A device and a method for thickening a slurry are disclosed. A pump is provided comprising an inner chamber, a pumping apparatus, an external wall, an inlet, and an outlet. The slurry comprises a solid and a liquid. The slurry enters the inner chamber through the inlet and is pumped and pressurized by the pumping apparatus through the inner chamber across a portion of the external wall comprising a porous wall, causing a portion of the liquid to be pressed through the porous wall as a liquid product stream and thickening the slurry into a thickened slurry stream. The thickened slurry stream leaves through the slurry outlet.