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Recycling of Plastics from Urban and Industrial Refuse.
Holamn JL; Stephenson JB; Adam MJ
NTIS: PB 237 837 :44 pages
The Bureau of Mines has devised methods for separating and reusing the major portion of waste plastics discarded in urban and industrial refuse. Waste plastic concentrates from a local collection drive, recycling center collections, urban refuse pilot plants, and the secondary metals industry were separated into three major thermoplastic families--polyolefins, styrenes, and vinyls-- based on differences in density using a Bureau-designed sink-float- elutriation hydraulic separator. Other separation methods and systems such as air classification, jigging, liquid media, screening, and electrostatics were studied. Vinyl plastics contain up to 50 percent hcl. It was found that over 90 percent of the hcl in vinyls can be recovered as usable hydrochloric acid by pyrolysis at 350 deg c. The remaining pyrolysis products, which had heats of combustion in excess of 12,000 btu/lb, could become valuable as a future source of energy. A characterization study conducted on eight chopped wire insulation wastes from secondary copper and aluminum processors showed that most wastes contained 2 to 7 percent residual metal and large percentages of vinyl. The residual metal content of some of these wastes was lowered to 0.1 percent and the vinyl portion segregated using various separation techniques. The research also suggests ways in which reclaimed thermoplastics may be fabricated into useful products.
IH; Report of Investigations
NTIS Accession No.
NTIS: PB 237 837
Page last reviewed: December 10, 2021Content source: National Institute for Occupational Safety and Health Education and Information Division