Preparation method for extracting silicon carbide from silicon carbide-wrapped polyurethane

The invention discloses a preparation method for extracting silicon carbide from silicon carbide-wrapped polyurethane. The preparation method comprises the following processes: (1) placing silicon carbide-wrapped polyurethane in a first beaker; (2) adding acetone and a solvent into polyurethane waste and stirring till a solution and a precipitate in the first beaker do not change obviously; (3) separating the precipitate from the solvent, washing the precipitate by using clean water to obtain a silicon carbide mixture, and recovering the acetone and DMF (dimethyl formamide) in the solvent by a distillation method under a reduced pressure; (4) placing caustic soda into a second beaker, and adding distilled water to prepare alkaline liquor; (5) adding the silicon carbide mixture obtained in the step (3) into the alkaline liquor obtained in the step (4), electrically stirring in a boiling state, adding an acid to remove part impurities and performing centrifugal separation, cleaning and drying on the precipitate