The interpreted sub-crop of Boikarabelo specifically consists of the following formations:
• the Eendragtpan Formation (Triassic age, within the Beaufort Group) which consists of barren sediments and overlies the coal zones,
• the Grootegeluk Formation (Permian age, within the Upper Ecca Group), which consists of intercalated bright coal (zones 5 to 11) and mudstone,and
• the Goedgedacht (Permian age, within the Middle Ecca Group), which consists predominantly of dull coal (zones 1 to 4) with minor
carbonaceous mudstone and sandstone intercalations.

The Grootegeluk Formation consists of easily identifiable cyclical repetitions of mudstone and coal with the coal seams named from the base upwards. Individual plies are named and correlated according to the known Grootegeluk Coal Mine nomenclature. This comprise of a sequence of sample names that group plies together in each classic Waterberg Zone. These samples can be correlated across the entire Waterberg Coalfield. A typical Waterberg borehole has 11 zones from Zone 1 at the base to Zone 11 at the top. The lower three zones do not comprise of alternating plies but more typical coal seams. The Eendragtpan Formation provides a thin covering of 25-35m thickness over the majority of the area and thus preserved the Grootegeluk and Goedgedacht Formations.

The Grootegeluk Formation was intersected during the drilling programme and varying thicknesses for the coal zones 1 to 11 have been reported. Intra-basin faults affect the coal bearing formations further to the south and north of the Boikarabelo mining area, so that the upper zones are either preserved or destroyed through up-lift and erosion.

The Grootegeluk Formation comprising the top zones (zones 5 to 11) consist of various coal and mudstone seams. These zones are well defined and can be correlated across the coalfield. This formation, from the top of zone 4 through to zone 11, is characterised by an increasing ratio of bright coal to dull coal. The zones typically start with bright coal at the base and the ratio of coal to shale decreases from the base of the zone in an upward direction. The ash content of these zones increases upwards in each zone and generally the “better quality” coals are present in zones 9 to 11 over the majority of the coalfield. The coal zones require beneficiation to produce a primary product of an acceptable coal quality.

The Grootegeluk Formation is underlain by the Goedgedacht Formation of the Middle Ecca Group. This formation consists predominantly of dull coal with minor carbonaceous mudstone and sandstone intercalations. The zones occur within a stratigraphic interval of approximately 40m and have thicknesses ranging from 1.5 metres to 9 metres. Zone 2 and 3 are the best developed coal zones within this formation. Zone 1 has not been developed throughout the Boikarabelo area and occur only in a few isolated intersections. These bottom three zones require limited beneficiation to upgrade the coal quality to be suitable for local power station feedstock.

Boikarabelo is planned as an open pit terrace mining operation, similar in many aspects to the neighbouring Grootegeluk Coal Mine which uses truck and hydraulic excavators (in varying configurations) on multiple benches linked to a common ramp. The optimised mine plan resulted in a LOM of 41 years and a reduction in the total number of years of out of pit dumping (OOPD) from seven to two. There was also an overall increase in the plant yield of 2%. These improvements were realised due to the repositioning of the box-cut from the centre to the western limit of the pit and conducting a mining aggregation exercise which excluded low yielding coal seams from the mineable coal.

The box-cut is planned at the western limit of the mining right area with a limit of oxidation (LOX) line in a down dip direction and to the base of the coal. Once the northern limit of the pit is reached, the mining direction changes to along strike. The position of the box-cut has shifted from its initial position (centre of the mining property) in the previous design. The updated box-cut position offers an advantage in that the haulage distances are minimised throughout the LOM, which in turn minimises the number of trucks required. On completion of the planned box-cut, the complete succession of coal horizons will be exposed, allowing for more selective mining. The counter effect of this revised strategy is a lower production capacity.

The updated position of the box-cut has resulted in an improved waste strategy, which will reduce the amount of OOPD and minimise the environmental footprint of the mine. In the updated design, OOPD will be minimised, with in-pit dumping commencing sooner. On completion of the box-cut, the waste material and low grade product from the mining operations, as well as the CHPP rejects will be dumped in-pit. The waste strategy has reduced the number of external years of dumping from seven to two. The haulage distance for dumping will be reduced once in-pit dumping commences. The waste strategy will in addition ensure concurrent rehabilitation, minimising the rehabilitation liability at the end of the mining operations. Backfilling will be done within the 60 to 90 days spontaneous combustion period. The waste that is dumped in-pit will be compacted as a means to further mitigate against spontaneous combustion. The proposed method to prevent spontaneous combustion in this project is acceptable.

The CHPP can be divided into different sections for the ease of discussions. These sections are as follows:
- coal sizing operation,
- ROM stockpile with a coal stacker and twin bucket bridge raw coal reclaimer,
- dense medium separation plant (2 modules),
- fine coal processing plant, and
- thickener and filtration.

The ROM feed will be tipped into a 700t bin where the material will be reduced in size to -300mm with a feeder breaker. Thereafter the coal will be conveyed to a coal sizing station. The -300mm coal will go through a secondary sizer (roll crusher) and the coal reduced to a 120mm top size. The secondary sizer product will go over a scalping screen to relief the load to the tertiary sizer. Only the +50mm to -120mm material will be fed to the tertiary sizer. The coal will then be reduced to -50mm.

The sized raw coal will then be stockpiled on two 75 000t live stockpiles. The strategy is to blend the coal from the stockpiles to obtain a constant yield through the coal processing plant (CPP). The coal will be reclaimed through a twin bucket wheel bridge conveyor. There is also an option to bypass the stockpiles and to feed sized coal straight into the CPP. Stacking and reclaiming is carried out in 50kt batches to enable analyses of the sampled ROM, which will provide the density cut point for the DMS in the processing plant.

Material is fed in to a 500t bin with limited surge capacity and will assist to regulate the feed to the CHPP. The bin feeds two identical dense medium separation plants. Material from the bin passes over a de-sliming screen that removes the -1.4mm from the feed that is routed to the coarse dense medium cyclones (DMC). The -1.4mm fraction reports to the fine coal processing circuit.

The overflow of the de-sliming screen reports to the primary large diameter cyclone, where waste is removed through a high density separation. The underflow reports to the discard bin, where it will be deposited in the mining void. The overflow from the primary cyclone is pumped to the secondary large diameter cyclone for further beneficiation. The secondary cyclone is a low density cut separation process were the overflow is an export product and the underflow is a domestic steam coal product. All product and waste streams run over drain and rinse screen to ensure maximum water and magnetite recovery before the products are placed on product stockpiles and the discard returned to the mining void.

The -1.4mm material from the de-sliming circuit passes over a sieve bend, the 0.25mm x 1.4mm material reports to the fines reflux classifier. The undersize material (-0.25mm) is pumped to a classifying cyclone. The cyclone overflow, the -0.075mm material, reports straight to the thickener. The underflow is pumped to the ultra-fine reflux classifier.

The floats of the fines reflux classifiers are dewatered through a screen bowl centrifuge to produce an export product. The sinks are thrown on the rejects belt. The ultra-fines cyclone floats are dewatered and placed on the domestic product stockpile with the sinks reporting to the thickener. The -0.075mm material from the classifying cyclone and the underflow from fine- and ultra-fine reflux classifiers reports to the thickener. The thickener underflow is pumped to a belt filter press to dewater the slurry. The filter cake is added to the reject conveyor. All rejects are placed on the rejects conveyor that feeds the reject bin for collection to be discarded in the mining void.

The two product streams are separately stacked through dedicated radial stackers onto their stockpiles. The stockpile capacity is 78 000t per product. The product is reclaimed through dual coal valves directly underneath the stockpile. The product belt transports the product to the train rapid load-out facility where train trucks are loaded on a rail siding. The plant process described above is well-known technology used by many coal operations through South Africa and Australia. The plant is based on the premise that the coal can be separated from the waste rock by means of their respective densities.