Modern Mining September 2023

for NRHR mining

As it is, we have collaborative capability, resources, and a suitable test facility that will allow modification of the machine during its development and testing stages for the NRHR environment.” Need for speed A key advantage of mechanical cutting equipment is that it offers speed and efficiency, and thereby increased productivity. The traditional drill and blast method is bound by construction work and is undertaken a few times a month, which allows for the development of between only 100 m to 200 m per month. In contrast, a tun nel boring machine, for instance, would be able to achieve significantly improved results – as much as 600 metres per month – almost three to four times what is currently achieved. “If mining is to continue in areas such as Rustenburg, where it takes place between 800 m and 2 000 m underground, and where the upper areas are about to be mined out, more shafts will need to be sunk. Having a piece of equipment, such as the tunnel-borer, that can rapidly develop an underground connecting highway infrastructure will significantly lower the capital costs of progress ing mining in the deeper, lower areas. Furthermore, given that the Rustenburg area is home to several mines, mining houses could potentially co-fund a machine modified for their local conditions, which would deliver significant advantage to the regional players. Such a machine would allow miners to access connecting points to multiple shafts and resources, which would become the starting point for next generation shafts – these could be inter linked using raise-boring equipment.” However, given that tunnel-boring machines are developed for single use application, after which the multi-million-rand machine is discarded, Pretorius believes that opportunity exists to modify a tunnel boring machine for extended use. Such a machine

would be used to tunnel from a centre point out, con necting mines that are contiguous. Importantly, high-speed tunnelling is becom ing a critical requirement to access replacement resources timeously. The strong demand for metals, particularly PGMs which have gained traction on the back of demand for clean energy sources, remains an impetus for introducing mechanical cutting equipment. Further to this, such equipment will reduce the number of people at the rock face, allowing them to oper ate within lower risk margins of semi-autonomous equipment.

Mechanised tunnel development. Exploration project using drilling and blasting and MTB methods, J Walls SANCOT 2022.

Left: NRHR infrastructure development.

Below: TBM tunnel intersection NRHR. Exploration project using drilling and blasting and MTB methods, J Walls SANCOT 2022.

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September 2023  MODERN MINING  27