title: Separation of packaging plastics by froth flotation in a continuous pilot plant.
abstract: The objective of the research was to apply froth flotation to separate post-consumer PET (Polyethylene Terephthalate) from other packaging plastics with similar density, in a continuously operated pilot plant. A representative sample composed of 85% PET, 2.5% PVC (Polyvinyl Chloride) and 11.9% PS (Polystyrene) was subjected to a combination of alkaline treatment and surfactant adsorption followed by froth flotation. A mineral processing pilot plant, owned by a Portuguese mining company, was adapted for this purpose. The experimentation showed that it is possible to produce an almost pure concentrate of PET, containing 83% of the PET in feed, in a single bank of mechanical flotation cells. The concentrate grade attained was 97.2% PET, 1.1% PVC and 1.1% PS. By simulation it was shown that the Portuguese recycling industry specifications can be attained if one cleaning and one scavenger stages are added to the circuit.
authors.affiliation: CERENA, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisbon, Portugal. teresa.carvalho@ist.utl.pt
authors.forename: Teresa
authors.initials: T
authors.lastname: Carvalho
authors.forename: Fernando
authors.initials: F
authors.lastname: Durão
authors.forename: Célia
authors.initials: C
authors.lastname: Ferreira
mesh_terms: D000327:Adsorption; D004867:Equipment Design; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D010969:Plastics / Q000737:chemistry*; D011093:Polyethylene Terephthalates / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D011174:Portugal; D019064:Product Packaging; D012037:Refuse Disposal / Q000379:methods*; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature; D018505:Waste Management / Q000379:methods
chemical_list: D010969:Plastics; D011093:Polyethylene Terephthalates; D011108:Polymers; D013501:Surface-Active Agents