Word: ores
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...hard hat and rubber boots, a radiation detector and a shoulder harness with a pair of joysticks that he manipulated through his heavy work gloves. The scoop tram looked like a dump truck with the cab lopped off. On solid-rubber tires 5 ft. high, it carried freshly mined ore in soccer-ball-size chunks to the "grizzly," the big grated dumping shaft, where the rocks begin their journey to the mill...
...only two dozen or so miners at work underground at McArthur River. Where Powder works, it's as dry as a bone, but a few hundred feet away, in a neighboring tunnel, a perpetual fine rain falls. The porous sandstone that encases the mine's ore zone is saturated, even in winter, with water melting from the frozen surface. To keep the water from pouring into the mining shafts, Cameco's engineers have pulled off a remarkable feat: using one of the world's largest refrigeration plants, they have literally frozen the ground immediately surrounding the mine. Within...
...technological innovations at McArthur River. The primary one is the method of production: known as "raisebore" mining, it has been commonly used to dig vertical elevator or ventilation shafts for close to 20 years. But before McArthur River came online in 1999, it had never been used to mine ore...
Here's how it works: McArthur River uses two horizontal floors, above and below the uranium-ore zone. One floor is 1,740 ft. underground and the other is at 2,100 ft., where Powder was stationed on the day of our visit. To start mining a new section of ore, a drill is used to dig a 15-in. pilot hole from the upper level to the lower one. Once the drill bit punches through the ceiling of the lower horizontal shaft, the drill is removed and a 10-ton, 10-ft.-wide reamer with tungsten-carbide teeth...
There, far underground, rock-breaking machines crumble and grind the ore and mix it with water to form a soupy slurry, which is piped to surface containers to await transport to the Cameco refining mill at Key Lake, about 50 miles away. This underground processing plant is McArthur River's third major innovation. "What we've done," says Doug Beattie, the mine's chief engineer, "is essentially bring the front end of the mill down to the mine...