Process for recovering polyolefin and polystyrene materials by

Abstract

A process for classifying plastic-containing wastes which comprises dissolving a mixture of plastics containing polyolefin-type plastics in a hydrocarbon solvent (preferably of a xylene type) at a temperature of not lower than 60.degree. C. (preferably not lower than 80.degree. C.), vacuum-evaporating the solvent of the solution to cause precipitation of the polyolefin-type plastics dissolved therein, separating and recovering the major portion of the precipitate, further dividing the resulting separated solution into the concentrated liquor of the precipitate yet remaining admixed in the separated solution and the phase of a solution hardly containing the precipitate, recycling the concentrated liquor and using again for dissolving the mixture of plastics, and removing the solvent from the phase of a solution hardly containing the precipitate so as to recover the polystyrene-type plastics. A process for classifying plastic-containing wastes by separating and recovering the precipitate of the polyolefin-type plastics from the mixture solution containing the same in the above-mentioned process, which comprises connecting in series a plurality of solid-liquid separating devices, sequentially disintegrating and dispersing the precipitate separated by the separating device at a preceding stage in the separated solution flowing out from the separating device at a subsequent stage and again separating the precipitate by the separating device at a still subsequent stage.