We made arrangements to tour the third largest copper mine in America. The Chino Mine, just outside Silver City is a strip mine some 4 and a half miles long and 2 and a half miles wide, descending some 1800 feet so far. We arrived at the main office early in the morning to meet with Fritz who, now retired, was going to be our guide. Fritz had spent 42 years in the mining business and done just about everything that there was to be done over the course of time. A big solid man, with a soft spoken voice, he was a wealth of knowledge, especially sharing those little trivia things that are so often missed on the formal tours. Right away we hopped in his van and headed out to the mine. As we began our slow descent down the winding switch back roadbed, he opened his monologue with the first startling revelation. Because of the size of the trucks, over 20 feet wide, the driver can only see out the left side, as the cab is mounted at the extreme left. Subsequently all traffic in the truck area, which is the entire mining area, must drive on the left side of the road, as they do in England. The big haulers only watch the left berm and don't much worry about the right side of the road. The story of copper mining started with a description of the land. Mostly soft conglomerate with copper veins running through it. For years it was mined in tunnels much as gold or silver but more recently, cost requirements have caused strip mining to be the more common method of extracting just about every mineral there is. We stopped at the end of one of the very wide roads where a large drilling machine was at work. This is the beginning of the mining process. A 13 inch hole is drilled about 60 feet deep every 25 feet or so. Core samples are examined and the material is grouped into three categories. High grade ore, low grade ore, and fill which is pretty much devoid of value. Next came my second surprise, the holes are packed with a mixture of Ammonium Nitrate and diesel fuel. That's right, the same stuff Timothy McVey used in the Oklahoma bombing. The stuff is mixed right on the site in a big vat, and then detonated with prima-cord all at once. It doesn't produce a bomb like crater with billowing white smoke. There is just a little pop and about a hundred yards of once very smooth roadway now looks like ice breaking up in a river. The solidly packed conglomerate has been shattered into three to six foot stones. On the road some 60 feet below the blast site, a gigantic electric shovel moves in and in four quick scoops fills a 320 ton dump truck, which, depending on the grade of material, will either drive it to the rock crusher, or to the top of a mountainous ridge with the low grade, or off several miles to a fill mountain. These behemoth trucks standing over 40 feet high cost several million dollars. Just one tire is valued at $25,000. It takes 55 quarts of oil at its regular oil change.
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