DRY-TYPE PRE-CONCENTRATION MACHINE

Provided in the present application is a dry-type pre-concentration machine. The dry-type pre-concentration machine comprises: a reverse air-blowing path and an eccentric magnetic rolling mechanism, wherein the eccentric magnetic rolling mechanism is partially arranged in the reverse air-blowing path, is configured to convey materials, and is further configured to provide an eccentric rotating magnetic field; a feeding area is provided above the eccentric magnetic rolling mechanism; and a tailing area, a middling area, and a concentrate area are arranged below the eccentric magnetic rolling mechanism. In the present application, materials in the feeding area are conveyed into the reverse air-blowing path and subjected to a rolling motion, so that strong magnetic materials are arranged on the innermost layer, weakly magnetic materials are arranged on a middle layer, non-magnetic materials are arranged on the outermost layer, and under the action of reversely blown air in the reverse air-blowing path, non-magnetic fine powdery materials on an outer layer leave a surface of the eccentric magnetic rolling mechanism and are carried by wind into or fall into the tailing area; and weakly magnetic minerals fall into the middling area along with rotation of a magnetic roller and reduction of the magnetic field, and concentrate falls into the concentrate area along with the rotation of the magnetic roller and the reduction of the magnetic field, so that ultra-fine crushed materials are sorted in a graded, efficient, and fine manner.