Scientists have invented a process that can turn waste glass into everything from tyres to toothpaste.
Currently, only a small amount of glass is actually recyclable, but researchers have come up with a way to use up mountains of unrecyclable glass and turn it into useful items.
University of Queensland PhD candidate Rhys Pirie said that a chemical found in ‘drain cleaner’ can break glass down and separate an amount of silica – a key ingredient in toothpaste.
This is then extracted for use in a commercial setting, meaning the liquid can be used for detergent, or even in crop fertiliser.
Picture: Save water by turning off the tapBecause of the effort required to sort out smaller fragments of glass, they tend to be discarded, stored, or sent to the landfill.
Mr Pirie and Professor Damien Batstone from the University of Queensland were able to dissolve fragments into liquid silicate.
Silicates are used in industry as adhesives, detergents, ingredients in cleaning compounds, cements, binders, and coatings.
Mr Pirie said: ‘We are taking waste glass that is currently going to the landfill because it is too small to be sorted into the right colour.
‘We are dissolving it in a chemical most people know as drain cleaner – and once it’s in that form it can be used to make things like tyres, detergent or silica gel.
‘We can get all that silicate out of the glass. Glass is about 70 to 75 per cent silica. You need about 1.3kg of glass to make 1kg of silica.
‘Most of that goes into saleable products so we have very little waste at the end of it.’
The technique requires relatively little energy, unlike traditional methods of producing liquid silicate, making it a lot cheaper.
Professor Batstone said: ‘We are looking around for lower cost silicates. The glass industry has a huge amount it cannot recycle because it is too broken or it is too small.
‘That is currently stockpiled at the moment as it can’t be used. That is when we started looking at processes which could turn that waste product into a commercial silicate product.
‘We’re going to take glass that has already been made and is actually waste, and take it through a much simpler process to turn it into this commercial silicate product.
‘It’s a way to use a product which is currently a waste, which is currently unusable.
‘You can’t ever make glass out of it again, but it’s a way to turn a cost negative waste into an absolute resource.’
The university’s commercialisation company, UniQuest, is now seeking partner companies that are interested in taking the technology to market.