lbs) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Indicated | 16 | 1.1 | 3.52 | 5.2 | 577 | 1.3 | ||||||
| Inferred | 243 | 14.8 | 1.71 | 6.0 | 4,170 | 9.2 |
Notes:
1. Ivanhoe’s Senior Exploration Geologist, Tim Dunnett, a Member of the Geology Society of South Africa and Professional Natural Scientist (Pr. Sci. Nat) with the South African Council for Natural Scientific Professions (SACNASP), estimated the Mineral Resources that were reviewed by Jeremy Witley, Pr.Sci.Nat SACNASP, FGSSA, who is the Qualified Person for the Mineral Resource estimate. The effective date of the estimate is 4 September 2023, and the cut-off date for drill data is 28 February 2023. Mineral Resources are reported using the CIM 2014 Definition Standards for Mineral Resources and Mineral Reserves. Mineral Resources are reported on a 100% basis. Ivanhoe holds an indirect 80% interest in the Makoko SA mining licences and 100% interest in the Lufupa exploration licences (see Table 6).
2. Mineral Resources are reported for Makoko using a total copper (TCu) cut-off grade of 1% TCu and a minimum vertical thickness of 3m. There are reasonable prospects for eventual economic extraction under the following assumptions: copper price $4.00/lb; employment of underground mechanized drift-and-fill mining methods; copper concentrates will be sold to the Kakula smelter or toll treated; average metallurgical recovery is 87.5%; mining costs are assumed to be $38/t; concentrator, tailings treatment, and general and administrative costs are assumed to be $15/t; smelter, refining and transport costs are assumed to be $13.5/t of ore at the cut-off grade; royalty of 3.5%, export tax of 1% and concentrate tax of $100/t NSR concentrate.
3. Reported Mineral Resources contain no allowances for hanging wall or footwall contact boundary loss and dilution. No mining recovery has been applied.
4. Approximate drill hole spacings are 400 m to 600 m for Inferred Mineral Resources and 200 m for Indicated Mineral Resources.
5. Rounding as required by reporting guidelines may result in apparent summation differences between tonnes, grade and contained metal content.
Table 2. Makoko Discovery Indicated and Inferred Mineral Resources, sensitivity cases.
| Category | Cut-off Grade (% Cu) | Tonnage (millions) | Area (km2) | Copper Grade (%) | Vertical Thickness (m) | Contained Copper (ktonnes) | Contained Copper (billion lbs) | |
|---|---|---|---|---|---|---|---|---|
| Indicated | 3.0 | 11 | 0.7 | 4.04 | 5.5 | 460 | 1.0 | |
| 2.5 | 13 | 0.9 | 3.85 | 5.3 | 515 | 1.1 | ||
| 2.0 | 16 | 1.1 | 3.63 | 5.2 | 561 | 1.2 |
| 1.5 | 16 | 1.1 | 3.55 | 5.2 | 574 | 1.3 | |||||||
| 1.0 | 16 | 1.1 | 3.52 | 5.2 | 577 | 1.3 | |||||||
| Inferred | 3.0 | 4 | 0.4 | 4.63 | 3.9 | 192 | 0.4 | ||||||
| 2.5 | 15 | 0.8 | 3.17 | 6.6 | 469 | 1.0 | |||||||
| 2.0 | 50 | 2.7 | 2.50 | 6.8 | 1,260 | 2.8 | |||||||
| 1.5 | 154 | 8.5 | 1.97 | 6.6 | 3,030 | 6.7 | |||||||
| 1.0 | 243 | 14.8 | 1.71 | 6.0 | 4,170 | 9.2 |
Freshly cut drill core from Makoko, during the ongoing Western Foreland exploration program. The core shows chalocite and bornite copper sulphide minerals. Diamond drilling is on track to exceed 40,000 metres for the year.
Core boxes from the diamond core drilling of the Makoko and Kiala deposit, alongside previously drilled Kakula core for comparison.
Figure 3. Estimated total copper grades in Makoko’s mineralized zone (defined at a 1.0% Cu cut-off).
Figure 4. A drilling strike section across the Makoko Sud looking north.
Figure 5. Estimated true thickness of Makoko’s selective mineralized zone (defined at a 1.0% Cu cut-off).
Figure 6. Depth below surface of Makoko’s selective mineralized zone (defined at a 1.0% Cu cut-off).
Drilling continues to test northern extensions of the high-grade Kiala deposit and shallow targets peripheral to current Mineral Resource
Kiala, discovered in 2020, adjoins the northern boundary of the Kamoa-Kakula mining licence and is a northern extension of mineralization from this licence along a north-trending controlling growth structure, whereby a sulfur-rich siltstone layer is brought progressively closer to, and eventually overlain on the aquifer. This onlapping relationship brings two key mineralizing controls in contact with one another, resulting in a zone of high-grade mineralization parallel to the growth fault.
Highlights of the maiden Kiala Mineral Resource estimate, prepared by Ivanhoe Mines under the direction of MSA, Johannesburg, South Africa, in accordance with the 2014 CIM Definition Standards for Mineral Resources and Mineral Reserves:
- Indicated Resources total 8 million tonnes at a grade of 2.67% copper, containing 0.5 billion pounds of copper at a 1.0% copper cut-off. At a higher
1.5% copper cut-off, Indicated Resources total 5 million tonnes at a 3.56% copper, containing 0.4 billion pounds of copper.
- Given the strong geology controls and drill hole spacing, there is no Inferred Resource currently at Kiala.
- The average vertical thickness of the selective mineralized zone at a 1.0% cut-off is 3.5 metres in the Indicated Resource area. At a higher 1.5% cut-off, the average vertical thickness of the selective mineralized zone is 3.7 metres in the Indicated Resource area.
The Kiala Mineral Resource has been defined by drilling covering an area of 0.9 square kilometres. The average dip of the mineralized zone within the Indicated Resource is 9 degrees.
The Mineral Resource estimate is based on the results from approximately 13,000 metres of drilling in 35 holes. An additional four holes totaling more than 1,650 metres have been completed since the closure of the database for resource estimation purposes.
Although most drill rigs on the Western Foreland Exploration Project are targeting other promising exploration targets during the favorable dry season, one drill rig tested the northern extension to the mineralization at Kiala as well as testing shallow targets on the periphery of domes west of the current Mineral Resource area through the end of September. The rig is currently drilling in the Makoko area as the rainy season approaches.
The Kiala Mineral Resource estimate was prepared by Ivanhoe Mines under the direction of Jeremy Witley of the MSA Group. Mr. Witley is the Qualified Person for the estimate and is considered independent of Ivanhoe for purpose of NI 43-101. The Kiala Mineral Resource estimate has an effective date of September 4, 2023. The Kiala Mineral Resources, along with sensitivities at various cut-offs, are shown in Tables 3 and 4.
Table 3. Kiala Discovery Indicated Mineral Resource at a 1.0% cut-off grade.
| Category | Tonnage (millions) | Area (km2) | Copper Grade (%) | Vertical Thickness (m) | Contained Copper (k tonnes) | Contained Copper (billion lbs) |
|---|---|---|---|---|---|---|
| Indicated | 8 | 0.9 | 2.67 | 3.5 | 212 | 0.5 |
Notes:
1. Ivanhoe’s Senior Exploration Geologist, Tim Dunnett, a Member of the Geology Society of South Africa and Professional Natural Scientist (Pr. Sci. Nat) with the South African Council for Natural Scientific Professions (SACNASP), estimated the Mineral Resources that were reviewed by Jeremy Witley, Pr.Sci.Nat SACNASP, FGSSA, who is the Qualified Person for the Mineral Resource estimate. The effective date for the estimate is 12