AuRico pours first gold from Young-Davidson
Exactly two years ago this month I flew 584 kilometres north from Toronto to Kirkland Lake, Ontario, then drove another 60 kilometres west along Highway 66 to the Town of Matachewan to attend the official re-launch of the historic Young-Davidson gold mine.
It was a rather modest event involving a few corporate and other mining dignitaries, but it was a significant occasion in the eyes of Ontario mining because it marked the rebirth of one of the province’s most “historic” gold mines.
Like many mines in Ontario, and Canada for that matter, Young-Davidson was discovered decades ago; in the 1930s, when there were actually two mines (Young Davidson and Matachewan Consolidated) on the site that produced more than one million ounces of gold from the mid 1930s to the mid 1950s.
Typical of many mining operations, however, the mines went through a number of owners and varying degrees of exploration and development over the years, and when the gates finally closed at the Young-Davidson mine almost 60 years ago, the Town of Matachewan pretty much closed too.
It’s a scenario that goes with the monicker of being a “Mining Town.” Every province has one, or two, or even three of them, and every small-town miner left without a job because of a mine closure knows the helpless and abandoned feeling of that day when the gates are locked for good.
But, as mentioned earlier, some mines do come back and thanks to Northgate Minerals of Toronto who bought the old Young-Davidson mine for $18 million in 2005, miners throughout the entire region were given renewed hope for future employment.
Again, like most gold mines, the Young-Davidson mine hadn’t run out of gold; it had just run out of money to go after it. Northgate knew the property still contained an inferred resource of about one million ounces of gold, and later it outlined a resource of four million ounces, which has since been converted into 3.8 million ounces of proven and probable reserves.
From 2005 to 2010, Northgate Minerals spent millions of exploration and development dollars preparing for the rebirth of the Young-Davidson mine and in late 2011, it was acquired by AuRico Gold of Toronto which allowed the new company to strengthen its financial and technical resources and as a result, the Young-Davidson mine project has skyrocketted to success.
Not only was the first gold poured (on April 30, 2012) less than two years into the operation but moreover, the site has been transformed from a “moon-like” scene in just two years into one of the more vibrant and structurally impressive mine sites in Canada.
And below ground, the entire operation is equally as advanced as what’s visible at surface.
In fact, AuRico Gold’s Young-Davidson General Manager Luc Guimond says that long before the mine starting taking shape on the surface, crews were underground assessing the existing workings and planning for expansion.
“On a given 10-hour shift, we have approximately 40 workers underground, with additional support staff present during the dayshift. Currently the deepest point in the mine is 925 metres, with a final design depth of 1500 metres,” said Guimond.
Access underground will eventually be through the historical MCM shaft, once shaft sinking is completed to a depth of 1500 metres. The current depth of the shaft is 822-metres. The main Northgate shaft (to be utilized for hoisting ore and waste only) is still under construction with the first leg completed to a depth of 450 metres. There are now two more legs being built to reach the final depth of 1500 metres, but the main traffic uses a six-kilometre ramp at a grade of 17 per cent.
“Everyday, all crews combine advance development of 16 metres horizontally in the mine’s expansion which produces around 1500 tonnes a day of waste that must be trucked up the ramp to the surface,” said Guimond.
Currently, 134 m(3)/sec of air is also pumped into the mine to ventilate working areas and Guimond says this will increase as more diesel equipment is put to work underground. There are approximately 60 pieces of heavy equipment underground now.
Because of the “historic” aspect of the mine, AuRico engineers encountered and solved a number of challenges in order to make the mine safe; one being a stope 160 meters below the surface that had been left open by previous miners.
“It took more than 500,000 tonnes of waste rock to fill and stabilize the stope; first from an underground access point, then through a 48-inch borehole to surface,” said Guimond.
“In addition, we have pumped out 1.7 million cubic metres of water from the historic Young-Davidson pit to facilitate our own underground mining and we pump out 45 cubic metres of water per hour to keep the underground mine from flooding.”
As mentioned earlier, the surface operations at the Young-Davidson mine have changed dramatically and aside from the most noticeable (the new head frame), other key structures have emerged and changed the landscape too.
Two years ago, the site contained little more than a newly clad head frame and a handful of portable and rather crude tin trailers serving as offices and crew quarters. Today, as is clearly evident by the adjacent photos, the Young-Davidson mine is anything but “crude” and it’s certainly not “portable” because the mine is expected to be operating and expanding at its 4,510-hectare site for the next 15 to 20 years.
The processing plant and the mine’s 115 kV electrical substation, for instance, are two of the site’s more prominent and obviously permanent components of the entire operation.
“The mill has 35 full-time personnel including operators, management, metallurgical, administrative, and training personnel, and it’s also supported by a site maintenance and assay lab team. It’s a busy place where approximately 6,000 metric tonnes of ore are processed per day,” said Guimond.
Ore from the mine is first crushed down to less than six inches in a jaw crusher, then fed into a 22-ft diametre x 36.5 ft long SAG mill. The mill is powered by two 4,475 kW motors and charged with steel balls to assist in grinding the rock down to slurry.
Guimond explained that once the sulphide minerals in the ore are recovered through a flotation process, they are further ground in a tower mill to assist in liberating the gold. Gold is then leached from one slurry with cyanide in seven leach tanks located outside the mill and later absorbed onto activated carbon which is then removed from the leach circuit and treated to recover the gold as a fine sludge.
Finally, said Guimond, the gold sludge is filtered, dried and then smelted into gold bars for shipment to a refinery for further processing.
AuRico is forecasting to produce 65,000-75,000 ounces in 2012 and 135,000-155,000 ounces in 2013. The mine is expected to ramp up to over 250,000 ounces of annual production by 2016.
Keeping this process going throughout the mine’s lifetime shouldn’t be problem because Guimond says AuRico is committed to an on-going exploration program in the heavily mineralized zones in and around the mine.
“Geologists continue to find significant deposits. For example, the mine’s gold deposits remain open in three directions: to the west, east and down dip and one of the newer discoveries made during the continuing exploration at the site was the YD (Young-Davidson) West Zone immediately adjacent to the current reserves, where drill hole YD10-198 returned 3.46 g/t gold over 79.5 m,” said Guimond.
“Other significant and further encouraging results came from hole YD10-198A, located about 60 metres west and below YD10-198, where it returned 6.16 g/t uncut over 21.3 metres and hole YD10-234, located about 50 metres east and just below hole YD10-198, that returned 4.37 g/t gold over 17.8 metres.”
Building a mine at such a fast pace and in such a short period of time requires teamwork and Guimond, credits all of the miners and contractors for thei
r skills but moreover, their attention to safety for everyone around them on the very busy site.
“With more than 1200 people on site at the height of construction, it would have been easy to bump into one another from time to time but I credit everyone for paying attention to what they’re doing at all times,” said Guimond.
Safety, like at most mines, is our Number One priority at Young-Davidson and it’s something that’s taken very seriously and touch wood, we’re an accident-free mine and we intend to stay that way!
Comments
John A. (Tony) Killingsworth
As the Grandson of Jake Davidson, co-founder of the Yonge-Davidson Mine, I am thrilled to read and see the progress being made at the current mine site. Having visited the mine property in the early 1950’s through subsequent years and again at the official re-opening, I can truly witness the change that the growth has brought about. I am pleased and excited that the spirit of my Grandfather Jake is still alive.
John A.(Tony)Killingsworth