Mill purchase moving

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Fact Box

The Humboldt plan:

Kennecott Minerals is moving ahead with its purchase of the old Humboldt Mill.

The mill rehab project will take approximately 12 to 18 months to complete.

Kennecott's investment will be approximately $80 million.

100 to 200 contractors will work on the rehabilitatation project. Operations will require 50 to 60 full-time employees.

The mill is expected to crush 1,500 to 2,000 tons of ore per day.

Kennecott will ship out copper and nickel concentrate, via railway, to Canada for smelting.

By SAM EGGLESTON

Journal Ishpeming Bureau

ISHPEMING - Kennecott Minerals anticipates winning several legal battles it faces on the way to building a mine on the Yellow Dog Plains.

Evidence of that confidence is the company completing the purchase of the old Humboldt Mill.

Kennecott will use the mill, which has been closed since the mid-1990s when Mineral Processing Corporation owned and operated it, to crush and concentrate ore from the Kennecott Eagle Project. According to Eagle Project Manager Jon Cherry, the mill will take about 12 to 18 months to rehabilitate into working condition and will require an investment of around $80 million.

"We're not proposing to do anything at that mill that hasn't been done there before," said Cherry, speaking Monday afternoon in front of the community advisory group that was assembled by Kennecott.

The 15-member advisory panel - composed of members ranging from county and township government officials to groups including Trout Unlimited and the Upper Peninsula Construction Council - has been meeting roughly quarterly since 2004.

"That mill was designed to crush 10,000 tons of ore a day. We're only going to be doing 1,500 to 2,000 tons a day," Cherry said.

The purchase of the mill was completed Sept. 29 by Kennecott Eagle Land - a subsidiary of Kennecott Minerals.

Work crews have started identifying what needs to be removed, such as asbestos and lead-based paint, as well as iron pyrite that was left from when ore from the Ropes Gold Mine was crushed there by Callahan Mining Company, Cherry said.

While the mill may not actually be in use until 2010, Cherry indicated it would bring economic benefits to the area well before then.

"It's going to take 100 to 200 contractors to rehabilitate the mill," he said. "Then we're going to have 50 to 60 full-time jobs to run it once it's operational."

Kennecott intends to clean up the site and replace wiring, plumbing and machinery next spring, Cherry said. By 2010, there will be additional space for offices and revamped technology inside. The mill will use common mining processes, Cherry said.

Ore rock the size of basketballs and smaller will be shipped via truck to the mill where it will be ground into a consistency "somewhere between sand and flour" and turned into slurry with the addition of water.

That slurry will be transported into flotation cells where alcohol and and attractors will be added and the tailings will sink to the bottom.

Copper and nickel will rise to the top where it will be scraped off and turned into a concentrate. That concentrate will then be shipped via rail to Canada where it will be smelted.

"There will absolutely be no smelting on site," Cherry said. "The only thing that we'll be doing there is what has already been done there."

The addition of the mill to the Kennecott Project has long-range potential, too, Cherry said. With a half-dozen additional exploration sites being examined in the north-central Upper Peninsula, having the Humboldt Mill will allow any future mines to send the ore there to be processed.

Kennecott holds the mineral rights to 450,000 acres of land in the U.P.

"If we end up mining anywhere around here we'll be able to send it to that mill," Cherry said. "There is a significant upside to owning it."

The original plan by Kennecott was to send the ore via truck to a railhead where it would be shipped to Canada to mills and smelters. Cherry said that plan was scrapped when the cost of diesel fuel skyrocketed from just above $2 a gallon when the plan was conceived to more than $4.15 a gallon now.

"Even with the $80 million to rehabilitate the mill, it was the more economical answer," Cherry said.