It's a Different World
It's a Different
Venture into an underground aggregate mine and you might think you've entered Moria, the underground dwarf kingdom in J.R.R. Tolkein's The Lord of the Rings.
n underground aggregate mine is something to behold. It's not for the claustrophobic, that's for sure, but it is said to be where aggregate mining is headed in the future. With permitting becoming more difficult and the ever-present NIMBY proponents, it seems to be a logical response to harvesting more aggregate without requiring more surface space. Underground mining presents a unique set of challenges, and no one knows that better than Sam Van, plant superintendent at Sterling Materials' underground mine located near the small town of Verona, in northern Kentucky. Van comes from a long line of miners -- his father worked at Pitcher Mine, a zinc mine, and his grandfather and greatgrandfather were miners -- so you might say mining is in his blood.
the market. "It was about nine years in the making before we put a spade in the ground in 1998, and the rest is history," says Alex Boone, president of Sterling Materials. The land was originally a farm. Van spent a month designing the mine, which he insists is still a work in progress. "When you're underground, you're always developing," Boone says. "The mine plan is that you always move in a circle. You keep going around the outside making it bigger. The drill moves either clockwise or counter-clockwise around the mine. Behind the drill comes the powder crew. Behind the powder crew comes the blast. Behind the blast comes the mucking out, then the trimming and bolting, and then back to drilling. It keeps running in that cycle." "We follow the contour of the deposits," Van says. "The drills are constantly drilling in different areas for blasts, and we shoot every day at about 5 o'clock." During the drilling and blasting process, 50-footThe idea for the Sterling Materials underground diameter pillars are left in place to support the ceilquarry started in 1989, but the location was up in the air. For the next eight years, the company went ing. If you could look down through the ground at the mine, it would look like a giant threethrough multiple zoning cases on a couple of difdimensional checkerboard, with the pillars as white ferent properties, neither of which was successful. The current location was the third attempt and was spaces and the open areas as black spaces. A scaler comes along behind the mucking crew to knock chosen for its good road access and nearness to
Digging out the mine
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AGGREGATES MANAGER April 2010