Method for purifying solutions containing cyanamide

The invention relates to a method for purifying solutions containing cyanamide, according to which the parent solution is subjected to a membrane filtration at temperatures of between -20 and +80 DEG C, whereby the separation membrane has an MWCO value of between 80 Da and 60 kDa and the parent solution is subjected to a pressure of between 2.5 and 60 bar. In said method, which preferably operates according to the feed-and-bleed principle and whereby the solution retained by the membrane is subjected to a circulatory flow in front of the membrane, parent solutions having a cyanamide content of between 5 and 60 wt. % are used. This permits over 80 % of compounds containing in particular calcium, iron, nickel and silicon to be eliminated from the solutions used.