The removal of sticky contaminants during the production of recycled paper is accomplished utilizing a hydrocyclone froth flotation process. Paper having sticky contaminants from labels, tapes, hot melts, and other tacky substances, is reduced to a finely comminuted liquid solids suspension of about 1-4% consistency. The suspension is introduced into a first end of a vortex in a hydrocyclone, and the air is sparged radially inwardly into the suspension vortex by passing it through a porous inner wall of the hydrocyclone. Ligher weight sticky contaminants move to the center of the hydrocyclone, facilitated by the radially inward movement of the sparging air, and hydrophobic sticky contaminants attach to the air bubbles and form a foam. The foam and lightweight sticky contaminants are removed from the first end of the vortex, while the pulp which has had sticky contaminants removed therefrom is discharged from the second end of the vortex, opposite the first end. A plurality of vertical axis hydrocyclones may be connected together in series, with a plurality of the series connected in parallel, to provide the most effective treatment. Removal of sticky contaminants can be practiced prior to or simultaneously with deinking.