Grand Clean Up Plans Present New Opportunities for Old Site
The Town of Snow Lake, Man., population 900, bills itself as a place of “breathtaking scenery, pristine lakes, untapped resources and friendly people.” Gold was discovered in the area in 1925 and mining has always been the economic mainstay of the remote community, which is located some 685 km north of Winnipeg, and roughly equidistant between Flin Flon and Thompson.
The Howe Sound Mining Company operated the Nor Acme Mine on the outskirts of Snow Lake from 1949 to 1958 and it left behind an enduring reminder of its presence–a massive stockpile of arsenic-laden rubble about the size of a football field and 20 to 30 feet high.
Along with arsenic and other toxic contaminants, some of which have oozed into nearby waterways, the 265,000-tonne stockpile also contains a lot of gold–some 9.7 grams per tonne, according to Toronto-based BacTech Environmental Corp.
The company is currently attempting to raise $25 million in order to build North America’s first commercial environmental bioleaching facility to extract the gold–along with smaller amounts of silver. In the process, BacTech will be relieving the Manitoba government of a major environmental problem by cleaning up the stockpile at “no cost to the taxpayer,” as company president and CEO Ross Orr puts it.
BacTech was able to sell the provincial Department of Innovation, Energy and Mines on its proprietary BACOX bioleaching technology, which is capable of freeing base and precious metals from sulfides while rendering inert the toxic byproducts of mining operations.
“We kept badgering and badgering them until we got in to see Minister of Mines Dave Chomiak,” says Orr. “We said: We want to clean up the mess at Snow Lake.
“He said: What’s it going to cost me?
“I said: Nothing. We’re going to do it because we think there’s enough value there in the gold to pay for the operation and provide ourselves with a decent return.
“He took two days to sign off on it.”
The department granted BacTech permission to remediate the stockpile in April, 2011 and since then the company has been developing plans to build a processing plant, seeking environmental approvals for it and attempting to raise money necessary to build it, which hasn’t been easy, concedes Orr, given current market conditions.
But he and his management team have developed a novel concept that he is calling the Green Gold Alliance. They are trying to persuade large gold producers, as well as the jewellery industry and other users of gold, to put money into the project.
“We’re going after companies with skin in the game,” he says. “I’m trying to convince the big companies, some of which are sitting on $1 billion cash, to give us $2 million at six per cent and join our alliance to build this facility. This technology will become the answer to some of the industry’s environmental challenges as opposed to capping and treating. That’s just a band-aid.”
Bioleaching is a proven technology though hitherto it has been used only in working mines. According to Orr, tailings are delivered to a flotation plant, which separates rock from sulfide minerals and metals. Afterward, the rock goes back to the tailings pile and the concentrate goes to bio-leach tanks loaded with sulphur-loving bacteria. Over the course of several days, these microscopic creatures consume the sulphur, thus freeing the locked up gold and silver, as well as iron, arsenic and other contaminants.
They leave behind a slurry containing solid silver and gold, as well as a liquid containing dissolved iron, arsenic and other metals. The slurry is pumped to another part of the facility that seperates solids from liquids. The solids (gold and silver) are then moved to a metals recovery plant. The liquids, meanwhile, are piped to neutralization tanks where limestone is added to produce several non-toxic byproducts such as gypsum and ferric arsenate and these are returned to the tailings pile.
South Africa-based precious metals producer Gold Fields began developing bioleaching technology in the late 1970s and since 1986 has built commercial and demonstration plants using its proprietary BIOX process. BacTech and its predecessor companies developed a proprietary variation called BACOX and since 1994 it has been licensed for use in operating mines in Western Australia, Tasmania and China.
There was one problem with merely licensing the technology, as Orr explains. “In the mid-2000s we realized that the only people making money from the technology were the people licensing it from us,” he says. “We were solving the problems of other companies by turning unminable deposits into mineable deposits. We were getting a $2 million fee and a pat on the back.”
In 2005-06, (under dirrecent management) BacTech Mining, as it was then known, acquired the rights to a Nevada property known as Tonkin Springs, south of Barrick Gold’s Cortez mine and attempted to use its bioleach process to unlock the gold contained in a very complex refractory deposit. The venture failed and nearly bankrupted BacTech. After being refinanced and restructured, the company re-emerged in 2010 as BacTech Environmental. And it had a new mission after Orr and the rest of his management team experienced a proverbial eureka moment.
“We were sitting around one day and we said there’s got to be good value in tailings due to increased metal prices,” says Orr. “You can accept a lower grade because all the heavy lifting has been done. You don’t have to sink shafts and develop a mine. We Googled arsenic problems and mine tailings and came up with lots of entries, including Snow Lake.”
BacTech’s proposed bioleach plant would be capable of processing 100 tonnes of concentrate a day or about 40,000 tonnes per year. Orr says that will yield 11,000 ounces of gold annually at a cost of $750 an ounce. The Snow Lake stockpile will keep the plant supplied for about seven years, but the company hopes to locate other supplies of tailings in northern Manitoba that can be likewise processed and would, therefore, extend the life of the plant to about 20 years.
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