Process for separating and recovering the constituents of an exhausted solvent mixture used for cleansing reactors for the polymerization of vinyl chloride

Claim 1

A process for separating and recovering the constituents of an exhausted toluene-dimethylformamide solvent mixture used for cleansing surfaces of equipment used for the polymerization of vinyl chloride by removing the deposits of polymer therefrom, which comprises: a. adding water to said exhausted solvent mixture and then distilling off toluene in the form of an azeotropic mixture with water, the amount of added water and the amount of toluene distilled off being so adjusted as to ensure in the distillation residue a water content of at least 2.5% by weight and a toluene content not exceeding 10% by weight; b. cooling said distillation residue, thereby to precipitate the polymer present therein; c. adding to the resulting suspension water in an amount of at least 20% of the weight of the dimethylformamide present therein; d. distilling off any toluene still present in the suspension; e. recovering the precipitated polymer from the residual suspension obtained in (d) and recovering by distillation the dimethylformamide from the resulting aqueous solution.