Overview

Deposit type

• Banded iron formation

Summary:

At Sishen Iron Ore Mine, high-grade hematite ore is extracted from specific stratigraphic units belonging to the Palaeo-Proterozoic (~ 2400 million years (Ma)) Transvaal and (~ 2070 Ma) Olifantshoek Supergroups, respectively.

The Superior-type banded iron-formations (BIF’s) of the Transvaal Supergroup lithologies were deposited in two related basins, one in an extensive continental shelf environment and the other in an intra-continental sea, both situated on the Kaapvaal craton.

At Sishen, the bulk of the high-grade iron ore is found as thick, continuous, undulose, strata-bound bodies in the upper parts of the Asbestos Hills Subgroup, which lie directly beneath the unconformity surface. This ore zone (referred to as Main Ore at Sishen) constitutes the primary source of high-grade laminated and massive ores in the Northern Cape Iron Ore Belt. Thin, discontinuous lenses of high-grade ore are occasionally found beneath the Main Ore within the host BIF, with sporadic occurrences of enrichment of some of the BIF to low and medium grade iron ores. Some shales and conglomerates of the Gamagara Subgroup immediately above the unconformity have also been enriched to low and medium grade iron ores. In some instances, mostly in the case of the conglomerates, ferruginisation to high-grade ores has occurred. Kumba concurs with the opinion of many researchers that the laminated and massive ores belonging to the Asbestos Hills Subgroup at Sishen are a product of supergene enrichment of primary BIF.

A highly altered, slickensided, intrusive sill is commonly found separating the BIF from the overlying laminated ore. At Sishen mine it is generally less than 2m thick. The sill is invariably folded into the basinal geometry and only rarely cross-cuts (intrudes) the ore bodies.

At the Sishen deposit, the upper parts of the Asbestos Hills Subgroup have been ferruginised to ore grade. These stratiform, laminated and massive ores constitute the bulk of the resource. The laminated and massive ores are commonly folded and faulted into basinal and pseudo-graben structures.

Deep palaeo-sinkholes, filled with brecciated ore and Gamagara sedimentary rocks, are found on the southern parts of the Sishen properties. The sinkholes are restricted to antiformal structures close to the Maremane Dome on the southern portions of the mine. They are an important mechanism for preserving collapse breccia ore.

The Olifantshoek Supergroup is the oldest recognised red-bed sequence in the region. It is some 400 Ma younger than the Transvaal Supergroup. Conglomerates of ore grade with well-rounded clasts and fine-grained, well-sorted, gritty ores are common at Sishen mine. Partly ferruginised shales, interbedded with ore conglomerates and thick flagstones are also a feature of the Gamagara Subgroup.

A buried glacial valley, filled with Dwyka tillite and mudstones, has been identified with reconnaissance drilling. The valley is located between the mine and Kathu. It has a north-south orientation that changes to northwest-southeast between Dibeng and the mine. The valley does not fall within the planned open pit. The Kalahari group comprises boulder beds, clays, calcrete, dolocrete and windblown sands. The Kalahari group is developed to a maximum thickness of 60 m. The clay beds at Sishen can attain a thickness of up to 30 m on the northern parts of the deposit. The Kalahari beds of calcrete, limestone and clay and Quaternary sand and detritus, blanket more than 90% of the Sishen mining area

Sishen mine is situated on the northern extremity of the Maremane anticline. At this location the lithologies strike north-south and plunge from the centre of the anticline in a northerly direction. The bulk of the resource comprises highgrade, laminated and massive ores belonging to the Asbestos Hills Subgroup.

The ore bodies are intensely folded and faulted. Dips vary according to local structures, but at Sishen, a regional dip of 11° in a westerly direction prevails.

Mining Methods

• Truck & Shovel / Loader

Summary:

Sishen Mine is a conventional open pit mining operation applying a pushback deployment strategy. The distinctive mining areas are North Mine (G80 and G50), Middle Mine, Dagbreek, Vliegveld, Far South and Lyleveld. Material is drilled, blasted, loaded by electric and diesel (rope and hydraulic) shovels and hauled by trucks to either the primary crusher, high-grade or low-grade stockpiles or waste dumps. Benches are 12.5 m high. The ore from the opencast pit is transported to the beneficiation plant where it is crushed, screened and beneficiated through dense media separation and Jig technology.

Sishen Mine produces ore from opencast extraction methods invloving drilling, blasting, and truck and shovel open-pit operations. There are 13 active pits where haematite is mined directly from the pit as well as designated buffer stockpiles. The mine operates 24 hours a day, seven days a week.

The mining process entails topsoil removal and stockpiling for later use during the waste dump rehabilitation process, followed by drilling and blasting of waste and ore. The waste material is in-pit dumped where such areas are available or hauled to waste rock dumps. The iron ore is loaded according to blend (grade) requirements and hauled to designated run-of-mine buffer stockpiles or the beneficiation plants.

Iron ore mining operations
Mining started in outcrop and shallow ore areas along the north to south strike of the ore body and is generally progressing in a westerly direction along the dip of the ore body, with the mine pit becoming increasingly deeper towards the west. Four types of hard iron ore, namely massive, laminated, conglomerated and brecciate iron ore are mined. Blast hole drilling is a continuous process and blasting is done once a day, typically in the early afternoons between 12h00 and 14h00, at each of the active mining areas within the mine pit.

Vliegveld West Satellite Pit
The Vliegveld West satellite pit is situated south of the Dingleton town and is part of the current mining right area. It extends onto the Sishen 543 prospecting right area and has a reserve of 14.7 Mt with an average JIG beneficiated Fe grade of 65.8%.

The Doornvlei Satellite Pit
Doornvlei is situated west of the Dingleton town and has an additional resource of 37.7 Mt with a high average DMS Beneficiated Fe grade of 66.3%. Doornvlei plays an important role to enhance the product grade in the life-of- operation schedule.

Parsons Satellite Pit
The Parsons Satellite pit is planned south of the current Sishen pit and has a speculative resource, categorised as a 15.4 Mt deposit, with an average in-situ Fe grade of 64%. The importance of the Parsons Satellite pit is that it can significantly contribute to the production schedule toward the end of the life- of-operation and may develop into a significant production area in the future. The geological confidence in the Parsons deposit needs to be improved by exploration and in-fill drilling.

Comminution

Crushers and Mills

Summary:

An additional primary crusher (UPC) will be required for the processing of some of the material as the existing DMS and JIG plant crushers do not have capacity to process all of the additional ROM. A-grade and/or C-grade ore shall be crushed by the existing primary and secondary DMS crushers which have capacity of 26 Mtpa.

Ultra High Dense Media Separation (UHDMS) Technology
The UPC will serve to crush additional feed material to the UHDMS and this could include both A-grade, B-grade & C-grade as well as lower grade material. The crushed material from these crushers shall then be delivered to the existing DMS tertiary crushers and the DMS stockpile. The material from the DMS stockpile is fed into the Washing & Screening Plant.

The upgraded process plant will have the capability of processing both high (A-grade) and low grade (C-grade) ore simultaneously, to produce a saleable iron ore product. A primary crusher was erected to provide additional crushing capacity for the processing of C-grade material. Low grade material to be processed will originate primarily during the run-of-mine and will be processed directly. However, some material originating from certain residue stockpiles will also be added to the process.

Processing

• Jig plant
• Wash plant
• Crush & Screen plant
• Dense media separation

Summary:

Following extraction, ore is transported to the benefication plant to be crushed, screened, and beneficated through dense media separation and jig technology. The benefication plant receives 20 percent ore and 80 percent feed from buffer stockpiles.

The screened ore size fractions are beneficiated through either:
• a ferro-silicon DMS plant, where most of the high-grade run-of-mine is treated, or
• a Jig plant where most of the medium-grade run-of-mine is treated, with two UHDMS modules treating some of the Jig discard to recover more Saleable Product.

As of 2023, the combined run-of-mine capacity of the processing facilities is 49.7 Mtpa (28.1 Mtpa for the DMS plant and 21.6 Mtpa for the Jig plant).

Plant slimes are not beneficiated and are pumped to evaporation dams while the DMS and Jig (and UHDMS) discard material is stacked on a plant discard dump. Four iron ore products (conforming to different chemical and physical specifications) are produced. The product is reclaimed from product beds and loaded into trains, to be transported either to local steel mills (domestic market) and Saldanha Bay (for export market), from where it is shipped together with Kolomela product and sold to international Clients under three KIO branded products referred to as premium Lump ore, standard Lump ore and standard Fines ore.

Three final iron ore products (derived from up to seven interim products produced on-site conforming to different chemical and physical specifications) are produced. The product is reclaimed from product beds and loaded into trains to be transported either to local steel mills (domestic market) and Saldanha Bay (for export market), from where it is shipped together with Kolomela product and sold to international Clients under three KIO-branded products referred to as premium Lump ore, standard Lump ore and standard Fines ore.

Ultra-High Dense Media Separation (UHDMS) is a recently proven technology that will allow for the processing of future low-grade material (particularly C-grade material) originating from the ongoing mining operations as run of mine (ROM) as well as some of the low-grade material that has historically been dumped on site due to the lack of available technology. C-grade material refers to lower grade ore types containing between 40% and 48% iron.

The C-grade material to be processed will be sourced from the ROM (is part of the hanging and footwall that are already included in the mining sequence) as well as surface stockpiles. Cgrade material arising from the ROM since January 2016 has also been stockpiled separately on some of the waste rock dump areas with the anticipation that it could be processed through the future UHDMS plant. The anticipated ROM of C-grade material is 7-26 Mtpa.

UHDMS project
The existing DMS Processing Plant at Sishen is to be upgraded to allow for the incorporation of UHDMS which will allow for the co-processing of both high (A-grade) and low (C-grade) grade material. The JIG plant will continue to process the B-grade material and some of the A- grade material due to a revised feed strategy. The current DMS plant comprises the following sections:
- Washing & Screening Plant;
- A Coarse Drum Plant;
- A Medium Drum Plant;
- A Coarse Cyclone Plant;
- A Fine Cyclone Plant;
- An Up-Current Classifier (UCC) Plant.

The UHDMS project will convert the current DMS processing plant at Sishen to UHDMS technology. This technology uses specialised ferrosilicon in the plant processing of raw iron ore and allows greater flexibility to process a wider range of Fe grades and densities. The implementation of the technology will improve the Fe quality, the proportion of premium iron ore, and lower the waste stripping ratio, while maintaining Sishen’s high lump:fine ratio of 70:30.

The implementation will follow a modular approach, with six UHDMS coarse modules out of eight and five fines modules out of seven being converted. The project resumed in November 2024 and is on track for the implementation of the first module in 2025. The main tie-in of the project is planned to take place in 2026, and the plant is expected to reach full capacity by the end of 2028. During the implementation phase, the modules not under construction, as well as the Jig plant, will continue to run, and production will be supplemented by finished product stock.

Once implemented, the proportion of premium iron ore is expected to increase to around 55% of Sishen’s production, up from a current c.18%.

The DMS components at the existing DMS Processing Plant will be converted to UHDMS processes by the replacement of the drums currently used in the beneficiation process with cyclones; and also modifying the existing media density circuits as well as crushing circuits. The following changes are currently envisaged for the existing DMS Plant:

- The existing Washing & Screening Plant at the DMS Plant will be modified. This will involve the modification of the screen panel sizes.
- The material from the Washing & Screening plant shall be sent to the Quaternary Crushing Plant to crush the material as required by UHDMS technology.
- A new oversize conveying system will be erected from the existing Washing & Screening Plant to the existing conveyor feeding the stockpiles ahead of the exiting Quaternary Crushing Plant.
- No changes will be made to the Quaternary Crushing Plant.
- The crushed material from the Quaternary Crushers shall be sent to the Quaternary Screening plant which will separate the material into three size fractions. The existing Quaternary Screening Plant will be modified to Screen Quaternary oversize material after Quaternary Crushing.
- Upgrade of the existing Drum Plant by removing drums and replacing with cyclones. The Drum Plant will be converted to a coarse UHDMS Plant.
- Development of a new conveyor from the Quaternary Screening Plant to the existing Drum Plant.
- Upgrade of the existing Coarse and Fine Cyclone Plant involving upgrades to specific densification systems.
- The existing Coarse Cyclone Plant will be converted to the Fine UHDMS Plant.
- The existing Fine Cyclone Plant will be converted to the Superfine UHDMS Plant.
- Development of a new conveyor from the Quaternary Screening Plant to the existing Fine Cyclone Plant.
- The UCC Plants will be modified to treat grits, if required.
- Feeders at the in-pit stockpile will be replaced next to the DMS Tertiary Crushers.
- Modification of the product transfer, common lump product and plant discard conveyor.
- Two new conveyors at the Discard Transfer Station and a new Discard Emergency Stockpile at the foot of the existing Discard Dump.

The value of the UHDMS technology includes the ability to reduce the current cut-off grade to between 40% and 48% Fe, increase product quality and extend the life-of-asset at Sishen to 2039.

Pipelines and Water Supply

Summary:

Each Kumba’s sites is implementing a water management plan that includes water security, water-use efficiency, tailings water-recovery projects and mine-dewatering strategy, stormwater management, and discharge management, complemented by a monitoring programme. The sites have Competent Persons for water management, who chair water teams established at each operation.

The main consumptive uses of water at operations are dust suppression, entrainment (water locked up in tailings and, to a lesser extent, in products), and evaporation from mine circuits (dams, tailings dams, other exposed areas).

Freshwater withdrawals are dominated by Sishen, where more fresh water has to be pumped to ensure dry conditions for safe mining in the open pit. Groundwater is our primary water source, accessed through dewatering boreholes. Kumba also makes use of municipal water for domestic purposes. Operations reduce their dependency, in line with our water strategy, on imported fresh water through the use of lowerquality treated sewage water. Sishen uses treated sewerage effluent (grey water) from the Kathu wastewater treatment works, to increase the export of groundwater to the Sedibeng reservoir. We continue to sell the excess water to the Sedibeng water authority, in line with WUL conditions, to supply bulk water to farmers, to compensate for their potential losses from private boreholes. We capture rainwater for use in dust suppression.

Water consumption at Sishen Mine increased due to the upgrade of the DMS to UHDMS and the installation of the UPC, driven primarily by the additional coarse waste and additional slurry tonnages, which result in increased losses in the system. The increase in make-up water demand is predicted to be below 100 m3/h and will be supplied predominantly by additional treated sewage effluent and recovered stormwater from the eastern and western stormwater sumps, and the PCD’s.

Use is made of the existing infrastructure at the DMS for the purposes of water supply and management. There are three thickener dams, with a combined storage capacity of 156 000 m3 and one existing process water supply dam with a storage capacity of 25 000 m3. These existing facilities will have sufficient capacity to facilitate the UHDMS plant.

Production

Operational metrics

Personnel

Job Title	Name	Profile	Ref. Date
Head of Mining	Chris Cloete		Mar 21, 2025
Health, Safety & Environment Manager	Ntokozo Khanyile		Mar 21, 2025
Mining Manager	Danie Fourie		Mar 21, 2025