Friday, January 18, 2013

Scientific Study Predicts Acid Runoff From Immense Iron Mine Blasting

This is the likely outcome from digging a massive open pit iron mine near the Bad River in Northern Wisconsin, scientists conclude. Read the entire report, and remember that the hundreds of millions of cubic yards of acid runoff-producing blasted waste rock (formerly the Penokee Hills) will be allowed to be dumped under rewritten environmental rules - - a/k/a Walker's 'environmentally safe' mining bill - - in or at the edge of waterways that drain to Lake Superior.

Unlike the Precambrian iron formations mined in Minnesota and Michigan, the Ironwood Iron Formation in the Gogebic Range is steeply tilted (ca. 60° to NNW) and has limited natural exposure at the surface.
A stably benched 200-300 m deep open pit mine in the Ironwood would therefore have a very large surface area and would require the removal of an immense volume (on the order of 330 million m3) of waste rock. Responsible monitoring and managing such a volume of waste rock, and a pit of such depth, over the long term would pose significant engineering challenges.
Although the economic target mineral in the Ironwood Formation is an iron oxide (magnetite), the overburden rock that would be stockpiled as waste (the Tyler Formation) contains significant amounts of reduced iron as sulfide (pyrite, pyrrhotite and related minerals), which could react with oxygen to generate acid mine drainage. The iron carbonate (siderite) present in small quantities in the Tyler Formation would not help to mitigate acid production, and the fine grain size of the rock would accelerate the generation of acidic solutions.
A 3-meter thick pyrite-bearing layer within the Ironwood Formation itself also has the potential to generate acid drainage, given the fine grain size to which the Ironwood would be crushed onsite for the magnetic separation process. The Tyler and Ironwood Formations also have surprisingly high phosphate concentrations, and mobilization of this material could lead to eutrophication of water bodies...

The scale of a modern open pit mine in the Gogebic Range would be completely different from historic mines in the region, which were localized, primarily underground mines that targeted high grade ore and did not involve excavation of the Tyler Formation.


Anonymous said...

Any potential problems with acid mine drainage can be solved by engineering, and if this cannot be engineered to prevent degradation of the water quality, then the mine cannot be permitted according to the proposed bill, unless the DNR approves it, as is currently the law for any construction project. The real core data will have to be made available during the permitting process and if there is a potential for acid runoff, then the placement and design of the waste piles can be made to prevent this from impacting surrounding water. Just another factor to consider and far from a limiting one.

Anonymous said...

But there's acid in my coke and pepsi and there are anti-acid tablets, so if this makes out-of-state multinational corporations immense wealth beyond avarice and allows them to continue ponying up dollars for scott walker's criminal defense fund; why would anyone want to stop it regardless of the environmental impact?

This is actually not about us -- its about creating dur furher walker to pick up where his cousin smirking-chimp Walker/Bush left off.

History shows that the gestapo is good and the fourth reich is destined to spread its fascism around thge world for thousands of years.

Or at least until we blow up the entire plant -- but in that case, why worry about a little acid indigestion?

We need to unify and rally around wisconsin's little furher.



Anonymous said...

HA HA HA This is the same environmentally aware group that went out and killed elk from a herd which is struggling to survive because wolves are killing them faster than they can produce. I am sure that the mining company has some real geologists who will actually take core samples on the actual site of the mine. HA HA HA

James Rowen said...

To Anon 8:38 a.m. You are spreading misinformation:

The study was written by these scientists.

Marcia Bjornerud

Professor of Geology, Lawrence University BS, Geophysics, University of Minnesota MS, PhD, Structural Geology, University of Wisconsin-Madison Fellow of the Geological Society of America

Andrew Knudsen

Associate Professor of Geology, Lawrence University BA, Geology, Hamilton College PhD, Mineralogy, University of Idaho

Josh Trotter

BA, Geology, Lawrence University

Anonymous said...

Maybe after these scientists finish their paid stint developing pre-conclusions for the anti-mining Indian agency they can get a job with AlGore proving that the climate is in crisis. It may be better to wait until next july to do that study.

Anonymous said...

Anon@8:38, this is the same kind of childish drivel that makes it impossible to be an engineer and a republican nowadays.

You can be damn sure that no professional geologist would be involved in any kind of study on elk and wolves.

Not. Their. Department.

Anonymous said...

Anon -- 4:44 is RIGHT!

We can drop HUGE ALKA-SELTZER tablets into the region and neutralize any acid just like we can quell our tummy aches.

And if that doesn't do it, we can spray Maalox chemtrails from airplanes, just like it soothes an ulcer in the stomach.

And we can use Internet technology and our FaceBooks to spread propaganda that none of this toxic acidity matters to anyone that racists like YOU care about anyhow.

Thanks for proving what a mind is indeed a terrible terrible thing to waste!

Anonymous said...

Anon 8:38

The mining companies DO have core samples -- have had them for many years -- this is why they won't mine if they don't get a blank check to polute and poison the land and water.

Every mining company that has looked into the matter in the past has seen that the cost of environmental damages greatly exceeds the profits from mining.

Socialists like you want taxpayers and innocent citizens to pay the business/operating costs for these mining companies.

The question isn't whether or not core samples exists -- the question is how BAD and uneconomical do they prove the mine to actually be.

This is why they won't release the core samples -- they are toxic. If released, there would be no talk about exemptions --- forcing taxpayers and the State of Wisconsin to entirely pay the direct and indirect costs for out-of-state multinational mining corporations.

You post shows you are really ignorant of everything you mention here -- you just seek to inflame and dumb-down the dialog.

Thanks for proving your opinion, absolutely without merit, deserves no attention much less response.

Anonymous said...

The Republicons have gone too far now to even consider alternatives. They have invested to much and to turn back now and admit this was a terrible idea just isn't in their DNA. Like the Iraq war - there is incredible amounts of misinformation yet they will believe what they want to believe. In the end - it will be a disaster in many ways. There's no turning back for them. So they pass the bill. Let them get off on it. The saving grace- litigation on this permit will be in courts for years to come. Will the mining company pick up the tab for the litigation. Nope - the taxpayers. Additionally - there is no demand for this type of ore. Layoffs in Michigan and Minnesota were seen in December of 2012. This isn't about jobs - it's about the pig headed and ignorant Walker prepping for reelection. Ironically, there will be no jobs created from this bill during his short tenure.

Anonymous said...

I am a retired Geologist/Geophysicst. The argument that an engineering solution can eliminate any down stream pollution is laughable. There is a an underground pollution plume going right now to the north-east along the Waukesha fault zone towards the Mequon subdivisions near Swan & Donges Bay. This is from the Omega Hills landfill that has liners and pumps to collect the pollution but some is still getting past that. Sulfide overburden creates sulfuric acid, bad stuff.