The final product

We are now producing slurry and pumping it down to Whyalla. The guys down the other end of the pipeline filter the slurry in large press filters, add fluxing materials like Dolomite or limestone, then feed the product into the Pellet plant for steel production.

The Concentrator is running fairly reliably, especially from an E&I perspective. The tramp metal detector issues have been resolved, thanks to a visit from a Tectron Field Service engineer (we had a dodgy interface board). It's a good feeling to arrive at work in the morning and see the plant running smoothly.

As we prepare to hand the plant over to the client, I'm starting to think about life in the "real world". It's been two years of project work, long hours and very little else.

It's time for a change...and time for some climbing!!!

Producing Slurry

We're progressing in leaps and bounds with ore commissioning. The last 5 days we have been running ore in one of our two HPGR's, through the ball mill, onto our Concentrate Thickener. It's early days yet, however it's good to be operating the plant and making slurry.

This photo shows a magnetic separator in operation. These rotating drums have internal magnets installed in their lower third, which "shuffle" iron particles in the direction of rotation, while non-magnetic particles flow in the other direction. Here you can see magnetite dropping into the concentrate launder.


In addition to ore trials, we have also been performing pre-commissioning work on the Geho slurry pump. It's a monster 3 piston / diaphragm positive displacement pump powered by a 1.1 Mega Watt motor. There's a cool animation of the pump here.

Ore Trials

We are now crushing ore with the HPGR's, and trialling our screens and magnetic separators. It's not long now before we commence grinding with the Ball Mill.

We have had a few teething problems - but that's all part of commissioning. The Electrical and Instrument side of things has gone really well so far, with only a few calibration issues with a tramp metal detector. Tramp metal detectors are designed to pick up over-size iron objects, like bolts, on conveyors, thereby protecting the equipment downstream of the conveyor. Calibrating these detectors to pick up iron objects in a stream of iron ore has got it's challenges, as you may expect.

Here are some awesome photos taken of the site at dawn, by Dave Barringhus. Enjoy!!!

The Worlds Biggest Chocolate Wheel...

Things are starting to happen at work. We have now bumped all our High Voltage motors, and expect to run our first water circuit this weekend.

In tandem to this, we also hope to spin the Ball Mill very soon. The mill is the beige coloured drum in the centre of the photo. After we have proven the lubrication systems for it's trunnion bearings and ring gear, it will be charged (or loaded) with a few hundred tonnes of steel balls, each about the size of an apple, in preparation for grinding.

Grinding medium is produced by mixing the crushed ore from the HPGR's with water, then passing the mixture through a series of screens and magnetic separators, to leave sand sized magnetite particles. The mill will then grind these sand sized particles down to a slurry with the consistency of a thick-shake.

But anyway, back to the Worlds Biggest Chocolate Wheel. There are exactly 100 bolts joining each of the three cylindrical sections of the mill together. We have numbered the bolts near the ring gear, and put a marker on the ring gear casing. Numbers were sold at $10 each. When the mill stops after it's first spin, the number closest to the marker will be the winner, and the lucky person will take $500 (with the other $500 going to charity).

Fingers crossed for number 99!!!

Project Magnet HPGR's

This photo shows the Plant Feed bin (left of photo) and the High Pressure Grinding Rollers (the blue machines in the centre of the photo with 2 large orange motors connected to them). Ore is fed by conveyors to the Plant Feed bin, and then fed into the two HPGR's.

A HPGR is basically a set of smooth, spinning 38 tonne rollers. These rollers grind the ore down to between 20mm and 50mm, depending upon the gap set between the rollers. More HPGR information can be found here...

We are currently performing "no-load" tests on the HPGR's. This involves running the machines without ore, and testing functionality such as start-up and shutdown sequences and safety interlocks that protect the machine during normal operation.

Sunny Days at Iron Duke

I am spending most of my time at the moment with the energisation and pre-commissioning of Project Magnet. Things are starting to get pretty busy for us, with our first run of ore through the plant not too far away.

The main reason I took this job was the proximity to the Flinders Ranges and the climate. We get mainly sunny days with temperatures around 22 - 24 deg C, and it's not long before the cold mornings kill off the last of the flies. You've got to love the Arid zone in Winter!

And the best thing about the job is the drive home, more specifically the view on the way home (I really need to work out blogger photo's to justify this statement).