The mine is will be the largest open pit mine in all of Canada (they just started mining about three years ago), most of Canada's gold mining historically has been the hazardous underground mining done through much of the history of gold mining, including (and especially here) in Val d'Or. Most of South Africa's gold is mined underground. Underground mining allows the mine owner to "follow the veins" of gold, the highest grades of gold ore. "Native" gold (where you can clearly see gold in/on a rock), the highest is often mined this way.
Open pit mining allows miners to go after lower grade ores, as long as there is enough to make it worthwhile. The typical cutoff for gold is about one gram per metric ton, depending on many variables. I had a chance in Montreal (at McGill University's engineering library) to read a bit about open pit mining. In addition to how rich the ore is, another key variable is how difficult it is to dig it out. The designs of open pit mines reflect this, the below is a crude drawing I did showing the general idea (*click* on the image for a better view):
The Malartic Gold Mine has about 10.7 million ounces of proven reserves. Mr. Jean Massicotte (more below) told me that they anticipate that there really is more gold there though. Current production is about 40,000 ounces per month, they have been gradually ramping up production, they started mining in 2011. The mine employs about 640 people and contractors are some 200 more. Osisko has invested about $1 billion dollars so far into the mine.
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Before I went to the mine itself, I went to the Musée Minéralogique (the mineralogy museum) of the town of Malartic. It is small, but full of interesting rock specimens (I studied Geology in college, so I like this kind of stuff). Also, the museum arranges the trips to Osisko's mine (rather than the company itself), so you get to visit both for the $18.00... Normally one views the museum first, then at 1:00 PM the mine tour starts, today's tour featured about 30 young pupils, almost all of them French speakers (yes, they are still in school).
The Director General of the museum, Mr. Jean Massicotte, was very kind and came along with me on the mine tour, which was in French... I would have missed a lot of interesting comments had he not come with me. Trust me, his English was much better than my French (a pattern I see in most foreign countries (except, of course, Peru) I go to, my attempts at Korean, French, Italian and so on are really pretty pathetic). Mr. Massicotte is a native of Malartic
Merci beaucoup, M. Massicotte!
Jean Massicotte, caught on candid camera making a phone call in his office:
Just in case any of you kind readers ever come up this way, here is some information:
Musée Minéralogique
650 rue de la Paix
Malartic, Quebec J0Y 1Z0
info@museemalartic.qc.ca
If anyone really does want to come to Malartic, I have some important suggestions, please email me if you really are going to go.
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Pictures from the museum. Here is yet another tiresome photo of a boulder with native gold in it, this is from the Malartic mine itself. The best "piece" of gold is just "northeast" of my camera case. There is a pipe through the boulder because of the way they mounted the rock.
Check out the giant trilobite (fossil from the Paleozoic Era), my glasses are for scale:
Just below the trilobite is a piece of petrified wood (from Arizona).
Rocks with gold in them (when there is a pretty fair amount of gold visible, it is known as "native gold"). The shiny yellow one at "eleven o'clock" has perhaps 0.3 oz of gold.
Nor were we taken to the part of the mine where they pour gold, what a pity... Many mines pour their unrefined gold into what are called "doré bars", which in Malartic's case are about 55% gold, most of the rest is silver. These bars weigh up to 60 kg, and are sent on the gold refineries to bring them up to .995 or .9999 fine. The below picture is what a doré bar looks like, it is a replica at the museum:
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Unfortunately, many of my pictures at the mine did not come out too well, so I will just go with what I did alright. The tour itself was mostly in a school bus (about 8 of us adults and 25 or so young schoolchildren, yes, they are still in school...). First up is a photo (taken from the bus) of a LeTourneau front-end loader loading up a Cat 793 truck (partly obscured by the loader). The capacity of the Cat 793 is some 230 tons I waas told, so each load from the bucket would be perhaps 40 - 50 tons. Mr. Massecotte told me that each Cat 793 truck costs some $4 million...
A general picture of the open pit mine itself (Osisko has a viewing platform along the side). You can see two Cat 793 trucks near the bottom, a loader behind to the left of one of the trucks and a drilling rig (just right of center). They drill holes into the hard rock ore, put dynamite in, and blast, typically twice per day. Once around 9:00 AM or so, once around 3:00 PM. They schedule it this way so as not to overly bother the town. Note the church steeple above (beyond) the overburden (waste rock they scrape aside to get down to the ore). Osisko had to move half the houses in Malartic, as the gold ore was directly under about half the town (population around 1200).
This is a pile of ore waiting to be crushed. The ore is crushed about five times to get it to a fairly fine powder so that the cyanide and charcoal can separate the gold. The ore looks just like the overburden rock that is moved away, perhaps they are the same, just with different amounts of gold...
A Cat 793 ready to dump its load into a building which is the front end of a 1.6 km conveyor belt taking the ore to the crushing mills.
We were not taken to the "primary crushing mill", but we were allowed into the secondary crushing mill (Mr. Massecotte told me that the ABB primary crushers were the third largest in the world of its type). The picture is not that good, but you can make out the round crusher about 35 ft (10 m or so) in diameter.
They also let us into the repair shed (large). Here is where both mine mechanics as well as some contractors (from LeTourneau and Caterpillar for example) maintain their machines. This is me next to a Caterpillar 994 loader, note how the reflective paint on the safety vests shines when the camera flashes... Those tires, by the way, are some 4 m (13 ft) in diameter. Here the tires have chains on them for better traction, especially in winter. Each tire costs some $50,000 and the chains $40,000 more... Alas, they had no bearings lying around for me to look at or take photos of...
Very cool stuff, Robert!
ReplyDeleteVery cool indeed!
ReplyDelete