Agrium Inc. announced Dec. 15 that its Dry Valley phosphate mine in Southeast Idaho’s Caribou County will be shut down during the first quarter of 2010, eliminating the jobs of about 120 employees who work for URS, Agrium’s mining contractor.
Agrium Mine Manager Lin Kramer said the Dry Valley Mine has a surplus of phosphate ore for its Conda fertilizer plant about 15 miles away, and would be idled starting Jan. 1 until tentatively late March.
“We hope this will only last two months, and then we will resume normal mining operations,” said Paul Poister, Agrium’s government relations manager in Denver.
Agrium’s Dry Valley open pit mine supplies more than 20,000 carloads of phosphate ore to the plant from April to November. If temperatures drop to 25 degrees below zero or colder for more than two hours, the mine has to shut down, said Kramer, who has managed it for about 2½ years.
“Last year, we did not shut down for temperature. The year before we did,” Kramer said, estimating up to 2.2 million tons of ore are shipped to the plant in a year. He noted reclamation efforts have returned the landscape almost to its original state when mining in a section is completed. “We’ve all learned a tremendous amount over the years.”
Agrium is winding down the Dry Valley Mine, which was acquired from FMC/Astaris in the 1990s before FMC’s Pocatello elemental phosphorus plant near Pocatello closed in December 2001. It is also transitioning into its North Rasmussen Ridge Mine a few miles from Dry Valley, which the BLM approved in 2003. FMC mined the A and B panels there. Agrium finished the C panel and continues to work the D panel.
At Dry Valley, the phosphate-rich area’s geologic faulting and folding present challenges. Blast hole drills are used to dynamite sections so the ore can be accessed. Six 150-ton trucks crisscross the mine site to haul the rock away.
Agrium plans a new Rasmussen Valley Mine, which would mostly be on the Caribou-Targhee National Forest, but the Blackfoot River Wildlife Management Area managed by Idaho Fish & Game also would be affected. It would be far south of a deposit that lies on Rasmussen Ridge, but it would be near the headwaters of the Blackfoot River near where Lanes Creek and Diamond Creek converge.