RBPlat is located on the Western Limb of the BIC, one of the three main portions or limbs which all comprise similarities in their formation, economic potential and type of commodity. The Bushveld Complex formed approximately 2.04 billion years ago, comprising three main suites, namely the Rooiberg Group, Lebowa Granite Suite and the Rustenburg Layered Suite. The Rustenburg Layered Suite comprises four main zones (the upper, main, critical and lower zones) with each zone characterized by signature igneous intrusive layering, known as stratigraphy. The critical zone hosts the platinum group element (PGE) bearing reef (the economically important layer) types of the Merensky reef and the Upper Group 2 reef (UG2). RBPlat’s operations mines Merensky and UG2 reefs.

The western extremity of the Maseve ore body subcrops 190m below surface. The northern boundry is the operational Wesizwe Platinum’s mining right area, and the remainder of the ore body borders RBPlat operations.

Proximity of the basement (and possibly its paleotopography) to the Merensky and UG2, by and large influenced the geometry and succession of the local stratigraphy, which primarily resulted from local basement upliftment. Upliftment caused the folded or rolling nature of the stratigraphic geometries which are preserved as anticlines and synclines. The frequency of the rolling towards the west becomes narrower with steeper dips resulting in some of the stratigraphic units not developed. The implication of the folding and or rolling nature of the stratigraphy results in opposite dip directions (westerly and easterly) with wide ranges of dip-regimes that exist. The aforementioned is contrary to traditional narrow tabular Merensky and UG2 stratigraphy with recognized local changes in the planarity of the ore bodies, which are mostly related to the different fancies types.

The Merensky and UG2 reefs are both sulphide enriched with the Merensky reef being the main economic horizon mined at RBPlat. The PGMs (platinum (Pt), palladium (Pd), rhodium (RH), osmium (Os), ruthenium (Ru)) as well as gold (Au) are found mostly within the sulphide minerals and include varieties of copper (Cu) and nickel (Ni) as accompanying base metals. The reef horizons dip towards the north-eastern direction between 50 and 120 . The steeper dips are in the north-eastern part of the Styldrift, with the shallower dips presents in the center and western of the farm.

The average depth of the Merensky reef is 505 metres below surface (mbs), with RBPlat having the advantage of being the Merensky reef dominant relatively mine. The newly operational Styldrift I shaft ore from a 50 dipping Merensky reef horizon at an average depth of 712mbs.

The Merensky reef across the RBPlat operational area comprises six different geological facies types, from west to east, namely the Abutment, Terrace, Central, Normal, Normal Thick and Main reef facies. Merensky reef facies delineation of the Maseve ore body ties in with the regional RBPl at Merensky reef facies; Abutment facies (divided into shallow Abutment, deep Abutment and transition to Terrace facies) on the most western side and Terrace facies further east towards the Styldrift I shaft area. Each facies type exhibits unique geological, geochemical and mineralization characteristics which has a fundamental role in planning the optimized mining method. The predominant facies type at Maseve Mine is the Abutment facies, which is commonly associated with intrusions.

The vertical separation between the Merensky and the UG2 reefs varies from an average 80m at BRPM to 50m around the Styldrift I shaft area and decreases to an estimated minimum of 25m in the far north-eastern region of the mining area (Styldrift II). This is due the overall thinning of the critical zone of the Bushveld Complex, in a north-eastern direction towards the Pilanesberg Complex. The UG2 ore body has been classified and subdivided into three main facies types based on the occurrence of the position of the leader UG2 chromitite bands in the hangingwall of the dominant mineralized main chromitite band. These facies variations are encountered on apparent dip in a north- eastern direction, ranging from the Central high facies, Leader facies and General facies, from the shallowest to deepest portions of the mining area. The predominant facies types are the Leader and General facies, which account for 85% of the total ore body.

The BRPM investment centre is divided into two mining areas by a northeast — southwest trending fault, known as the Railway fault. The northern (BRPM North shaft) and southern (BRPM South shaft) areas are both accessed and serviced by an inclined shaft complex, conveyor shaft, material shaft, chairlift shaft and vertical up-cast ventilation shafts.

North and South shaft declines started developing in 1998, providing access to the shallow dipping, narrow reef ore body, which sub-outcrops and extends to approximately 430mbs at South shaft and 635mbs at North shaft. Production started with open-cast mining of the Merensky and UG2 reefs to a depth of approximately 30mbs. The Merensky reef is being replaced by UG2 reef using the same infrastructure, with South shaft becoming a UG2 reef mine in 2022.

Declines developed below the Merensky reef service North and South shaft strike haulages at approximately 50m vertical intervals, from which a cross-cut layout or lay bye method is employed to gain access to the reef plane at between 180 to 200m intervals, followed by raising on-reef between levels for conventional breast stoping to take place.

Main support includes rock-bolts in development and stoping faces, pre-stressed elongates installed in the stope panels and temporary support (mechanical props) installed on the stope face during drilling operations. Crush pillars are left at the top of the panel with ventilation holings separating the pillars. Regional pillars are left to ensure regional stability according to geotechnical requirements and local geological losses.

Stope drillhole length of 1.2m to 1.5m with shock tube used to initiate holes charged with low density Anfex. Blasted ore is cleared from the panel face into the ASG and then into the centre gulley (on-reef raise) by means of a dedicated winch. A centre gully winch then scrapes the ore into the box hole. The box hole is equipped with a grizzly and a Spilmanator chute at the bottom, feeding ore into hoppers. The footwall is serviced by 10-tonne locos and hoppers that transport ore to the station where it is tipped into shaft ore passes and fed onto the decline belt system.

A semi-hybrid system is employed at the bottom of North shaft Phase III, where the development includes two on-reef ends. This includes a belt drive which services the conventional stopes, as described, by scraping the ore down the raise into the drive where it is loaded by a load, haul, dump machine (LHD) and tipped onto the belt.

The BRPM concentrator, was designed to receive Merensky ore from BRPM’s two decline shafts and is able to treat 10% of UG2. The original design capacity of 200ktpm, was upgraded to 250ktpm to accommodate production from Styldrift.

The concentrator can be described as a robust maintenance intensive environment which produces 2.7 tonnes of saleable product from every 100 tonnes of ore processed

The plant operates on a 24 hours, 365 days a year basis and follows a traditional Mill- Float, Mill-Float (MF2) process which includes a conventional three stage crushing process prior to milling and flotation. The flotation processes produce a platinum rich PGM concentrate which is collected and sold as a final product for further processing and refining. RBPlat has an offtake agreement with Rustenburg Refineries (owned by Anglo American Platinum) for the sale of RBPlat concentrate.