The surface geology to the far south and south-east of the study area consists predominantly of lithologies of the Magaliesberg Formation. The sandstones and quartzites of the Magaliesberg Formation are highly resistant to weathering and as a result give rise to the Magaliesberg Mountain Range. The surface geology to the north of the Magaliesberg Formation and within the southern extent of the study area (to the south of HERNIC) consists of Kroondal Norites of the BIC which intruded into and above the lithological units of the Magaliesberg Formation and Silverton Formation of the Pretoria Group.

The Ruighoek Pyroxenites are further overlain by the Mathlagame Norites and Anorthosites of the BIC. These norites and anorthosites make up most of the northern area of the HERNIC site boundary. Pyramid Gabbro-Norites overly the Mathlagame Norites and Anorthosites and outcrop to the north of the HERNIC site boundary.

The depth of weathering and weathering related fracturing is relatively deep and varies between 13.0 m and 22.5 m, with an average depth of 17.6 m. The norites weather down to a soft gritty matrix, which is unevenly distributed across the study area. The weathering / fracturing profile depth is combination of the primary weathering profile and the transitional fracturing zone which occurs immediately above the fresh bedrock interface.

The mining operations at HERNIC are directly dependent on the nature of the underlying geology and associated chromite ore layers. The MG-1, MG-2 and MG-4 chromitite layers have historically been mined by opencast mining operations and are currently still being mined by underground mining operations within the eastern extent of the site.

Mining is currently taking place by means of underground mining methods at HERNIC. The underground mining operations are taking place below the Farms De Kroon 444 JQ and Elandsfontein 440 JQ and are accessed via the Morula Shaft Complex.

The stoping method used at Maroelabult is conventional breast mining. Advance strike gullies spaced at 21.5m are 1.5m wide and 2.8m deep and will be developed on reef. The panel width will be maintained below 22.5m for stability and safety reasons. The panels will have 6.0m long by 4.0m wide strike pillars with 2m holings between pillars, with the ASG maintained approximately 3m ahead of the advancing stope face.

At the ferrochrome beneficiation plant (Morula Operation), the run of mine (RoM) material is crushed and screened. The coarse fraction (120 x 20 mm) is processed through a heavy media separation. The fines (–20 mm) are milled to –1 mm and then fed to the spiral separator. The concentrate has a Cr content of 42%. Approximately 80% of these chromite fines have a grain size < 32 µm. They are pelletised and sintered through Outokumpu technology to produce competent pellets of 13 mm in diameter. The annual production is about 600,000 t of pellets. The pellets are heated in a steel belt sintering furnace, to form strong bonds between the chromite grains to yield and agglomerate the material. The sintered pellets are then sized and fed to the smelter by belt conveyor.

The Company commissioned the Dense Medium Separation (DMS) Plant in June 2015. The plant is designed to process 120 000 ROM per month.