The Marikana mining rights areas are underlain by the Merensky and UG2 Reefs over a strike length of approximately 27km. The strata and reefs strike in an approximately east-west direction and generally dip between 8°N in the west, gradually increasing to 13°N in the extreme east of the property.

The UG2 Reef normally comprises a narrow tabular chromitite layer, which varies in thickness between 1.0m and 1.4m. Localised internal waste comprising pyroxenite or anorthosite can occur which is included in the Mineral Resource. To the west of the property the Leader Chromitite layer separates from the main UG2 Chromitite creating a zone of “split facies”. This affects the far western areas of K3 and K4 and the future K5 mining blocks. The UG2 Reef underlies the Merensky Reef by between 130m and 210m, the middling between the two reefs gradually increasing across the operations from west to east The Merensky Reef varies across the Marikana operations. This variability is used to define several facies (or reef sub-types) based on the occurrence of distinct lithological units within the reef. Two major types, pegmatoidal and non-pegmatoidal facies, occur.

At the Marikana operation, the Merensky Reef varies, and this variability is used to define several facies (or reef sub-types) based on the occurrence of distinct lithological units within the reef. Two major types, pegmatoidal and nonpegmatoidal facies, occur. These have been separated further into a total of six different facies based on the occurrence of thin chromitite layers in the order of several millimetres thick. The Merensky Reef contains economically important base metal sulphide and PGM mineralisation. Mineralisation of the Merensky Reef generally occurs in the pegmatoidal feldspathic pyroxenite and, to a limited extent, in the hangingwall and footwall, with highest PGM concentration peaking at the chromitite layers.

At the Marikana operation, the UG2 Reef normally comprises a narrow tabular chromitite layer, which varies in thickness between 1.0m and 1.4m. Localised internal waste comprising pyroxenite or anorthosite can occur creating a zone of “split facies” to the west of the property.

Marikana currently has five contributing shafts: 4Belt, Karee 3 (K3), Rowland, Saffy and E3. The Merensky and the UG2 Reefs are mined simultaneously at an average depth of 500m and are accessed via infrastructure consisting of shallow incline and deep vertical shafts. The 4Belt shallow incline and K3 and Rowland vertical shafts target both the Merensky Reef and UG2 Reef horizons, whilst the E3 shallow incline and Saffy vertical shaft, target only the UG2 Reef. The primary vertical shaft complexes account for the largest portion of the Mineral Reserves.

The Mineral Resource is accessed from surface using conventional underground mining methods. The 4Belt and E3 shallow incline shafts extend to depths of approximately 400m below surface and the K3, Rowland and Saffy vertical shafts to approximately 900m below surface.

Apart from the underground operations, there is one tailings retreatment operation. The remining of eastern tailings dam 1 (ETD1) occurs by hydraulic mining with high pressure water guns and the tailings are retreated at the Bulk Tailings Treatment (BTT) plant.

Mining method:
• Vertical shafts: conventional up-dip down-dip mining with a limited amount of breast mining;
• Shallow inclines: conventional breast mining with a limited amount of up-dip down-dip mining.

Marikana is a large, established operation, with all the necessary surface infrastructure to support mining operations. Apart from the five operating shafts, it hosts a number of shafts under care and maintenance.

During 2020, the feasibility study into the K4 project was concluded, and the project was approved for construction by the Board during the first quarter of 2021. The Karee 4 (K4) vertical shaft ore-body is located on the western boundary of the Marikana operations and represents the down-dip extension to the currently producing K3 sub-incline shaft block and the Rowland sub-incline shaft block. The K4 Shaft is earmarked as the production replacement shaft for Sibanye-Stillwater’s 4 Belt Shaft as well as part of the K3 shaft. Development of the 8.6m concrete lined vertical shaft and 6.1m diameter ventilation shaft as well as access development on the shaft stations have been completed. The K4 Shaft services ten levels will enable mining from 26 level down to 35 level on the Merensky and 28 level to 35 level on the UG2 reef ranging in depth from 837m to 1287m below surface. The underground opportunity at K4 covers both the Merensky and UG2 Reefs, on a 60:40 split during steady state. At steady state, mining production is planned at 191,000RoM ore tonnes per month, yielding 21.5Koz 4E PGMs per month. The mining method will be conventional breast mining.

The ore mined at the Marikana operations is processed through six concentrators on site with a combined milling capacity of approximately 600,000t per month. The concentrate produced is dispatched to the smelter where a sulphide-rich matte is produced for further processing at the Base Metal Refinery (BMR). At the BMR, base metals (nickel and copper) are removed and the resulting PGM-rich residue is sent to Precious Metal Refinery (PMR) in Brakpan for final treatment. PMR produces the final precious metal products.