To contrive reuse of a polystyrene foam and fixation of titanium dioxide.

Using acetone, polystyrene becomes a paste because an air layer of the polystyrene foam is eliminated and acetone cannot break the interaction of benzene rings in the polystyrene molecule, the main component of polystyrene foam, and the molecular structure is kept intact. By this method, the volume of the polystyrene is reduced and the polystyrene can be reused as a spherical polystyrene resin, by adding a titanium dioxide powder in the polystyrene paste for fixation, and then hot water. The acetone as a solvent is vaporized and then cooled and reused.