SELECTIVE FROTH FLOTATION OF PVC FROM PVC PET MIXTURES FOR THE PLASTICS RECYCLING INDUSTRY/

It was found that strongly alkaline solutions of sodium hydroxide are able to destroy the hydrophobicity of polyethylene terephthalate (PET) whereas the hydrophobicity of polyvinyl chloride (PVC) remains only s lightly affected by these solutions. On this basis, a technology invol ving treatment of PET and PVC particles with alkaline solutions follow ed by froth flotation of PVC with nonionic surfactants has been develo ped and tested at a laboratory scale. In both steps of this technology , appropriate experimental conditions, such as concentration of reagen ts, temperature and residence time, have been optimized through a deta iled examination of all these variables on the efficiency and selectiv ity of PVC separation from PVC/PET mixtures of varying composition. It is demonstrated that using this technology 95-100% recovery of PET an d PVC can be achieved in separate products from a variety of PVC/PET m ixtures.