If you tour by Google Maps that part of South Africa where I grew up (mainly the East Rand around Brakpan and Springs) you will not see the many slimes dams that I knew and played around. They are long since gone—reworked for gold and uranium and consolidated into a mega-slimes dam that I recall is called ERGO.
This is good as the dust that blew onto our school desks was no doubt higher in uranium than would now be considered reasonable or safe. This is bad as those great places for kids to ride bike are gone.
Now a new and similar project is planned: take back a number of old slimes dams, rework them to get the gold and uranium left behind by those old process engineers, and consolidate the cleaner tailings into one major, modern slimes dam.
Yet this project is being fought by South African environmentalists, who in my opinion, are simply crazy. Here is a link to the full story. In part it reads:
It’s a strange irony that one of the country’s foremost environmental activists – Mariette Liefferink and her Federation for a Sustainable Environment – should make every effort to sabotage one of the mining industry’s most important cleanup projects, and manage to do so. If truth be told, the mining industry has a history extending over more than a hundred years of breaking up, excavating and leaching some of the most poisonous substances known to man, and then abandoning such operations. In South Africa miners have built up a reputation of being the economic version of scorched-earth terrorists. It is therefore entirely understandable that civil organisations and government authorities put every dotted ‘i’ and crossed ‘t’ of an environmental impact study and rehabilitation plan for a mining project under the microscope before approving it. The Mine Waste Solutions (MWS) and First Uranium Kareerand mega-tailings dam is probably one of the most sensitive mining projects ever tackled in South Africa’s gold fields. The cleaning of 15 enormous tailings dams around Stilfontein and Khuma – the township which was established, in the apartheid tradition, 3km to the south-east of the town, away from the N12 freeway – is probably the community’s last chance to transform a typical mining town into a productive rural community.
No doubt Mariette Liefferink would justify her opposition. Not sure how. But probably on the basis of protecting the new site. But in reality, on the basis of a comparison of current harm, probably continuing harm if nothing is done, and the harm of the new dam, I cannot see how her arguments can prevail.
I am encouraged to see this description of the new slimes dam and the innovative thinking by Fraser Alexander engineer Beric Robinson (who I hope comes to Vancouver for the Tailings and Mine Waste Conference, November 7 on.)
The techniques being applied to the design and building of the enormous tailings dam, which will hold 450 tonnes of processed mine tailings in the first stage of its lifetime, have never been used elsewhere. The walls of tailings dams are always built at a 45-degree slope, but the Kareerand Dam’s slope is 15 degrees. This is to reduce the wind resistance on the wall. The final wall is also being constructed with scalloped inlets to retain the rainwater that runs down and thus prevent erosion, said Fraser Alexander engineer Beric Robinson, who designed the tailings dam. He is regarded as a worldwide expert in tailing dam design.
“We try to imitate nature, but managing to do so is not a daydream. The techniques being used are based on comprehensive analysis and years of observing tailings dams,” said Robinson. “The challenge to the question as to whether the dam will improve current conditions is not scientific. Rather, it is an economic challenge to construct the tailings dam and operate it economically.”
In building the dam, surface soil from the 2km terrain was collected in an outside weir right around the dam. When the dam wall has finally set, this will be pushed up and positioned against the final wall. Unlike other tailings dams, Kareerand’s drainage system has a discharge point right in the middle of the dam, which feeds water to smaller supplementary dams beside the big dam, for recirculation from those points. The water will then be used in a sophisticated water irrigation system. This system, which consists of different batteries of sprinklers, will be controlled by a wind-monitoring system so that dust is spread across the tailings dam when the wind speed reaches particular levels.
SOunds like they are thinking right, planning right, and trying hard to do the right thing. Sad to see crazy ladies shrill at them. If my assessment of this situation is incorrect, please let me know.