Our deep level gold and platinum mines are in trouble. At today’s prices, most are not profitable. There are many explanations for the high cost: mines are getting deeper, infrastructure is old, and energy and labour costs exceed inflation. Given that we have little control over the price of the commodities, the only solution is improved productivity.
A Mineweb Op-Ed exclusive by Dr Declan Vogt from the Wits School of Mining Engineering:
In many other industries, technology has enabled huge strides in productivity. Even in South Africa, almost all underground coal mining is now mechanised. So what about deep-level hard rock?
Technically, our orebodies present a challenge. Both the Witwatersrand and the Bushveld orebodies are hosted in very hard rock – quartzite and shales, or norites and anorthosites. The ore itself is also hard and abrasive, so rock cutting is not economic at present.
Conventional drill-and-blast mining can be mechanised, but orebody geometry is a challenge. The metal-bearing reefs are narrow, varying from centimetres to about a metre in thickness. The reefs dip at between about 10° and 30°, too steep for easy use of wheeled vehicles, but too level for broken rock to flow on its own.
Despite the challenges, there are extra-low profile (XLP) and ultra-low profile (ULP) machines available to mechanise the tasks of drilling, cleaning and supporting the face. They have started to be used in platinum mines, and roughly 30% of current underground production now comes from mechanised areas.
They have not yet been widely deployed in older mines that were designed for hand-held drill and blast techniques, for reasons mainly related to labour costs.
Witwatersrand gold mines are very large, relatively predictable orebodies, but have low ore grades. To make them payable, they must be operated on a large scale. At a time when labour was the only way of mining, they were only viable because of the low cost of labour.
It was also the availability of this cheap labour that let gold mines avoid the need to implement mechanisation. Each major drop in the gold price sparked interest in alternative technologies, but as the economic cycle turned, it once again became possible to mine profitably without mechanisation, and development efforts were stopped.
So what has changed?
The creation of the National Union of Mineworkers, the abolition of apartheid, and the growing recognition that mine workers were underpaid compared to other workers in South Africa, were factors behind the steady rise in wages.
Mining is also not as popular a source of employment as it used to be. Widespread access to media has exposed people in the labour sending areas to other kinds of jobs. At the same time there is growing awareness of the downside of mining jobs, particularly health problems and accidents.
Workers are less enthusiastic about working on mines, and they are demanding better pay.
Against this background newer platinum mines in the Eastern Bushveld were planned as mechanised mines, and several are running very successfully. A majority of the lowest-cost underground platinum mines are mechanised, as is the lowest-cost underground gold mine.
Further mechanisation in older mines depends on people.
The very high labour intensity on gold mines led to a rigidly hierarchical command-and-control management structure, similar to that traditionally used by the military. While the structure was effective for managing large workforces, it also encouraged a culture of compliance rather than a culture of learning.
In a mechanised mine, one operator will produce a significant portion of the mine’s total production. That operator needs the skills and freedom to act to adapt the work plan as the situation changes. This level of skill and flexibility is orders of magnitude more complex than that of the traditional gold miner.
The change to a skilled, flexible workforce has been made in other industries; South African car manufacturers are on a par with the best in the world. While there is some question about appropriate technology for deep mines to mechanise, the real issue is the need for a radical cultural transformation in the workforce.
There is a need for generally higher levels of skills in operators, supervisors and technical support. More generally though, there is a need for a new way of thinking. In the manufacturing industry, there has been a worldwide shift to what is called Lean manufacturing. The Lean principles incorporate a strong emphasis on teamwork, collective problem solving and meaningful work.
With the legacy of existing workers and managers in a conservative industry, achieving the culture in which mechanisation will work best, is the primary challenge. Within a learning organisation, the will and ability to solve the technical issues will overcome the hurdles that remain.
It’s a prize worth fighting for: mining is worth about 15% of South Africa’s GDP with multiplier effects, and significantly influences our success as a nation. Mechanisation will support the deep mines to continue their contribution.