Process for the purification of caprolactam from a solution of crude caprolactam without organic solvent extraction

A process for the purification of caprolactam from a solution of crude caprolactam, characterized in that said process comprises the following steps:

• (i) treating the solution of crude caprolactam by means of direct contact with one or more alkaline compounds of polyvalent metals, at a temperature between 50° C. and 110° C., for a duration from 1 hour to 5 hours, under stirring, so as to thus obtain a suspension, wherein said one or more alkaline compounds of polyvalent metals are selected from the group formed of:
• bivalent alkaline earth metal hydroxides, bivalent alkaline earth metal oxides, amphoteric polyvalent metal hydroxides having alkaline behavior when placed in contact with acids, amphoteric polyvalent metal oxides having alkaline behavior when placed in contact with acids and mixtures thereof;
• (ii) cooling the suspension of step (i) and holding it at a temperature between 20° C. and 35° C., for a duration between 1 hour and 6 hours, under stirring;
• (iii) separating the solids from the suspension of step (ii) to obtain an aqueous solution of crude caprolactam.