Khwezela Operation (Landau and Kleinkopje Collieries) consists of two sections, namely the Kromdraai Section and the Navigation Section (Navigation West extention). Surface material at Khwezela consists of weathering products of the sandstones, siltstones and mudstones of the Vryheid Formation, with a small area of weathered doleritic material found in the southern-most corner of Khwezela North. The top layer consists of reddish-brown sandy soil, with clayey-sandy subsoil below. The depth of weathering across Navigation and Bokgoni varies between five and twelve metres; the overburden material is therefore likely to be relatively competent. However, deep weathering may be encountered below the wetlands in the SACE Lifex areas. Navigation Washouts have been intersected in the north where the coal seams have been eroded by palaeo-rivers, with the resultant channels filled with clastic sediments. The edges of the washouts are irregular due to differential compaction. Northeast – southwest trending floor rolls are also encountered. Both the No 1 and the No 2 Seam occur, separated by the No 1 Seam parting (P1). The floor to the No 1 Seam consists of a thin carbonaceous shale band, which conformably overlies a reworked tillite of the Dwyka Formation. The No 1 Seam is present over the majority of the Navigation area and has been previously mined via underground workings (bord and pillar). It averages 1.27 m thick but reaches a maximum thickness of 2.63 m. The P1 is variable in ........

Khwezela North (previously known as Landau) consists of the current operating Navigation pit as well as the Kromdraai and Umlalazi pits, which are currently being rehabilitated. The Navigation pit is an opencast operation with a pre-strip operation allocated to a truck and shovel fleet. The overall stripping ratio is low compared to other similar opencast operations. Khwezela South (formerly known as Kleinkopje) consists of the Bokgoni 2A pit and the MRD (also known as Landau 3), both of which were placed on care and maintenance with effect from the first quarter of 2021. No Coal Reserves are declared. The Navigation pit is located approximately 120km east of Johannesburg, 22km west of the town of eMalahleni in the Mpumalanga province of South Africa. It forms part of the SACE complex, together with Khwezela South (formerly known as Kleinkopje) and the Greenside Colliery (refer to the Greenside overview). The Navigation pit is constrained by the MR boundary, Eskom powerlines, the Transnet railway to the north, bounding the Clewer settlement in the west, the Navigation CHPP and the Blaauwkrans MRD to the south. The RLT as well as the EWRP lie south of the pit. The Navigation pit is an opencast operation with a pre-strip operation allocated to a truck and shovel fleet. The overall stripping ratio is low compared to other similar opencast operations. The main operational risks are the potential for spontaneous combustion in the old workings. The primary mining equipment ........

Navigation CHPP
The Navigation Tip consists of a 1200x1200 mm static grizzly above a primary bin. The -1200 mm material is extracted via an apron feeder and fed onto a vibrating grizzly with an aperture size of between 80-100 mm. The grizzly oversize is fed into a jaw crusher and crushed to -350 mm. The material is then fed into a single rotary breaker for reduction to between 80-100 mm. The crushed material from the rotary breaker joins the vibrating grizzly undersize material and conveyed to the RoM bunkers which were previously used to receive railed and trucked RoM coal. Rotary breaker waste is fed to a 300 t rock bin for disposal back to the pit.

Bokgoni CHPP
Each tip has grizzlies with 750 mm x750 mm apertures onto which coal is tipped by trucks. The coal passes through the grizzlies into the RoM bins, each of which has a 1 200 t capacity. Below each of the RoM bins are feeders which feed raw coal into their respective rotary breakers. The rotary breaker picks the coal up four to five times, the coal preferentially breaks and falls through 150 mm diameter holes. Numerous magnets are positioned to attempt to remove some of the extraneous metal in the feed. Some material will not break, passes through the breaker and is rejected.

From Tip B (and previously Tip A), the reject from the rotary breakers passes to the W1 Conveyor and into a stone bin. This waste is taken back to the mine by trucks loaded from the stone bin. The coal from the Tip C bin is also fed onto a vibrating grizzly cutting at 150 mm, with the +150 mm material being fed into the rotary breaker.

In the past, the rotary breaker reject was fed into a jaw breaker to reduce all the material to -150 mm as the roof coal and the discard material is considerably harder and potentially contains more of the lower grade product coal for which it will be washed. The crushed oversize material is then combined with the rotary breaker underflow. However, this has now been changed and the jaw crusher has been taken out of circuit. The circuit is now essentially the same as Tip B, with the waste rejected from the rotary breaker joining the waste from Tip B.

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