The invention is concerned with a process for the production of cellulose molded bodies. This process has the following steps: (A) dissolving cellulose in an aqueous solution of a tertiary amine-oxide to produce a moldable cellulose solution, (B) molding said cellulose solution and conducting said molded cellulose solution into an aqueous precipitation bath, wherein the cellulose is precipitated, thus producing a molded body and a spent precipitation bath, and (C) purifying said spent precipitation bath by contacting said precipitation bath with an ion exchanger, thus producing a purified aqueous amine-oxide solution which, optionally after concentration, is re-used again in step (A) as a cellulose solvent. In this process, the ion exchanger comprises a cellulose carrier which has attached groups which are capable of exchanging ions.