Well this looks pretty bad...

Metallurgist at a mine here.

Got to say that these last posts are pretty intelligent and a good read. I have to agree with Jack's initial assessment too. Here's a bright fellow and a decades long expert in tailings impoundments.

One comment: The biggest unknown no-one appears to have touched on is the degree of bio-availability of the minerals/elements. It's one thing to say that X is present but it's completely different to imply all X is in the bioavailable form to cause environmental [HTML_REMOVED] health issues and omgwtfpanic! over it. Unfortunately, there is a bit of grey area to be considered… and an elemental water analysis alone won't clear anything up. (a good example is metal mercury vs methylated mercury, big differences).

What may be key to the drinkable water results, and Farmer hit this, is that in Polley's case is that the mine appears to be non acid generating. A huge win for immobilizing metals from ever even getting into the water. Don't get me wrong this is still a huge cock-up.

We're all apart of this. So please put the bloodlust into every other mine that is still operating so that they do things right and do things better. But if you still want to stop all the mining and omgwtf panic! I recommend this: take a look at your ring finger and connect that wedding band's gold to this mine. Now ask what is more important. Don't believe in marriage? That's cool. Then ask Siri what you should think.

I was under the impression that MT Polley is a flotation mill. Do they have a CN circuit as well?

http://www.env.gov.bc.ca/eemp/incidents/2014/pdf/2014Aug4_WaterSampleResults_20140807.pdf

Well that looks promising. They don't have a "before", so we don't know if anything has changed significantly, but it looks like the overwhelming majority of elements were below detection limits.

This mine was already permitted and operating, the genie is already out of the bottle so the degree of fuckup is a moot point to me, now the question in my mind is "what went wrong and why, so how do we prevent it happening again ??

Fortunately Quesnel lake is a fucking big very deep lake and as my mining buds will often repeat in the bar on friday nights "dilution is the solution"

I hope we are not going to hear the "because you use this stuff, STF up and take one for the team" argument which is the standard rhetoric from the pro mining/oil side every time a disaster happens ? Obviously I use metal/oil/whatever but that does not mean any company should be allowed to develop the natural resources which WE the FN/BC/Canada all own by cutting corners to put profits ahead of good mining practice and I hope this fuckup puts a huge dent into their profits but the max fine will be peanuts compared to their annual profits

Maybe the fines for non-compliance should increase AND actually be enforced?

http://thetyee.ca/News/2014/08/08/Mine-and-Dam-Inspections-Dropped/

if you wana believe the leaf-liking journalists^^ at "The Tyee" mine inspections under the libs have been cut back

I have paddled the significant WW of both the lower and upper quesnel many times had some magic moments cuz its a magic place and its a beautiful place … very sad to hear about this fuckup

I hope we are not going to hear the "because you use this stuff, STF up and take one for the team" argument which is the standard rhetoric from the pro mining/oil side every time a disaster happens ? Obviously I use metal/oil/whatever but that does not mean any company should be allowed to develop the natural resources which WE the FN/BC/Canada all own by cutting corners to put profits ahead of good mining practice and I hope this fuckup puts a huge dent into their profits but the max fine will be peanuts compared to their annual profits

Maybe the fines for non-compliance should increase AND actually be enforced?

… very sad to hear about this fuckup

This is key to my thoughts as well. I don't expect resource extraction to go away. That would be naive. There is a desperate need to keep improving the practices to limit (remove) damage to drinking water/air quality etc. I'm willing to pay for the increase in cost as long as share holders and CEOs take a hit as well.

I was under the impression that MT Polley is a flotation mill. Do they have a CN circuit as well?

Youre right; copper float with gold credits.

When I looked up the annual report to get a few of the number for the concentration calculations, something struck me as odd, and maybe you, as a mill dolly, can shed some light on it freestyler. Cu recovery was just under 75%, and Au rec. Was something like 66%. That seems awfully low to me. My only guess is that there is a reasonable portion of non - sulphide Cu and Au, with little attempt to recover them. You would think if there was much, if any free gold a gravity concentration circuit would make sense. A bit of NaSH could help with any NS-Cu. What is your take?

When I looked up the annual report to get a few of the number for the concentration calculations, something struck me as odd, and maybe you, as a mill dolly, can shed some light on it freestyler. Cu recovery was just under 75%, and Au rec. Was something like 66%. That seems awfully low to me. My only guess is that there is a reasonable portion of non - sulphide Cu and Au, with little attempt to recover them. You would think if there was much, if any free gold a gravity concentration circuit would make sense. A bit of NaSH could help with any NS-Cu. What is your take?

could be the fine grained sulphides. the imperial metals website states sulphides are sub 50 micron. mill may not be optimized for this small grain size? the gold occurs as free milling gold and within the sulphide minerals. so if not all of the copper is being liberated in milling, i'm guessing neither is that gold fraction.

Get a room you two (three). We're discussing a mining company, a government and apparently some Indians fucking up a pristine watershed.

The Art Of Deception by Miss Directed.

could be the fine grained sulphides. the imperial metals website states sulphides are sub 50 micron. mill may not be optimized for this small grain size? the gold occurs as free milling gold and within the sulphide minerals. so if not all of the copper is being liberated in milling, i'm guessing neither is that gold fraction.

It's not only that, but the gold grade is also very low. 0.3g/mt overall - 0.26g/mt in the main ore body definitely means finely disseminated. Even if it was freemilling gold the size of the centrifuges and the number of passes needed to be meaningful most likely outstrips any economics or practicality. Gravity has a very hard time at picking micro sized gold as well.

Getting 66% overall recovery out of what they have is actually pretty great. Think of it this way, the potential of getting all the missing 33% (which is impossible) is only ~17,000 oz out of their 2015 prod… peanuts relative to the cost of installing and running gravity in the big picture.

More … chemistry …

http://www.vancouversun.com/news/metro/Firm+that+designed+original+Mount+Polley+tailings+says+warned/10102799/story.html