Veolia and Knauf: transforming glass waste into mineral wool

Veolia logo
Type of organisation or company
United Kingdom
Language for original content
Project elaborated in partnership
Submitted by
Technopolis Group
Start/End date

Glass making uses raw materials, such as sand, limestone and sodium carbonate. There is clearly a limited supply of these and the process of extracting them damages the environment.

Knauf Insulation has partnered with Veolia to manufacture mineral wool from scrap glass, called "cullet". The Veolia plant cleans collected glass waste and uses first infrared and X-ray sorting to extract microplastics and heat-resistant glass, and then optical sorters to filter out contaminants such as plastic or metal. The cleaned and sorted cullet is then transferred to the Knauf Insulation production plant and transformed into mineral wool which is used as an insulator.

Main results
  • Recycling scrap glass reduces the use of natural resources and saves substantial greenhouse emissions
  • 95% of the glass collected by the plant is processed into cullet, while the remaining 5% (ceramics, porcelain and stone) is used in the aggregate industry
  • 80% of the mineral wool produced originates as glass waste.