Environment

New process converts unrecyclable glass into saleable product

New process converts unrecycla...
The recycling process can be used on mixed glass fragments of various colors
The recycling process can be used on mixed glass fragments of various colors
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PhD candidate Rhys Pirie with glass dishes containing waste glass and the silicate end product
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PhD candidate Rhys Pirie with glass dishes containing waste glass and the silicate end product
The recycling process can be used on mixed glass fragments of various colors
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The recycling process can be used on mixed glass fragments of various colors

Although glass is recyclable, the recycling process is generally limited to large pieces that can be easily sorted by color. Because it's not worth the effort to sort smaller fragments, they tend to simply be discarded. A new process, however, can convert them into a useful substance.

The proprietary technique was developed by PhD candidate Rhys Pirie and Prof. Damien Batstone, both of Australia's University of Queensland. It incorporates what is described as "a chemical that most people would know as drain cleaner," which is used to dissolve miscellaneous glass fragments into liquid silicate.

That liquid can subsequently be used in a wide variety of products, such as tires, detergents, toothpaste, concrete sealant and even crop fertilizer. It's also utilized to make silica gel, which is the desiccant contained in little packets with electronic devices. It cannot, however, be made into new glass on a commercial scale.

PhD candidate Rhys Pirie with glass dishes containing waste glass and the silicate end product
PhD candidate Rhys Pirie with glass dishes containing waste glass and the silicate end product

Because glass consists of around 70 to 75 percent silica – which is what gets converted to liquid silicate – the process results in little waste. According to Pirie (pictured above), approximately 1.3 kg (2.9 lb) of waste glass is required to make 1 kg of silica gel.

The technique also requires relatively little energy, unlike traditional methods of producing liquid silicate. Partially because of this, the researchers estimate that their process is over 50 percent cheaper than existing production systems.

"At the moment these kinds of silicates […] are generated through a glass production route where you make glass effectively and you then turn it into a silicate product that is a soluble gel-type product," says Batstone. "Instead of doing that, 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."

The university's commercialization company, UniQuest, is now seeking partner companies that are interested in taking the technology to market.

Source: University of Queensland

2 comments
christopher
UniQuest "seeking partner companies" ... don't hold your breath. Universities can't commercialise anything - greed over IP destroys every deal...
paul314
Would that be sodium hydroxide, aka lye? What kind of concentration do they need to dissolve/reduce glass which is usually kinda corrosion-resistant?