Digging deep for reserves of gold

八月 20, 1999

As supplies of gold, the backbone of South Africa's economy, are depleted, researchers are exploring mining five kilometres

underground. Karen MacGregor reports on this and other fruitful collaborations between universities and industry As central banks sold gold and the price plunged last month, so did the hearts of South Africans. Oh no! another roller-coaster ride. Just as the economy was edging upwards and growth estimates were being revised, the bottom got yanked out of the market yet again.

Undaunted by the flailing metal prices, 200 researchers around the country continued work on a massive research programme into the challenges of mining gold three to five kilometres below the earth's surface. In fact, their work became more imperative.

Some researchers are developing the technology needed to cope with heat and rock burst problems bound to be encountered at such depth; others are investigating the skills, health and psychological needs of the miners, who will face hazards and break deep-mining records every metre further they descend.

It was realised some years back that many gold mines - the backbone of the South African economy - were nearly depleted to three kilometres down and would have to dig much deeper to reach veins of the size and quality needed to stay in business.

Mining companies, the government and experts got together to seek ways of making this possible, and set up a four-year, R70 million (Pounds 7 million) Deepmine Collaborative Research Programme.

"Deepmine" is itself part of an even bigger national initiative called the Technology and Human Resources for Industry Programme, funded by business and the Department of Trade and Industry and managed by the National Research Foundation.

THRIP brings together the state, industry, and research and higher education institutions in joint ventures aimed at developing the technology and skills needed to improve South Africa's global competitiveness in key fields.

This year the hugely successful programme will pump at least R160 million (Pounds 65 million) - half from government and half from industry - into collaborative research in the areas of science, engineering and technology. Humanities projects are only supported as part of larger S&T programmes.

The Deepmine concept was first floated in May 1996, when mining experts from the Council for Scientific and Industrial Research and the University of the Wi****ersrand (Wits) in Johannesburg started to talk. Mining companies and the government were keen and a research programme was drawn up.

Deepmine's 200 researchers are working on projects in nine areas, says Ray

Durrheim, manager of the programme and a geophysicist in the division of mining technology at the CSIR. About half of the researchers are from the CSIR and the rest are from universities, research organisations and consultancies.

Wits has a major role - industrial psychology, physiology, geophysics and mining, civil and mechanical engineering are some of the departments involved. Other institutions contributing include the universities of Pretoria, Natal, Stellenbosch, Cape Town, and Wits Technikon.

The first year of research, completed in March, consumed R15.5 million of the R70 million budget: R5.9 million came from mining companies, R5.9 from the CSIR and R3.7 million from THRIP.

The focus of the first year was on two areas - developing the expertise and the technology needed to mine ultra deep.

"We have been trying to predict what conditions will be like at such depth. What the rock mass will be like, how fractured it will be, how it will behave when we drill holes in it, what the temperatures will be, and so on," Dr Durrheim explains.

"We have also been setting performance criteria. What temperature we want it to be down there, for instance, and how fast and efficiently companies will have to mine to be productive and profitable."

In addition, researchers have been looking into the technology and current capacity of the mining industry locally and internationally, with a view to identifying best practices able to meet the performance criteria.

The best scenario was that it would be possible to adapt existing technology successfully to mine ultra-deep. A second scenario was that new technology would have to be introduced.

"There are two certain problems: rock burst and heat. If we cannot solve both of those problems we cannot continue," Dr Durrheim says. "We found in the first year that there doesn't seem to be a show stopper - anything that will require new technology. With good equipment and well-trained people it can be done."

It will be critical, when mining deeper than three kilometres, to detect weaknesses in the rock hundreds of metres ahead of mining. The Deepmine programme will need to develop and adapt ground-penetrating radar technology and antennae that can be slipped up boreholes drilled ahead of mining to produce accurate images of the surrounding geological structure.

"We need to be able to identify even small faults, along which a lot of seismic action can occur, before companies mine into them. You cannot mess around with weak structures."

The second central problem is heat. Refrigeration costs are very high. Temperatures that deep will be 65° to 80° C, it is estimated, and it will take a lot of energy to cool the environment down to 24° to 25°.

"We have to find ways of making refrigeration and ventilation as effective as possible. We are investigating how to insulate rock so heat doesn't keep coming through into the tunnels, for example, and seeing how chilled water can best get to where it is needed. Existing systems need to be improved," says Dr Durrheim.

One of many social areas of research is being undertaken by the industrial psychology department at Wits, under Eddie Webster. It is a project investigating the occupational culture of workers.

People who work closely together, especially under hazardous conditions, develop a culture - a view of the world and each other that is characteristic of their occupation.

Five postgraduate students are living with miners, trying to understand their experiences of working at different depths, the psychological effects and how they cope with danger. The idea is to develop psychological support systems for people who will be working ultra-deep.

Deepmine will help decide the future of the goldmining industry in South Africa - one of the country's strategic economic industries. It is exactly the kind of project THRIP loves, and just one of 450 projects - albeit the biggest - supported last year.

Another example is the R6 million (Pounds 2,440,000) "winetech" programme in the Western Cape. It is based at the University of Stellenbosch, but also involves other institutions and the local wine industry, and comprises more than 50 projects researching ways of improving the quality of wines, right through from the growing of grapes to fermentation.

THRIP, explains its manager Rocky Skeef, "is about collaboration with very focused intended outputs that benefit the industrial partners involved, and South Africa in terms of international competitiveness. It is about getting people to identify common problems and objectives and putting money into tackling them."

Established in 1992, the programme - whose initial state budget was R2.3 million - first struggled to get going. It was undersubscribed, with researchers and businesses failing to take up all the funds.

By 1995, however, it had begun to take off. In 1996 the budget grew to R48 million in total - half from government and half from industry - and last year R144 million worth of funds were awarded to research projects. The current budget of R160 million is already oversubscribed.

"Research consortia of universities, science councils and groups of industries are now coming together and strategically positioning themselves to attract THRIP funds," says Dr Skeef.

"We are being forced to prioritise, and are considering approaching government departments for extra funds to support projects related to them, such as agriculture."

THRIP has been reluctant to impose on people what they should research, although it favours projects that are related to manufactured products - especially with export potential - and those that meet its objectives of promoting high-level skills training (especially of black people and women), collaboration between companies and research institutions, and industrial research and innovation.

Currently it tends to support industrial partners who want to improve their competitive edge and are prepared to sink money into research to that end. But this might change somewhat in the future. With the government's S&T foresight exercise identifying key national strategic areas, increasingly the state might begin to influence research areas being supported.

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