PREPARATION OF FOAMED GLASS BEADS USING WASTE GLASS AS RAW MATERIAL AND COMPOSITION THEREFOR

摘要

PURPOSE: Provided is a preparation method of foamed glass beads with low density, low thermal conductivity and high mechanical strength by adding chemical components to waste glass unlike a conventional method demanding high temperature melting or hydrolysis. CONSTITUTION: The preparation method comprises the steps of: mixing 75-98wt.% of soda lime glass with 3000-50000cm¬2/g of surface area with 2-25wt.% of additives; grinding to less than 200 mesh; adding water and forming into spherical or cylindrical beads; attaching an anti-blocking powder which has less than 200 mesh in size and comprises clay and graphite in the ratio of 1:1-1:1.5; preheating at 400-700deg.C and foaming; stabilizing at 500-700deg.C and annealing. The additives contain foaming aids comprising 0.1-3.5wt.% of carbon(activated carbon black) with 40-500m¬2/g of surface area, 0.5-5.5wt.% of sulfate, such as Na2SO4, K2SO4, CaSO4, etc., 0.5-15.0wt.% of activated silica, and 0.2-8.0wt.% of boric oxide to increase mechanical property, and binders comprising 0.1-5.0wt.% clay(kaolin) and 0.1-5.0 wt.% of polyvinyl alcohol(PVA).