It’s been close to 4 months since we moved to Australia, and I suppose many of you are wondering what it is exactly that I do here. Why does Rio Tinto send me out into the middle of nowhere anyway?
It may not be as exciting as discovering a gold vein – I constantly get asked if I’ve found gold when people learn that I’m a geologist…. even when I’ve told them I work for Rio Tinto Iron Ore, or the Iron Ore Company of Canada… – but I’m up here helping assess the extent and quality of the company’s big prospects. I’m on one particular project at the moment, but I’m not sure if I’m supposed to say exactly where or what the name is (it may be fine to disclose, but I’ll keep it very general just in case it isn’t). Me and a dozen or so other geologists spend most of our days here logging rock chips that the drillers bring up for us.
Back at IOC, we pretty much always did diamond (core) drilling, which consists of removing a tube of rock from the earth, by driving rods with a diamond-studded bit through them and capturing the sample within an inner tube, which the driller retracts to the surface using a cable. Rods come in 3 metre lengths usually, and by breaking the string of rods at the surface (that is, unthreading it), you can add another one on, and keep doing that until you’ve reached up to several hundred metres depth. The more powerful the rig, the deeper you can go, but for open pit mining purposes there’s never really any reason to go deeper than a few hundred metres.
RC (reverse circulation) drilling is similar, but instead of returning core, the bit at the end of the drill string pulverises the rock, then the driller uses compressed air to drive the sample back up through the inside of the rod string (a continuous inner tube). The hammer (bit) is driven up and down using pistons (also powered by compressed air) to crush the rock, so instead of logging nice, clean core, you get a pile of dirt. To the untrained eye, each pile pretty much looks the same!
That picture above makes it pretty clear where the actual rods are. To the left of the driller, there’s a contraption from which dust is pouring forth; this is called the cyclone, and it’s from here that our samples issue. They’re carried from the top of the drill string, through that long, winding tube that’s draped over a bracket, and then split into 3 parts by the cyclone. 2 parts are caught in bags and one in a bucket. We log the stuff in the bucket, one of the bags goes to the lab to be assayed, and the other bag is retained as a backup in case things go awry (which, for the record, is pronounced “a rye”, not “aww ree”; trust me, it’s embarrassing when you make that mistake in public).
Here’s a close up of our typical logging set up:
We like to place the ute (truck) at a point from which the drilling is visible, usually 10 or 15m away, and then we lay out all our tools. The essentials are as follows:
Hammer and bash plate: to crush the chunks open and see what’s inside – this is the only way to really know what those piles of dirt consist of
Rubber mat: because it would be really annoying and loud to bash a metal plate with a metal hammer on a metal truck bed
Brush: to brush away the already-logged material between samples
Magnetic susceptibility metre (the yellow thing): read this article if you’re actually interested
Sieve: to sieve out the fine material from the coarse – we need to estimate “chip” percent (proportion of coarse material) as this provides an indication of material hardness/type
Water bucket: to help assess the composition of the fines, or to spill all over your pants and make it look like you peed (happened to me yesterday)
The last essential piece of equipment is the logging computer, which is a Panasonic Toughbook. I’ve gotta say, I’m pretty impressed with these things; they really are tough! Ours get absolutely filthy, but I just clean it using the same brush I use to clean my bash plate, and the back of the ute for that matter:
You may be thinking that even with that hammer and bash plate to crush your chips with, it still seems like it would be awfully difficult to differentiate between material types. Maybe this picture will change your mind:
Yeah, so now you see where the ochreous hematite is, the vitreous goethite, the limonite, and maybe even the secondary silica if you’re sharp. If you don’t quite see those yet, no worries mate, these skills are rarely needed in the day to day life of normal people (i.e. non-geologists). But I’m disappointed in you, personally, just so you know.
All the dust, noise, and sun out here makes it necessary to cover up in many ways, so by the time you get all your gear on you generally look like this:
You tend to sweat a lot when it’s in the 40’s!
So this is where I’ll be hanging out and what I’ll be doing most of every day that I’m away from home. Shifts go from 6am to 6pm, every day of the week, but depending on how the drilling’s going, you typically spend only 5 to 7 of those hours actually out in the sun. Other time is spent back in the office preparing for the day, backing up data, sitting in the ute interpreting results, scarfing down food and water, drawing pictures (often work-related), and so on. My favourite pencil crayons are the Crayola Kidz! ones.
When it’s time to kick back and relax, I head to my little room. It’s actually a very nice camp, so I have nothing to complain about: air con in every room, your own bathroom with shower, a mini fridge, a TV, a phone with free long distance, and internet if you’re close enough to the main office (my room isn’t, but oh well!).
And every morning when I get up, at about 5am, I walk out to see the sun rising in the east. It seems like every morning is beautiful here, even if it is sometimes already 30+ degrees at 5am.
I hope you’ve enjoyed this insight into my living conditions while on the FIFO roster. I look forward to hearing your comments, as always 🙂