A process for separating a phase (A) comprising at least one ionic liquid from a phase (B), where phase (A) has a higher viscosity than phase (B), comprising: a) providing a stream (S1) comprising a dispersion (D1) in which phase (A) is dispersed in phase (B), b) introducing stream (S1) into a coalescing device (KV), where the inflow rate of stream (S1) is from 0.05 to 150 kg/(cm2*h) based on the average cross-sectional area of coalescing device (KV), wherein the packing density of coalescing device (KV) is from 50 to 500 kg/m3, separating phase (A) from phase (B) in coalescing device (KV), discharging a stream (S2) comprising at least 70% by weight of phase (A) from coalescing device (KV) and discharging a stream (S3) comprising at least 70% by weight of phase (B) from coalescing device (KV).