Mining Mirror June 2019 | Page 18

Mine excursion Accessing the seams Coal unearthed at Khanye is railed to the Richards Bay Coal Terminal, and then exported. [16] MINING MIRROR JUNE 2019 CMS uses sequential strip-mining methods to unearth the three coal seams at South Pit. “The three main seams that we mine are 2 Upper Seam, 2 Lower Seam and 1 Seam. Whenever we do mine a patch of 3 Seam it is sent to the plant separately and blended with the other coal in the processing operation,” he says. The overburden consists of a soft sub-soil clay, which occurs on top of a two- to eight- metre-thick sandstone layer. The first coal seam (2 Upper Seam) is encountered at the bottom of the sandstone, about nine metres from surface, but it dips and the sandstone seems to disappear halfway through the pit. There is a thin shale band on top of 2 Upper Seam. The strip ratio is on average about 2:1 in this area. Underlying the shale is 2 Lower Seam, followed by a parting which is about one- and-a-half to four metres thick, before 1 Seam is accessed. As soon as the coal has been removed, sequential roll-over rehabilitation takes place. “We will be opening three benches at a time, so we will be mining one of the seams at all times. In other words, there will always be coal www.miningmirror.co.za