The Elandspruit, Khanyisa, Vanggatfontein and Moabsvelden Collieries are located within the Witbank Coalfield. The northern extent of the Coalfield is defined by the limit of coal-bearing sediments of the Vryheid Formation which abut against pre-Karoo basement rocks of the Transvaal Sequence, the Waterberg Group and Bushveld Complex. The southern limit of the central sector of the Coalfield is marked by a series of Bushveld Complex inliers known as the Smithfield Ridge while in the east and west sectors, the boundary between the Witbank Coalfield and the Highveld Coalfield to the south is somewhat arbitrary.

The five major coal seams of the coalfield are contained within a stratigraphic interval averaging approximately 70m in thickness. The seams are numbered, from the base upwards and include the No. 1 Coal Seam, the No. 2 Coal Seam (split into the No. 2 Lower Coal Seam and No. 2 Upper Coal Seam), the No. 3 Coal Seam, the No. 4 Coal Seam (split into the No. 4 Lower Coal Seam and No. 4 Upper Coal Seam) and the uppermost No. 5 Coal Seam.

Five principal seams are developed at Khanyisa, namely the No. 1, No. 2, No. 3 and the No.4 Lower and No. 4 Upper Coal Seams. The No. 5 Coal Seam is not present at all. The No. 1 Coal Seam is not considered economic as it is either very thin (~1m thick) or not developed. Similarly, the No. 3 Coal Seam is also not considered economic as it is on average only around 0.3m in thickness.

No. 1 Coal Seam
The No. 1 Coal Seam occurs directly on top of the Dwyka Group sediments in both the Triangle and Catwalk Project areas. Undulations in the paleo-topography at the time of peat accumulation resulted in zones where the No. 1 Coal Seam did not develop. The coal is highly variable in nature, ranging from Shaley to dull-lustrous. Due to the fact that the seam is thin with relatively poor qualities, it is not considered economic at this stage. The depth of weathering across the Catwalk and Triangle Areas averages 17m. It has been modelled and considered when estimating resources.

No. 2 Coal Seam
The No. 2 Coal Seam is the main economic target. It is present in the Triangle Area as in situ coal, and in the Catwalk area as pillar and roof coal, as well as a small portion of in-situ coal.

Triangle Project Area
The No. 2 Coal Seam is present as in-situ coal in the Triangle Project Area, and is on average 5.90m thick. The average depth to the No. 2 Coal Seam roof is 40.9 m, ranging from 38 m to 43 m. The coal is dull to lustrous in nature with an average CV of 20.90 MJ/kg. The No 2 Seam is separated from the No. 4 Lower Seam above by a parting ranging in thickness from 9.92 m to 12.22 m (average 10.84m).

No. 4 Lower Coal Seam
The No. 4 Lower Coal Seam occurs across the majority of the Triangle Area, with the exception of a few areas to the South where it has been eroded. The No. 4 Lower Coal Seam is not present in either Catwalk North or South. The No. 4 Lower Coal Seam lies on average 0.6m above the No. 3 Coal Seam, where it is separated by a sandstone band. The seam thickness is relatively constant, ranging in thickness from 3.7 to 4 m, averaging 3.84m in thickness. The average coal quality is good; raw ash content around 25% and a raw CV of 22.7 MJ//kg. The seam is unaffected by either faulting or dolerite.

No. 4 Upper Coal Seam
The No. 4 Upper Coal Seam occurs over the majority of the Triangle Project Area, with the exception of a few areas in the south, where the seam has been removed by erosion. The seam is on average 4.10m thick, and occurs directly above the No. 4 Lower Coal Seam. The coal quality is considerably poorer than the No. 4 Lower Coal Seam. The ash content is in the region of 39.70% and the CV is on average 17.20 MJ/kg

The majority of the holes in the Catwalk Project area intersected dolerite, which has affected both the quality and distribution of the coal measures. However, during the historical mining, the area where the No. 2 Coal Seam was mined out underground, was limited to those areas where the coal was unaffected by the dolerite. As the current Catwalk Project is a roof and pillar reclamation project of the existing mined out areas, this remaining coal is unaffected as well.

Within the Triangle Project area, only 2 boreholes in the south-western corner of the licence area intersected dolerite, and this had no effect on the coal qualities in that area. The No. 4 Upper Coal Seam to the east is however devolatilised and a large portion removed from resources. Within triangle North, the seams are totally unaffected. No faulting or dolerite has been encountered in any of the boreholes, or during the mining process.

The Khanyisa Complex comprises the Triangle resource area and the Catwalk resource area. Both the Triangle and Catwalk areas are mined via opencast truck and shovel methods, with the difference being that Catwalk extracts the No. 2 Seam pillars and roof coal left by previous underground mining, whereas the coal seams are in situ at both Triangle North and South.

Current mining at Khanyisa is taking place on the remainder of Triangle South and on Triangle North, as well as mining of the No. 2 Seam remaining in the Catwalk pillar area. The No. 2 Seam constitutes the larger portion of the remaining resources, with some peripheral coal remaining on the No. 4 Seam.

Coal reserves for the Khanyisa Complex were based on the proven opencast strip and pillar mining strategies, and operations were executed as such throughout FY21. Mining focused on the Triangle North Block, extracting most of the No. 4 Seam coal and commenced on the No. 2 seam. Mining continued on the Catwalk South pillar mining area.

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

Triangle ROM coal reserves of 1.42mt opencast, as at 31 March 2021, will be crushed, screened and blended to achieve the average product quality of >19MJ/kg and higher. The yield for raw products is conservatively based on a 98% recovery as the mine only has crush and screening processing facilities.