• Great Noligwa mine. Picture: ANGLOGOLD ASHANTI

  • Peter Craven Aiming for better utilisation of resources

Intensive research into solving the problems around how to mine safely at depths of more than 5km will completely change the face of the industry over the next 50 years.

Shaun Newberry, AngloGold Ashanti vice-president of strategic project design and spokesman for collaborative research group the Technology Innovation Consortium (TIC), says all the gold miners are facing the same challenges that the TIC is addressing. These are how to mine deeper and particularly make advances in safety and productivity.

At the moment, conventional SA deep-level mining uses hand-held drills to bore holes into the rock for the insertion of explosives. Also, the necessity of making tunnels wide enough to accommodate people and equipment causes significant dilution of grade, sometimes halving it, or worse. About 40% of an ore body has to be left behind as safety pillars to reduce seismic risks.

The TIC is investigating mechanical rock-breaking techniques called continuous reef boring, which would be considerably safer and more efficient than hand-held drilling. It is looking at ways of improving extraction ratios and infrastructure efficiency by refining knowledge of the ore bodies and replacing mined rock with material of similar strength, called ultra high-strength backfill. This backfill is very different in its composition and strength from the material being used in the industry at present.

Newberry says if you think of the gold-bearing reef as the ham in the sandwich and the rock as the bread, improved mining techniques would allow miners to take the ham out and leave the bread behind. Peter Craven, GM of business development at Mintek, says the biggest focus areas of mining research are, firstly, improving access to and processing of low-grade, complex ore bodies, as mining goes deeper and resources are depleted. A second area is beneficiation, which is a government requirement for mining companies. Another is finding energy- and water-efficient technology. Scarcity of water is one of the biggest issues facing mining companies. A fourth focus is technology to reduce carbon emissions. Finally, the international trend is towards greater recycling and "urban mining".

Craven believes the greatest shift in mining in future will be better utilisation of resources, a reduced impact on the environment and production of metals that can be recycled more easily. Newberry envisages "an industry that is safe and sustainable, where employees are highly skilled and where secondary and tertiary industries that support these new mining methods are established and mature".

Gold mining in SA will stage a comeback as countries now producing more gold than SA will mine out their limited resources quickly, Craven says, prompting solutions for ultra-deep mining. SA is also likely to become a bigger producer of technology metals, like titanium, tantalum and rare earths, which are used in hi-tech applications.

Research into mining technology is taking place at a number of government institutions as well as the private sector. "Mintek co-operates, rather than competes, with other research institutions, and in fact the boundaries are fairly clear," Craven says.

"The universities have always focused on fundamental research. The Council for Geoscience focuses on the exploration stage of mining, maintaining a database of geological information. The Council for Scientific & Industrial Research (CSIR) has taken over from the Chamber of Mines Research Organisation in mining technology research, and is also involved in minerals applications, where there is some crossover with Mintek. Mintek's area embraces minerals processing and refining as well as minerals applications."

Craven says Mintek is satisfied with the level of support it receives from government. It now has a better balance between state and private-sector funding than a few years ago, when it was 30:70. Mintek receives a basic grant from government but recently has also received funding under the Economic Competitiveness Support Programme. It receives grants from other government agencies, like the Technology Innovation Agency and the National Research Foundation, and runs some research programmes for the department of science & technology.

The advantage of government funding is that it allows Mintek to do more discretionary research than it does under specific programmes funded by the private sector. However, government-funded research is not unconstrained, as government projects have to fulfil policy priorities of job creation, skills development and natural resource development, Craven says.

Several large companies have closed their in-house R&D divisions and now fund programmes at dedicated research institutions instead. Others continue to do research in-house that is suited to their own particular needs. In SA, the TIC is probably the biggest collaborative private-sector project into deep-level mining technology. It taps into the expertise of a range of partners, from original equipment manufacturers to suppliers, tertiary institutions and other innovators. The relationship between the TIC and its partners varies from information sharing and concept design to testing and prototyping.

"While traditional, closed innovation implies that a company exercises control over the ideas generated around a specific topic, open innovation encourages collaboration between various companies and parties not necessarily associated with the mining industry," states AngloGold's latest annual report. "One of the major benefits of open innovation is the speed with which results are produced."

Another example of public-private partnership in mining technology is global technology group Micromine, which offers a resource modelling and mine design system. Micromine was founded by three Australian mining surveyors who developed a 3D geological modelling programme. The company's mine operations management system, Pitram, received funding from the Australian government, which matched the private developers dollar for dollar in the research costs, Micromine regional manager for Africa, Marc Ramsay, says.

He says automation is a major trend in mining because of labour issues but technology does not destroy jobs, it creates better jobs and takes people out of harm's way. It also helps with utilisation of assets, whether it is an employee's time or being able to use more junior staff in certain jobs to free more qualified people.

Another innovation that has moved in the past decade from conceptual to practical application in deep-level mining is the Rail-Veyor, an electrically driven train which loads and tips ore by remote control. It was designed by an American, Mike Dibble. Harmony Gold Mining introduced the Rail-veyor into its Phakisa mine several years ago. Investor relations manager Henrika Basterfield says it is only being used at Phakisa, which is one of Harmony's newest mines, since the technology is fairly new and there was an opportunity to implement it when the mine was built.

Globally, another area receiving closer scrutiny is technologies to enable deep-sea mining, though that will have to overcome resistance from conservationists. De Beers has been mining marine diamonds for several years using vertical drilling and a remote-controlled seabed crawler. Nautilus Minerals, a Canadian company, has been exploring for copper, gold, zinc and silver at depths of nearly 2km in the ocean off Papua New Guinea.

Last month Mineweb reported the UN's International Seabed Authority had issued 17 deep-sea exploration permits already and expected companies could apply for mining licences by 2016. And there's talk of extracting minerals from outer space some time in the future ... but that may be in the very far distant future.