South Africa's platinum and gold mining companies are being told to cut their workforces and introduce more mechanisation - but this is not as easy as it sounds.
With the focus over the past couple of months first on South Africa's platinum mines, and subsequently its gold mines as labour problems have appeared to intensify we find the international mining community, for the most part, totally baffled by the sizes of the huge labour workforces working at some of these properties.
As an example - although this is going back a bit - after working on a South African gold mine where perhaps you would find a gang of 20-30 miners working on a single 3m x 3m development tunnel, the writer went to work on a Canadian underground mine where a similar sized development drive would be staffed by a gang of just two people.
The part answer to this, of course, was mechanisation, whereby the drilling itself would be undertaken by an early stage single boom drill jumbo rather than by four or five rock drill operators plus their attendants, working off and under a drill platform in the South African case. But it went far further than this and much would be down to the exemplary clean-up and track laying standards demanded in South Africa's case - and while these were deemed totally necessary in the South African context, with study crews measuring the distance between each rail track tie, and penalising the miner overseer if these were as much as a centimetre or two out of place, in Canada the regime was far less strict. If it worked it was OK. The high standards in South Africa could be seen all across the mine. Main haulageways were painted white up to the red grade lines, you could almost eat off the floor at the shaft stations - OK that's perhaps a slight exaggeration, but it makes the point.
Now those days are indeed gone even at the South African mines. Development headings are now largely trackless with drilling with drill jumbos, loading with LHDs, and white paint consumption will have died, although the working gangs are still far larger than those of their Canadian counterparts. Why? In South Africa labour is relatively plentiful and for years has been cheap (although the mining companies will tell you labour is one of the most expensive parts of their costs - which isn't surprising if you employ 20,000 people on your mine!). But the biggest problem in this particular case will have been paring down numbers from what would have been seen as the acceptable norm for work in a development heading involving not only drilling, blasting and mucking out, but also hanging water and compressed air lines, electrical cables and ventilation ducting etc. In Canada the miners did it all. In South Africa there was a hierarchical work gang social and cultural structure to take into account.
However, development drives are the easy part of the mechanisation process. It is the narrow reef mining necessary at many of the platinum and gold mines which really creates mechanisation difficulties and so far virtually none of the mines have been able to control this problem. Again, for example in the days, many years ago when I was a shift boss at Rustenburg Platinum Mines (then run by JCI) the miners I had under my supervision were mining at a stoping width of around 28 inches - around 70 cm. - even narrower in some cases - as the Merensky reef being mined was itself only a matter of centimetres wide and the mine wanted as little dilution as possible. With the reef dipping at a consistent 90 and faces perhaps 30 m in length, the rock drill operators would drill lying on their backs with their feet applying the pressure to push the drill forward. After blasting, mucking out was by workers with shovels, working in this narrow 28 inch stope width moving the blasted rock into the path of the 'mechanised' cleaning system - a winch driven scraper -down to a strike gulley where it was again either shovelled into small cars and pushed to a central dip gulley, where it was tipped into the path of another scraper which handled it down to the ore pass and thence to the main haulage system below, or delivered by another scraper to the central dip gulley - a process which was described as mechanised. Because the platinum group metals are relatively heavy, the areas back from the face were swept and washed clean with the sweepings and the washings ending up in the gulleys for delivery, along with the rest of the ore, to the orepasses and main haulages. As you can tell an extremely labour intensive system.
Now this has changed - but only to a relatively small extent as far as the stoping is concerned and much today will be worked as it was thirty to forty years ago. The biggest problem faced by miners working the very narrow Merensky reef horizons is dilution - both in terms of mining the working face and drilling the strike gulleys. Amplats has undertaken considerable work with eXtra Low Profile (XLP) equipment but no-one has succeeded in developing this to operate in widths below 1.2m, which is substantially wider than the mining widths that can be achieved by conventional mining and thus dilutive. And even where it has been implemented it has not generally proved to be as efficient cost-wise as the traditional methods. With the platinum mines operating on very tight margins, this loss in cost efficiency, coupled with the high capital costs of the special equipment, just hasn't been economic. As labour costs increase these methods will be revisited, but far higher platinum prices may yet be needed to make even partially more mechanised mining viable.
On the wider UG2 reef horizons, mechanised room and pillar methods have been, and are being, used much more successfully, but still work gangs tend to be larger than those in say North American or European operations, although this may be as much a factor of management and worker culture and prior experience as of actual necessity. Some mines too have, even so, opted for more traditional and labour intensive mining methods even in these wider reef horizons, but this is likely the first area which will change as true mechanisation is at least a proven technical option.
Many of the factors present in the platinum mines are mirrored in the gold mines where narrow tabular reefs are also mined. Again there has been very limited success with mechanisation achievable in sub 1m wide workings for similar reasons to those noted above for the Merensky miners on the Bushveld Complex, while again mechanisation has been able to be implemented more successfully where wider reef horizons are able to be worked.
Overall there have been substantial workforce reductions and productivity improvements over the years. When I worked at Rustenburg there were some 24,000 employees on the operation whereas now the number appears to be more like 14,000 managing higher production levels. Even so, more needs to be done to bring workforce sizes down in order for the more marginal operations to survive in a higher labour cost environment barring big upwards movements in gold and platinum prices. However whether this is socially acceptable in a country with such high unemployment levels is perhaps another point which needs to be taken into account by the mine operators, their workforces, the unions and politicians alike. There is no easy path to mechanisation and workforce reduction either technically, socially or politically.
Source: Mineweb
