On another hot day in January 2019, just around noon, as the sun was reaching its peak, hundreds of miners at the Córrego do Feijão mine were settling down for a break. And why not? Iron mining is hard work – especially in a poor part of Brazil like Minas Gerais, where miners often make less than £4 ($5.6) an hour.
But barely could the workers begin their meals than their moment of rest was destroyed suddenly and irreparably. After a nearby dam collapsed, 12,000,000 cubic metres of mud and debris catapulted at 50mph into the building and the miners.
After days of frantic searches, the terrible toll of the accident became clear: 259 people, most of them miners, were confirmed dead. 11 victims were never found, their bodies lost forever in the flood. In the investigation that followed, it became clear that Vale, the mine’s owner, had made serious mistakes. Among other things, the sirens meant to alert workers of a collapse failed to ring.
Yet examine what happened that terrible day, and these problems pale in comparison to something much more fundamental – the reason the dam was there in the first place. Because it used a traditional form of ore separation, creating a colossal pile of muddy waste known as tailings, Vale had to build a dam to store all the slurry.
A disaster was, arguably, just a matter of time. And even if the Córrego do Feijão dam had never collapsed, these tailings create problems all of their own, eroding landscapes, releasing toxic metals and poisoning water supplies.
Not that the situation is hopeless. Apparently spurred on by the catastrophe in Minas Gerais, Vale has worked hard to develop a solution, with other experts close behind.
Known as fines dry magnetic separation (FDMS), this approach has the potential to sweep tailings from the mining lexicon forever – keeping miners safer and the environment cleaner along the way.
