Spiral classifier is dressing equipment a very classic grading equipment, mainly has high weir type single spiral and double spiral, submerged four single spiral and double spiral classifier. Spiral classifier structure: mainly by the transmission device, helix, tub, lifting mechanism, top and bottom of bearing and row ore valve. High weir type spiral classifier is suitable for the coarse grain grading, the grading the overflow particle size generally greater than 0.15 mm; Submerged spiral classifier is suitable for fine particle grading, the grading the overflow particle size is less than 0.15 mm in general.