Khanyisa Colliery falls within the Witbank Coalfield. There are five major coal seams – named 1 Seam through to 5 Seam from the base upwards - which are generally contained in an approximately 70 m thick succession of Karoo sediments (Vryheid Formation) consisting predominantly of sandstone with subordinate mudstone, siltstone and shale.

Although the parting thicknesses between coal seams are regionally constant, they become variable towards the northern margin of the coalfield. Strata overlying the 5 Seam are mainly arenaceous.

The period of Dwyka glaciations resulted in a highly irregular and undulating floor onto which the Karoo sediments were subsequently deposited. The result is that the coal seams are discontinuous over prominent palaeographic highs. Not all the seams are always present and the distribution, nature and thickness of the seams are strongly influenced by the palaeotopography of the original surface of accumulation, as well as by post-Karoo erosion.

The Khanyisa Colliery asset hosts the Witbank Coalfield coal seams, of which 4 and 2 Seam within the Vryheid Formation (Ecca Group) are exploited at Khanyisa and the 4 Seam is exploited at Sarie Marais in opencast operations. Post-Karoo dolerite sills have greatly affected the distribution and quality of the coal measures in the Khanyisa Colliery area.

Fixed infrastructure is utilised with all major mining activities contracted out, together with the crushing and screening plants. Additional mining contractor infrastructure was established to provide for the full service.

Mining focused on the Triangle South Block and the Catwalk South pillar mining area. Both Triangle and Catwalk Areas are mined opencast, with the difference that Catwalk extract mainly 2 seam pillars and roof coal left by previous underground mining.

Current mining in Triangle, is taking place in Block 3 (No. 4 and No. 2 Seams). The Catwalk area to the south of the Triangle Resource Area, has been divided into opencast in-situ areas where the coal has not been historically mined (Blocks 7, 9 and 10), as well as opencast Coal Resources comprising roof and pillar coal in the previously underground mined out areas (Block 12). Blocks 8 and 11 were completely mined out as at 31 March 2018. Current mining is taking place in Block 7 (No. 4 and No. 2 Seam), and Block 12 (No. 2 Seam Roof and Pillar Coal).