WASTE MANAGEMENT IN ACTION – MACHINERY
A greener alternative
Stockpiles of waste plasterboard.
ASTEC AUSTRALIA’S MOBILE SCREEN PLANT IS GIVING PLASTERBOARD WASTE NEW LIFE AND REDUCING A RELIANCE ON LANDFILL.
H
ome improvements and renovations boomed during the COVID-19 pandemic as lockdowns forced people to stay at home. According to Australian Bureau of Statistics figures, during the 12 months to October 2021 renovations approvals totalled $11.82 billion nationally. Hand-in-hand with the building frenzy was an increase in construction and demolition waste. While resource recovery rates for C&D materials is increasing, there is still millions of tonnes of waste dumped in landfills. Plasterboard is usually a harmless material but when placed with biodegradable waste in airless, moist landfill sites it can create hydrogen sulphide. Latest engineering, such as Astec Australia’s GT205MF
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Tracked Mobile Screen Plant, means plasterboard waste is almost 100 per cent recyclable. “Plasterboard is a very good quality resource that was previously going to waste,” says Adam Gordon, Astec Business Line Manger – Materials Solutions. “It is high-grade gypsum sandwiched between two layers of cardboard. We need to better use it instead of burying it in landfill.” The key ingredient in plasterboard is gypsum, a sulphate mineral mixed with water and pressed between two lining sheets, usually cardboard, before being dried out to create a solid board. Once recycled, the gypsum can be reused as an agricultural soil improver, or as an ingredient in the production of cement. The cardboard can also be broken down and added into wood
mulch. Any small gypsum particles left over help the compost process. The plasterboard first needs to be shredded. Adam says most grinders on the market will be able to shred plasterboard effectively, the final solution is “having the right screen” to separate the materials. He says the GT205MF Mobile Screen Plant produces three products – oversized which will be re-shredded, cardboard, and a minus 2-millimetre gypsum. The GT205MF is ideal to recycle plasterboard because it can screen the smaller, more difficult pieces. “Traditionally, a standard screen has one motion, which may be okay for bigger material, but once you start getting down to one or two millimetres you will struggle,” Adam says. “Astec has added isolation frames
