Spiral classifier made by our company can be divided into single screw and double screw by quantity of screw shaft; it also can be divided into high weir type and submerged type.Down flow weir position of high weir spiral classifier is higher than bearing central of screw shaft but lower than upper end of the screw. It has a certain area for settlement and applied for coarse grain classification, can get over flow grain more than 100 meshes.The Working principle:Fine grinding pulp enters into water tank through feed inlet located in settlement area central part; settlement area locates on lower part of water tank. Screw rotates at low speed and mixes pulp, lighter grains suspend and over flow out from weir and enter into next process; while heavy grains settle to cell bottom and be sent to outlet by screw and be discharged by sand return lift. Usually, spiral classifier and ball mill form a close circuit and sand will return back to ball mill for re-grinding.