The mining occurs on the Merensky Reef. Although the Merensky Reef (W3) is generally regarded as a uniform reef type, large variations occur in reef thickness, reef composition, as well as the position of the mineralisation. The rock forming minerals of the Merensky Reef comprise approximately equal amounts of dark iron magnesium silicate minerals and lighter calcium-aluminium-sodium silicate minerals (called a feldspathic pyroxenite) under- and overlain by thin (5 to 15 mm) often discontinuous layers of chrornite concentrations, see Figure 3. The total thickness of this package is generally less than 30 cm. This zone, commonly known as the Merensky pegmatoid, contains the base metal sulfide grains and associated platinum group minerals. The Merensky Reef has been traced for 300 km around the entire outcrop of the eastern and western limbs of the Bushveld Complex, and to depths of 5 km.

The rock-forming silicate minerals of the Merensky Reef consist predominantly of orthopyroxene (- 60 per cent), plagioclase feldspar (- 20 per cent), pyroxene (- 15 per cent), phlogopite (5 per cent), and occasional olivine, see Table I, which lists the composition of some of the common minerals found in the Bushveld-type rocks.

Secondary minerals such as talc, serpentine, chlorite and magnetite have widespread occurrence. The base metal sulfides consist of pyrrhotite (-40 per cent), pentlandite (- 30 per cent), chalcopyrite (- 15 per cent), and trace amounts of millerite (NiS), troilite (FeS), pyrite (FeSJ, and cubanite (Cu5FeS4). The major platinum group minerals are cooperite (PtS), braggite [(Pt,Pd)NiS], sperrylite (DtAsz) and PGE alloys, although in some areas minerals such as laurite) can be abundant.

Trackless bord and pillar methods will be employed in the thick Merensky resource areas with mining heights varying between 1.8m and 2.0m. The narrow Merensky reef area will be mined using a conventional breast mining layout.

A mining optimisation study completed in the fourth quarter of 2012 resulted in a change of scope, which was approved by the RBPlat Board in February 2013. The major changes approved included:
- Reducing mining bord widths from 13 metres (m) to 8m;
- The use of ore transport in footwall drive by means of trucks was replaced with on-reef strike conveyors;
- Shaft depths were increased by 18 metres to mitigate the geotechnical risk associated with UG1 strata intersecting key life of mine excavations.

RBPlat needs to construct a 230 000 tpm Concentrator to treat ore from the Styldrift Phase 1 mine and investigated different Concentrator strategies to accommodate the additional Merensky and UG2 ore from the Styldrift Mine Complex.

A stand-alone Concentrator close to Styldrift Phase 1 Mine has been chosen from the three Concentrator options that were defined to cater for the shorter term Styldrift Mine Complex. Future Concentrator layout allowance has been the primary consideration for the planned Styldrift Phase 2 mine output.

The function of the Concentrator Plant is to effectively separate and recover PGMs and base metal sulphides from the waste minerals in flotation cells. The Concentrator Plant will be comprised of mills, flotation cells and thickeners in various configurations.

The run-of-mine ore will be crushed in a set of crushers, screened, and milled. It will then be sent to the primary rougher flotation circuit. The tailings from the primary rougher flotation circuit will be dewatered in a set of cyclones, after which the coarse fraction from the cyclones will be grinded finer in the secondary milling circuit. The product from the secondary milling circuit is sent to the secondary rougher flotation circuit. The final tailings from the secondary rougher flotation circuit, together with the tailings from the cleaner flotation circuit, are then transferred to the TSF.