Olympic Dam mine expansion- Environmental impacts of tailings & water by Dr Gavin Mudd – Pt 1

After I first worked on Olympic Dam back in
the late nineties, the next project that we worked on was Beverley, the proposed Beverley
mine. Looking at acid-leach mining of the groundwater to get uranium out of the sandstone
etcetera. We got stuck into the groundwater, the science
and the impacts of a lot of the uncertainties and the pathetic state of a lot of the claims
that were put forward by General Atomics at the time. Now the day after it got approved,
this was in The Age. So despite all the debate about the mine, initial impacts and everything
else it’s like that. It’s like ‘well, it’s a mushroom cloud.’ At the end of the day,
that is still one of the most iconic images of the 20th century. Now that’s really a way
of bringing you back down to earth. The fallout from Fukushima reminds you that fundamentally,
this stuff is dangerous. We’re not talking about gold, you know, this little badge that
I wear is the standard ‘no nuclear’ logo but my dad found the gold that made this. There
was no cyanide, no tailings, no waste-rock. And overall biodiversity was improved because
he got rid of the tea-tree and allowed the eucalypt forest to regrow. So in that sense,
there is such a thing as good mining… but there can never be such a thing as good uranium
mining. So, it’s a good image. Now, notice I’ve laid out this sort of picture. Man people
who know me know that I’m a bit o a data junkie. I like real evidence, real hard numbers. Currently
the Olympic Dam mine processes around about 9 million tonnes of ore per year and that
gives us of the order of 200,000 tonnes per year of copper, about 4,000 tonnes per year
of uranium oxide, and about 100,000 ounces of gold per year. And also just under 1,000,000
ounces of silver per year. Of course the current expansion is talking about going to around
about 72 million tonnes of ore per year, 750,000 tonnes per year of copper, and a god chunk
of uranium, gold and everything else so, one of the things I like always keep an eye on,
you know you look at the geology or the mining literature or you talk to folks and listen…
this resource is a hell of a lot bigger than that. One of the reasons why Olympic Dam gets
so much credibility out there in the mining industry and why it attracts so much political
gravitas… It’s huge! It’s ginormous! Over 9 billion tonnes… and I always feel like
I should do a Dr Evil impression when I do that, but if you look at that.. 9 billion
tonnes of ore… that’s just the ore. There’s also about another 150 million tonnes of gold-only
ore as well. And it’s got a fair bit of copper, gold, uranium, silver. It’s also got rare
earths. It’s actually got 20 times more rare earths than Olympic Dam than uranium. It’s
also got low grade iron ore, but because of the radioactivity, of course that means that
that would be quite radioactive as well, which is not the sort of stuff you want to make
steel out of. If you look at the numbers and you add up all of that, most of the value
is copper. Not the uranium. Now one of the things, I haven’t put the number on there,
but I you actually look at the value of the rare earths alone, just the rare earths, depending
o which number you use, I think the price has gone up since I last did the calculations…
but it’s around about 4.2 trillion. Just for rare earths alone! So if we’re looking at
the economics of things, why are BHP ignoring that? Now if anyone in this room can explain
it to me, with a good, logical reason for that, I’d love to know… because I can’t
think of one! It’s not about the technology, it’s not about anything else, the markets
or anything else like that. It just doesn’t make sense to me. So in that sense, when we’re
looking at Olympic Dam, we’re looking at all of the things that are really part of a mix.
So in that sense, when you look at it, the 72 million tonnes is only the first stage
of the expansion. I hate having to really admit that to myself, but what they’re really
talking about, in order to reach say maybe 1.5 million tonnes per year of copper, so
double the current proposal, they’d probably have to be processing 160 million tonnes of
ore per year. Which means they probably need to be mining at say 6 or 7 million tonnes
per year and it really annoys the BHP engineers… they can’t wonk out a way to do that! They
can’t work out a way to get to that scale. I’ve looked at mines all over the world. I’ve
looked at Escondida, looked at their production capacity or Codalco, Grassberg. People often
think that BHP’s legacy at Ok Tedi makes Ok Tedi one of the worst mines in the world.
Actually, no there are worse mines in the world, called Grassberg, where they dump a
million tonnes a day into a river. I’m not making that number up, it’s actually about
a million tonnes a day that goes straight down the Ashwa River. Jump onto Google Earth
and have a look. So we need to be thinking about a lot of the expansion debate is not
just the sense of 70 million tonnes per year, because at the moment, the current expansion
only takes it up to about 2.7 billion tonnes. So we’ve still got well over 6 billion tonnes
left by the time we’ve finished in 2050. So really it’s a much bigger project and the
implications of it are much, much, much bigger. Of course with mega projects come mega impacts.
Now I thought I’d just quickly go through this. This is the basic configuration of the
mine at Olympic Dam. So they’ve got an underground mine. It goes to a concentrator, a standard
location concentrator. The copper concentrate that comes from that is quite uranium rich,
relatively, so that concentrate is also acid-leached… but the tailings that come out of the concentrator
then also go off to the plant to also get acid-leached, and that’s where they get most
of the uranium out, and a tiny bit of extra copper. Then you go through the copper smelter,
coper refinery and so on. So if I was a worker at Olympic Dam and I wanted to receive the
most exposure on average, that would be the smelter stage. So the mine and the mill also
get exposure, but the highest exposure is typically at the smelter, because the radioactivity…
there’s still a fair bunch left in that copper concentrate as well. So in that sense, when
we think about China’s record on human rights and workers’ standards and so on, that’s the
sort of opportunity we’re potentially going to afford them in the future. Now if we look
at the expanded project, basically, as David Noonan’s already outlined, basically all they’re
doing is… exactly the same. You know, I hate being proven right, but initially when
they were talking up the expansion, they were talking the fact that uranium would initially
be 30,000 tonnes per year ‘isn’t that great’. We said ‘well no, if you look at the numbers,
the evidence, Olympic Dam has never achieved an extraction efficiency, recovery of uranium
more than 65%. When you take the ore group that’s already been talked about, to get say
the 1 million tonnes per year of copper, to get to that 30,000 tonnes per year of uranium,
you have to assume 100% extraction. So when these numbers started becoming obvious, sure
enough, it’s actually 65%. Everything is exactly the same, just bigger, bigger, bigger.. and
by the way, one of the world’s biggest open cuts… and that open cut is not even a third
of the ore body. So at the moment, that world’s biggest proposed open cut, is actually only
less than a third of what it could be. So again, a lot of the concentrate from the expanded
operation will go to the great nation of China. So to look at water use, I’m going to focus
just on the Great Artesian Basin. It’s something I think a lot of us have, not forgotten about,
but it hasn’t got as much profile as some of the issues around the desal and I’ll leave
it to Jochen to talk to that a lot more. That’s where I started. Really trying to get my head
around it, and I’m looking at the science of the impacts. At the moment there are two
borefields for Olympic Dam. There’s borefield A, which is right on the shores of Lake Eyre
South and smack bang in the middle of all the mound springs that are environmentally
and culturally important. It reached a maximum of around about 18 or 20 million litres per
day (that’s ML per day). They built borefield B as part of the expansion just over a decade
ago. Currently they’re taking roughly about 24. With the last expansion, they gradually
reduced the amount they were taking from borefield A and increased the amount from borefield
B once they’d drilled that. We know that borefield B, borefield A, sorry, has had very significant
impacts. I’m sure Uncle Kevin here can probably talk a lot more about that, but they’re both
environmental and cultural impacts. You know, we can’t afford to forget that. Now, when
WMC was around, before they got taken over by BHP, they had committed to shutting down
borefield A and switching over that 6 million litres a day to borefield B. At the moment,
the current indenture allows them a license based on the amount of draw-down or declines
in groundwater levels from that borefield, that gives them an approximate value of around
about 42 million litres per day. Now BHP haven’t maintained that sort of commitment. Certainly
the draft Environmental Impact Statement and the Supplementary EIS has been very weak on
actually locking that in. So I think in that sense, there are still issues because if we
go to a bigger scale with borefield B, and it almost doubles the scale of borefield B.
It’s not that far away from the springs, and there’s still unresolved issues about the
long term impacts that that will have.

2 thoughts on “Olympic Dam mine expansion- Environmental impacts of tailings & water by Dr Gavin Mudd – Pt 1

  1. Gavin and other critics are suggesting the radioactive tailings from Olympic Dam's expansion are used as landfill, to be buried back in the pit or in another alternative pit, as occurs in some mines in Canada and elsewhere. On the surface, the tailings stand to cause more ecological impacts


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