WRAP has completed a project where ground recycled glass has been used as a fluxing agent in the manufacture of bricks from clay at a site in Stourbridge. Previous smaller studies showed concerns that generally available ground glass was too coarse resulting in uneven vitrification and localised melt spots leading to unacceptable colour variation in the bricks. Another concern was the inconsistent quality of ground glass, and the limited quantities available. Ceram research undertook a project with WRAP to define a more precise specification for the ground glass and, through its addition to clay bricks and subsequent lower firing temperatures, reported benefits to the process and to the end product. A clear case was made for potential savings in gas and a reduction in harmful emissions such as hydrogen fluoride and carbon dioxide.
