The tank washer is used for the second stage of washing operations, scrubbing -50mm (or -20mm) material (including mud) separated from the cylinder washer. Its main tasks are two: one is to scrub the clay (or fine ore) that is more than 2mm and is adhered to the surface of the ore (or gravel); the second is to suspend the suspension less than the design requirements (such as -2mm). The material (clay or fines) is recovered (or discarded) from the overflow to the discharge, while the lump ore (or gravel) larger than the design requirements (eg +2 mm) is separated (or discarded) by countercurrent flow.