Wednesday, July 20, 2011

ASRA Day 2- Fort Knox Gold Mine

Every morning at ASRA, after breakfast but before we go to our modules, everybody gathers in a large lecture hall for “Morning Explosures”. These are fun lectures, visitors, or experiments. For instance today, Jeff Drake, the ASRA director brought in a keg of liquid nitrogen and did some experiments (sticking a tube in it, pouring it on the floor, sticking his hand in it), all of them demonstrating something cool and the scientific explanation.
After the morning explosure, we learned about plate tectonics, and did some experiments with frosting, fruit roll-ups, jam, honey, ketchup, etc. We used these to learn about viscosity, density, polymerization, etc, so we could understand the differences between the two types of volcanoes (shield and cone).
After this, we all got in the van and drove out to Fort Knox. On the way we stopped at the Trans-Alaska pipeline and had lunch.
Fort Knox was very cool. First of all, we were all equipped with safety equipment. Then, our guide got in our van and we followed a pilot car on the tour. On the way, we learned about the different types of ore trucks. The biggest ones had wheels taller than a school bus and could hold 250 tons of rock. They had 30 trucks on site, but not all of them were the really big ones. They once did a experiment with a smaller truck. They took a Super Duty Ford F-250 (a “small” truck) and ran over it with a big truck. The small truck was, well, see fore yourself. The big truck was undamaged, and the driver didn’t even know he had run over it. The wheels were also amazing, with each one worth $50,000 (no typo). Speaking of big costs, each truck uses 1000 gallons of fuel a day. Multiply that times 30: 30,000 gallons a day. Times 5 (about the cost of gas): ~$150,000 dollars, just for fuel. Yikes!
Our first stop was a look out over the mine.  It was about 1600 ft. deep. Now you can imagine that it would be a ways below the water table. To counteract that, they pump out 900 gallons every minute. But if they were to stop pumping, it would take still 100 years to fill up.
Next we went to look at the crusher. A big truck came in right as we did, and dumped all of the rock into a big crusher. It only took 3 minutes for it to crush it all.
(These are captures from a video, since I forgot to take any stills. This should be in our final video, which I will post at the end of the course)
Of course, it still was pretty big, so next it goes to the mill. The mill was very loud, so we all had to wear earplugs. In the mill, the rock goes into a big turning cylinder with some steel balls and water. The rotation crushes it all into pieces a few centimeters in diameter. If it takes too long to be crushed, it is sent to a leach field, where cyanide is sprayed on and the gold is dissolved out.
DSC_7314Rock Bouncer
(Again, this isn’t very cool as a picture, so wait until the video at the end.)
Next we got to see a gold bar. It was a small one, for tour purposes, only weighing 257 ounces. That means it was only worth, oh, about $417,000. The bars they usually make are about twice that. They can usually make one of those in a day, meaning a million dollars, but they have operating costs of about $500,000.
It was a cool tour, although the environmental friendliness of the mine was in my mind. While I now that mines have huge amounts of environmental monitoring and regulations, burning 30,000 gallons of fuel a day can’t be that good for the planet. Of course, the computer I am writing this on does no doubt have gold in it, and both of my parents work in gold mines (although they work in underground mines, which are probably less impact), so I can’t say that I’m not benefiting from it.
Anyway, after the tour we stopped at the Large Animal Research Station, then went back for dinner. We played a good game of capture the flag, and now I am writing this. Goodnight!
P.S. This probably won’t get posted till the morning, since I have some image processing to do.

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