Concentration of suspensions

Gravity sedimentation of a first aqueous suspension of solid particles in a vessel results in formation of a second aqueous suspension of solid particles in the present invention. The process involves adding at least one organic polymeric flocculant to the first aqueous suspension to form a suspension of flocculated solid. The flocculated solids settle to form a bed of consolidated solids. Introducing an effective amount of an agent into the bed of consolidated solids or into the flocculated solids that are settling leads to formation of the second aqueous suspension. The second aqueous suspension of solid particles has a higher solids content than the first aqueous suspension of solid particles. The agent is a free radical agent or an oxidizing agent.