A feedwell assembly for a thickener/clarifier including a feedwell body, at least one feed channel connected at a downstream end to the body, and a plate member disposed in the feed channel for separating froth from an incoming slurry stream to where the separated froth may be dissipated by a liquid spray directed onto the plate member. The plate member may include a planar upstream portion inclined upwardly from an upstream end of the plate member and may further include a planar downstream portion inclined downwardly from a downstream end of the upstream portion. At least one spray nozzle may be disposed above an elevated portion of the plate member so as to direct a liquid spray onto the plate member in a region about the joint, for further dissipating froth guided onto the plate member.