Gold mine in Tooele County would use cyanide to get metal

Published: Monday, Feb. 18 2013 9:20 p.m. MST

Miners have pulled gold, silver, arsenic and tungsten out of the ore in southwestern Tooele County dating back to the 1860s.

Don Grayston, Deseret News archives

GOLD HILL, Tooele County  — Miners have pulled gold, silver, arsenic and tungsten out of the ore in southwestern Tooele County dating back to the 1860s.

Now, under a proposal pitched to the Bureau of Land Management, the Clifton-Gold Hill Mining District may become home to the area's first large mining operation to tap gold and silver deposits.

Seattle-based Desert Hawk Corp., wants to set up camp in the west desert and process a million tons of ore a year for two years. The entire life of the mining operation would be for six years, with another three years to reclaim the land.

Desert Hawk President Rick Havenstrite said about $12 million has been spent so far to get the project rolling, including money sunk into documentation for regulators that there won't be a problem with acid mine drainage, which is acidic water laden with iron, sulfate and other metals.

"Our system doesn't have sulfate in it — that's the beautiful thing," he said.

What's been dubbed the Kiewit Mine Project has gone through an environmental analysis by the Bureau of Land Management because part of it is on federal lands east of Iabapah and west of the salt flats. The public has a chance to weigh in on the proposal through March 14 and a similar public review of a state mining permit has already been completed.

Jim Springer, spokesman with the state Division of Oil, Gas and Mining, said no negative comments were received on the project, which involves exploratory drilling, blasting, an open-pit mine and a process to extract the gold and silver using cyanide.

While the division is a long way off in the permitting arena, the project's proposed use of what's called "cyanide heap leach pads," would be the state's only active mining operation using this extraction method.

Using cyanide

Cyanide is highly toxic and state mining regulators say the word itself alarms people. They say if it is handled properly it is safe in these types of applications.

The compound has been used in gold mining since the 1880s and continues to be used in more than 90 percent of the world's gold production today. In neighboring Nevada, there are about 30 mines that use the cyanide process to separate gold and silver from ore.

"Even though this may be slightly new to Utah, the regulatory environment is well known," Havenstrite said, adding that it is a fairly simple process.

Basically, the mounds of rock are piled on a lined pad that receive a cyanide solution through a drip application, he said.

"We mine it, crush it and sprinkle it on," he said. "Cyanide bonds to the gold and silver and carries it out. They are all in liquid form."

In its analysis of the project, the BLM notes that the cyanide would be trucked to the site from Nevada from a company with employees certified in safety procedures for handling the compound.

At the Kiewit site, a lined, 12,000-gallon tank of the material would sit inside a secondary container on top of another liner and be "triple-protected," according to the analysis. Desert Hawk plans to fence the entire project area, post warning signs and put netting over the process ponds containing the compound so bats and birds are protected.

State water quality regulators also required Desert Hawk to get a groundwater discharge permit to ensure adequate protections are in place to guard against any discharge of contaminated water.

Protection of any water resources in the area is critical, said Rob Herbert, a supervisor in the state Division of Water Quality.

"It's very important that they have lining systems properly constructed to prevent any groundwater contamination."

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