An insulating material made from recycled glass –in partnership with Veolia

Posted on 25 February 2020.

In partnership with Veolia, the British company Knauf Insulation transforms glass waste into mineral wool. The idea is to limit the use of natural resources.

In addition to cutting back on the need for natural resources, using waste glass helps avoid greenhouse gas emissions.

Sand, limestone, sodium carbonate... Various raw materials are used in glass-making. Extracting them depletes natural resources and is not without repercussions on the environment: in addition to consuming significant amounts of energy, they cause lasting damage to the landscape. Every year, 40 billion metric tons of sand are thus extracted worldwide and lead to the erosion of coastlines. 
So how about limiting the use of raw materials and preserving the planet by recycling waste glass to make insulation material? A great idea and the solution developed by the British insulation company Knauf Insulation. In March 2018, it joined forces with Veolia to manufacture mineral wool from scrap glass - also known as cullet.
"We are delighted to be working with Veolia on this project, which is fully in line with our sustainability and circular economy objectives," said John Sinfield, Knauf Insulation Managing Director for Northern Europe.  

State-of-the-art sorting

After being collected from a UK network of waste collection centers, the glass is transported to Veolia's treatment plant in Saint Helens, Merseyside, in the north of England. Wine and beer bottles, sauce bottles, jam jars, and more. Some 60,000 metric tons of glass are cleaned, crushed and then sorted using state-of-the-art technology.
The Veolia plant for example uses infrared and X-ray sorting to extract microplastics and heat-resistant glass. Optical sorters filter out contaminants such as plastic or metal that would negatively impact the recycling process. An incredible 95% of the glass is processed into cullet, while the remaining 5% - ceramics, porcelain and stone - is used in the aggregate industry (aggregate being any inert material used in concrete and mortar).
The scrap glass is then transferred to the Knauf Insulation production plant, near the Veolia site. In addition, its close proximity means lower greenhouse gas emissions caused by transportation. There, the scrap glass is transformed into mineral wool, representing more than 80% of the finished product. 
Not only does recycling waste glass cut the use of natural resources, it also saves the equivalent of the greenhouse gas emissions of 7,000 cars a year!
Another aim of this initiative is to create a knock-on effect within the industry. 
Veolia is hoping to see more key players in the sector emulate Knauf Insulation and integrate circular economy thinking into their production.