Abstract: Shaped cellulosic bodies and especially cellulosic fibers or filaments are produced by precipitating cellulose from a solution containing cellulose and NMMO. To allow elevated concentrations of NMMO in the precipitating bath without detriment to the properties of the fibers or filaments produced, the temperature of the precipitating bath is held at most at 0.degree. C.

Abstract: A solution of cellulose in water and N-methylmorpholine-N-oxide (NMMO) containing 2 to 44% by weight cellulose is stabilized at 0.01 to 1%, preferably 0.1% H.sub.2 O.sub.2 and 0.01 to 2%, preferably 0.1% of an H.sub.2 O.sub.2 stabilizer, preferably oxalic acid or a salt thereof during formation of the solution and during heating to prevent discoloration of the cellulose and reduce the composition of NMMO.

Abstract: An aqueous N-methylmorpholine-N-oxide solution which was used as a spinning bath in the production of cellulosic products is regenerated by contacting it with active coal, silicon dioxide or alumina adsorbent and filtering, thereby reducing turbidity, eliminating nitrosoamine, decolorizing the solution and removing transition metals like iron therefrom.

Abstract: For the removal of water from dilute aqueous solution of NMMO, N-methylmorpholine or morpholine or mixtures thereof, the solution is subjected to reverse osmosis at a pressure in excess of the osmotic pressure and probably around 40 bar and a temperature of 25.degree. C. to 75.degree. C. to form a retentate containing the amines and a permeate which is practically free from the amines. The permeate can be used as process water while the retentate can be worked up to NMMO for reuse in the cellulose solubilization process.

Abstract: There is disclosed a process for purifying aqueous solutions of N-methyl-morpholine N-oxide (NMMO), such as spinning bath solutions incurred in the production of cellulose products, in which process the solutions to be purified are contacted with an anion exchanger and the purified solutions are separated from the anion exchanger. The process is carried out in one step and the anion exchanger, as functional groups, exclusively contains quaternary tetraalkylammonium groups of the formulae--CH.sub.2 --N.sup..sym. (CH.sub.3).sub.3 X.sup..crclbar. or --CH.sub.2 --N.sup..sym. [(CH.sub.3).sub.2 (CH.sub.2 OH)]X.sup..crclbar.wherein X.sup..crclbar. represents the anion of an inorganic or organic acid. After this, the anion exchanger is regenerated with an aqueous acidic solution.