Process for continuous xanthation and production of viscose spinning solution

In a process for xanthating alkali cellulose by contacting said alkali cellulose with carbon disulfide, the improvement consisting of continuously feeding alkali cellulose at a predetermined rate first in dry form to a vessel where it is brought into contact for 3-20 minutes with 5-35% of the CS.sub.2 necessary to provide partial xanthation of the cellulose and then, prior to completion of reaction between said CS.sub.2 and said dry cellulose, passing said cellulose on to a vessel containing an alkali hydroxide slurry, immersing said cellulose therein while continuously introducing carbon disulfide into said vessel at a controlled rate, continuously feeding alkali hydroxide solution into said vessel at a controlled rate, and continuously withdrawing a portion of said slurry from the bottom of said vessel at a rate, selected to maintain a preselected minimum residence time of alkali cellulose in said vessel, then passing said withdrawn slurry through a screw extruder mixer, introducing further carbon disulfide and alkali hydroxide solution thereto, as required, to effect further xanthation therein.