Description of Spiral Classifier: 
Spiral classifier is a mechanical grading equipment which works based on the different proportion of solid particles with different sedimentation rate in the liquid. Fine mineral particles floating in the water to overflow while the coarse mineral particles sink to the bottom, then pushed out by the screw to the ball mill feed mouth, thus filter out the fine material discharged from the overflow tube. 
The spiral classifier has simple structure, reliable performance and easy to operate. The spiral classification machine base adopts channel steel and the body uses welded steel. Water head, screw shaft and shaft head use cast iron sleeve making it wear-resistant and durable. Lifting devices can be electric and manual. The spiral classifier can be different types such as high weir single spiral or double spirals, sinking single spiral or double spirals. 
  
Application of Spiral Classifier: 
Spiral classifier is widely used in the ore dressing plant working with the ball mill to form a closed loop process, or used in the gravity separation plant grading ore and fine mud, and applied to classify pulp particals in metal beneficiation process, as well as being used for mud removal, dehydration in ore washing operations. 

See more at 
http://www.xgdryer.com/Product/Ore_Dressing_Equipment/Spiral_Classifier.html  
Email: lola@xgcrusher.com