Friday, October 9, 2015

Exploration Project Drilling For Gold Kerr-Sulphurets-Mitchell mining

A KSM drill rig perches above a deep valley about 80 miles east of Wrangell. (Photo by Ed Schoenfeld/CoastAlaska News)
A KSM drill rig perches above a deep valley about 80 miles east of Wrangell. (Photo by Ed Schoenfeld/CoastAlaska News)
British Columbia’s Kerr-Sulphurets-Mitchell mining project wrapped up its 2015 exploration season in late September. The KSM, about 30 miles east of the Alaska border, is the largest of 10 or so such projects near waterways that flow into Southeast. 

Its owner, Toronto-based Seabridge Gold, The Kerr-Sulphurets-Mitchell (KSM) mine, owned by Seabridge Gold, is located approximately 65km north-west of Stewart in British Columbia, Canada. It is one of the world's biggest gold / copper projects under development has already spent close to $200 million searching for ore. We take you there, during the previous season, to learn about the exploration process.

A drill rig grinds into the bedrock of a high ridge, overlooking a wilderness of snow-capped mountains and lushly vegetated valleys. The bright blue rig juts up through the roof of a rough shack of sturdy tarps, sheets of plywood and heavy timber.

Inside, Jeff Skinner is setting up the diesel-powered, hydraulic drill rig for its next run.

“Well, we’re doing mineral exploration for these gentlemen. We’re drilling the hole, pulling the rock samples out of the ground and sending them down to the geologists and they take care of it from there,” he says.

A glacier reflects in a naturally occurring pool of rusty, acidic water at the site of one of the KSM  prospect’s planned open-pit mines. (Photo by Ed Schoenfeld/ CoastAlaska News).

Long, brownish pipes are lined up outside the shack, waiting to be used.

“They put the steel in a giant drill chuck like you’d have in a hand drill. And turn it at high speed with a diamond bit at the end,” says Bill Threlkeld, senior vice president for exploration for Seabridge Gold, which has drilled 383 holes at the KSM over the past 10 years.

The pipes are sent deep into the ground and an inner sleeve brings back cylindrical samples, called cores. Threlkeld says they help pinpoint the location of the richest gold and copper deposits.

“It was at roughly 700 meters depth, so 2,100 feet, more or less, down. Before the work on this hole is done, the drill will reach more than two-thirds of a mile into the Earth,” he says.
“We have Mitchell 0-6, so it’s Mitchell, drilled in 2006, zero-one, first hole,” he says.

He’s taken me to near the end of a valley that can only be described as “raw.” It’s bare rock, with no trees or bushes.

At the valley’s upper end is what’s left of the glacier that once filled this U-shaped valley. Murphy says “once” wasn’t that long ago.

“We’re walking to an area where six years ago, where we’re standing, the ice would have been 10 feet above our outstretched arms. So you can see how much it’s receded,” he says.

The valley is splotched and streaked with rust, reddish-brown streams flowing down its sides. The color comes from exposed iron, which reacts with air and water.

Sulphurets Creek, which drains naturally occurring rusty water from the KSM prospect, enters the Unuk River. (Photo by Ed Schoenfeld/CoastAlaska News)
Sulphurets Creek, which drains naturally occurring rusty water from the KSM prospect, enters the Unuk River. (Photo by Ed Schoenfeld/CoastAlaska News)
“This is oxidation. Natural oxidation. And this is what produces the acid, which everyone has concerns about for water contamination,” he says.

Acidic water from mines and stored waste rock can hurt or kill fish, including those Alaskans depend on for food and jobs. KSM developers say it will be treated and stored properly at the site, about 80 miles east of Wrangell. Critics in Southeast cast strong doubts.

Up one side of the valley is a much different color. It looks like someone spilled a very large can of paint while ascending the ridge.

The blueish-green is just an indication that there’s copper in the system here. It gets exposed to the atmosphere and the copper comes out of solution. It’s an indication we’re in a mineral-rich area.

Because in this part of the world, where you find copper, you find gold.

After the cores are drilled out of the bedrock, they’re flown by helicopter to the KSM’s analysis operation, farther down the valley.

They’re cut into clearly labeled pieces for examination.Inside another wood-and-tarp building, Michelle Campbell points to the computer screen of what’s called a hyperspectral imaging device.

“A regular camera just looks at three spectral bands. But this one looks at 214 different spectral bands, so it’s much more precise,” she says.

The picture is electronically enhanced to show what’s on the surface of the rock core. She’s happy with what she sees, the presence of valuable metals.

“So in this one it would be like the reds and some of these darker, like brownie, colors. [They’re] the good stuff,” she says.

The cores and the enhanced images undergo further scrutiny before being shipped south for more detailed analysis by an independent lab. Those results determine whether and where the company will mine.
But other factors come into play. Seabridge Gold has the main provincial and federal permits needed to turn its exploration project into a mine. But it’ll still need to raise more than $5 billion, U.S., from potential investors.

Rock cores wait for analysis at the Kerr-Sulphurets-Mitchell project, one of the British Columbia mines planned for near the Southeast Alaska border. (Photo by Ed Schoenfeld, CoastAlaska News)

Source : News Gold Mining In The World

Thursday, October 8, 2015

High Grade Gold Vein In Fire Creek Gold Mine Nevada

Gold nuggets in mines are not just a thing of the past. Fire Creek gold mine is one of the few mines in the world that can boast visible gold ore. The Fire Creek property is located in north central Nevada
The underground mine is in Lander County and is about seven miles northwest of Crescent Valley. The mine is owned by Klondex Mines Ltd.

Klondex acquired the Fire Creek property in 1975. From that time until 1999, Klondex had leased the property to four different companies, said Fire Creek Mine Manager Mike Isaak. Those companies did various stages of exploration. One of the companies even did a production heap leach test, but that didn’t prove out very well due to the nugget effect of the ore, Isaak said.

Klondex didn’t become “serious” about the property until 2004, he said.
“Over a short period of time they drilled 360,000 feet of drilling, which was all done from the surface at that time,” Isaak said.

The Fire Creek underground project was started in April 2011. Prior to that, people thought the mine would be a surface mine, but a change in leadership at the company was a turning point for how the mine was conceived, Isaak said.
“Paul Huet became CEO in September of 2012,” he said. “That was really a turning point for Klondex and for Fire Creek.”
In March 2014, Klondex announced the mine had 717,000 ounces of measured and indicated resources available.
“That started to get some people really excited about what’s the potential of Fire Creek,” Isaak said.
After that, the property’s next milestone was a gold pour, which was made possible when Klondex bought the Midas Mine in Elko County from Newmont Mining Corp.
“All the material that we produce is processed at Midas,” Isaak said.

Production Fire Creek gold mine Nevada

Joyce, Vonnie and Karen are the “premier veins” in Fire Creek, Isaak said. These veins are the main sources for the ore. The site plans on mining about 76,000 ounces of gold this year, he said.
The fourth vein is Hui Wu, said Fire Creek Chief Geologist John Marma.
“They’re all banded high-grade veins, the result of an epithermal vein system,” he said. “The grades speak for themselves.”

The Joyce Vein is 5.481 ounces per ton over 1.7 feet and the diluted grade is 1.422 opt over slightly more than 7 feet at particular faces, Marma said. He also went through select faces of the other veins: Vonnie is 1 foot of 80.056 opt and the diluted grade is 25.213 opt over slightly more than three feet. Karen is 2.5 feet at 8.324 opt and the diluted grade is 3.299 opt over 6.4 feet. The Hui Wu Vein is 5 opt over 1 foot.
Marma said the mine has “bonanza grades” because it is an epithermal system.
“It’s very typical of these systems,” he said. “With those bonanza grades we have seen upwards of 800 to 900 ounces per ton in some faces. … It’s a really well developed deposit and we expect to be here for awhile.”
An epithermal system is normally narrow, high grade and typically underground, he said. To mine the ore, they need to mill it. When asked to describe the type of ore in the mine, Marma said none of the ore is refractory or oxide. He said 60 percent is done on the course portion of the mill, because it still is found in nugget or visible form.
Part of the reason visible gold is found at Fire Creek is because the site wasn’t touched in the 1800s, Marma said.
“We’re mining high volume at quality tons,” he said.
The mine and the veins are open in all directions, Marma said. For example, the Joyce Vein has been mined for a quarter mile, but the end has not been reached yet.
“The property is grossly under-explored,” Marma said. “Only 2 to 3 percent has been mapped. The mineralization goes all the way to the surface but we haven’t found the end yet.”
Fire Creek is the highest grade gold producer in the world. According to, Fire Creek’s average grade is 1.5 ounces per ton. The next closest underground operation is Macassa Mine in Canada and it has an average grade of 0.77 opt. Turquoise Ridge Joint Venture, owned by Barrick Gold Corp. and Newmont Mining Corp., has the most reserves in tons for an underground gold mine, but its average grade is 0.59 opt.

The diluted grades for the Karen Vein ranged from 1 opt to 5 opt, Marma said.
“It was kind of a surprise,” he said. “She’s been a good vein.”
The veins consist of quartz, calcite and gold and silver. The host rock of the veins is basalt. Marma said the basalt holds a fracture open well and is a competent rock host. This means the mine needs very little shotcrete.
All of the ore at Fire Creek has been mined through cut-and-fill method, Isaak said.
“We’re transitioning to long-hole mining or open stoping,” he said.
The miners use jackleg and mechanized drills. The development mining is done with a mechanized drill and a lot of the vein mining is done with jackleg drills.
“We’re pretty excited about the transition,” Isaak said about changing to open stoping. “It will help lower costs. We won’t be able to do it everywhere, but where we can, we will.”

Employees Fire Creek gold mine Nevada

The staff as Fire Creek is mostly veterans of the mining industry.
Isaak came to Fire Creek in June 2014. He has 40 years of mining experience and has worked in underground mines all over the world throughout his career.
Marma has 17 years of underground and surface geology experience. He was hired by Klondex in January 2014. He worked previously for Newmont at the Midas Mine.
Doug Crawford has worked in the mining industry for 34 years. He has worked mostly underground and was hired to work at Fire Creek in December 2013.
Rob Crommelin is the senior safety manager and has worked in the industry for 14 years. Ten of those have been spent underground.
Fanuel Banda has 11 years of experience and most of that has been spent underground. He has worked in the U.S. and in Zambia.
Mike Baum has been in the mining industry for 22 years.

“We’ve pulled together quite a talent pool,” Isaak said. “Of the people that we just introduced, we have 135 years of mining experience here at this site. That’s very comforting for myself, as a mine manager, to know that we have that level of experience here, and we truly have people that are passionate about safety and making this property very successful.”
The site has 42 hourly and 21 salaried employees. Klondex started mining the site with a contractor, but took over operations in the early part of 2014. The company also has offices in Reno, Winnemucca and Elko. The property does have about 31 contractors who perform drilling, maintenance and security. The drilling on the surface and underground is done by American Drilling.
“It puts us just under 100 people on a regular basis,” Isaak said.
He said all the employees are proud of the site’s safety record. Last year it was awarded the safest small underground mine in the state for 2013.
“On the heels of that, in October of last year, Fire Creek had achieved two years of lost time free,” Isaak said. “We are currently at over a thousand days and will be celebrating three years of lost time free in October again this year. … In the mining industry that’s not easy to accomplish.”