Fantastic Tailing Failures: A Necessary Evil to Mining Engineering?

“Twelve died by drowning underground in the disaster…the foreman’s desperate attempt to save the dyke may have caused its destruction.”

[Bafokeng 1974]

 

“…before the inhabitants could be warned a load bang was heard, followed by the wave of tailings [2.5m high] that engulfed the village.” 17 killed.

[Merriespruit 1994]

 

“…there was a tremor and a loud rumbling. He clung to the tailings delivery pipe…and was let down gently as this subsided into the gap.” [Simmergo]

I was absorbed this afternoon reading a chapter in Geoffrey Blight’s Geotechnical Engineering for Mine Waste Storage Facilities entitled Failures of mine waste storages. The quotes above are taken from examples of overtopping failures, one of the most common failure modes. The recounting of these disasters is gripping, fascinating, and crucial; as learning from mistakes is how engineering has historically advanced. Between 1965 to 1996, there were 1,065 people killed by failures – an average of 34 deaths per year. Although this risk is miniscule compared to motor vehicle death rates, it’s obviously unacceptable, and these stories are tragic because they are real and should have been avoided. Other failures often highlighted:

1965
El Cobre
Chile
300
village buried
1966
Aberfan
Wales
114
116 children
1972
Buffalo Creek
USA
118
4,000 homeless
1985
Stava
Italy
268
1996
Sgurigrad
Bulgaria
107

 

Anyone reading Jack Caldwell’s excellent Blog I THINK MINING will be familiar with these stories and many others deftly described by an expert. I think it’s important reading material to any aspiring mining employee, and to rip off another good quote from Blight:

Mine waste storages are very large structures, easily visible from space, that have very long operating lives and have often not been properly planned or carefully operated. They are under construction for the whole of their operating lives and are operated by a succession of people, not all of whom are dedicated to carrying out their assigned tasks o the best of their abilities, not all of whom are properly trained and not all of whom understand why they have to undertake certain tasks and what the consequences of negligence may be. Not all of the workers can recognized that a dangerous situation may be developing, and not all of them know the correct course of action to be taken in an emergency…Most important of all, the operation of a mine’s waste storage is a net cost to the mine, a deduction from the bottom line and …is operated for the benefit of its share-holders and there are few mine managers who, to safeguard their livelihood, will not view the waste storage operation with an ungenerous eye and attitude.

Inspiring, exciting – if not very flattering – stuff; maybe there should be a mine waste Hippocratic Oath for maintenance staff, equipment operators, foremen, engineers and managers? I only wish I had started learning about the complicated, unpredictable world of soil mechanics earlier.