Quarry Southern Africa May 2017 - Page 22

Winning In the mine the Wirtgen 2500SM cuts limestone with a working width of 2.5 metres and a working depth of between 450 and 500 millimetres. WPI gives the machine operator a fast and simple overview of the degree of wear of the picks – without causing downtimes. 20 _ QUARRY SA | MAY 2017 The longer the pit is, the more cost-effective it becomes to use the Wirtgen machine because you have less stoppage times for turning around. So, one challenge currently faced is that going in to an existing mine is a real challenge because the mines must be converted and optimised for surface mining by opening up longer pits. “Because of the potential difficulties of switching to using the machine at already existing mines, we are mainly targeting those that are undergoing – or planning – expansion, as well as greenfields operations where the mine can be designed to facilitate use of the surface miners from the get-go,” says Newby. “The other area we’re looking at is existing mines that are coming to the end of their life, where there is material remaining but they are unable to mine it because of safety concerns. It might be a mine that has underground ball-and-pillar tunnels and they can’t blast or have machines working there because it might all cave in. Our machines can work in those sorts of conditions because of the minimal ground pressure.” n