title: Separation of polyethylene terephthalate from municipal waste plastics by froth flotation for recycling industry.
abstract: Recycling is an effective way to manage plastic wastes and receives considerable attention. Since plastic mixtures are difficult to recycle because of their intrinsic characteristics, separation of mixed plastics is the key problem for recycling. Separation of polyethylene terephthalate (PET) from municipal waste plastics (MWP) by froth flotation combined with alkaline pretreatment was investigated for recycling industry. The effect of process variables was estimated by L9 (3(4)) orthogonal array of experiments and single factor experiments. The optimum conditions of alkaline pretreatment are 10 wt% sodium hydroxide, 20 min and 70°C. After alkaline pretreatment under optimum conditions, flotation separation PET from acrylonitrile-butadiene-styrene, polystyrene, polycarbonate or polyvinyl chloride was achieved with high purity and efficiency. The purity of PET is up to 98.46% and the recovery is above 92.47%. A flow sheet of separation PET from MWP by a combination of froth flotation and sink float separation was designed. This study facilitates industrial application of plastics flotation and provides technical insights into recycling of waste plastics.
authors.affiliation: School of Chemistry and Chemical Engineering, Key Laboratory of Resources Chemistry of Nonferrous Metals, Ministry of Education, Central South University, Changsha, 410083 Hunan, China.
authors.forename: Chong-Qing
authors.initials: CQ
authors.lastname: Wang
authors.affiliation: School of Chemistry and Chemical Engineering, Key Laboratory of Resources Chemistry of Nonferrous Metals, Ministry of Education, Central South University, Changsha, 410083 Hunan, China. Electronic address: huiwang1968@163.com.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.affiliation: School of Chemistry and Chemical Engineering, Key Laboratory of Resources Chemistry of Nonferrous Metals, Ministry of Education, Central South University, Changsha, 410083 Hunan, China.
authors.forename: You-Nian
authors.initials: YN
authors.lastname: Liu
mesh_terms: D000181:Acrylonitrile / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D010316:Particle Size; D010969:Plastics; D011093:Polyethylene Terephthalates; D011137:Polystyrenes / Q000737:chemistry; D011143:Polyvinyl Chloride / Q000737:chemistry; D059027:Recycling; D012972:Sodium Hydroxide / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D018505:Waste Management / Q000379:methods*
chemical_list: D010969:Plastics; D011093:Polyethylene Terephthalates; D011137:Polystyrenes; D012972:Sodium Hydroxide; D011143:Polyvinyl Chloride; D000181:Acrylonitrile
keywords: Flotation; Municipal waste plastics; Polyethylene terephthalate; Recycling