Abstract: The invention relates to a continuous process for separating a mixture of hydrocarbons which has been obtained by extractive distillation of a C4 fraction (C4) using a selective solvent (LM) and comprises the hydrocarbons from the C4 fraction (C4) which are more readily soluble in the selective solvent (LM) than are the butanes and the butenes. The mixture is fed into a first distillation column (K I) in which it is separated into a stream (K I-K) which is taken off at the top and comprises 1,3-butadiene, propyne, possibly further low boilers and possibly water and a bottom stream (K I-S) comprising 1,3-butadiene, 1,2-butadiene, acetylenes and possibly further high boilers, with the proportion of 1,3-butadiene in the bottom stream (K I-S) from the distillation column (K I) being regulated in such a way that it is at least sufficiently high to dilute the acetylenes to outside the range in which there is a risk of spontaneous decomposition.