CAPROLACTAM PREPARATION METHOD

A caprolactam preparation method provided in the present invention comprises the following steps: (1) in the presence of an oxime catalyst and absence of any organic solvent, conducting an ammoximation on cyclohexanone, ammonia, and hydrogen peroxide in an aqueous solvent and at a temperature between 50 and 200 °C to obtain a solvent containing a cyclohexanone oxime; (2) extracting the solvent containing the cyclohexanone oxime with an inert organic solvent to obtain an extract phase containing the cyclohexanone oxime and a raffinate phase containing the oxime catalyst and water; (3) conducting a Beckmann rearrangement reaction on the extract phase and an oleum, then conducting a neutralization reaction between a product of the Beckmann rearrangement reaction and the ammonia. The method preparing caprolactam increases a yield of the caprolactam and eliminates refining process of the cyclohexanone oxime, thus greatly shortening a manufacturing procedure and lead time, while recycling the inert organic solvent by a rearrangement reaction heat recovery.