South Africa’s gold mines have been technology trailblazers for much of the last century, and produced some unique technologies, such as continuous and blast-free mining.
“Deep-level mining is undoubtedly the country’s speciality, delving to over 4 000 m to extract gold. But this depth is only one of a range of factors that make the auto- mation of mining processes difficult,” says SRK Consulting chairperson Roger Dixon.
He adds that many mining countries have made great strides in automating mining operations, but the starting point has usually been suitable geological conditions.

Dixon explains that massive mining techniques are applicable where large and uniform orebodies occur close to the surface and allow access by a variety of mining machines, and are often well automated and highly efficient.
However, he states that, given South Africa’s great depths, narrow reefs, high temperatures and large amounts of rock pressure, it has been difficult to apply many of those high-tech solutions that promise to make mining more profitable and safer.

For many years, gold miners have invested millions of rands into research, initially through the Chamber of Mines Research Organisation and then through the Council for Scientific and Industrial Research. Many mines also partnered with their suppliers – and continue to do so – to explore and test ideas around non- explosive mining of gold ore at depth.
“Gaining access to sophisticated proto- types and machinery, able to operate in the hot and humid environments of mines, poses a challenge in itself,” says Dixon.

“The high rock pressures at depth result in the rapid closure of mining spaces, which inhibited some of the ideas that could have transformed our industry. Such space closures impede the tunnel- and-raiseboring methods that work well nearer to the surface, but not at depth,” he explains.
As gold grades have dropped across the industry and mining costs have steadily risen, the margins available to mining companies have declined accordingly. The result has been a decrease in research and development in recent decades.

However, there are shallower deposits that could well benefit from modern automation technology. Dixon states that the Modder East and Burnstone mines, in Gauteng, are both only about 500 m deep and are accessible through decline shafts.

But new technology is easier to plan and implement in new projects, where technical integration can be done from the start; and, in South Africa, the greenfield opportunities tend to be the smaller operations.
“Unfortunately, our large gold reserves are deep – and come with a history. The infrastructure that has got us to these deep deposits also places certain restrictions on the way we develop them in future. Any modern technology to be implemented needs to accommodate, for example, the vertical shafts and narrow haulages of South Africa’s mines,” Dixon believes.
He is optimistic about South Africa’s gold industry and says these obstacles should not dampen the industry’s resolve to make the most of its remaining gold reserves. “The key to our future is how we use our human resources to undertake gold mining in this modern age. We are not training enough people for engineering professions within the minerals sector and this must change,” adds Dixon.
“Even where our mining conditions are suitable for greater mechanisation, we cannot expect new technology to work effectively without higher average levels of engineering expertise on our mines. There is no short cut to building and maintaining a skills foundation for South Africa’s gold mining sector,” he concludes.