GLASS COMPOSITION DEVELOPMENT FOR A THERMAL SPRAY VITRIFICATION PROCESS

摘要

The U. S. Army Corps of Engineers Construction Engineering Research Laboratory (USACERL) is developing flame spray technologies to remove and stabilize lead containing organic coatings. A development effort was completed to identify glass formulations suitable for use in these processes. The acceptability of prospective compositions was primarily based on the leachability of the hazardous constituents of the glasses as determined by the Toxic Characteristic Leaching Procedure (TCLP). Attempts were also made, however, to develop glasses with physical characteristics and processing properties similar to previous successful formulations. Four waste permutations, representing typical organic coating hazardous constituents, were examined in this study including: lead only; copper only; lead and copper; and lead, cadmium and chromium. Glass formulations tested included: alkali borosilicate, sodium barium silicate, lead iron phosphate, and a "commercial" lead silicate. The borosilicate glasses were the most successful in stabilizing the hazardous constituents. The most successful glass frit composition for stabilizing all waste permutations was: 5.1 wt percent Al_2O_3, 10.0 wt percent B_2O_3, 12.3 wt percent Fe_2O_3, 2.0 wt percent Li_2O, 16.5 wt percent Na_2O and 54.1 wt percent SiO_2.