Bob the blender fires up waste recovery


What do you call a multimillion dollar machine that can chew through 200L steel barrels of hazardous waste, spitting out clean metal for recycling and an alternative fuel product for use in cement kilns? The answer is BOB - the "big oversize blender" and it has just been switched on at Geocycle's Dandenong facility. It will divert an extra 6,000-7,000 tonnes of hazardous material from Melbournes landfills annually.

Some $4 million in federal funding and $600,000 from EPA Victoria has gone into the "megablender". Rather than having staff open and decant the contents of incoming steel drums (which remain a hazardous waste even when empty), the drums can now be fed straight into the process.

Material passes through a series of augers to shred the material before it enters a 10m3 blender, with a propeller spinning at 500rpm over a shear plate. Magnetic conveyors pull out metal in sizes from a 10c piece up to "a couple of kilos in size," before it is washed and recovered, ready for recycling, in around six minutes.

Geocycle claims the machine will save over 1,000 tonnes of steel from being landfilled annually.

The company is the alternative fuels arm of Cement Australia and uses the blended organic waste outputs as an alternative fuel for firing cement kilns, displacing the need for coal. It currently supplies around 5% of the feedstock for Australia's cement industry (some 15,000 tonnes a year), but could theoretically provide up to 30%.

The new blending process, which comes on top of improvements to the dewatering system made last year, will allow it to increase its output to around 20,000 tonnes per annum in the next couple of years.

According to EPA Victoria, by 2012 "Bob the Blender" will also cut some 16,000 tonnes of CO2 equivalent: "These kinds of leading edge projects make a big difference to the impact of industry on the environment," says chairman Mick Bourke.

"The government is committed to reducing waste to landfill across the state, and stopping all high hazard waste disposal at landfills by 2020. Every project like this makes those goals easier to achieve."

Funding was provided as part of the Victorian Governments HazWaste Fund program.

While none of Bobs three main component technologies are particularly novel, their combination into one process is
considered unique and is attracting some international attention from cement makers.