Lots of trucking involved in producing silicon

By: Steve Skinner


ATN visits Australia’s only plant producing an essential ingredient for alloy wheels

Lots of trucking involved in producing silicon
Simcoa silicon being poured

 

Alloy wheels seem to be nearly everywhere these days, and not just because they look good when they’re shiny.

They’re stronger but lighter than steel, and when used around entire truck and trailer combinations they can either save a lot of fuel or allow extra payload, or both.

Another advantage pushed by the makers of alloy wheels is that they allow quicker heat dissipation, which is good for brakes and tyres.

Of course a major catch is they’re also more expensive.

"Alloy" wheels are often also called "aluminium" wheels. Maybe the most correct name is "aluminium alloy", because these wheels are mostly aluminium, but with a couple of other metals thrown in.

One of these is silicon, a hard but brittle metal which has all sorts of beneficial properties when used in truck wheels.

ATN recently visited Australia’s only producer of silicon metal – Simcoa, near Bunbury, south of Perth in Western Australia.

Simcoa stands for "Silicon Metal Company of Australia", and it’s a Japanese-owned smelter which employs about 180 people directly.

The basic ingredient for producing silicon is quartzite, which is a rock with its key compound scientifically known as silicon dioxide.

High purity quartzite is trucked in from a big Simcoa quarry at Moora, 180 kilometres north of Perth.

Carting in 120,000 tonnes of quartz a year from Moora are two contractors, JJ Hawkins & Co and BGC Transport.

Low-ash charcoal – which is basically pure carbon − is produced on-site in a giant "retort" from forest residue logs and sawmill off-cuts.

K&S is the main contractor for 60,000 tonnes a year of woodchips, which come from local sawmills within 120 kilometres to the south.

The quartzite, charcoal, coal and pine woodchips are mixed together in three electrically-powered arc furnaces. In a complex set of chemical reactions, with temperatures reaching up to 3,000 degrees Celsius, the carbon in the charcoal, coal and chips "extracts" the oxygen in the quartzite, ultimately producing silicon metal.

The pure silicon is poured into moulds and crushed into small pieces after cooling.

It’s then loaded into big bags or loaded bulk, trucked off to the port of Fremantle in containers by contractor Qube, and shipped overseas – at the rate of 50,000 tonnes a year.

Silicon usually makes up about 7 per cent of an alloy wheel, and it has numerous important properties which make it essential.

One of these is that the lower density of silicon compared with aluminium means the total mixture is also less dense than aluminium – in other words reducing the total weight, at the same time as helping to make it stronger.

For more check out the next issue of ATN

Like ATN on Facebook

Follow ATN on Twitter

You can also follow our updates by joining our LinkedIn group or liking us on Facebook