In this article I will be reflecting on cyanide and safety measures at Avocet’s Inata gold mine in the north of Burkina Faso. This is the second article in a series of four. If you missed the first one, here it is: A Visit to Avocet’s Inata Gold Mine
1. The tailings dam
Critics of mining activity usually end up talking about tailings dams sooner or later, so let’s get it out of the way. A tailings dam is where the mine’s contaminated sludge ends up, a veritable Gehenna of toxic waste. The reason environmentalists get upset about tailings dams is that if ever they spill, leak or otherwise fail, environmental catastrophe ensues. On average worldwide there is one big accident involving a tailings dam each year.
The best case scenario, of course, is that a mine’s tailings dam be so well designed that the cyanide, pyrites, xanthates and other miscellaneous nasties be confined in one place for all eternity. What is needed is the mining equivalent of Azkaban, a maximum security prison from which no dangerous prisoner will ever escape.
The tailings dam will outlast the mine. No one at Inata knows the day or the hour that the mine will cease to be profitable, but they already have a plan for when the End is near. ‘The sealing of the tailings dam is an important element of the mine’s closure plan,’ says Andy Mortimore, processing manager (and chief eschatologist) at Inata. ‘This closure plan was presented to the government as part of our application for the mining license.’
We drive up onto the top of the tailings dam. At first sight it reminds me of a meteorite crater in Arizona more than of anything manmade, but as we get closer I see giant water pipes running around the lip of the crater and plunging down its steep sides into an evil glistening slurry. Engineering Muggle though I am, I can appreciate that this thing is more than just a giant potty. ‘A tailings dam like this costs millions of dollars to build,’ says Andy. ‘It is designed to self-seal as it fills.’ Clever.
Could this tailings dam fail? Avocet’s vice-president Richard Gray for one has seen it happen before, not in Burkina Faso but in Ghana. He was at Goldenstar’s Bogoso mine in 2004 when their tailings dam leaked cyanide into the river Aprepre, killing hundreds of fish, crabs and shrimps and poisoning (but not killing) 30 people. ‘That was not a weakness in the dam itself,’ Gray explains. ‘It was a simple case of human error. A valve which should have been closed was left open. Contaminated water escaped.’
So in principle could the same thing happen at Inata?
‘No’ says Gray firmly. ‘The tailings dam at Inata does not have valves like the one at Bogoso. It’s a completely different system. And we have a backup system in the case of emergency. Say we have a catastrophic failure in our tailings pipeline for half an hour or an hour. The contaminated water will flow back down into our “event dam”, a smaller dam lined with a high density polymer. The problem will be contained until the pipeline is fixed.’
So there you have it. Even if the unthinkable happens at Inata, the truly unthinkable will not.
‘Having a tailings dam at all is something,’ muses Andy. ‘I spent a couple months at a mine in the Congo where they simply released the tailings into a local lake.’
TMI? At least Andy said ‘they’ and not ‘we’.
2. Delivery of cyanide to the mine
Ever since the July 2011 cyanide spill at Djibo dam, I have been communicating with Avocet about the safety of their cyanide deliveries. Legally, Avocet have always been in the clear. In 2011 Samsung was responsible for the safe transport of cyanide all the way from Korea to Inata. On 29 July they failed in this responsibility.
Morally, you might argue, Avocet are less in the clear, and in our meeting Richard Gray admits this possibility before I even suggest it. ‘Legal obligation is one thing,’ he says. ‘Moral obligation is another.’ That, presumably, is why Avocet dispatched its damage-limitation team to the scene of the accident as soon as they got the news.
And that is also why, more recently, they have changed suppliers. Samsung were spectacularly non-communicative after the accident, not just towards nosy English missionaries, but also, it now transpires, towards Avocet. Perhaps Samsung were worried about being sued for damages. Either way, they’re fired.
‘It is in our interests to ensure that our contractors are legitimate and professional,’ says Gray.
‘That’s right,’ says Andy. ‘We don’t want the Cohen Brothers Ltd delivering our cyanide or Basil Fawlty Inc delivering our caustic soda.’
‘Bit strange having Samsung delivering cyanide in the first place,’ says Gray. ‘They make TVs, don’t they?’
‘Who’s the new supplier?’
‘Sony,’ says Andy.
We all laugh.
Avocet’s new cyanide supplier is not in fact Sony. It is a Ghanaian company called Kamsak who supply mining chemicals across West Africa. And if first appearances count, Kamsak do not seem to be cowboys.
Transition was relatively smooth. Two of Samsung’s deliveries were cancelled and the first Kamsak delivery took place in February. The containers were brand new, according to Avocet’s maintenance manager, and the packaging on the cyanide was better than anything he had seen with Samsung.
A pickup truck travels ahead of the cyanide truck and acts as an escort, clearing the road of donkeys, children and other potential obstacles. A maintenance crew follows the cyanide truck in case of breakdown or emergency. There will be a dozen deliveries a year but Kamsak aim to deliver as much cyanide as possible during hot season so as to limit (if not eliminate) the rainy season deliveries. Less cyanide travelling across dodgy cement spillways in full flood has got to be a good thing.
The chances of another accident are very small. But I have to wonder if very small is good enough where cyanide is concerned.
Andy is keen to reassure. ‘People hear the word cyanide and it scares them, but you would have to spill a lot in the lake for it to have an effect on anything but fish. It takes a lot to kill a goat let alone a person. And it breaks down quickly in sunlight.’
‘What about cyanates?’ I ask. ‘I have read that cyanide reacts with other chemicals to create cyanates which are highly toxic and can hang around for a very long time in plant and animal tissues.’
‘Cyanates are present in nature already,’ says Andy. ‘People inhale cyanates every time they puff on a cigarette. Besides, we use plenty of other dangerous chemicals here. Caustic soda, sulphamic acid, sodium bicarbonate, hydrochloric acid, diesel fuel, you don’t hear people making a fuss about those, do you?’
Hmm. Not yet you don’t.
3. International Cyanide Management Certification
Okay, so this is a piece of good news which I have reported already. But it bears repeating. Avocet have set in motion the longish process towards signing up to the Cyanide Code, which is an internationally approved way of promising to play nice with their cyanide. The Code covers transport, handling, usage and disposal of cyanide. It is a significant hassle because all documents need to be presented in a very particular style and format – lots of procedure checking and box ticking involved. Well done Avocet for initiating this process. Andy is hiring a consultant from South Africa to come and advise him how best to prepare for their 2015 Cyanide Code audit. The consultant will visit later this year to point out any weaknesses in Inata’s current systems.
4. Are there viable alternatives to cyanide?
‘I haven’t looked into it,’ says Andy. ‘But if there were a powerful laundry detergent that could do the same job as cyanide at a quarter of the price, don’t you think we would have heard about it and be using it already?’
Fair point, but I can’t help thinking about the Haber Gold Process, which claims to extract gold just as efficiently as cyanide leaching. I did not raise this question during my visit (because I forgot Haber’s name) but have since emailed Andy to ask for his thoughts about the Haber Process. I’ll post his response as an update here asap.