Waste glass has proven to be effective for the production of foam glass insulation both in the bulk or rigid board form and pellet form. Problems inherent with the use of water, carbon black and calcium carbonate as the foaming agents, have been identified and many have been solved by various techniques. Water was found to be best suited for micrometer sized particles to 0.6 cm pellets, while carbon and CaCO3 yielded better products for larger objects. Large amounts of water can be rapidly incorporated into glass by using a sodium hydroxide (NaOH) solution in a heated autoclave. Smaller amounts can be incorporated into the glass by placing pellets formed by adding NaOH to a glass-clay mixture and directly heating in a furnace. The foaming process with carbon black was examined by analysis of the density, pore size, and open porosity of the foamed piece. Also, the addition of clay made foam glass less soluble to water.

Grant No. R 800 937-02.