Today we attended Coleraine Minerals Research Lab to learn more about the mining process. Our teacher was a retired geologist who had seen almost all of the mining processes ever used, including those that are still being used today. It was very interesting to hear about how efficient the process has become over the years. Most of the tailing piles that can be seen across the Iron Range, actually contain valuable Taconite ore they are now working to extract. The way they used to mine entailed only going after the pure ore chunks that were in the ground below. Surrounding that ore was rock that only contained a percentage of the valuable material. They now are able to seperate the two using a slurry mix of the crushed minerals and a magnet that pulls the ore out, but back then they had to leave everything that wasn't pure for waste. They have actually went back to some of the piles to try remove the taconite, but due to oxidation (aka rust) most of the mineral isn't suitable to make pellets that hold their shape.
He also touched on the new projected mine, Polymet. The mine is going to try extract the copper and nickel that are embedded below the surface. He stated that many worry about the waste sulfuric materials becoming an environmental hazard, but using a metalurgical process and a newly available chemical they now have, he does not see it being a problem. Years ago when they drilled and attempted to mine the metals, they did not have the chemical they do now that will actually absorb the sulfuric gases out of the compounds leaving behind the nickel and copper along with other precious metals such as platinum. The chemical can then actually be used to fire the metal, this due to the flammability of the absorbed gases. I was still suprised to learn that only about ten percent of the material removed will be of value. It should be interesting to hear more about Polymet as Brianna, Andrew, and I job shadow there next week.
Proofed by Christine and Richie
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