The invention relates to the technical field of
crystallization engineering, in particular to a preparation method of
erythromycin thiocyanate. The method comprises the following steps that a solventis added into crude
erythromycin thiocyanate, a
sodium hydroxide solution is used for regulating the pH value, and a
mixed solution is obtained;
sodium chloride solids are added into the
mixed solution, standing is performed after stirring is performed, and
phase splitting is performed to a supernate I; then, a saturated
sodium chloride solution continues to be added into the supernate I, standingis performed after stirring is performed,
phase splitting is performed, and a supernate II is obtained; a
sodium thiocyanate solution is added into the supernate II, then, glacial
acetic acid is added to regulate pH, reduced pressure
distillation is performed, cooling is performed to reach 15-30 DEG C, and centrifuging is performed to obtain a wet
erythromycin thiocyanate product; the wet
erythromycin thiocyanate product is smashed and dried to obtain
erythromycin thiocyanate. The preparation method of the
erythromycin thiocyanate has the advantages that the technology is simple, control is easy, little
wastewater is produced, the yield of the prepared erythromycin thiocyanate is high, and the purity of the prepared erythromycin thiocyanate is high.