A method for separating solids from liquids is disclosed. A double-roller system is provided. A process fluid is provided to the double-roller system. The process fluid comprises a suspended solid and a process liquid. The suspended solid comprises non-fibrous solid particles. A portion of the process fluid is compressed through the double-roller system to produce a compressed portion of the suspended solid. A product stream and a dilute fluid stream are separated. The product stream comprises a compressed portion of the suspended solid and a first portion of the process liquid. The dilute fluid stream comprises a second portion of the suspended solid and a second portion of the process liquid.