The initial phase of shaft sinking and drilling company Redpath Mining South Africa’s infrastructure development at Zambia-based copper and cobalt producer Mopani Copper Mines’ (MCM’s) Mindola deep shaft is currently under way, says Redpath Mining South Africa MD Ockert Douglas.

The 2000-m-deep shaft, which will be used to access deeper parts of the copper ore, comprises four 6.1-m-diameter holes at 500 m intervals, with designated areas at each interval for the placement of the drilling machine.

The company is using its proprietary Redbore 90 Raisebore machine – which is the second- largest of the company’s product offering – for the drill shaft, which will have an extended height of 5.56 m and a retracted height of 4.2 m. The unit weighs about 34.75 t, without the base plates, pipe loader or erector.

The raised Redbore drill uses a hydraulic cylinder thrust system, which has a maximum pilot hole force of 667.2 kN and a maximum reaming force of 8896.4 kN. The thrust system also has an operating pressure of up to 310.26 bar.

Douglas tells Mining Weekly that Redpath will use directional drilling to ensure that the holes are aligned from one level to the next.

Further, the company is undertaking horizontal and decline development of about 9 km to establish the required infrastructure for the new shaft and associated access development to reef horizons.

Douglas highlights that there are only three Redbore 90 machines in the global Redpath fleet; the other two machines are being used on mining projects in Australia and Canada.

Meanwhile, despite the recent economic downturn and ongoing strike action in the local mining industry, and notwithstanding the volatile copper price, the Mindola project has not been significantly affected, as proper budget planning was undertaken prior to the start of the project, says Douglas.

He describes the project as an “excellent opportunity” for Redpath Mining South Africa, as it places the company in a very strong position for the next three years.

Douglas highlights that the project employs about 400 people, 10% of which comprises foreign labour. There are 76 Redpath personnel on site, equally comprised of South African expatriates and members of the local Copperbelt community.

Further, Redpath Mining South Africa last year established an on-site training centre in Johannesburg to train local workers for job-specific tasks before they start work underground. Training takes between three weeks and three months, depending on the skills level and qualification of the workers.