Use of polystyrene wastes for manufacturing environmentally acceptable carriers of lustrous carbon for foundry engineering

Polymer-bitumen (1:1) blends prepared from expanded polystyrene wastes and secondary petroleum bitumens (heavy "clarified oil" from catalytic cracking or furfural extract of middle distillates) were thermally treated In the presence of small amounts of poly(vinyl chloride) at 150-200° C for 1-3 h. The resulting thermolyzates were analyzed for softening points (110-145° C or 95-120° C, respectively), lustrous carbon yield (57-60% or 50-55%, respectively) and emission of aromatic hydrocarbons under conditions of founding (1200° C). The best properties were found In the thermolyzate made of the "clarified oil" and expanded polystyrene waste at 150° C for 1 h after addition of 1% poly(vinyl chloride). The thermolyzate showed a softening point of 118.9° C, lustrous carbon yield 57.7% and emission of aromatic hydrocarbons about 60 ppm (emission of benzo[a]pyrene, 2 ppm) and met the quality requirements of the foundry Industry.