Industrial crystallization method for synthetic L-menthol

The invention provides an industrial crystallization method for synthetic L-menthol. The industrial crystallization method for synthetic L-menthol comprises the following steps: (1) preparing crystallization mother liquor, namely heating and dissolving the synthetic L-menthol and a solvent A in a mass ratio of (1:1)-(9:1) at the temperature of 50-70 DEG C; and (2) crystallizing the mother liquor, injecting the mother liquor prepared in the step (1) into a square cone crystallization bucket, producing colorless prism-shaped or needle-shaped crystals by adopting a slow gradient cooling way, removing the mother liquor, drying to obtain colorless or transparent prism-shaped or needle-shaped crystals, and recycling the crystallization mother liquor. The industrial crystallization method provided by the invention has the advantages that the colorless or transparent prism-shaped or needle-shaped synthetic L-menthol crystals are obtained by using industrial synthetic L-menthol, the adhesion and caking phenomena of various types of compression molding synthetic L-menthol are effectively avoided, and the synthetic L-menthol crystals have the advantages of convenience in application and storage relative to the synthetic L-menthol; and meanwhile, the synthetic L-menthol crystals are completely consistent with natural L-menthol in appearance, and fragrance of the synthetic L-menthol crystals is closer to the fragrance of the natural L-menthol.