The primary geology and stratigraphy at Khutala is typical of the Witbank Coalfield. The development of the No.2 and No.4U Seams occurred mainly in a broad valley of low topographic relief where coal seams terminated towards the east and west of the property. This thinning or absence of coal seams towards the east and west is due to a gentle rising of the pre-Karoo relief. Coal Resources in the No.2 and No.4U Seams within the Khutala mining right area is contracted to Eskom and mined coal is delivered raw to Kendal Power Station.

The No.1 and No.2A Seams are either absent or only locally developed with restricted extents across the area due to elevation differences in the palaeo-floor which consists of either basement felsite or Dwyka Formation.

Two prominent hilltops within the Khutala boundary represent major felsite palaeo-high ridges that truncated the coal measures during deposition. These no-coal areas are shown in Figure 5.44 and their effect on coal seams is illustrated in Figure 5.45. Seam dips can reach 15o on the flanks of palaeo-highs.

The No.4L, No.3, No.2A and No.1 Seams are not economically significant. These seams are either too thin, inconsistently developed, or of too poor quality to be considered.

In general, the coal-bearing strata are flat lying with little structural disturbance to the coal seams. However, a major graben structure bisects the Khutala property striking northeast-southwest and effectively divides ........

The mine is predominantly an underground bord and pillar mining operation.

The underground mine is accessed by a large diameter vertical shaft for men and materials and there is an access decline which is used to transport the coal on a conveyor from underground to the surface stockpiles. In total there are currently 12 working areas (known as sections), with eight sections in the No.2 Seam and four sections in the No.4 Seam. The current underground mining method is to use modern mechanised continuous miners in all working sections. Both the No.2 and No.4 Seams are mined using continuous miners, mechanised roof bolters, electric shuttle cars and feeder breakers. The broken coal is loaded onto a network of conveyor belts, which transport the coal to surface.

Each continuous miner section comprises nine roadways; seven of these are used as intake airways and the remaining two as return airways. In plan view, this creates chequerboard pattern of ‘bords’ (comprising headways and cut-throughs), which provide access, and blocks of uncut virgin coal blocks (‘pillars’). The pillars support the overlying strata, while the headings/cut-throughs are supported by roofbolts. The depth of working is the key determinant impacting on the dimensions of the pillars and the size of each bord. As depth increases so does the size of the pillar, which then affects extraction and production rates. This nine-road configuration minimises the frequency of belt extensions, without ........

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