Modern Mining Marchh 2017

MINING CONTRACTING

Largest raiseborer in the world deployed in Zambia Redpath Mining Africa currently has what it says is the largest raisebore machine in the world, the Redbore 100, in operation at the Synclinorium Vent Shaft project for Mopani Copper Mines (MCM) in Zambia.

I n addition, the mining contracting and engineering company has several other raiseboring machines at work in Africa. “Even though the market has been quite depressed, we have grown to the tune of 40 % year-on-year,” Redpath Mining Africa Managing Director Ockert Douglas comments. Douglas says that Redpath’s strategy has been to secure projects locally, so that the South African business could be in a comfort- able position, at which point it could begin to look for opportunities outside the country. This resulted in Redpath Mining Africa’s long-term involvement with MCM, for which it is undertaking three projects. Commencing in 2014, the Synclinorium Vent Shaft project is scheduled for completion this year. The shaft is 6,1 m in diameter and is being completed in two legs, of which the longest is 738 m. “We have completed the first leg, and are currently busy with the second,” says Redpath Mining’s General Manager of Raiseboring, Johan Davel. At Mindola Deeps, Redpath Mining Africa is raise drilling a 2 000 m vertical shaft in four legs of 500 m each. The company has currently completed two legs, and is busy with the third. “This is the first time in the world that a 2 000 m shaft is being raise bored,” Davel observes. Lastly, Redpath Mining Africa is involved in a joint venture project with Rig Resources Zambia, undertaking development, long-hole drilling and stoping work for MCM at the Nkana and Mufulira mines. Redpath Mining Africa’s successful collabo- ration with MCM is helping increase awareness about raise drilling in the African mining industry. “A significant feature of our raisebore machines is that they are low-profile,” Davel points out. Fully extended, the Redbore 100 has a height of only 7,6 m. With energy-saving a major driver in the African mining industry, Redpath Mining’s raisebore machines all feature variable speed electric drives, which reduce energy consump- tion by 25 % to 30 %, compared to traditional hydraulically-driven units. Billed as the ‘crown jewel’ of the series,

the Redbore 100 is the most powerful, larg- est-capacity proven raiseboring system ever manufactured by Redpath Mining. It has the ability to bore raises of up to 8 m in diameter and to depths exceeding 1 000 m. The development of the Redbore series is integral to the company’s philosophy of modernisation and mechanisation. “We are a frontrunner in terms of reducing the human element in sinking development work. Our sinking methodology differs from the tradi- tional, tried-and-tested way,” Davel explains. “Redpath Mining is represented on all conti- nents, which bolsters the entire group in terms of technological development. In South Africa, for example, we are able to draw expertise from Australia, Canada, North and South America, and even Europe, where we are undertaking massive projects. In Indonesia, we are work- ing on one of the largest sinking projects in the world. Being able to access that level of inno- vation is a major advantage for us,” Douglas stresses. An example of this ongoing development is the Redtrax raise drill carrier, which can blind-bore a 1,6 m diameter shaft. “The major advantage of this machine is that it has the ability to swing 360 degrees and carry out con- ventional raise boring as well,” Davel notes. 

The Redbore 100 in operation at the

Synclinorium Vent Shaft project on the Zambian Copperbelt.

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March 2017  MODERN MINING  43