METHOD FOR PROCESSING USED PLASTIC PARTS TO RECOVER THEIR CONSTITUENTS

Abstract

------ METHOD FOR PROCESSING USED PLASTIC PARTS TO RECOVER THEIR CONSTITUENTS To treat according to the invention a used plastic part comprising an organic filler and an inorganic filler, (A) at least one organic solvent (S1), immiscible with water, a good solvent for plastic and capable of solvating the organic filler and the plastic and releasing the inorganic filler, is added to pieces of the part to be treated; (B) to the mixture obtained, an aqueous solution of an agent complexing the inorganic filler is added, the aqueous solution being capable of transferring by liquid-liquid extraction the inorganic filler from the mixture to the aqueous solution, the inorganic filler then being in a dissolved state in the aqueous solution;(C) to the two immiscible phases obtained, a solvent (S2) immiscible with water, miscible with solvent (S1), a poor solvent for the plastic material and a good solvent for the organic filler, is added to precipitate, following at least one solid phase, the plastic material in dispersed form while leaving the organic filler in the mixture of solvents (S1) and (S2), composing an organic liquid phase, the inorganic filler remaining dissolved in the aqueous solution, composing an aqueous phase; the solid phase of plastic material is recovered by a solid-liquid separation; from each of the organic and aqueous phases obtained, separated by their difference in density, the organic and inorganic fillers respectively are isolated.