Wednesday, June 12, 2024

Lucky Friday will dig deeper

by Nicole Nolan
| December 2, 2010 8:00 PM


<p>Work on the No. 4 Shaft project continues as Cementation USA contractors work to create the shaft collar, working within a steel ring featuring an 18-foot inside diameter surrounded by a pattern of rebar that will soon reinforce cement.</p>

MULLAN - Hecla Mining Company has been working diligently on their No. 4 Shaft Project at the Lucky Friday mine for one year, and just recently announced that the decision has been made to bottom out the new shaft at 8800 feet. This will make the Lucky Friday mine the deepest mine in the Silver Valley, pushing it deeper than the previous record holder the Star mine in Burke.

This extension from the original bottom level of 7800 feet will add six months to the projected schedule, with an approximate completion date of late 2014 or early 2015.

Final approval for the project by the Hecla Board of Directors is expected mid-2011, but much progress has already been made as the underground hoist room at the 4900 level has been excavated ahead of schedule this year. Work to construct the foundations for the main production hoist as well as the formation of the shaft collar is currently underway.

"Logistically it is a real challenge," said Mike Dexter, Lucky Friday mine manager. Crew schedules are coordinated between the Cementation, USA contractors working on the No. 4 Shaft Project and the Lucky Friday miners going about their day-to-day production. "We have to continue to feed the mill, which pays the bills."

Once on the surface or working underground the two operations are divorced, and only the shaft time coming up and going down is shared.

The entire project is estimated to cost from $150 to $200 million and it is believed that, once completed, the new shaft will increase the mine's annual silver production by approximately 50 percent from current levels. This increase in production is influenced by the expectation of ore grade to increase from its current grade of 10.4 ounces of silver per ton to more than 14 ounces of silver per ton. Also, mill throughput of ore is expected to increase from approximately 350 to 375 thousand tons each year.

With no debt and approximately $200 million on hand in cash as of June 2010, Hecla Mining Company is poised to fund all of the capital requirements for the No. 4 Shaft Project internally.

The Lucky Friday mine has been operating in the Silver Valley since 1942, and the operation milled their 10 millionth ton this year. Development of the No. 4 Shaft is expected to extend the life of the mine beyond 2030.

"It's not inconceivable to see another 100 years of production," Dexter said. "That makes us pretty unique in the world."

Further work to be done is shaft sinking and station development, which is scheduled to be completed by the fourth quarter of 2011. Major components of the project that have arrived at the site include the permanent hoist to go underground, underground concrete trucks and temporary sinking plant facilities.

"This truly is a large undertaking," Dexter said. "If appropriate and when completed, the (No. 4 Shaft) will provide a long future for a terrific ore body."