Leeuwpan mine is in the Delmas coalfield, on the western border of the Witbank coalfield. The geology within the Delmas coalfield is similar to that of the Witbank coalfield. Like the Witbank coalfield, the Delmas coalfield has up to five coal seams in the middle Ecca group sediments of the Karoo supergroup. The Karoo sequence in the area is represented by the Dwyka formation and the middle Ecca with little or no lower Ecca development. The middle Ecca sequence of coal horizons, interbedded with sediments, is highly truncated due to erosion with only very minor areas where the full sequence is developed.

The basement is generally the Malmani dolomites from the Transvaal supergroup.

Two coal seams have been identified at Leeuwpan: top coal seam (TC) and bottom coal seam (BC). BC correlates with the seam 2 (S2) of the Witbank and Highveld coalfields and TC correlates to the seam 4 (S4) and seam 5 (S5). BC qualities are generally higher than TC qualities.

The coal seams at Leeuwpan are primarily interbedded with sandstone, shale and carbonaceous shale. The coal was deposited on glacial sediments of Dwyka tillite which, in turn, were deposited on dolomite of the Transvaal Supergroup. A significant amount of magma intruded as concordant sills of dolerite in the Karoo strata in the Delmas area. Associated with the dolerite intrusion are numerous thin dolerite dyke structures that transgress the stratigraphy. Factors controlling geological and quality continuity are mainly surface weathering, significant variation in seam thickness due to an undulating tillite floor, faulting associated dolerite activity and dolomitic basement, and devolatilisation and weathering due to dolerite intrusions (sills and dykes).

The average total seam thickness at Leeuwpan is 10.9m, with an average raw calorific value of 20.1MJ/kg, raw volatile matter of 18.7% and raw ash content of 31.4% (adb). These qualities require beneficiation for export-quality products.

Leeuwpan is an opencast operation with various Reserves, in various pits, mined simultaneously. Current mining operations are on the OJ (depleted in 2018), OL and OWM Reserves with the introduction of OI Reserves. The OI box-cut was completed in September 2018 and first coal was produced in Q1 2019. The mine uses trucks and shovels for mining-related operations. We estimate that the mine will be in production until 2031, with the mining right lapsing in 2039. Leeuwpan supplies domestic and export markets. The mine is equipped with a rapid rail load-out station, which is the preferred means of coal offtake, although road transport is accommodated.

Mine Waste
Originally, the mine residue consisting of carbon-carrying shales, plant residue and fine coal recovered from the slimes dams, was compacted and disposed of into the mined-out pits below the groundwater table. It was then covered with a clay layer and topsoil so that it would be suitable for agricultural purposes at a later stage.

Discard material from these Blocks was placed back into the open pits.

Leeuwpan has two dense medium separator plants that beneficiate export thermal coal and two dry plants, crush-and-stack and bypass plants that handle selectively mined thermal coal either for the local market or the export market. The second dense media separation plant, commissioned in 2016, is operated by Fraser Alexander whereas the original plant is operated by Exxaro. Both plants are geared for 5 300kcal/kg production. The crush-and-stack and bypass can produce either 5 300kcal/kg, 4 800kcal/kg or 4 200kcal/kg products. All plants produce mainly thermal coal.